Parkinson's disease dementia

{{Short description|Form of dementia associated with Parkinson's disease}}

Parkinson's disease dementia (PDD) is dementia that is associated with Parkinson's disease (PD).{{cite journal |vauthors=Weil RS, Lashley TL, Bras J, Schrag AE, Schott JM |title=Current concepts and controversies in the pathogenesis of Parkinson's disease dementia and Dementia with Lewy Bodies |journal=F1000Res |volume=6 |pages=1604 |date=2017 |pmid=28928962 |pmc=5580419 |doi=10.12688/f1000research.11725.1 |type=Review |doi-access=free }} Together with dementia with Lewy bodies (DLB), it is one of the Lewy body dementias characterized by abnormal deposits of Lewy bodies in the brain.{{cite journal |vauthors=Gomperts SN |title=Lewy Body Dementias: Dementia With Lewy Bodies and Parkinson Disease Dementia |journal=Continuum (Minneap Minn) |volume=22 |issue=2 Dementia |pages=435–63 |date=April 2016 |pmid=27042903 |pmc=5390937 |doi=10.1212/CON.0000000000000309|type=Review}}{{cite journal |vauthors=Pezzoli S, Cagnin A, Bandmann O, Venneri A |title=Structural and Functional Neuroimaging of Visual Hallucinations in Lewy Body Disease: A Systematic Literature Review |journal=Brain Sci |volume=7 |issue=12 |pages= 84|date=July 2017 |pmid=28714891 |pmc=5532597 |doi=10.3390/brainsci7070084|type=Review |doi-access=free }}{{cite journal |vauthors=Galasko D |title=Lewy Body Disorders |journal=Neurol Clin |volume=35 |issue=2 |pages=325–338 |date=May 2017 |pmid=28410662 |pmc=5912679 |doi=10.1016/j.ncl.2017.01.004|type=Review }}{{cite journal |vauthors=Walker Z, Possin KL, Boeve BF, Aarsland D |title=Lewy body dementias |journal=Lancet |volume=386 |issue=10004 |pages=1683–97 |date=October 2015 |pmid=26595642 |pmc=5792067 |doi=10.1016/S0140-6736(15)00462-6 |type=Review}}

Parkinson's disease starts as a movement disorder, but progresses in most cases to include dementia and changes in mood and behavior.{{cite web|title=Lewy body dementia: Hope through research |url= https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope-Through-Research/Lewy-Body-Dementia-Hope-Through-Research |website= National Institute of Neurological Disorders and Stroke |publisher = US National Institutes of Health |access-date= April 6, 2018|date=December 8, 2017}} The signs, symptoms and cognitive profile of PDD are similar to those of DLB; DLB and PDD are clinically similar after dementia occurs in Parkinson's disease. Parkinson's disease is a risk factor for PDD; it speeds up decline in cognition leading to PDD. Up to 78% of people with PD have dementia. Delusions in PDD are less common than in DLB, and persons with PD are typically less caught up in their visual hallucinations than those with DLB.{{cite journal |vauthors=Burghaus L, Eggers C, Timmermann L, Fink GR, Diederich NJ |title=Hallucinations in neurodegenerative diseases |journal=CNS Neurosci Ther |volume=18 |issue=2 |pages=149–59 |date=February 2012 |pmid=21592320 |doi=10.1111/j.1755-5949.2011.00247.x |type=Review |pmc=6493408 }} There is a higher incidence of tremor at rest in PD than in DLB, and signs of parkinsonism in PDD are less symmetrical than in DLB.{{cite journal |vauthors=St Louis EK, Boeve AR, Boeve BF |title=REM sleep behavior disorder in Parkinson's disease and other synucleinopathies |journal=Mov. Disord. |volume=32 |issue=5 |pages=645–58 |date=May 2017 |pmid=28513079 |doi=10.1002/mds.27018|s2cid=46881921 |type=Review }}

Parkinson's disease dementia can only be definitively diagnosed after death with an autopsy of the brain. The 2017 Fourth Consensus Report established diagnostic criteria for PDD and DLB. The diagnostic criteria are the same for both conditions, except that PDD is distinguished from DLB by the time frame in which dementia symptoms appear relative to parkinsonian symptoms. DLB 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 well established before the dementia occurs; that is, the onset of dementia is more than a year after the onset of parkinsonian symptoms.{{cite journal |vauthors=McKeith IG, Boeve BF, Dickson DW, et al |title=Diagnosis and management of dementia with Lewy bodies: Fourth consensus report of the DLB Consortium |journal=Neurology |volume=89 |issue=1 |pages=88–100 |date=July 2017 |pmid=28592453 |pmc=5496518 |doi=10.1212/WNL.0000000000004058 |type=Review }}

Cognitive behavioral therapy can help people with Parkinson's disease with parkinsonian pain, insomnia, depression, anxiety, and impulse disorders, if those interventions are properly adapted to the motor, cognitive and executive dysfunctions seen in Parkinson's disease, including Parkinson's dementia.{{cite journal |vauthors=Zečević I |title=Clinical Practice Guidelines Based on Evidence for Cognitive-Behavioral Therapy in Parkinson's Disease Comorbidities: A Literature Review |journal=Clin Psychol Psychother |date=March 2020 |volume=27 |issue=4 |pages=504–514 |pmid=32196842 |doi=10.1002/cpp.2448 |s2cid=214601157 |type=Review}}