View source for Aphasia

{{Short description|Inability to comprehend or formulate language}}
{{Hatnote group|
{{Distinguish|aphakia|aphagia|aphantasia}}
{{Other uses}}
}}
{{Unreliable sources|date=April 2022}}
{{Infobox medical condition
| name = Aphasia
| synonyms = 
| image = Aphasia.png
| caption = Regions of the left hemisphere that can give rise to aphasia when damaged<ref name="Lesion correlates of patholinguisti">{{cite journal | vauthors = Henseler I, Regenbrecht F, Obrig H | title = Lesion correlates of patholinguistic profiles in chronic aphasia: comparisons of syndrome-, modality- and symptom-level assessment | journal = Brain | volume = 137 | issue = Pt 3 | pages = 918–930 | date = March 2014 | pmid = 24525451 | doi = 10.1093/brain/awt374 | doi-access = free }}</ref>
| field = [[Neurology]], [[Psychiatry]]
| pronounce = {{IPAc-en|ə|ˈ|f|eɪ|ʒ|ə}}, {{IPAc-en|ə|ˈ|f|eɪ|z|i|ə}} or {{IPAc-en|eɪ|ˈ|f|eɪ|z|i|ə}}
| symptoms = 
| complications = 
| onset = 
| duration = 
| types = 
| causes = 
| risks = 
| diagnosis = 
| differential = 
| prevention = 
| treatment = [[Sign language]], [[speech therapy]]
| medication = 
| prognosis = 
| frequency = 
| deaths = 
}}

'''Aphasia''', also known as '''dysphasia''',{{efn|name=dysphasia}} is an impairment in a person's ability to comprehend or formulate language because of dysfunction in specific [[brain]] regions.<ref name = "Damasio 1992">{{cite journal | vauthors = Damasio AR | title = Aphasia | journal = The New England Journal of Medicine | volume = 326 | issue = 8 | pages = 531–539 | date = February 1992 | pmid = 1732792 | doi = 10.1056/NEJM199202203260806 }}</ref> The major causes are [[stroke]] and head trauma; prevalence is hard to determine, but aphasia due to stroke is estimated to be 0.1–0.4% in [[Developed country|developed countries]].<ref>{{Cite journal |last1=Code |first1=Chris |last2=Petheram |first2=Brian |date=2011-02-01 |title=Delivering for aphasia |journal=International Journal of Speech-Language Pathology |volume=13 |issue=1 |pages=3–10 |doi=10.3109/17549507.2010.520090 |issn=1754-9507 |pmid=21329405|s2cid=44461150 |doi-access=free }}</ref> Aphasia can also be the result of [[brain tumor]]s, [[epilepsy]], autoimmune neurological diseases,<ref>{{cite journal |last1=Rook |first1=Janine |last2=Llufriu |first2=Sara |last3=de Kok |first3=Dörte |last4=Rofes |first4=Adrià |title=Language impairments in people with autoimmune neurological diseases: A scoping review |journal=Journal of Communication Disorders |date=November 2023 |volume=106 |article-number=106368 |doi=10.1016/j.jcomdis.2023.106368|pmid=37717472 |doi-access=free }}</ref> brain infections,<ref>{{cite journal |last1=Rofes |first1=Adrià |last2=van de Beek |first2=Diederik |last3=Miceli |first3=Gabriele |title=Language impairments and CNS infections: a review |journal=Aphasiology |date=3 October 2022 |volume=36 |issue=10 |pages=1206–1248 |doi=10.1080/02687038.2021.1937922 |doi-access=free }}</ref> or [[neurodegenerative disease]]s (such as [[dementia]]s).<ref name=":6">{{Cite web |title=An overview of aphasia |url=https://www.webmd.com/brain/aphasia-causes-symptoms-types-treatments#1 |website=WebMD}}</ref><ref name="ASHA Aphasia">{{cite web |url=http://www.asha.org/public/speech/disorders/Aphasia/ |title=American Speech-Language-Hearing Association (ASHA): Aphasia |work=asha.org }}</ref>

To be diagnosed with aphasia, a person's language must be significantly impaired in one or more of the four aspects of communication. In the case of progressive aphasia, a noticeable decline in language abilities over a short period of time is required. The four aspects of communication include spoken language production, spoken language comprehension, [[written language]] production, and written language comprehension. Impairments in any of these aspects can impact functional communication.

The difficulties of people with aphasia can range from occasional trouble finding words, to losing the ability to speak, read, or write; intelligence, however, is unaffected.<ref name="ASHA Aphasia"/> Expressive language and receptive language can both be affected as well. Aphasia also affects [[visual language]] such as [[sign language]].<ref name="Damasio 1992" /> In contrast, the use of [[formulaic language|formulaic expressions]] in everyday communication is often preserved.<ref name = "Sidtis 2015">{{cite journal | vauthors = Stahl B, Van Lancker Sidtis D | title = Tapping into neural resources of communication: formulaic language in aphasia therapy | journal = Frontiers in Psychology | volume = 6 | issue = 1526 | page = 1526 | year = 2015 | pmid = 26539131 | pmc = 4611089 | doi = 10.3389/fpsyg.2015.01526 | doi-access = free }}</ref> For example, while a person with aphasia, particularly [[expressive aphasia]] ([[Broca's area|Broca's]] aphasia), may not be able to ask a loved one when their birthday is, they may still be able to sing "Happy Birthday". One prevalent deficit in all aphasias is [[Anomic aphasia|anomia]], which is a difficulty in finding the correct word.<ref name=Manasco>{{cite book|last1=Manasco|first1=M. Hunter | name-list-style = vanc |title=Introduction to Neurogenic Communication Disorders|date=2014|publisher=Jones & Bartlett Learning |isbn=978-1-4496-5244-9 |url=https://books.google.com/books?id=tSRjCwAAQBAJ|location=Burlington, MA}}</ref>{{Reference page|72}}

With aphasia, one or more modes of communication in the brain have been damaged and are therefore functioning incorrectly. Aphasia is ''not'' caused by damage to the brain resulting in motor or sensory deficits, thus producing [[dysarthria|abnormal speech]]&nbsp;— that is, aphasia is not related to the ''mechanics'' of [[speech]], but rather the individual's language cognition. However, it is possible for a person to have both problems, e.g. in the case of a hemorrhage damaging a large area of the brain. An individual's language abilities incorporate the socially shared set of rules, as well as the thought processes that go behind communication (as it affects both verbal and nonverbal language). Aphasia is not a result of other peripheral motor or sensory difficulty, such as [[paralysis]] affecting the speech muscles, or a general hearing impairment.{{citation needed|date=April 2024}}

[[Neurodevelopmental disorder|Neurodevelopmental]] forms of [[auditory processing disorder]] (APD) are differentiable from aphasia in that aphasia is by definition caused by acquired brain injury, but acquired epileptic aphasia has been viewed as a form of APD<!--ref in APD article body at discussion of that epileptic condition-->.

{{TOC limit|3}}

==Signs and symptoms==
People with aphasia may experience any of the following behaviors due to an acquired brain injury, although some of these symptoms may be due to related or concomitant problems, such as [[dysarthria]] or [[apraxia]], and not primarily due to aphasia. Aphasia symptoms can vary based on the location of damage in the brain. Signs and symptoms may or may not be present in individuals with aphasia and may vary in severity and level of disruption to communication.<ref>American Speech-Language-Hearing Association (1997–2014)</ref> Often those with aphasia may have a difficulty with naming objects, so they might use words such as ''thing'' or point at the objects. When asked to name a pencil they may say it is a "thing used to write".<ref>Nolen-Hoeksema, S. (2014). Neurodevelopmental and Neurocognitive Disorders. In ''Abnormal Psychology'' (6th ed.). New York: McGraw-Hill. {{ISBN|9780078035388}}</ref>

{{Div col|colwidth=27em}}
* Inability to [[language comprehension|comprehend language]]
* Inability to [[pronounce]], not due to muscle paralysis or weakness
* Inability to form words
* Inability to recall words (anomia)
* Poor [[enunciation]]
* Excessive creation and use of [[protologism]]s
* Inability to repeat a phrase
* Persistent repetition of one syllable, word, or phrase (stereotypies, recurrent/recurring utterances/speech automatism) also known as perseveration.
* [[Paraphasia]] (substituting letters, syllables or words)
* [[Agrammatism]] (inability to speak in a grammatically correct fashion)
* speaking in incomplete sentences
* Inability to [[Reading (process)|read]]
* Inability to [[writing|write]]
* Limited verbal output
* Difficulty in naming
* [[Speech disorder]]
* Speaking [[gibberish]]
* Inability to follow or understand simple requests
{{Div col end}}

===Related behaviors===
Given the previously stated signs and symptoms, the following behaviors are often seen in people with aphasia as a result of attempted compensation for incurred speech and language deficits:
* Self-repairs: Further disruptions in fluent speech as a result of mis-attempts to repair erred speech production.<ref>{{cite journal | vauthors = Middleton EL, Schwartz MF, Brecher A, Gagliardi M, Garvey K | title = Does naming accuracy improve through self-monitoring of errors? | journal = Neuropsychologia | year=2016 | volume = 84 | pages = 272–281 | doi=10.1016/j.neuropsychologia.2016.01.027 | pmid = 26863091| pmc = 4826482 }}</ref>
* Struggle in non-fluent aphasias: A severe increase in expelled effort to speak after a life where talking and communicating was an ability that came so easily can cause visible frustration.
* Preserved and automatic language: A behavior in which some language or language sequences that were used frequently prior to onset are still produced with more ease than other language post onset.

====Subcortical====
* Subcortical aphasia's characteristics and symptoms depend upon the site and size of subcortical lesion. Possible sites of lesions include the [[thalamus]], internal capsule, and basal ganglia.

=== Cognitive deficits ===
While aphasia has traditionally been described in terms of language deficits, there is increasing evidence that many people with aphasia commonly experience co-occurring non-linguistic [[cognitive deficit]]s in areas such as attention, memory, executive functions and learning.<ref>{{cite journal |last1=Helm-Estabrooks |first1=Nancy |date=March–April 2002 |title=Cognition and aphasia: a discussion and a study |url=https://www.sciencedirect.com/science/article/abs/pii/S0021992402000631 |journal=Journal of Communication Disorders |volume=35 |issue=2 |pages=171–186 |doi=10.1016/S0021-9924(02)00063-1 |pmid=12036150 |access-date=15 October 2021|url-access=subscription }}</ref><ref>{{cite journal |last1=Vallila-Rohter |first1=Sofia |last2=Kiran |first2=Swathi |date=January 2013 |title=Non-linguistic learning and aphasia: Evidence from a paired associate and feedback-based task |journal=Neuropsychologia |volume=51 |issue=1 |pages=79–90 |doi=10.1016/j.neuropsychologia.2012.10.024 |pmc=3626426 |pmid=23127795}}</ref><ref name=":1">{{Cite journal |last=Murray |first=Laura L. |name-list-style=vanc |date=May 2012 |title=Attention and Other Cognitive Deficits in Aphasia: Presence and Relation to Language and Communication Measures |url=http://aphasiology.pitt.edu/2222/1/38-45-1-RV.pdf |url-status=live |journal=American Journal of Speech-Language Pathology |language=en |volume=21 |issue=2 |pages=S51–64 |doi=10.1044/1058-0360(2012/11-0067) |issn=1058-0360 |pmid=22230179 |archive-url=https://ghostarchive.org/archive/20221009/http://aphasiology.pitt.edu/2222/1/38-45-1-RV.pdf |archive-date=2022-10-09}}</ref> By some accounts, cognitive deficits, such as attention and working memory constitute the underlying cause of language impairment in people with aphasia.<ref>{{cite journal |vauthors=Hula WD, McNeil MR |date=August 2008 |title=Models of attention and dual-task performance as explanatory constructs in aphasia |journal=Seminars in Speech and Language |volume=29 |issue=3 |pages=169–187; quiz C 3–4 |doi=10.1055/s-0028-1082882 |pmid=18720315 |s2cid=260319083}}</ref> Others suggest that cognitive deficits often co-occur, but are comparable to cognitive deficits in stroke patients without aphasia and reflect general brain dysfunction following injury.<ref>{{cite journal |vauthors=Fonseca J, Raposo A, Martins IP |date=March 2018 |title=Cognitive performance and aphasia recovery |journal=Topics in Stroke Rehabilitation |volume=25 |issue=2 |pages=131–136 |doi=10.1080/10749357.2017.1390904 |pmid=29072540 |s2cid=3884877}}</ref> Whilst it has been shown that cognitive neural networks support language reorganisation after stroke,<ref name=":16">{{Cite journal |last1=Brownsett |first1=Sonia |last2=Wise |first2=Richard |name-list-style=vanc |date=2014-10-24 |title=Cognitive control and its impact on recovery from aphasic stroke |journal=Brain |volume=137 |issue=1 |pages=242–54 |doi=10.1093/brain/awt289 |s2cid=151445078|doi-access=free |pmid=24163248 |pmc=3891442 }}</ref>
The degree to which deficits in attention and other cognitive domains underlie language deficits in aphasia is still unclear.<ref name=":2">{{Cite journal |last1=Villard |first1=Sarah |last2=Kira n |first2=Swathi |name-list-style=vanc |date=2017-10-03 |title=To what extent does attention underlie language in aphasia? |journal=Aphasiology |volume=31 |issue=10 |pages=1226–1245 |doi=10.1080/02687038.2016.1242711 |s2cid=151445078}}</ref>

