Lewy body dementia

Template:Short description Lewy body dementia (LBD) is an umbrella term for two similar and common subtypes of dementia:<ref name=Walker2015>Template:Cite journal</ref> dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD).<ref name=Gomperts2016>Template:Cite journal</ref><ref name=Pezzoli2017>Template:Cite journal</ref><ref name= Galasko2017>Template:Cite journal</ref><ref name=Kon2020/> Both are characterized by changes in thinking, movement, behavior, and mood.<ref name=Walker2015/> The two conditions have similar features and may have similar causes, and are believed to belong on a spectrum of Lewy body disease<ref name=Gomperts2016/> that includes Parkinson's disease.<ref name=Kon2020>Template:Cite journal</ref> As of 2014, they were more often misdiagnosed than any other common dementia.<ref name=Taylor2014/>

The exact cause is unknown, but involves widespread deposits of abnormal clumps of protein that form in neurons of the diseased brain.<ref>Template:Cite journal</ref> Known as Lewy bodies (discovered in 1912 by Frederic Lewy<ref name=NINDS2025>Template:Cite web</ref>) and Lewy neurites, these clumps affect both the central nervous system and the autonomic nervous system.<ref name= Lin2019>Template:Cite journal</ref> The fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) gives Lewy body disease as the causative subtype of dementia with Lewy bodies, and Parkinson's disease as the causative subtype of Parkinson's disease dementia.<ref name="DSM5"/> Dementia with Lewy bodies is marked by the presence of Lewy bodies primarily in the cortical regions, and Parkinson's disease dementia with Lewy bodies primarily in the subcortical basal ganglia.<ref name="DSM5A"/>

Classification

Template:Further The synucleinopathies (dementia with Lewy bodies, Parkinson's disease dementia, and Parkinson's disease) are characterized by shared features of parkinsonism motor symptoms, neuropsychiatric symptoms, impaired cognition, sleep disorders, and visual hallucinations.<ref name=Valayudhan2017>Template:Cite journal</ref><ref name=McKeithConsensus2017>Template:Cite journal</ref> The Lewy body dementias—dementia with Lewy bodies (DLB), and Parkinson's disease dementia (PDD)—are distinguished by the timing when cognitive and motor symptoms appear.<ref name= Connors2018>Template:Cite journal</ref> The two Lewy body dementias are often considered to belong on a spectrum of Lewy body disease that includes Parkinson's disease.<ref name=Gomperts2016/><ref name=Kon2020/>

MeSH lists Lewy body disease in several categories: as a nervous system disease in two listings, one as a basal ganglia Parkinsonian movement disorder and the other under brain disease as a dementia; as a neurodegenerative disorder listed as a synucleinopathy; and as a neurocognitive disorder listed with dementia.<ref name="MeSH">Template:Cite web</ref>

A genetic architecture that predisposes an individual to some disease phenotypes is found in Parkinson's disease and the Lewy body dementias. The presence of Lewy bodies is a link between these disorders; the term "diseases with Lewy bodies" therefore may be more accurate than "Lewy body disease".<ref>Template:Cite journal Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License</ref>

Cause and mechanisms

Dementia with Lewy bodies and Parkinson's disease dementia are similar in many ways, suggesting there may be a common pathophysiological mechanism, with PDD and DLB at opposite ends of a Lewy body disease spectrum,<ref name=Gomperts2016/> and a shared component of protein deposits in Lewy bodies and Lewy neurites.<ref name=Weil2017>Template:Cite journal</ref> Lewy bodies and neurites have been found to develop from the aggregation of misfolded alpha-synuclein, a protein thought to assist in neurotransmitter release and vesicle turnover; whether these misfolded proteins are responsible for the neurodegenerative effects remains unclear, and no definitive link between Lewy bodies and neurodegenerative effects has been found.<ref name=Latimer2018/> DSM-5 gives Lewy body disease as the causative subtype of DLB, and Parkinson's disease as the causative subtype of PDD.<ref name="DSM5">Template:Cite book</ref> DLB is marked by the presence of Lewy bodies primarily in the cortical regions, and PDD with Lewy bodies primarily in the subcortical basal ganglia.<ref name="DSM5A">Template:Cite book</ref>

