[Neuropsychologic changes in Parkinson syndrome].

In Parkinson's disease various cognitive deficits occur of which impairments of perception, memory, speech, vigilance, reaction-time, and shifting aptitude in cognitive tasks can be distinguished. Also depression is frequently observed. Personality changes are discussed originating from organic mental factors, the experience of the disease, and possible premorbid personality traits. Mental processing is probably slowed down in Parkinson's disease (bradyphrenia). However, it is not yet clarified in which cognitive categories bradyphrenia may play a role.