[Dementia in Parkinson's disease]

Abstract

Background: Parkinson's disease has traditionally been considered as a pure motor condition; characterized by tremor, rigidity, bradykinesia and slow postural reflexes. The concomitant presence of neuropsychiatric symptoms, including dementia, has been increasingly recognized during the last decade.

Material and methods: Literature on epidemiology, neuropathology and clinical characteristics of dementia in Parkinson's disease was retrieved from PubMed.

Results and interpretation: Dementia in Parkinson's disease is more common than previously assumed. According to cross-sectional studies, up to 30% of the Parkinson patients have dementia and almost all patients with Parkinson' disease develop dementia over time. Dementia is associated with higher mortality, an increased risk of institutionalisation and increased caregiver distress. Reduced visuospatial and executive functions, severe motor symptoms and high age are risk factors for development of dementia. REM sleeping disorders, psychotic symptoms and depression are frequent comorbid conditions. Dementia in Parkinson's disease correlates with increased Lewy body pathology and reduced levels of neurotransmitters (especially acetylcholine) in neocortical and limbic structures of the brain. Treatment with acetylcholine esterase inhibitors has been shown to have moderate symptomatic effect.