In particular, people with aphasia often demonstrate short-term and working memory deficits.<ref name=":1" /> These deficits can occur in both the verbal domain<ref>{{cite journal |vauthors=Martin N, Ayala J |date=June 2004 |title=Measurements of auditory-verbal STM span in aphasia: effects of item, task, and lexical impairment |journal=Brain and Language |volume=89 |issue=3 |pages=464–483 |doi=10.1016/j.bandl.2003.12.004 |pmid=15120538 |s2cid=11497057}}</ref><ref>{{cite journal |vauthors=Laures-Gore J, Marshall RS, Verner E |date=January 2011 |title=Performance of Individuals with Left-Hemisphere Stroke and Aphasia and Individuals with Right Brain Damage on Forward and Backward Digit Span Tasks |journal=Aphasiology |volume=25 |issue=1 |pages=43–56 |doi=10.1080/02687031003714426 |pmc=3090622 |pmid=21572584}}</ref> as well as the visuospatial domain.<ref>{{cite journal |vauthors=Kasselimis DS, Simos PG, Economou A, Peppas C, Evdokimidis I, Potagas C |date=August 2013 |title=Are memory deficits dependent on the presence of aphasia in left brain damaged patients? |journal=Neuropsychologia |volume=51 |issue=9 |pages=1773–1776 |doi=10.1016/j.neuropsychologia.2013.06.003 |pmid=23770384 |s2cid=14620782 |doi-access=free}}</ref> Furthermore, these deficits are often associated with performance on language specific tasks such as naming, lexical processing, and sentence comprehension, and discourse production.<ref name=":3">{{cite journal |vauthors=Wall KJ, Cumming TB, Copland DA |date=2017-05-05 |title=Determining the Association between Language and Cognitive Tests in Poststroke Aphasia |journal=Frontiers in Neurology |volume=8 |article-number=149 |doi=10.3389/fneur.2017.00149 |pmc=5418218 |pmid=28529495 |doi-access=free}}</ref><ref name=":1" /><ref>{{cite journal |last1=Cahana-Amitay |first1=Dalia |last2=Jenkins |first2=Theodore |name-list-style=vanc |date=November 2018 |title=Working memory and discourse production in people with aphasia 6 |journal=Journal of Neurolinguistics |language=en |volume=48 |pages=90–103 |doi=10.1016/j.jneuroling.2018.04.007 |s2cid=53183275}}</ref><ref>{{cite journal |vauthors=Minkina I, Martin N, Spencer KA, Kendall DL |date=March 2018 |title=Links Between Short-Term Memory and Word Retrieval in Aphasia |journal=American Journal of Speech-Language Pathology |volume=27 |issue=1S |pages=379–391 |doi=10.1044/2017_AJSLP-16-0194 |pmc=6111490 |pmid=29497750}}</ref> Other studies have found that most, but not all people with aphasia demonstrate performance deficits on tasks of attention, and their performance on these tasks correlate with language performance and cognitive ability in other domains.<ref name=":1" /> Even patients with mild aphasia, who score near the ceiling on tests of language often demonstrate slower response times and interference effects in non-verbal attention abilities.<ref>{{Cite journal |vauthors=Hunting-Pompon R, Kendall D, Bacon Moore A |date=June 2011 |title=Examining attention and cognitive processing in participants with self-reported mild anomia |journal=Aphasiology |volume=25 |issue=6–7 |pages=800–812 |doi=10.1080/02687038.2010.542562 |s2cid=145763896}}</ref>

In addition to deficits in short-term memory, working memory, and attention, people with aphasia can also demonstrate deficits in executive function.<ref>{{cite journal |vauthors=Murray LL, Ramage AE |date=2000 |title=Assessing the executive function abilities of adults with neurogenic communication disorders |journal=Seminars in Speech and Language |volume=21 |issue=2 |pages=153–167; quiz 168 |doi=10.1055/s-2000-7562 |pmid=10879547 |s2cid=260320569}}</ref> For instance, people with aphasia may demonstrate deficits in initiation, planning, self-monitoring, and cognitive flexibility.<ref>{{Cite journal |last=Murray |first=Laura L. |name-list-style=vanc |date=2017-07-03 |title=Design fluency subsequent to onset of aphasia: a distinct pattern of executive function difficulties? |journal=Aphasiology |language=en |volume=31 |issue=7 |pages=793–818 |doi=10.1080/02687038.2016.1261248 |issn=0268-7038 |s2cid=151808957}}</ref> Other studies have found that people with aphasia demonstrate reduced speed and efficiency during completion of executive function assessments.<ref>{{Cite journal |last=Purdy |first=Mary |name-list-style=vanc |date=April 2002 |title=Executive function ability in persons with aphasia |journal=Aphasiology |language=en |volume=16 |issue=4–6 |pages=549–557 |doi=10.1080/02687030244000176 |issn=0268-7038 |s2cid=144618814}}</ref>

Regardless of their role in the underlying nature of aphasia, cognitive deficits have a clear role in the study and rehabilitation of aphasia. For instance, the severity of cognitive deficits in people with aphasia has been associated with lower quality of life, even more so than the severity of language deficits.<ref>{{Cite journal |vauthors=Nicholas M, Hunsaker E, Guarino AJ |date=2017-06-03 |title=The relation between language, non-verbal cognition and quality of life in people with aphasia |journal=Aphasiology |volume=31 |issue=6 |pages=688–702 |doi=10.1080/02687038.2015.1076927 |s2cid=146960778}}</ref> Furthermore, cognitive deficits may influence the learning process of rehabilitation<ref>{{cite journal |last1=Vallila-Rohter |first1=Sofia |date=January 2017 |title=Considering Learning Ability in Language Rehabilitation Plans |url=https://pubs.asha.org/doi/abs/10.1044/persp2.SIG2.23 |journal=Perspectives of the ASHA Special Interest Groups |volume=2 |issue=2 |pages=23–30 |doi=10.1044/persp2.SIG2.23 |access-date=15 October 2021|url-access=subscription }}</ref><ref>{{cite journal |last1=Middleton |first1=Erica L. |last2=Schwartz |first2=MyrnaF. |last3=Rawson |first3=Katherine A. |last4=Traut |first4=Hilary |last5=Verkuilen |first5=Jay |date=October 2016 |title=Towards a Theory of Learning for Naming Rehabilitation: Retrieval Practice and Spacing Effects |journal=Journal of Speech, Language, and Hearing Research |volume=59 |issue=5 |pages=1111–1122 |doi=10.1044/2016_JSLHR-L-15-0303 |pmc=5345556 |pmid=27716858}}</ref> and language treatment outcomes in aphasia.<ref>{{cite journal |vauthors=Dignam J, Copland D, O'Brien K, Burfein P, Khan A, Rodriguez AD |date=February 2017 |title=Influence of Cognitive Ability on Therapy Outcomes for Anomia in Adults With Chronic Poststroke Aphasia |url=https://espace.library.uq.edu.au/view/UQ:505087/UQ505087_OA.pdf |journal=Journal of Speech, Language, and Hearing Research |volume=60 |issue=2 |pages=406–421 |doi=10.1044/2016_JSLHR-L-15-0384 |pmid=28199471}}</ref><ref>{{cite journal |vauthors=Lambon Ralph MA, Snell C, Fillingham JK, Conroy P, Sage K |date=April 2010 |title=Predicting the outcome of anomia therapy for people with aphasia post CVA: both language and cognitive status are key predictors |journal=Neuropsychological Rehabilitation |volume=20 |issue=2 |pages=289–305 |doi=10.1080/09602010903237875 |pmid=20077315 |s2cid=23062509}}</ref> Non-linguistic cognitive deficits have also been the target of interventions directed at improving language ability, though outcomes are not definitive.<ref>{{cite journal |vauthors=Murray LL, Keeton RJ, Karcher L |date=January 2006 |title=Treating attention in mild aphasia: evaluation of attention process training-II |journal=Journal of Communication Disorders |volume=39 |issue=1 |pages=37–61 |doi=10.1016/j.jcomdis.2005.06.001 |pmid=16039661}}</ref> While some studies have demonstrated language improvement secondary to cognitively-focused treatment,<ref>{{cite journal |vauthors=Peach RK, Beck KM, Gorman M, Fisher C |date=August 2019 |title=Clinical Outcomes Following Language-Specific Attention Treatment Versus Direct Attention Training for Aphasia: A Comparative Effectiveness Study |journal=Journal of Speech, Language, and Hearing Research |volume=62 |issue=8 |pages=2785–2811 |doi=10.1044/2019_JSLHR-L-18-0504 |pmid=31348732 |s2cid=198934220}}</ref> others have found little evidence that the treatment of cognitive deficits in people with aphasia has an influence on language outcomes.<ref>{{cite journal |display-authors=6 |vauthors=Nouwens F, de Lau LM, Visch-Brink EG, van de Sandt-Koenderman WM, Lingsma HF, Goosen S, Blom DM, Koudstaal PJ, Dippel DW |date=June 2017 |title=Efficacy of early cognitive-linguistic treatment for aphasia due to stroke: A randomised controlled trial (Rotterdam Aphasia Therapy Study-3) |journal=European Stroke Journal |volume=2 |issue=2 |pages=126–136 |doi=10.1177/2396987317698327 |pmc=5992741 |pmid=29900407}}</ref>

One important caveat in the measurement and treatment of cognitive deficits in people with aphasia is the degree to which assessments of cognition rely on language abilities for successful performance.<ref>{{cite journal |vauthors=Mayer JF, Murray LL |date=September 2012 |title=Measuring working memory deficits in aphasia |journal=Journal of Communication Disorders |volume=45 |issue=5 |pages=325–339 |doi=10.1016/j.jcomdis.2012.06.002 |pmid=22771135}}</ref> Most studies have attempted to circumvent this challenge by utilizing non-verbal cognitive assessments to evaluate cognitive ability in people with aphasia. However, the degree to which these tasks are truly "non-verbal" and not mediated by language is unclear.<ref name=":2" /> For instance, Wall et al.<ref name=":3" /> found that language and non-linguistic performance was related, except when non-linguistic performance was measured by "real life" cognitive tasks.

