Progress in Clinical Neurosciences: Parkinson's Disease with Dementia and Dementia with Lewy Bodies

Richard Camicioli, Nancy Fisher
2004 Canadian Journal of Neurological Sciences  
P a r k i n s o n 's disease (PD) is the most common neurodegenerative movement disorder, affecting about 0.5-5% of the population older than age 65, both in European and non-European populations. 1,2 The prevalence of PD increases with age in most studies from less than 1% in people aged 65-69 years to 2-3% or more in people older than age 90. The prevalence might decrease in the very elderly, possibly reflecting diagnostic uncertainty, overlap with other diseases, a disproportionate effect on
more » ... survival in the oldest old with PD or inadequate sample sizes in studies of the oldest old (greater than age 85 years). 3,4 At a societal level, PD increases health care utilization and costs. 5, 6 Parkinson's disease is a progressive disorder associated with acquired parkinsonism and the loss of substantia nigra neurons in the presence of Lewy bodies (http://www. I C D N S . o rg ) . Parkinsonism is defined by the presence of two cardinal signs among resting tremor, rigidity, bradykinesia and postural or gait impairment, and can be caused by disorders other than idiopathic PD. Lewy bodies are eosinophilic inclusions that stain with antibodies directed against alpha-synuclein, a ubiquitous synaptic protein evident in a number of neurodegenerative disorders. 7 Clinical features that make a diagnosis of idiopathic PD more likely include asymmetrical onset, resting tremor, and a favorable response to levodopa. 8 Good accuracy (approximately 90% positive predictive value) and sensitivity (90%) can now be achieved. 9,10 Nevertheless in the general ABSTRACT: Dementia occurs in up to 30% of people with Parkinson's disease and is a major cause of disability. Pathologically, Parkinson's dementia, where dementia follows the onset of parkinsonism by at least one year, overlaps with dementia with Lewy bodies. We review the functional impact, definitions, neuropsychology, epidemiology and pathophysiology of Parkinson's dementia, dementia with Lewy bodies and their overlap. Associated psychiatric and imaging findings are also considered. Lastly, current and emerging approaches to assessment and treatment in patients with these Lewy body associated dementias are presented. RÉSUMÉ: Maladie de Parkinson avec démence et démence à corps de Lewy. La démence est présente chez plus de 30% des patients atteints de la maladie de Parkinson et constitue une cause importante d'invalidité. Au point de vue anatomopathologique, la démence de la maladie de Parkinson (DMP) apparaissant au moins un an après le début de la maladie chevauche la démence à corps de Lewy (DCL). Nous révisons l'impact fonctionnel, les définitions, la neuropsychologie, l'épidémiologie et la physiopathologie de la DMP et de la DCL et leur chevauchement. Les manifestations psychiatriques et l'imagerie sont également discutées. Finalement, les approches actuelles et émergentes d'évaluation et de traitement chez les patients porteurs de ces démences à corps de Lewy sont présentées.
doi:10.1017/s0317167100002791 fatcat:o322gcy27vfwnohm5mo3ixsxsu