Despite differences in the timing of the appearance of symptoms, the two dementias "show remarkably convergent neuropathological changes at autopsy".<ref name=Gomperts2016/> The relationship between Parkinson's disease dementia and dementia with Lewy bodies is unclear as of 2020, but there is likely to be genetic overlap, and the two conditions may represent different points on a continuum.<ref name=Taylor2020>Template:Cite journal</ref>

Diagnosis

Template:Further Dementia with Lewy bodies and Parkinson's disease dementia have similar neuropathological features, but these features are highly variable and the conditions cannot be distinguished on pathological features alone.<ref name= Latimer2018>Template:Cite web</ref> Generally, dementia with Lewy bodies is distinguished from Parkinson's disease dementia by the time frame in which dementia symptoms appear relative to parkinsonian symptoms and is diagnosed when cognitive symptoms begin before or at the same time as parkinsonism. Parkinson's disease dementia is the diagnosis when Parkinson's disease is already well established before the dementia occurs.<ref name=McKeithConsensus2017/>

Epidemiology

Template:Further Between 5% and 25% of diagnosed dementias in older adults are due to one of the Lewy body dementias.<ref name= Connors2018/>Template:Efn As of 2014, the Lewy body dementias affect about 1.3 million people in the US and 140,000 in the UK.<ref name=Taylor2014>Template:Cite journal</ref>

LBD usually develops after the age of 50.<ref name= NINDS2025/> Men are more likely to be diagnosed than women.<ref name= NINDS2025/>

Prognosis

Template:Further Life expectancy of people with one of the LBD is reduced; following diagnosis it ranges on average from five to eight years.<ref>Template:Cite journal</ref>

Society and culture

Advocacy and awareness

As of 2014, the Lewy body dementias were more often misdiagnosed than any other common dementia.<ref name=Taylor2014/> Most people with DLB had not heard of the condition prior to diagnosis; general awareness about LBD lags well behind that of Parkinson's and Alzheimer's diseases, even though LBD is the second most common dementia, after Alzheimer's.<ref name=Taylor2014/> It is not only frustrating for families and caregivers to find that few people, including many healthcare professionals, are knowledgeable about LBD; lack of knowledge can have significant health consequences because people with LBD have severe sensitivity to antipsychotics often used to treat the symptoms.<ref name= Taylor2014/> The Lewy Body Dementia Association (LBDA) and the UK Lewy Body Society promote awareness and provide support that helps society, by reducing costly use of healthcare, and families with LBD, by reducing stress.<ref name=Taylor2014/> These organizations, and others in Argentina, Australia and Japan, help raise knowledge and help families with LBD become advocates to raise awareness about the disease.<ref name= Taylor2014/>

Notable individuals

Robin Williams (shown in 2011): his widow said he was diagnosed on autopsy with Lewy bodies.<ref name=RobinWidow/><ref name=Williams2016/>

Robin Williams, the American actor and comedian, died on August 11, 2014. Before his suicide, he had been diagnosed with Parkinson's disease,<ref name=RobinWidow>Template:Cite news</ref> and according to his widow, Susan Schneider Williams, he experienced depression, anxiety, and increasing paranoia.<ref name=Williams2016>Template:Cite journal</ref> Upon autopsy, his widow said he was found to have diffuse Lewy body disease,<ref name=RobinWidow/><ref name=Williams2016/><ref name=HowLewy>Template:Cite news</ref> while the autopsy used the term diffuse Lewy body dementia.<ref name=LBDA/> The vocabulary associated with Lewy pathology causes confusion.<ref name= Armstrong2021/> Lewy body dementia (the umbrella term that encompasses the clinical diagnoses of dementia with Lewy bodies and Parkinson's disease dementia) differs from Lewy body disease (the term used to describe pathological findings of Lewy bodies on autopsy).<ref name= Armstrong2021>Template:Cite journal</ref> Dennis Dickson, a spokesperson for the Lewy Body Dementia Association, clarified the distinction by stating that diffuse Lewy body dementia is more commonly called diffuse Lewy body disease and refers to the underlying disease process.<ref name=LBDA>Template:Cite web</ref> According to Dickson, "Lewy bodies are generally limited in distribution" in early Parkinson's disease, while in dementia with Lewy bodies, "the Lewy bodies are spread widely throughout the brain, as was the case with Robin Williams."<ref name=LBDA/> Ian G. McKeith, professor and researcher of Lewy body dementias, commented that Williams' symptoms and autopsy findings were explained by dementia with Lewy bodies.<ref>Template:Cite news</ref>