==Causes==
Aphasia is most often caused by stroke, where about a quarter of patients who experience an acute stroke develop aphasia.<ref name=":4">{{Cite journal|last=Berthier|first=Marcelo L.|date=2005-02-01|title=Poststroke Aphasia|journal=Drugs & Aging|language=en|volume=22|issue=2|pages=163–182|doi=10.2165/00002512-200522020-00006|pmid=15733022|s2cid=22725166|issn=1179-1969}}</ref> However, any disease or damage to the parts of the brain that control language can cause aphasia. Some of these can include brain tumors, traumatic brain injury, epilepsy and progressive neurological disorders.<ref>{{Cite web|title = Aphasia|url = http://www.asha.org/public/speech/disorders/Aphasia/|website = www.asha.org|access-date = 2015-11-18}}</ref> In rare cases, aphasia may also result from [[herpesviral encephalitis]].<ref>{{cite journal | vauthors = Soares-Ishigaki EC, Cera ML, Pieri A, Ortiz KZ | title = Aphasia and herpes virus encephalitis: a case study | journal = Sao Paulo Medical Journal| volume = 130 | issue = 5 | pages = 336–341 | year = 2012 | pmid = 23174874 | doi = 10.1590/S1516-31802012000500011 | doi-access = free | pmc = 10836473 }}</ref> The [[herpes simplex virus]] affects the frontal and temporal lobes, subcortical structures, and the hippocampal tissue, which can trigger aphasia.<ref>{{cite journal | vauthors = Naudé H, Pretorius E | title = Can herpes simplex virus encephalitis cause aphasia? | journal = Early Child Development and Care | date = 3 Jun 2010 | volume = 173 | issue = 6 | pages = 669–679 | doi = 10.1080/0300443032000088285 | s2cid = 143811627 }}</ref> In acute disorders, such as head injury or stroke, aphasia usually develops quickly. When caused by brain tumor, [[infection]], or [[dementia]], it develops more slowly.<ref name="ASHA Aphasia" /><ref name="medicinenet.com">{{cite web | url = http://www.medicinenet.com/aphasia/article.htm | title = Aphasia | access-date = 2011-05-23 | work = MedicineNet.com}}</ref>

Substantial damage to tissue anywhere within the region shown in blue (on the figure in the infobox above) can potentially result in aphasia.<ref name="Lesion correlates of patholinguisti" /> Aphasia can also sometimes be caused by damage to subcortical structures deep within the left hemisphere, including the thalamus, the [[Internal capsule|internal]] and [[external capsule]]s, and the [[caudate nucleus]] of the basal ganglia.<ref>{{cite journal | vauthors = Kuljic-Obradovic DC | title = Subcortical aphasia: three different language disorder syndromes? | journal = European Journal of Neurology | volume = 10 | issue = 4 | pages = 445–448 | date = July 2003 | pmid = 12823499 | doi = 10.1046/j.1468-1331.2003.00604.x | s2cid = 19945519 }}</ref><ref>{{cite journal | vauthors = Kreisler A, Godefroy O, Delmaire C, Debachy B, Leclercq M, Pruvo JP, Leys D | title = The anatomy of aphasia revisited | journal = Neurology | volume = 54 | issue = 5 | pages = 1117–1123 | date = March 2000 | pmid = 10720284 | doi = 10.1212/wnl.54.5.1117 | s2cid = 21847976 }}</ref> The area and extent of brain damage or [[atrophy]] will determine the type of aphasia and its symptoms.<ref name="ASHA Aphasia" /><ref name="medicinenet.com" /> A very small number of people can experience aphasia after damage to the [[right hemisphere]] only. It has been suggested that these individuals may have had an unusual brain organization prior to their illness or injury, with perhaps greater overall reliance on the right hemisphere for language skills than in the general population.<ref>{{cite journal | vauthors = Coppens P, Hungerford S, Yamaguchi S, Yamadori A | title = Crossed aphasia: an analysis of the symptoms, their frequency, and a comparison with left-hemisphere aphasia symptomatology | journal = Brain and Language | volume = 83 | issue = 3 | pages = 425–463 | date = December 2002 | pmid = 12468397 | doi = 10.1016/s0093-934x(02)00510-2 | s2cid = 46650843 }}</ref><ref>{{cite journal | vauthors = Mariën P, Paghera B, De Deyn PP, Vignolo LA | title = Adult crossed aphasia in dextrals revisited | journal = Cortex; A Journal Devoted to the Study of the Nervous System and Behavior | volume = 40 | issue = 1 | pages = 41–74 | date = February 2004 | pmid = 15070002 | doi = 10.1016/s0010-9452(08)70920-1 | s2cid = 4481435 }}</ref>

[[Primary progressive aphasia]] (PPA), while its name can be misleading, is actually a form of dementia that has some symptoms closely related to several forms of aphasia. It is characterized by a gradual loss in language functioning while other cognitive domains are mostly preserved, such as memory and personality. PPA usually initiates with sudden word-finding difficulties in an individual and progresses to a reduced ability to formulate grammatically correct sentences (syntax) and impaired comprehension. The etiology of PPA is not due to a stroke, traumatic brain injury (TBI), or infectious disease; it is still uncertain what initiates the onset of PPA in those affected by it.<ref>{{Cite web|title = Primary Progressive Aphasia|url = http://www.asha.org/Glossary/Primary-Progressive-Aphasia/|website = www.asha.org|access-date = 2015-11-15}}</ref>

[[Epilepsy]] can also include transient aphasia as a [[prodromal]] or episodic symptom.<ref>{{cite journal | vauthors = Blumenfeld H, Meador KJ | title = Consciousness as a useful concept in epilepsy classification | journal = Epilepsia | volume = 55 | issue = 8 | pages = 1145–1150 | date = August 2014 | pmid = 24981294 | pmc = 4149314 | doi = 10.1111/epi.12588 }}</ref> However, the repeated seizure activity within language regions may also lead to chronic, and progressive aphasia. Aphasia is also listed as a rare side-effect of the [[fentanyl]] patch, an opioid used to control chronic pain.<ref>{{cite web |url=https://www.drugs.com/pro/fentanyl-transdermal.html#A02A9CB6-35CF-4F01-A980-C3733E0F861A |title=Fentanyl Transdermal Official FDA information, side effects and uses |work=Drug Information Online }}</ref>

== Diagnosis ==
=== Neuroimaging methods ===
[[Magnetic resonance imaging]] (MRI) and [[functional magnetic resonance imaging]] (fMRI) are the most common neuroimaging tools used in identifying aphasia and studying the extent of damage in the loss of language abilities. This is done by doing MRI scans and locating the extent of lesions or damage within brain tissue, particularly within areas of the left frontal and temporal regions- where a lot of language related areas lie. In fMRI studies a language related task is often completed and then the BOLD image is analyzed. If there are lower than normal BOLD responses that indicate a lessening of blood flow to the affected area and can show quantitatively that the cognitive task is not being completed.

There are limitations to the use of fMRI in aphasic patients particularly. Because a high percentage of aphasic patients develop it because of stroke there can be [[Infarction|infarct]] present which is the total loss of blood flow. This can be due to the thinning of blood vessels or the complete blockage of it. This is important in fMRI as it relies on the BOLD response (the oxygen levels of the blood vessels), and this can create a false hyporesponse upon fMRI study.<ref>{{Cite journal |last1=Crinion |first1=Jenny |last2=Holland |first2=Audrey L. |last3=Copland |first3=David A. |last4=Thompson |first4=Cynthia K. |last5=Hillis |first5=Argye E. |date=2013-06-01 |title=Neuroimaging in aphasia treatment research: Quantifying brain lesions after stroke |journal=NeuroImage |language=en |volume=73 |pages=208–214 |doi=10.1016/j.neuroimage.2012.07.044 |issn=1053-8119 |pmc=3534842 |pmid=22846659}}</ref> Due to the limitations of fMRI such as a lower spatial resolution, it can show that some areas of the brain are not active during a task when they in reality are. Additionally, with [[stroke]] being the cause of many cases of aphasia the extent of damage to brain tissue can be difficult to quantify therefore the effects of stroke brain damage on the functionality of the patient can vary.

;Neural substrates of aphasia subtypes
MRI is often used to predict or confirm the subtype of aphasia present. Researchers compared three subtypes of aphasia&nbsp;— nonfluent-variant primary progressive aphasia (nfPPA), logopenic-variant primary progressive aphasia (lvPPA), and semantic-variant primary progressive aphasia (svPPA), with [[primary progressive aphasia]] (PPA) and Alzheimer's disease. This was done by analyzing the MRIs of patients with each of the subsets of PPA.<ref>{{Cite journal |last1=Sajjadi |first1=S. A. |last2=Sheikh-Bahaei |first2=N. |last3=Cross |first3=J. |last4=Gillard |first4=J. H. |last5=Scoffings |first5=D. |last6=Nestor |first6=P. J. |date=2017-05-01 |title=Can MRI Visual Assessment Differentiate the Variants of Primary-Progressive Aphasia? |url=http://www.ajnr.org/content/38/5/954 |journal=American Journal of Neuroradiology |language=en |volume=38 |issue=5 |pages=954–960 |doi=10.3174/ajnr.A5126 |issn=0195-6108 |pmc=7960364 |pmid=28341715}}</ref> Images which compare subtypes of aphasia as well as for finding the extent of lesions are generated by overlapping images of different participant's brains (if applicable) and isolating areas of lesions or damage using third-party software such as MRIcron. MRI has also been used to study the relationship between the type of aphasia developed and the age of the person with aphasia. It was found that patients with fluent aphasia are on average older than people with non-fluent aphasia. It was also found that among patients with lesions confined to the anterior portion of the brain an unexpected portion of them presented with fluent aphasia and were remarkably older than those with non-fluent aphasia. This effect was not found when the posterior portion of the brain was studied.<ref>{{Cite journal |last1=Basso |first1=Anna |last2=Bracchi |first2=Maurizio |last3=Capitani |first3=Erminio |last4=Laiaconal |first4=Marcella |last5=Zanobio |first5=M. Ester |date=1987-09-01 |title=Age and Evolution of Language Area Functions. A Study on Adult Stroke Patients |journal=Cortex |language=en |volume=23 |issue=3 |pages=475–483 |doi=10.1016/S0010-9452(87)80008-4 |issn=0010-9452 |pmid=3677734 |s2cid=4478097 |doi-access=free}}</ref>

;Associated conditions
In a study on the features associated with different disease trajectories in [[Alzheimer's disease]] (AD)-related primary progressive aphasia (PPA), it was found that metabolic patterns via PET SPM analysis can help predict progression of total loss of speech and functional autonomy in AD and PPA patients. This was done by comparing an MRI or CT image of the brain and presence of a radioactive biomarker with normal levels in patients without Alzheimer's Disease.<ref>{{Cite journal |last1=Mazzeo |first1=Salvatore |last2=Polito |first2=Cristina |last3=Lassi |first3=Michael |last4=Bagnoli |first4=Silvia |last5=Mattei |first5=Marta |last6=Padiglioni |first6=Sonia |last7=Berti |first7=Valentina |last8=Lombardi |first8=Gemma |last9=Giacomucci |first9=Giulia |last10=De Cristofaro |first10=Maria Teresa |last11=Passeri |first11=Alessandro |last12=Ferrari |first12=Camilla |last13=Nacmias |first13=Benedetta |last14=Mazzoni |first14=Alberto |last15=Sorbi |first15=Sandro |date=2022-09-01 |title=Loss of speech and functional impairment in Alzheimer's disease-related primary progressive aphasia: predictive factors of decline |url=https://www.sciencedirect.com/science/article/pii/S0197458022001087 |journal=Neurobiology of Aging |language=en |volume=117 |pages=59–70 |doi=10.1016/j.neurobiolaging.2022.05.002 |issn=0197-4580 |pmid=35665686 |s2cid=248726399|url-access=subscription }}</ref> Apraxia is another disorder often correlated with aphasia. This is due to a subset of apraxia which affects speech. Specifically, this subset affects the movement of muscles associated with speech production, [[apraxia]] and aphasia are often correlated due to the proximity of neural substrates associated with each of the disorders.<ref>{{Cite journal |last1=Ogar |first1=Jennifer |last2=Slama |first2=Hilary |last3=Dronkers |first3=Nina |last4=Amici |first4=Serena |last5=Luisa Gorno-Tempini |first5=Maria |date=2005-12-01 |title=Apraxia of Speech: An overview |journal=Neurocase |volume=11 |issue=6 |pages=427–432 |doi=10.1080/13554790500263529 |issn=1355-4794 |pmid=16393756 |s2cid=8650885}}</ref> Researchers concluded that there were 2 areas of lesion overlap between patients with apraxia and aphasia, the anterior temporal lobe and the left inferior parietal lobe.<ref>{{Cite journal |last1=Goldenberg |first1=Georg |last2=Randerath |first2=Jennifer |date=2015-08-01 |title=Shared neural substrates of apraxia and aphasia |url=https://www.sciencedirect.com/science/article/pii/S002839321530035X |journal=Neuropsychologia |language=en |volume=75 |pages=40–49 |doi=10.1016/j.neuropsychologia.2015.05.017 |issn=0028-3932 |pmid=26004063 |s2cid=46093007|url-access=subscription }}</ref>

