[Comparative psychological test studies of the intellectual ability of Parkinson patients].

Patients with Parkinson's disease (n = 81) are compared with normal controls and three clinical groups, each representing a different level of cerebral impairment (TIA; Stroke; Alzheimer's disease (AD) and multi-infarct dementia (MID). Psychometric measures of abstract reasoning, speed of information processing, verbal and visual memory, visuospatial perception and psychomotor functions are taken using a neuropsychological test battery with appropriate age-correction and normalized scaling. Following differentiation between the uncomplicated idiopathic Parkinson's syndrome and Parkinson plus (signs of cerebral polypathy and/or a degenerative process exceeding the nigro-striatal system) the neuropsychological profile reveals intellectual impairments approaching the dementia level (AD/MID) only in the Parkinson plus subgroup. With the exception of the severe motor deficiencies, the overall performance of patients with an uncomplicated Parkinson's syndrome is largely on the level of age-matched controls. Slight deficits exist only in the speed of information processing (action under time restriction) and in visuoconstructive performance.