The British author and poet Mervyn Peake died in 1968 and was diagnosed posthumously as a probable case of DLB in a 2003 paper published in JAMA Neurology.<ref name=Sahlas2003>Template:Cite journal</ref> Sahlas said his death was "variously ascribed to Alzheimer disease, Parkinson disease, or postencephalitic parkinsonism".<ref name=Sahlas2003/> Based on signs in his work and letters of progressive deterioration, fluctuating cognitive decline, deterioration in visuospatial function, declining attention span, and visual hallucinations and delusions, his may be the earliest known case where DLB was found to have been the likely cause of death.<ref name=Sahlas2003/>

Other entertainers and artists who have or died from LBD include Estelle Getty, the actress known for her role as Sophia on the television series The Golden Girls,<ref name=guardian-obit>Template:Cite news</ref> Nicholas King, a US actor and horticulturist,<ref>Template:Cite news</ref> actress Dina Merrill,<ref>Template:Cite news</ref> Donald Featherstone, who created the plastic pink flamingo,<ref>Template:Cite news</ref> American radio and television host Casey Kasem,<ref>Template:Cite news</ref> Canadian singer Pierre Lalonde,<ref>Template:Cite news</ref><ref>Template:Cite web</ref> graphic artist/film set designer Ron Cobb,<ref>Template:Cite news</ref> American actor Frank Bonner,<ref>Template:Cite web</ref> Canadian musician and actor André Gagnon,<ref>Template:Cite web</ref> and Mark Volman, founding member of the band the Turtles.<ref>Template:Cite web</ref>

British author Michael Bywater died of LBD.<ref>Template:Cite news</ref>

Individuals from industry or government who have or died from LBD include Seymour Berry, US Director of the Bureau of Engraving and Printing,<ref>Template:Cite news</ref> Los Angeles Times publisher Otis Chandler,<ref name=LatObit>Template:Cite news</ref> Philip J. Rock, a US Democratic politician of the Illinois Senate,<ref>Template:Cite news</ref> U.S. media mogul and philanthropist Ted Turner,<ref>Template:Cite news</ref> and Indian-born British billionaire S. P. Hinduja.<ref>Template:Cite web</ref>

Arnold R. Hirsch, an American historian who taught at the University of New Orleans,<ref>Template:Cite news</ref> and Jessie Isabelle Price, an American veterinary microbiologist,<ref>Template:Cite news</ref> died from LBD.

In the sports realm, Jerry Sloan, American professional basketball player and coach, died from LBD.<ref>Template:Cite press release</ref> Major League Baseball players Tom Seaver,<ref>Template:Cite news</ref> Andy Carey,<ref>Template:Cite news</ref> and Bill Buckner died of LBD.<ref>Template:Cite web</ref> Stan Mikita, Canadian ice hockey player, was diagnosed with possible LBD,<ref name=Kuc>Template:Cite news</ref> but a post-mortem brain autopsy found that he had chronic traumatic encephalopathy.<ref>Template:Cite news</ref>

In popular culture

Robin's Wish, a documentary exploring Robin Williams's Lewy body disease and how it contributed to his death, was released in September 2020.<ref name="ew-6aug2020">Template:Cite magazine</ref><ref>Template:Cite web</ref><ref>Template:Cite web</ref>

Sleepwalk with Me is a book, one-man comedy, and film about a young man with relationship problems and RBD, a precursor to synucleinopathy, including LBD.<ref>Template:Cite web</ref>