;Treatment and neuroimaging
Evidence for positive treatment outcomes can also be quantified using neuroimaging tools. The use of fMRI and an automatic classifier can help predict language recovery outcomes in stroke patients with 86% accuracy when coupled with age and language test scores. The stimuli tested were sentences both correct and incorrect and the subject had to press a button whenever the sentence was incorrect. The fMRI data collected focused on responses in regions of interest identified by healthy subjects.<ref>{{Cite journal |last1=Saur |first1=Dorothee |last2=Ronneberger |first2=Olaf |last3=Kümmerer |first3=Dorothee |last4=Mader |first4=Irina |last5=Weiller |first5=Cornelius |last6=Klöppel |first6=Stefan |year=2010 |title=Early functional magnetic resonance imaging activations predict language outcome after stroke |journal=Brain |volume=133 |issue=4 |pages=1252–1264 |doi=10.1093/brain/awq021 |pmid=20299389 |doi-access=free}}</ref>  Recovery from aphasia can also be quantified using diffusion tensor imaging. The accurate fasciculus (AF) connects the right and left superior temporal lobe, premotor regions/posterior inferior frontal gyrus. and the primary motor cortex. In a study which enrolled patients in a speech therapy program, an increase in AF fibers and volume was found in patients after 6-weeks in the program which correlated with long-term improvement in those patients.<ref>{{Cite journal |last1=Schlaug |first1=Gottfried |last2=Marchina |first2=Sarah |last3=Norton |first3=Andrea |date=July 2009 |title=Evidence for Plasticity in White-Matter Tracts of Patients with Chronic Broca's Aphasia Undergoing Intense Intonation-based Speech Therapy |journal=Annals of the New York Academy of Sciences |language=en |volume=1169 |issue=1 |pages=385–394 |bibcode=2009NYASA1169..385S |doi=10.1111/j.1749-6632.2009.04587.x |pmc=2777670 |pmid=19673813}}</ref> The results of the experiment are pictured in Figure 2. This implies that [[Diffusion MRI|DTI]] can be used to quantify the improvement in patients after speech and language treatment programs are applied.

=== Classification ===
Aphasia is best thought of as a collection of different disorders, rather than a single problem. Each individual with aphasia will present with their own particular combination of language strengths and weaknesses. Consequently, it is a major challenge just to document the various difficulties that can occur in different people, let alone decide how they might best be treated. Most classifications of the aphasias tend to divide the various symptoms into broad classes. A common approach is to distinguish between the fluent aphasias (where speech remains fluent, but content may be lacking, and the person may have difficulties understanding others), and the nonfluent aphasias (where speech is very halting and effortful, and may consist of just one or two words at a time).<ref>{{cite journal |last1=Damasio |first1=Antonio |title=Aphasia |journal=The New England Journal of Medicine |date=1992 |volume=326 |issue=8 |pages=531–539 |doi=10.1056/NEJM199202203260806 |pmid=1732792 |url=https://www.nejm.org/doi/full/10.1056/NEJM199202203260806 |access-date=21 February 2022|url-access=subscription }}</ref>

However, no such broad-based grouping has proven fully adequate, or reliable. There is wide variation among people even within the same broad grouping, and aphasias can be highly selective. For instance, people with naming deficits (anomic aphasia) might show an inability only for naming buildings, or people, or colors.<ref>{{cite book |author1=Kolb, Bryan |author2=Whishaw, Ian Q. |title=Fundamentals of human neuropsychology |publisher=Worth |location=[New York] |year=2003 |pages= 502, 505, 511|isbn=978-0-7167-5300-1 |oclc=464808209 }}</ref> Unfortunately, assessments that characterize aphasia in these groupings have persisted. This is not helpful to people living with aphasia, and provides inaccurate descriptions of an individual pattern of difficulties.

There are typical difficulties with speech and language that come with normal aging as well. As we age, language can become more difficult to process, resulting in a slowing of verbal comprehension, reading abilities and more likely word finding difficulties. With each of these, though, unlike some aphasias, functionality within daily life remains intact.<ref name="Manasco" />{{Reference page|7}}

==== Boston classification ====
{| class="wikitable sortable"
|+ Major characteristics of different types of aphasia according to the Boston classification<ref name="Ref4 from the Broca's area article">{{Cite web|url=http://www.atlantaaphasia.org|title=What is Aphasia|year=2006|publisher=Atlanta Aphasia Association|access-date=2008-12-01}}</ref><ref>{{Cite book|title=Acquired Speech and Language Disorders| vauthors = Murdoch BE |date=1990|publisher=Springer, Boston, MA|isbn=978-0-412-33440-5|pages=60–96|language=en|doi=10.1007/978-1-4899-3458-1_2|chapter = Bostonian and Lurian aphasia syndromes}}</ref>
! Type of aphasia
! [[Speech repetition]]
! Naming
! Auditory comprehension
! Fluency
|-
| [[Expressive aphasia]] (Broca's aphasia)
| Moderate–severe
| Moderate–severe
| Mild difficulty
| Non-fluent, effortful, slow
|-
| [[Receptive aphasia]] (Wernicke's aphasia)
| Mild–severe
| Mild–severe
| Defective
| Fluent paraphasic
|-
| [[Conduction aphasia]]
| Poor
| Poor
| Relatively good
| Fluent
|-
| [[Mixed transcortical aphasia]]
| Moderate
| Poor
| Poor
| Non-fluent
|-
| [[Transcortical motor aphasia]]
| Good
| Mild–severe
| Mild
| Non-fluent
|-
| [[Transcortical sensory aphasia]]
| Good
| Moderate–severe
| Poor
| Fluent
|-
| [[Global aphasia]]
| Poor
| Poor
| Poor
| Non-fluent
|-
| [[Anomic aphasia]]
| Mild
| Moderate–severe
| Mild
| Fluent
|}
* Individuals with [[receptive aphasia]] ([[Wernicke's area|Wernicke's]] aphasia), also referred to as fluent aphasia, may speak in long sentences that have no meaning, add unnecessary words, and even create new "words" ([[neologism]]s). For example, someone with receptive aphasia may say, "delicious taco", meaning "The dog needs to go out so I will take him for a walk". They have poor auditory and reading comprehension, and fluent, but nonsensical, oral and written expression. Individuals with receptive aphasia usually have great difficulty understanding the speech of both themselves and others and are, therefore, often unaware of their mistakes. Receptive language deficits usually arise from lesions in the posterior portion of the left hemisphere at or near Wernicke's area.<ref name="Manasco" /><ref>{{cite journal | vauthors = DeWitt I, Rauschecker JP | title = Wernicke's area revisited: parallel streams and word processing | journal = Brain and Language | volume = 127 | issue = 2 | pages = 181–191 | date = November 2013 | pmid = 24404576 | pmc = 4098851 | doi = 10.1016/j.bandl.2013.09.014 }}</ref>{{Reference page|71}} It is often the result of trauma to the temporal region of the brain, specifically damage to [[Wernicke's area]].<ref>{{Cite news|url=https://www.nidcd.nih.gov/health/aphasia|title=Aphasia|date=2015-08-18|work=NIDCD|access-date=2017-05-02|language=en}}</ref> Trauma can be the result from an array of problems, however it is most commonly seen as a result of stroke<ref name=":0">{{Cite web|url=http://www.asha.org/Practice-Portal/Clinical-Topics/Aphasia/Common-Classifications-of-Aphasia/|title=Common Classifications of Aphasia|website=www.asha.org|language=en|access-date=2017-05-02}}</ref>
* Individuals with [[expressive aphasia]] ([[Broca's area|Broca's]] aphasia) frequently speak short, meaningful phrases that are produced with great effort. It is thus characterized as a nonfluent aphasia. Affected people often omit small words such as "is", "and", and "the". For example, a person with expressive aphasia may say, "walk dog", which could mean "I will take the dog for a walk", "you take the dog for a walk" or even "the dog walked out of the yard." Individuals with expressive aphasia are able to understand the speech of others to varying degrees. Because of this, they are often aware of their difficulties and can become easily frustrated by their speaking problems.<ref name="Brookshire 2007">{{cite book |author=Brookshire R |url=https://archive.org/details/introductiontone0000broo_i6r7|title=Introduction to neurogenic communication disorders|edition=7th|year=2007|location=St. Louis, MO|publisher=Mosby|isbn=978-0-323-07867-2}}{{page needed|date=August 2023}}</ref> While Broca's aphasia may appear to be solely an issue with language production, evidence suggests that it may be rooted in an inability to process syntactical information.<ref>{{cite journal | vauthors = Embick D, Marantz A, Miyashita Y, O'Neil W, Sakai KL | year = 2000 | title = A syntactic specialization for Broca's area | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 97 | issue = 11| pages = 6150–6154 | doi = 10.1073/pnas.100098897 | pmid = 10811887 | pmc = 18573 | bibcode = 2000PNAS...97.6150E | doi-access = free }}</ref> Individuals with expressive aphasia may have a speech automatism (also called recurring or recurrent utterance). These speech automatisms can be repeated lexical speech automatisms; ''e.g.'', modalisations ('I can't&nbsp;..., I can't&nbsp;...'), expletives/swearwords, numbers ('one two, one two') or non-lexical utterances made up of repeated, legal, but meaningless, consonant-vowel syllables (e.g.., /tan tan/, /bi bi/). In severe cases, the individual may be able to utter only the same speech automatism each time they attempt speech.<ref name="Code">{{cite journal | author = Code C | year = 1982 | title = Neurolinguistic analysis of recurrent utterances in aphasia | journal = Cortex | volume = 18 | issue = 1 | pages = 141–152 | doi = 10.1016/s0010-9452(82)80025-7 | pmid = 6197231 | s2cid = 4487128 | doi-access = free }}</ref>
* Individuals with [[anomic aphasia]] have difficulty with naming. People with this aphasia may have difficulties naming certain words, linked by their grammatical type (''e.g.'', difficulty naming verbs and not nouns) or by their [[semantic]] category (''e.g.'', difficulty naming words relating to photography, but nothing else) or a more general naming difficulty. People tend to produce grammatic, yet empty, speech. Auditory comprehension tends to be preserved.<ref name="Squire 2009">{{cite encyclopedia |editor=Squire LR |author1=Dronkers NF |author2=Baldo JV |title=Language: Aphasia|encyclopedia=Encyclopedia of neuroscience |year=2009 |pages=343–348|doi=10.1016/B978-008045046-9.01876-3 |isbn=978-0-08-045046-9}}</ref> Anomic aphasia is the aphasial presentation of tumors in the language zone; it is the aphasial presentation of Alzheimer's disease.<ref>{{cite book|title=Aphasia| vauthors = Alexander MP, Hillis AE | chapter = Chapter 14 Aphasia |series=Handbook of Clinical Neurology|year=2008| isbn=978-0-444-51897-2|editor=Georg Goldenberg |editor2=Bruce L Miller |editor3=Michael J Aminoff |editor4=Francois Boller |editor5=D F Swaab|edition=1|volume=88|pages=287–310|doi=10.1016/S0072-9752(07)88014-6|pmid=18631697|oclc=733092630}}</ref> Anomic aphasia is the mildest form of aphasia, indicating a likely possibility for better recovery.<ref name="Squire 2009" />{{Additional citation needed|date= April 2022|reason= source does not mention possibility for better recovery}}
* Individuals with transcortical sensory aphasia, in principle the most general and potentially among the most complex forms of aphasia, may have similar deficits as in receptive aphasia, but their repetition ability may remain intact.
* Global aphasia is considered a severe impairment in many language aspects since it impacts expressive and receptive language, reading, and writing.<ref>{{cite journal |author1=Demeurisse G. |author2=Capon A. | year = 1987 | title = Language recovery in aphasic stroke patients: Clinical, CT and CBF studies | journal = Aphasiology | volume = 1 | issue = 4| pages = 301–315 | doi=10.1080/02687038708248851}}</ref> Despite these many deficits, there is evidence that has shown individuals benefited from speech language therapy.<ref name="Basso 2011">{{cite journal | vauthors = Basso A, Macis M | title = Therapy efficacy in chronic aphasia | journal = Behavioural Neurology | volume = 24 | issue = 4 | pages = 317–325 | year = 2001 | pmc = 5377972 | doi = 10.1155/2011/313480 | pmid = 22063820 | doi-access = free }}</ref> Even though individuals with global aphasia will not become competent speakers, listeners, writers, or readers, goals can be created to improve the individual's quality of life.<ref name="Brookshire 2007" /> Individuals with global aphasia usually respond well to treatment that includes personally relevant information, which is also important to consider for therapy.<ref name="Brookshire 2007" />
* Individuals with conduction aphasia have deficits in the connections between the speech-comprehension and speech-production areas. This might be caused by damage to the [[arcuate fasciculus]], the structure that transmits information between [[Wernicke's area]] and [[Broca's area]]. Similar symptoms, however, can be present after damage to the [[insular cortex|insula]] or to the [[auditory cortex]]. Auditory comprehension is near normal, and oral expression is fluent with occasional paraphasic errors. Paraphasic errors include phonemic/literal or semantic/verbal. Repetition ability is poor. Conduction and transcortical aphasias are caused by damage to the white matter tracts. These aphasias spare the cortex of the [[language center]]s, but instead create a disconnection between them. Conduction aphasia is caused by damage to the arcuate fasciculus. The arcuate fasciculus is a white matter tract that connects Broca's and Wernicke's areas. People with conduction aphasia typically have good language comprehension, but poor speech repetition and mild difficulty with word retrieval and speech production. People with conduction aphasia are typically aware of their errors.<ref name="Brookshire 2007" /> Two forms of conduction aphasia have been described: ''reproduction conduction aphasia'' (repetition of a single relatively unfamiliar multisyllabic word) and ''repetition conduction aphasia'' (repetition of unconnected short familiar words.<ref>{{Cite journal|last1=Shallice|first1=Tim|last2=Warrington|first2=Elizabeth K.|date=October 1977|title=Auditory-verbal short-term memory impairment and conduction aphasia|journal=Brain and Language|volume=4|issue=4|pages=479–491|doi=10.1016/0093-934x(77)90040-2|pmid=922463|s2cid=40665691|issn=0093-934X}}</ref>
* Transcortical aphasias include transcortical motor aphasia, transcortical sensory aphasia, and mixed transcortical aphasia. People with transcortical motor aphasia typically have intact comprehension and awareness of their errors, but poor word finding and speech production. People with transcortical sensory and mixed transcortical aphasia have poor comprehension and unawareness of their errors.<ref name="Brookshire 2007" /> Despite poor comprehension and more severe deficits in some transcortical aphasias, small studies have indicated that full recovery is possible for all types of transcortical aphasia.<ref>{{cite journal | vauthors = Flamand-Roze C, Cauquil-Michon C, Roze E, Souillard-Scemama R, Maintigneux L, Ducreux D, Adams D, Denier C | display-authors = 6 | title = Aphasia in border-zone infarcts has a specific initial pattern and good long-term prognosis | journal = European Journal of Neurology | volume = 18 | issue = 12 | pages = 1397–1401 | date = December 2011 | pmid = 21554494 | doi = 10.1111/j.1468-1331.2011.03422.x | s2cid = 26120952 }}</ref>

