chapter  64
Cognitive impairment and dementia in Parkinson’s disease
ByDag Aarsland, Kolbjørn Brønnick, Milica G. Kramberger, Joana B. Pereira
Pages 8

Parkinson’s disease (PD) is a common neurodegenerative disorder aecting about 1.5% of people aged 65 or older (de Rijk et al., 1997). PD is dened pathologically as cell loss in the pigmented dopaminergic cells of the substantia nigra pars compacta and synuclein pathology (Lewy neurites and Lewy bodies) in the surviving cells. In addition, cholinergic forebrain nuclei and other brain stem nuclei including the serotonergic raphe nuclei and the noradrenergic locus coeruleus are usually aected. e topographical progression subsequently involves the anteromedial temporal mesocortex, including the transentorhinal region, and reaches into adjoining high-order sensory association areas and important limbic structures such as amygdalae and hippocampus (Braak et al., 2003). e cardinal clinical features of PD are resting tremor, bradykinesia, rigidity and postural abnormalities. However, owing to the wide distribution of neurodegeneration, it is not surprising that a wide range of non-motor symptoms occur as well, including neuropsychiatric symptoms and autonomic dysfunction.