==== Classical-localizationist approaches ====
[[File:Brain - Broca's and Wernicke's area Diagram.svg|thumb|Cortex]]
Localizationist approaches aim to classify the aphasias according to their major presenting characteristics and the regions of the brain that most probably gave rise to them.<ref name="Goodglass, H. 2001">Goodglass, H., Kaplan, E., & Barresi, B. (2001). The assessment of aphasia and related disorders. Lippincott Williams & Wilkins.</ref><ref>Kertesz, A. (2006). Western Aphasia Battery-Revised (WAB-R). Austin, TX: Pro-Ed.</ref> Inspired by the early work of nineteenth-century neurologists [[Paul Broca]] and [[Carl Wernicke]], these approaches identify two major subtypes of aphasia and several more minor subtypes:
* [[Expressive aphasia]] (also known as "motor aphasia" or "Broca's aphasia"), which is characterized by halted, fragmented, effortful speech, but well-preserved comprehension ''relative to expression''. Damage is typically in the anterior portion of the left hemisphere,<ref name="Common Classifications of Aphasia">{{Cite web|title = Common Classifications of Aphasia|url = http://www.asha.org/Practice-Portal/Clinical-Topics/Aphasia/Common-Classifications-of-Aphasia/|website = www.asha.org|access-date = 2015-11-19}}</ref> most notably [[Broca's area]]. Individuals with Broca's aphasia often have [[hemiplegia|right-sided weakness]] or paralysis of the arm and leg, because the left frontal lobe is also important for body movement, particularly on the right side.
* [[Receptive aphasia]] (also known as "sensory aphasia" or "Wernicke's aphasia"), which is characterized by fluent speech, but marked difficulties understanding words and sentences. Although fluent, the speech may lack in key substantive words (nouns, verbs, adjectives), and may contain incorrect words or even nonsense words. This subtype has been associated with damage to the posterior left temporal cortex, most notably Wernicke's area. These individuals usually have no body weakness, because their brain injury is not near the parts of the brain that control movement.
* [[Conduction aphasia]], where speech remains fluent, and comprehension is preserved, but the person may have disproportionate difficulty repeating words or sentences. Damage typically involves the [[arcuate fasciculus]] and the left parietal region.<ref name="Common Classifications of Aphasia" />
* [[Transcortical motor aphasia]] and [[transcortical sensory aphasia]], which are similar to Broca's and Wernicke's aphasia respectively, but the ability to repeat words and sentences is disproportionately preserved.

Recent classification schemes adopting this approach, such as the Boston-Neoclassical Model,<ref name="Goodglass, H. 2001" /> also group these classical aphasia subtypes into two larger classes: the nonfluent aphasias (which encompasses Broca's aphasia and transcortical motor aphasia) and the fluent aphasias (which encompasses Wernicke's aphasia, conduction aphasia and transcortical sensory aphasia). These schemes also identify several further aphasia subtypes, including: [[anomic aphasia]], which is characterized by a selective difficulty finding the names for things; and [[global aphasia]], where both expression and comprehension of speech are severely compromised.

Many localizationist approaches also recognize the existence of additional, more "pure" forms of language disorder that may affect only a single language skill.<ref name="KolbWhishaw1">{{cite book|title=Fundamentals of human neuropsychology|author1=Kolb, Bryan|author2=Whishaw, Ian Q.|publisher=Worth|year=2003|isbn=978-0-7167-5300-1|location=[New York]|pages=502–504|oclc=464808209}}<!-- The whole paragraph "fluent, non-fluent and pure aphasias" is written with help of this reference.--></ref> For example, in [[pure alexia]], a person may be able to write, but not read, and in [[pure word deafness]], they may be able to produce speech and to read, but not understand speech when it is spoken to them.

==== Cognitive neuropsychological approaches ====
Although localizationist approaches provide a useful way of classifying the different patterns of language difficulty into broad groups, one problem is that most individuals do not fit neatly into one category or another.<ref>{{cite journal | vauthors = Godefroy O, Dubois C, Debachy B, Leclerc M, Kreisler A | title = Vascular aphasias: main characteristics of patients hospitalized in acute stroke units | journal = Stroke | volume = 33 | issue = 3 | pages = 702–705 | date = March 2002 | pmid = 11872891 | doi = 10.1161/hs0302.103653 | doi-access = free }}</ref><ref>{{cite journal |author1=Ross K.B. |author2=Wertz R.T. | year = 2001 | title = Type and severity of aphasia during the first seven months poststroke | journal = Journal of Medical Speech-Language Pathology | volume = 9 | pages = 31–53 }}</ref> Another problem is that the categories, particularly the major ones such as Broca's and Wernicke's aphasia, still remain quite broad and do not meaningfully reflect a person's difficulties. Consequently, even amongst those who meet the criteria for classification into a subtype, there can be enormous variability in the types of difficulties they experience.<ref>{{Cite web |title=What Is Aphasia? — Types, Causes and Treatment |url=https://www.nidcd.nih.gov/health/aphasia |access-date=2022-06-17 |website=NIDCD |date=6 March 2017 |language=en}}</ref>

Instead of categorizing every individual into a specific subtype, cognitive neuropsychological approaches aim to identify the key language skills or "modules" that are not functioning properly in each individual. A person could potentially have difficulty with just one module, or with a number of modules. This type of approach requires a framework or theory as to what skills/modules are needed to perform different kinds of language tasks. For example, the model of [[Max Coltheart]] identifies a module that recognizes [[phonemes]] as they are spoken, which is essential for any task involving recognition of words. Similarly, there is a module that stores phonemes that the person is planning to produce in speech, and this module is critical for any task involving the production of long words or long strings of speech. Once a theoretical framework has been established, the functioning of each module can then be assessed using a specific test or set of tests. In the clinical setting, use of this model usually involves conducting a battery of assessments,<ref>{{cite book |author1=Coltheart, Max |author2=Kay, Janice |author3=Lesser, Ruth |title=PALPA psycholinguistic assessments of language processing in aphasia |publisher=Lawrence Erlbaum Associates |location=Hillsdale, N.J |year=1992 |isbn=978-0-86377-166-8 }}</ref><ref>Porter, G., & Howard, D. (2004). CAT: comprehensive aphasia test. Psychology Press.</ref> each of which tests one or a number of these modules. Once a diagnosis is reached as to the skills/modules where the most significant impairment lies, therapy can proceed to treat these skills.

==== Progressive aphasias ====
[[Primary progressive aphasia]] (PPA) is a neurodegenerative focal dementia that can be associated with progressive illnesses or dementia, such as [[frontotemporal dementia]] / [[Pick's disease|Pick Complex]] [[Motor neuron disease]], [[Progressive supranuclear palsy]], and [[Alzheimer's disease]], which is the gradual process of progressively losing the ability to think. Gradual loss of language function occurs in the context of relatively well-preserved memory, visual processing, and personality until the advanced stages. Symptoms usually begin with word-finding problems (naming) and progress to impaired grammar (syntax) and comprehension (sentence processing and semantics). The loss of language before the loss of memory differentiates PPA from typical dementias. People with PPA may have difficulties comprehending what others are saying. They can also have difficulty trying to find the right words to make a sentence.<ref>{{cite journal | vauthors = Mesulam MM | title = Primary progressive aphasia | journal = Annals of Neurology | volume = 49 | issue = 4 | pages = 425–432 | date = April 2001 | pmid = 11310619 | doi = 10.1002/ana.91 | s2cid = 35528862 }}</ref><ref>{{cite journal | vauthors = Wilson SM, Henry ML, Besbris M, Ogar JM, Dronkers NF, Jarrold W, Miller BL, Gorno-Tempini ML | display-authors = 6 | title = Connected speech production in three variants of primary progressive aphasia | journal = Brain | volume = 133 | issue = Pt 7 | pages = 2069–2088 | date = July 2010 | pmid = 20542982 | pmc = 2892940 | doi = 10.1093/brain/awq129 | url = }}</ref><ref name="Harciarek Kertesz 2011">{{cite journal | vauthors = Harciarek M, Kertesz A | title = Primary progressive aphasias and their contribution to the contemporary knowledge about the brain-language relationship | journal = Neuropsychology Review | volume = 21 | issue = 3 | pages = 271–287 | date = September 2011 | pmid = 21809067 | pmc = 3158975 | doi = 10.1007/s11065-011-9175-9 }}</ref> There are three classifications of Primary Progressive Aphasia : [[Progressive nonfluent aphasia]] (PNFA), [[Semantic Dementia]] (SD), and [[Logopenic progressive aphasia]] (LPA).<ref name="Harciarek Kertesz 2011" /><ref name="Gorno-Tempini 2011">{{cite journal | vauthors = Gorno-Tempini ML, Hillis AE, Weintraub S, Kertesz A, Mendez M, Cappa SF, Ogar JM, Rohrer JD, Black S, Boeve BF, Manes F, Dronkers NF, Vandenberghe R, Rascovsky K, Patterson K, Miller BL, Knopman DS, Hodges JR, Mesulam MM, Grossman M | display-authors = 6 | title = Classification of primary progressive aphasia and its variants | journal = Neurology | volume = 76 | issue = 11 | pages = 1006–1014 | date = March 2011 | pmid = 21325651 | pmc = 3059138 | doi = 10.1212/WNL.0b013e31821103e6 }}</ref>

[[Jargon aphasia|Progressive Jargon Aphasia]]{{citation needed|date=August 2012}} is a fluent or receptive aphasia in which the person's speech is incomprehensible, but appears to make sense to them. Speech is fluent and effortless with intact [[syntax]] and [[grammar]], but the person has problems with the selection of [[noun]]s. Either they will replace the desired word with another that sounds or looks like the original one or has some other connection or they will replace it with sounds. As such, people with jargon aphasia often use [[neologism]]s, and may [[perseveration|perseverate]] if they try to replace the words they cannot find with sounds. Substitutions commonly involve picking another (actual) word starting with the same sound (e.g., clocktower – colander), picking another semantically related to the first (e.g., letter – scroll), or picking one phonetically similar to the intended one (e.g., lane – late).

==== Deaf aphasia ====
There have been many instances showing that there is a form of aphasia among deaf individuals. Sign languages are, after all, forms of language that have been shown to use the same areas of the brain as verbal forms of language. Mirror neurons become activated when an animal is acting in a particular way or watching another individual act in the same manner. These mirror neurons are important in giving an individual the ability to mimic movements of hands. Broca's area of speech production has been shown to contain several of these mirror neurons resulting in significant similarities of brain activity between sign language and vocal speech communication. People use facial movements to create, what other people perceive, to be faces of emotions. While combining these facial movements with speech, a more full form of language is created which enables the species to interact with a much more complex and detailed form of communication. Sign language also uses these facial movements and emotions along with the primary hand movement way of communicating. These facial movement forms of communication come from the same areas of the brain. When dealing with damages to certain areas of the brain, vocal forms of communication are in jeopardy of severe forms of aphasia. Since these same areas of the brain are being used for sign language, these same, at least very similar, forms of aphasia can show in the Deaf community. Individuals can show a form of Wernicke's aphasia with sign language and they show deficits in their abilities in being able to produce any form of expressions. Broca's aphasia shows up in some people, as well. These individuals find tremendous difficulty in being able to actually sign the linguistic concepts they are trying to express.<ref>{{cite book |last=Carlson |first=Neil| name-list-style = vanc |title=Physiology of Behavior |url=https://archive.org/details/physiologybehavi00carl_811 |url-access=limited |year=2013 |publisher=Pearson |location=New York |pages=[https://archive.org/details/physiologybehavi00carl_811/page/n514 494]–496 |isbn=978-0-205-23939-9}}</ref>

==== Severity ====
The severity of the type of aphasia varies depending on the size of the stroke. However, there is much variance between how often one type of severity occurs in certain types of aphasia. For instance, any type of aphasia can range from mild to profound. Regardless of the severity of aphasia, people can make improvements due to spontaneous recovery and treatment in the acute stages of recovery.<ref name=":5">{{cite journal |vauthors=Robey RR |date=February 1998 |title=A meta-analysis of clinical outcomes in the treatment of aphasia |journal=Journal of Speech, Language, and Hearing Research |volume=41 |issue=1 |pages=172–187 |doi=10.1044/jslhr.4101.172 |pmid=9493743}}</ref> Additionally, while most studies propose that the greatest outcomes occur in people with severe aphasia when treatment is provided in the acute stages of recovery, Robey (1998) also found that those with severe aphasia are capable of making strong language gains in the chronic stage of recovery as well.<ref name=":5" /> This finding implies that persons with aphasia have the potential to have functional outcomes regardless of how severe their aphasia may be.<ref name=":5" /> While there is no distinct pattern of the outcomes of aphasia based on severity alone, global aphasia typically makes functional language gains, but may be gradual since global aphasia affects many language areas.{{citation needed|date=August 2021}}

==Prevention==
Aphasia is largely caused by unavoidable instances. However, some precautions can be taken to decrease risk for experiencing one of the two major causes of aphasia: stroke and traumatic brain injury (TBI). To decrease the probability of having an ischemic or hemorrhagic stroke, one should take the following precautions:
* Exercising regularly
* Eating a healthy diet, avoiding cholesterol in particular<ref>{{cite journal |last1=Sabih |first1=Ayan |last2=Prasanna |first2=Tadi |title=Stroke Prevention |url=https://www.ncbi.nlm.nih.gov/books/NBK470234/ |website=National Library of Medicine |publisher=StatPearls Publishing |access-date=22 June 2025 |date=2023 |pmid=29262078 }}</ref>
* Keeping alcohol consumption low and avoiding tobacco use
* Controlling blood pressure<ref name="autogenerated1" />
* Going to the emergency room immediately if you begin to experience unilateral extremity (especially leg) swelling, warmth, redness, and/or tenderness as these are symptoms of a deep vein thrombosis which can lead to a stroke<ref>{{Cite web| url=https://www.emedicinehealth.com/blood_clot_in_the_legs/article_em.htm | title=DVT (Deep Vein Thrombosis Blood Clot in the Leg) }}</ref>

To prevent aphasia due to traumatic injury, one should take precautionary measures when engaging in dangerous activities such as:
* Wearing a helmet when operating a bicycle, motor cycle, ATV, or any other moving vehicle that could potentially be involved in an accident
* Wearing a seatbelt when driving or riding in a car
* Wearing proper protective gear when playing contact sports, especially American football, rugby, and hockey, or refraining from such activities
* Minimizing anticoagulant use (including aspirin) if at all possible as they increase the risk of hemorrhage after a head injury<ref>{{Cite journal|doi=10.1001/jamainternmed.2014.2534 |pmid=24915005 |pmc=4527047 |title=Benefits and Risks of Anticoagulation Resumption Following Traumatic Brain Injury |journal=JAMA Internal Medicine |volume=174 |issue=8 |pages=1244–1251 |year=2014 |last1=Albrecht |first1=Jennifer S. |last2=Liu |first2=Xinggang |last3=Baumgarten |first3=Mona |last4=Langenberg |first4=Patricia |last5=Rattinger |first5=Gail B. |last6=Smith |first6=Gordon S. |last7=Gambert |first7=Steven R. |last8=Gottlieb |first8=Stephen S. |last9=Zuckerman |first9=Ilene H. }}</ref>
Additionally, one should always seek medical attention after sustaining head trauma due to a fall or accident. The sooner that one receives medical attention for a traumatic brain injury, the less likely one is to experience long-term or severe effects.<ref>{{Cite web |url=https://www.medicalnewstoday.com/articles/179837.php#diagnosis | title=Causes and effects of traumatic brain injuries | date=22 January 2018 }}</ref>

==Management==

Most acute cases of aphasia recover some or most skills by participating in [[Speech–language pathology|speech and language therapy]]. Recovery and improvement can continue for years after the stroke. After the onset of aphasia, there is approximately a six-month period of spontaneous recovery; during this time, the brain is attempting to recover and repair the damaged neurons. Improvement varies widely, depending on the aphasia's cause, type, and severity. Recovery also depends on the person's age, health, motivation, [[handedness]], and educational level.<ref name="medicinenet.com" />

Speech and language therapy that is higher intensity, higher dose or provided over a long duration of time leads to significantly better functional communication, but people might be more likely to drop out of high intensity treatment (up to 15 hours per week).<ref name="Brady2016">{{cite journal |vauthors=Brady MC, Kelly H, Godwin J, Enderby P, Campbell P |date=June 2016 |title=Speech and language therapy for aphasia following stroke |journal=The Cochrane Database of Systematic Reviews |volume=2016 |issue=6 |article-number=CD000425 |doi=10.1002/14651858.CD000425.pub4 |pmc=8078645 |pmid=27245310 |hdl-access=free |hdl=1893/26112}}</ref> A total of 20–50 hours of speech and language therapy is necessary for the best recovery. The most improvement happens when 2–5 hours of therapy is provided each week over 4–5 days. Recovery is further improved when besides the therapy people practice tasks at home.<ref name=":7">{{Cite journal |last1=Brady |first1=Marian C |last2=Ali |first2=Myzoon |last3=VandenBerg |first3=Kathryn |last4=Williams |first4=Linda J |last5=Williams |first5=Louise R |last6=Abo |first6=Masahiro |last7=Becker |first7=Frank |last8=Bowen |first8=Audrey |last9=Brandenburg |first9=Caitlin |last10=Breitenstein |first10=Caterina |last11=Bruehl |first11=Stefanie |last12=Copland |first12=David A |last13=Cranfill |first13=Tamara B |last14=di Pietro-Bachmann |first14=Marie |last15=Enderby |first15=Pamela |date=October 2022 |title=Complex speech-language therapy interventions for stroke-related aphasia: the RELEASE study incorporating a systematic review and individual participant data network meta-analysis |url=https://www.journalslibrary.nihr.ac.uk/hsdr/RTLH7522 |journal=Health and Social Care Delivery Research |language=en |volume=10 |issue=28 |pages=1–272 |doi=10.3310/RTLH7522 |pmid=36223438 |issn=2755-0060|doi-access=free |hdl=10072/419101 |hdl-access=free }}</ref><ref name=":8">{{Cite journal |last= |first= |date=2023-09-01 |title=Speech and language therapy for aphasia after a stroke |url=https://evidence.nihr.ac.uk/alert/therapy-for-language-problems-after-a-stroke-is-most-effective-when-given-early-and-intensively/ |access-date=2023-09-08 |website=NIHR Evidence |publisher=National Institute for Health and Care Research |language=en-GB |type=Plain English summary |doi=10.3310/nihrevidence_59653|s2cid= 261470072|url-access=subscription }}</ref> Speech and language therapy is also effective if it is [[Telerehabilitation|delivered online through video]] or by a family member who has been trained by a professional therapist.<ref name=":7" /><ref name=":8" />

Recovery with therapy is also dependent on the recency of stroke and the age of the person. Receiving therapy within a month after the stroke leads to the greatest improvements. Three or six months after the stroke more therapy will be needed, but symptoms can still be improved. People with aphasia who are younger than 55 years are the most likely to improve, but people older than 75 years can still get better with therapy.<ref name=":7" /><ref name=":8" />

There is no one treatment proven to be effective for all types of aphasias. The reason that there is no universal treatment for aphasia is because of the nature of the disorder and the various ways it is presented. Aphasia is rarely exhibited identically, implying that treatment needs to be catered specifically to the individual. Studies have shown that, although there is no consistency on treatment methodology in literature, there is a strong indication that treatment, in general, has positive outcomes.<ref name="Schmitz O'Sullivan 2007">{{cite book |author1=Schmitz, Thomas J. |author2=O'Sullivan, Susan B. |title=Physical rehabilitation |publisher=F.A. Davis |location=Philadelphia |year=2007 |isbn=978-0-8036-1247-1 |oclc= 70119705 }}</ref> Therapy for aphasia ranges from increasing functional communication to improving speech accuracy, depending on the person's severity, needs and support of family and friends.<ref>{{cite web|url=http://www.asha.org/PRPSpecificTopic.aspx?folderid=8589934663&section=Treatment|title=Aphasia|work=asha.org}}</ref> Group therapy allows individuals to work on their pragmatic and communication skills with other individuals with aphasia, which are skills that may not often be addressed in individual one-on-one therapy sessions. It can also help increase confidence and social skills in a comfortable setting.<ref name="Manasco" />{{Reference page|97}}

Evidence does not support the use of [[Transcranial direct-current stimulation|transcranial direct current stimulation]] (tDCS) for improving aphasia after stroke. Moderate quality evidence does indicate naming performance improvements for nouns, but not verbs using tDCS<ref>{{Cite journal|last1=Elsner|first1=Bernhard|last2=Kugler|first2=Joachim|last3=Pohl|first3=Marcus|last4=Mehrholz|first4=Jan|date=21 May 2019|title=Transcranial direct current stimulation (tDCS) for improving aphasia in adults with aphasia after stroke|journal=The Cochrane Database of Systematic Reviews|volume=2019|issue=5 |article-number=CD009760|doi=10.1002/14651858.CD009760.pub4|issn=1469-493X|pmc=6528187|pmid=31111960}}</ref>

Specific treatment techniques include the following:
* Copy and recall therapy (CART) – repetition and recall of targeted words within therapy may strengthen orthographic representations and improve single word reading, writing, and naming<ref>Beeson, P. M., Egnor, H. (2007), Combining treatment for written and spoken naming, Journal of the International Neuropsychological Society, 12(6); 816–827.</ref>
* Visual communication therapy (VIC) – the use of index cards with symbols to represent various components of speech
* Visual action therapy (VAT) – typically treats individuals with global aphasia to train the use of hand gestures for specific items<ref>"Aphasia". American Speech Language Hearing Association. Retrieved from http://www.asha.org/PRPSpecificTopic.aspx?folderid=8589934663&section=Treatment {{Webarchive|url=https://web.archive.org/web/20201001222338/https://www.asha.org/PRPSpecificTopic.aspx?folderid=8589934663&section=Treatment |date=2020-10-01 }}</ref>
* Functional communication treatment (FCT) – focuses on improving activities specific to functional tasks, social interaction, and self-expression
* Promoting aphasic's communicative effectiveness (PACE) – a means of encouraging normal interaction between people with aphasia and clinicians. In this kind of therapy, the focus is on pragmatic communication rather than treatment itself. People are asked to communicate a given message to their therapists by means of drawing, making hand gestures or even pointing to an object<ref>{{cite book | vauthors = Alexander MT, Hillis AE | title = Neuropsychology and Behavioral Neurology: Handbook of Clinical Neurology | chapter = Aphasia | volume = 88 | veditors = Goldenberg G, Miller BL, Aminoff MJ, Boller F, Swaab DF | publisher = Elsevier Health Sciences | year = 2008 | pages = 287–310 | isbn = 978-0-444-51897-2 | oclc= 733092630}}</ref>
* Melodic intonation therapy (MIT) – aims to use the intact melodic/prosodic processing skills of the right hemisphere to help cue retrieval of words and expressive language<ref name="Manasco" />{{Reference page|93}}
* Centeredness Theory Interview (CTI) - Uses client centered goal formation into the nature of current patient interactions as well as future / desired interactions to improve subjective well-being, cognition and communication.<ref>{{Cite journal |last1=Peter |first1=Meulenbroek |last2=C. |first2=Keegan |title=The life participation approach and social reintegration after traumatic brain injury  |journal=Apa Psycnet |date=2021 |url=https://psycnet.apa.org/record/2021-16502-008 }}</ref>
* Other – ''i.e.'', drawing as a way of communicating, trained conversation partners<ref name="Schmitz O'Sullivan 2007" />

Semantic feature analysis (SFA)&nbsp;— a type of aphasia treatment that targets word-finding deficits&nbsp;— is based on the theory that neural connections can be strengthened by using related words and phrases that are similar to the target word, to eventually activate the target word in the brain. SFA can be implemented in multiple forms such as verbally, written, using picture cards, etc. The SLP provides prompting questions to the individual with aphasia in order for the person to name the picture provided.<ref>{{cite journal | author = Davis , Stanton | year = 2005 | title = Semantic Feature Analysis as a Functional Therapy Tool | journal = Contemporary Issues in Communication Science and Disorders | volume = 35 | pages = 85–92 | doi = 10.1044/cicsd_32_F_85 }}</ref> Studies show that SFA is an effective intervention for improving confrontational naming.<ref>{{cite journal | vauthors = Maddy KM, Capilouto GJ, McComas KL | title = The effectiveness of semantic feature analysis: an evidence-based systematic review | journal = Annals of Physical and Rehabilitation Medicine | volume = 57 | issue = 4 | pages = 254–267 | date = June 2014 | pmid = 24797214 | doi = 10.1016/j.rehab.2014.03.002 | doi-access = free }}</ref>

[[Melodic intonation therapy]] is used to treat non-fluent aphasia and has proved to be effective in some cases.<ref>{{cite journal | vauthors = Norton A, Zipse L, Marchina S, Schlaug G | title = Melodic intonation therapy: shared insights on how it is done and why it might help | journal = Annals of the New York Academy of Sciences | volume = 1169 | pages = 431–436 | date = July 2009 | pmid = 19673819 | pmc = 2780359 | doi = 10.1111/j.1749-6632.2009.04859.x }}</ref> However, there is still no evidence from [[randomized controlled trial]]s confirming the efficacy of MIT in chronic aphasia. MIT is used to help people with aphasia vocalize themselves through speech song, which is then transferred as a spoken word. Good candidates for this therapy include people who have had left hemisphere strokes, non-fluent aphasias such as Broca's, good auditory comprehension, poor repetition and articulation, and good emotional stability and memory.<ref>{{cite journal | vauthors = van der Meulen I, van de Sandt-Koenderman ME, Ribbers GM | title = Melodic Intonation Therapy: present controversies and future opportunities | journal = Archives of Physical Medicine and Rehabilitation | volume = 93 | issue = 1 Suppl | pages = S46–52 | date = January 2012 | pmid = 22202191 | doi = 10.1016/j.apmr.2011.05.029 }}</ref> An alternative explanation is that the efficacy of MIT depends on neural circuits involved in the processing of rhythmicity and [[formulaic language|formulaic expressions]] (examples taken from the MIT manual: "I am fine," "how are you?" or "thank you"); while rhythmic features associated with melodic intonation may engage primarily left-hemisphere subcortical areas of the brain, the use of formulaic expressions is known to be supported by right-hemisphere cortical and bilateral subcortical neural networks.<ref name="Sidtis 2015" /><ref>{{cite journal | vauthors = Stahl B, Kotz SA | title = Facing the music: three issues in current research on singing and aphasia | journal = Frontiers in Psychology | volume = 5 | issue = 1033 | page = 1033 | year = 2013 | pmid = 25295017 | pmc = 4172097 | doi = 10.3389/fpsyg.2014.01033 | doi-access = free }}</ref>

Systematic reviews support the effectiveness and importance of partner training.<ref>{{Cite journal | doi=10.1016/j.apmr.2016.03.023| pmid=27117383| title=Communication Partner Training in Aphasia: An Updated Systematic Review| journal=Archives of Physical Medicine and Rehabilitation| volume=97| issue=12| pages=2202–2221.e8| year=2016| last1=Simmons-Mackie| first1=Nina| last2=Raymer| first2=Anastasia| last3=Cherney| first3=Leora R.}}</ref> According to the National Institute on Deafness and Other Communication Disorders (NIDCD), involving family with the treatment of an aphasic loved one is ideal for all involved, because while it will no doubt assist in their recovery, it will also make it easier for members of the family to learn how best to communicate with them.<ref name="Aphasia">{{cite web |url=https://www.nidcd.nih.gov/health/aphasia |title=Aphasia |website=National Institute on Deafness and Other Communication Disorders |access-date=December 16, 2017|date=2015-08-18 }}</ref>

When a person's speech is insufficient, different kinds of [[augmentative and alternative communication]] could be considered such as alphabet boards, pictorial communication books, specialized software for computers or apps for tablets or smartphones.<ref>{{Cite journal|last=Russo|first=Maria Julieta| name-list-style = vanc |date=2017|title=High-technology Augmentative Communication for adults with post-stroke aphasia: a systematic review|journal=Expert Review of Medical Devices|volume=April 26|issue=5|pages=355–370|pmid=28446056|doi=10.1080/17434440.2017.1324291|s2cid=10452302|hdl=11336/40999|hdl-access=free}}</ref>

When addressing Wernicke's aphasia, according to Bakheit et al. (2007), the lack of awareness of the language impairments, a common characteristic of Wernicke's aphasia, may affect the rate and extent of therapy outcomes.<ref>{{cite journal |vauthors=Bakheit AM, Shaw S, Carrington S, Griffiths S |date=October 2007 |title=The rate and extent of improvement with therapy from the different types of aphasia in the first year after stroke |journal=Clinical Rehabilitation |volume=21 |issue=10 |pages=941–949 |doi=10.1177/0269215507078452 |pmid=17981853 |s2cid=25995618}}</ref> Robey (1998) determined that at least 2 hours of treatment per week is recommended for making significant language gains.<ref name=":5" /> Spontaneous recovery may cause some language gains, but without speech-language therapy, the outcomes can be half as strong as those with therapy.<ref name=":5" />

When addressing Broca's aphasia, better outcomes occur when the person participates in therapy, and treatment is more effective than no treatment for people in the acute period.<ref name=":5" /> Two or more hours of therapy per week in acute and post-acute stages produced the greatest results.<ref name=":5" /> High-intensity therapy was most effective, and low-intensity therapy was almost equivalent to no therapy.<ref name=":5" />

People with global aphasia are sometimes referred to as having irreversible aphasic syndrome, often making limited gains in auditory comprehension, and recovering no functional language modality with therapy. With this said, people with global aphasia may retain gestural communication skills that may enable success when communicating with conversational partners within familiar conditions. Process-oriented treatment options are limited, and people may not become competent language users as readers, listeners, writers, or speakers no matter how extensive therapy is.<ref name="Brookshire 2007" /> However, people's daily routines and quality of life can be enhanced with reasonable and modest goals.<ref name="Brookshire 2007" /> After the first month, there is limited to no healing to language abilities of most people. There is a grim prognosis, leaving 83% who were globally aphasic after the first month that will remain globally aphasic at the first year. Some people are so severely impaired that their existing process-oriented treatment approaches offer no signs of progress, and therefore cannot justify the cost of therapy.<ref name="Brookshire 2007" />

Perhaps due to the relative rareness of conduction aphasia, few studies have specifically studied the effectiveness of therapy for people with this type of aphasia. From the studies performed, results showed that therapy can help to improve specific language outcomes. One intervention that has had positive results is auditory repetition training. Kohn et al. (1990) reported that drilled auditory repetition training related to improvements in spontaneous speech, Francis et al. (2003) reported improvements in sentence comprehension, and Kalinyak-Fliszar et al. (2011) reported improvements in auditory-visual short-term memory.<ref>{{cite journal |vauthors=Kalinyak-Fliszar M, Kohen F, Martin N |date=January 2011 |title=Remediation of language processing in aphasia: Improving activation and maintenance of linguistic representations in (verbal) short-term memory |journal=Aphasiology |volume=25 |issue=10 |pages=1095–1131 |doi=10.1080/02687038.2011.577284 |pmc=3393127 |pmid=22791930}}</ref><ref>{{cite journal |last1=Francis |first1=Dawn |last2=Clark |first2=Nina |last3=Humphreys |first3=Glyn |name-list-style=vanc |year=2003 |title=The treatment of an auditory working memory deficit and the implications for sentence comprehension abilities in mild 'receptive' aphasia |journal=Aphasiology |volume=17 |issue=8 |pages=723–750 |doi=10.1080/02687030344000201 |s2cid=145088109}}</ref><ref>{{cite journal |vauthors=Kohn SE, Smith KL, Arsenault JK |date=April 1990 |title=The remediation of conduction aphasia via sentence repetition: a case study |journal=The British Journal of Disorders of Communication |volume=25 |issue=1 |pages=45–60 |doi=10.3109/13682829009011962 |pmid=1695853}}</ref>

===Individualized service delivery===
Intensity of treatment should be individualized based on the recency of stroke, therapy goals, and other specific characteristics such as age, size of lesion, overall health status, and motivation.<ref name="Cherney 2011">{{cite journal | vauthors = Cherney LR, Patterson JP, Raymer AM | title = Intensity of aphasia therapy: evidence and efficacy | journal = Current Neurology and Neuroscience Reports | volume = 11 | issue = 6 | pages = 560–569 | date = December 2011 | pmid = 21960063 | doi = 10.1007/s11910-011-0227-6 | s2cid = 10559070 }}</ref><ref name="Sage 2011">{{cite journal | vauthors = Sage K, Snell C, Lambon Ralph MA | title = How intensive does anomia therapy for people with aphasia need to be? | journal = Neuropsychological Rehabilitation | volume = 21 | issue = 1 | pages = 26–41 | date = January 2011 | pmid = 21181603 | doi = 10.1080/09602011.2010.528966 | s2cid = 27001159 | url = https://www.research.manchester.ac.uk/portal/en/publications/how-intensive-does-anomia-therapy-for-people-with-aphasia-need-to-be(b982a0b5-3bd8-41ba-ba2b-b847318cd3c9).html }}</ref> Each individual reacts differently to treatment intensity and is able to tolerate treatment at different times post-stroke.<ref name="Sage 2011" /> Intensity of treatment after a stroke should be dependent on the person's motivation, stamina, and tolerance for therapy.<ref name="Palmer 2015">{{cite journal|author=Palmer R|year=2015|title=Innovations in aphasia treatment after stroke: Technology to the rescue|journal=British Journal of Neuroscience Nursing|volume=38|pages=38–42|doi=10.12968/bjnn.2015.11.sup2.38}}</ref>

==Outcomes==
If the symptoms of aphasia last longer than two or three months after a stroke, a complete recovery is unlikely. However, it is important to note that some people continue to improve over a period of years and even decades. Improvement is a slow process that usually involves both helping the individual and family understand the nature of aphasia and learning compensatory strategies for communicating.<ref>{{cite web |url=http://www.aphasia.org/aphasia-faqs/ |title=Aphasia FAQs |website=National Aphasia Association |access-date=December 16, 2017}}</ref>

After a traumatic brain injury (TBI) or cerebrovascular accident (CVA), the brain undergoes several healing and re-organization processes, which may result in improved language function. This is referred to as spontaneous recovery. Spontaneous recovery is the natural recovery the brain makes without treatment, and the brain begins to reorganize and change in order to recover.<ref name="Brookshire 2007" /> There are several factors that contribute to a person's chance of recovery caused by stroke, including stroke size and location.<ref name="M2015" /> Age, sex, and education have not been found to be very predictive.<ref name="M2015" /> There is also research pointing to damage in the left hemisphere healing more effectively than the right.<ref name=":4" />

Specific to aphasia, spontaneous recovery varies among affected people and may not look the same in everyone, making it difficult to predict recovery.<ref name="M2015">{{cite journal | vauthors = Watila MM, Balarabe SA | title = Factors predicting post-stroke aphasia recovery | journal = Journal of the Neurological Sciences | volume = 352 | issue = 1–2 | pages = 12–18 | date = May 2015 | pmid = 25888529 | doi = 10.1016/j.jns.2015.03.020 | s2cid = 136750791 }}</ref>

Though some cases of Wernicke's aphasia have shown greater improvements than more mild forms of aphasia, people with Wernicke's aphasia may not reach as high a level of speech abilities as those with mild forms of aphasia.<ref name="Laska 2001">{{cite journal | vauthors = Laska AC, Hellblom A, Murray V, Kahan T, Von Arbin M | title = Aphasia in acute stroke and relation to outcome | journal = Journal of Internal Medicine | volume = 249 | issue = 5 | pages = 413–422 | date = May 2001 | pmid = 11350565 | doi = 10.1046/j.1365-2796.2001.00812.x | s2cid = 32102500 | doi-access = free }}</ref>

== Prevalence ==
Aphasia affects about two million people in the U.S. and 250,000 people in Great Britain.<ref>{{Cite web |title=Aphasia Statistics |work=The National Aphasia Association |url=https://www.aphasia.org/aphasia-resources/aphasia-statistics/}}</ref> Nearly 180,000 people acquire the disorder every year in the U.S.,<ref>{{cite web |title=Aphasia Fact sheet - National Aphasia Association |url=http://www.aphasia.org/aphasia-resources/aphasia-factsheet/ |access-date=18 December 2017 |website=National Aphasia Association}}</ref> 170,000 due to stroke.<ref>{{Citation |last1=Acharya |first1=Aninda B. |title=Broca Aphasia |date=2022 |url=https://www.ncbi.nlm.nih.gov/books/NBK436010/ |work=StatPearls |access-date=2022-04-18 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=28613781 |last2=Wroten |first2=Michael}}</ref> Any person of any age can develop aphasia, given that it is often caused by a traumatic injury. However, people who are middle aged and older are the most likely to acquire aphasia, as the other etiologies are more likely at older ages.<ref>{{Cite web |title=Aphasia: Who is at risk for aphasia? |url=https://my.clevelandclinic.org/health/diseases/5502-aphasia}}</ref> For example, approximately 75% of all strokes occur in individuals over the age of 65.<ref>{{Cite web |title=Stroke Statistics |url=http://www.strokecenter.org/patients/about-stroke/stroke-statistics/ |archive-url=https://web.archive.org/web/20210225192236/http://www.strokecenter.org/patients/about-stroke/stroke-statistics/ |archive-date=2021-02-25 |access-date=2019-12-10}}</ref> Strokes account for most documented cases of aphasia:<ref>{{cite web |title=Aphasia FAQ |work=National Aphasia Association |url=https://www.aphasia.org/aphasia-faqs/ |access-date=2019-12-10 |archive-date=2015-03-06 |archive-url=https://web.archive.org/web/20150306205959/https://www.aphasia.org/aphasia-faqs/ |url-status=dead }}</ref> 25% to 40% of people who survive a stroke develop aphasia as a result of damage to the language-processing regions of the brain.<ref name=":6" />

==History==
The first recorded case of aphasia is from an Egyptian [[papyrus]], the [[Edwin Smith Papyrus]], which details speech problems in a person with a [[traumatic brain injury]] to the [[temporal lobe]].<ref name=McCrory>{{cite journal | vauthors = McCrory PR, Berkovic SF | title = Concussion: the history of clinical and pathophysiological concepts and misconceptions | journal = Neurology | volume = 57 | issue = 12 | pages = 2283–2289 | date = December 2001 | pmid = 11756611 | doi = 10.1212/WNL.57.12.2283 | s2cid = 219209099 }}</ref>

During the second half of the 19th century, aphasia was a major focus for scientists and philosophers who were working in the beginning stages of the field of psychology.<ref name="Damasio 1992"/>
In medical research, speechlessness was described as an incorrect prognosis, and there was no assumption that underlying language complications existed.<ref>{{cite book |doi=10.1016/S0072-9752(08)02136-2 |pmid=19892139 |chapter=Chapter 36 History of aphasia |title=History of Neurology |volume=95 |pages=571–582 |series=Handbook of Clinical Neurology |year=2009 |last1=Eling |first1=Paul |last2=Whitaker |first2=Harry | name-list-style = vanc |isbn=978-0-444-52009-8 }}</ref> Broca and his colleagues were some of the first to write about aphasia, but Wernicke was the first credited to have written extensively about aphasia being a disorder that contained comprehension difficulties.<ref>{{cite journal | vauthors = Boller F | title = Johann Baptist Schmidt. A pioneer in the history of aphasia | journal = Archives of Neurology | volume = 34 | issue = 5 | pages = 306–307 | date = May 1977 | pmid = 324450 | doi = 10.1001/archneur.1977.00500170060011 }}</ref> Despite claims of who reported on aphasia first, it was F.J. Gall that gave the first full description of aphasia after studying wounds to the brain, as well as his observation of speech difficulties resulting from vascular lesions.<ref>{{cite journal | vauthors = Riese W | title = The early history of aphasia | journal = Bulletin of the History of Medicine | volume = 21 | issue = 3 | pages = 322–334 | date = 1947-05-01 | pmid = 20257374 }}</ref> A recent book on the entire history of aphasia is available (Reference: Tesak, J. & Code, C. (2008) ''Milestones in the History of Aphasia: Theories and Protagonists''. Hove, East Sussex: Psychology Press).

===Etymology===
''Aphasia'' is from [[Greek language|Greek]] [[alpha privative|''a-'']] ("without", negative [[prefix]]) + ''phásis'' (''φάσις'', "speech").

The word ''aphasia'' comes from the word ἀφασία ''aphasia'', in [[Ancient Greek]], which means<ref name=autogenerated1>{{cite news|url=http://www.medicalnewstoday.com/articles/217487.php|title=What is aphasia? What causes aphasia?|work=Medical News Today|date=21 February 2017}}</ref> "speechlessness",<ref>[https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Da%29fa%29si%2Fa ἀφασία], Henry George Liddell, Robert Scott, ''A Greek-English Lexicon'', on Perseus.</ref> derived from ἄφατος ''aphatos'', "speechless"<ref>[https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0058%3Aentry%3Da)%2Ffatos ἄφατος], Henry George Liddell, Robert Scott, ''A Greek-English Lexicon'', on Perseus.</ref> from ἀ- ''a-'', "not, un" and φημί ''phemi'', "I speak".

==Further research==
Research is currently being done using functional magnetic resonance imaging (fMRI) to witness the difference in how language is processed in normal brains vs aphasic brains. This will help researchers to understand exactly what the brain must go through in order to recover from Traumatic Brain Injury (TBI) and how different areas of the brain respond after such an injury.<ref>{{Cite web|title=What Is Aphasia? – Types, Causes and Treatment|url=https://www.nidcd.nih.gov/health/aphasia|access-date=2021-10-18|website=NIDCD|date=6 March 2017 |language=en}}</ref>

Another intriguing approach being tested is that of drug therapy. Research is in progress that will hopefully uncover whether or not certain drugs might be used in addition to speech-language therapy in order to facilitate recovery of proper language function. It is possible that the best treatment for aphasia might involve combining drug treatment with therapy, instead of relying on one over the other.<ref>{{Cite journal |last1=Berthier|first1=Marcelo L. |last2=Pulvermüller |first2=Friedemann |last3=Dávila |first3=Guadalupe |last4=Casares |first4=Natalia García |last5=Gutiérrez|first5=Antonio|date=September 2011|title=Drug Therapy of Post-Stroke Aphasia: A Review of Current Evidence|url=http://link.springer.com/10.1007/s11065-011-9177-7|journal=Neuropsychology Review |language=en|volume=21|issue=3|pages=302–317|doi=10.1007/s11065-011-9177-7|pmid=21845354 |s2cid=39980301 |issn=1040-7308|url-access=subscription}}</ref>

One other method being researched as a potential therapeutic combination with speech-language therapy is brain stimulation. One particular method, Transcranial Magnetic Stimulation (TMS), alters brain activity in whatever area it happens to stimulate, which has recently led scientists to wonder if this shift in brain function caused by TMS might help people re-learn language.{{Citation needed|date=March 2024}} Another type of external brain stimulation is transcranial Direct Current Stimulation (tDCS), but existing research has not shown it to be useful for improving aphasia after a stroke.<ref name="Aphasia"/>

== See also ==
{{Div col|colwidth=30em}}
* [[Agnosia]], inability to process sensory information (e.g. inability to recognize objects)
* [[Aphasiology]], study of language impairment (usually from brain damage)
* [[Apraxia of speech]], difficulty connecting speech messages from the brain to the mouth
* [[Aprosodia]]
* [[Auditory processing disorder]]
* [[Lethologica]]
* [[Lists of language disorders]]
* ''[[My Beautiful Broken Brain]]'', a 2014 documentary
* [[Origin of speech]]
{{Div col end}}

== Notes ==
{{notelist|refs=
{{efn|name=dysphasia|Some sources suggest that ''aphasia'' and ''dysphasia'' differ in the severity of the language impairment, e.g., ''aphasia'' is more severe and involves a complete loss of speech and comprehension abilities, while ''dysphasia'' only involves moderate language impairments. However, these terms are often used interchangeably to refer to full and partial disruptions of language abilities. Nowadays, the term ''dysphasia'' is no longer used in the healthcare field since it is often confused with ''[[dysphagia]]'' (a swallowing disorder).<ref>{{cite web |url=https://blog.encompasshealth.com/2022/11/30/aphasia-vs-dysphasia-understanding-the-differences/ |title=Aphasia vs. Dysphasia: Understanding the Differences |author=Nita Crighton |date=August 13, 2024 |website=Encompass Health |access-date=April 22, 2025}}</ref>}}
}}

== References ==
{{Reflist}}

== External links ==
{{Library resources box|by=no|onlinebooks=no|about=yes|wikititle=aphasia}}
{{Wiktionary|aphasia|aphemia}}
* [https://www.aphasia.org/ National Aphasia Association]

{{Medical resources
| DiseasesDB      = 4024
| ICD11           = {{ICD11|6A01.20}}, {{ICD11|6A01.21}}, {{ICD11|MA80.0}}, {{ICD11|MA80.1}}
| ICD10           = {{ICD10|F80.1}}, {{ICD10|F80.2}}, {{ICD10|R47.0}}
| ICD9            = {{ICD9|315.31}}, {{ICD9|315.32}}, {{ICD9|784.3}}, {{ICD9|438.11}}
| ICDO            =
| OMIM            =
| MedlinePlus     = 003204
| eMedicineSubj   = neuro
| eMedicineTopic  = 437
| MeshID          = D001037
| ICD10CM         = {{ICD10CM|R47.01}}
}}
{{Brain and brainstem lesion symptoms and signs}}
{{Dyslexia and specific developmental disorders}}
{{Authority control}}

[[Category:Aphasias| ]]
[[Category:Alexia (condition)]]
[[Category:Communication disorders]]
[[Category:Language disorders]]
[[Category:Symptoms and signs: Speech and voice]]