Abstract

The possibility that dementia in Parkinson's disease is associated with specific cerebral abnormalities identifiable by magnetic resonance imaging (MRI) was examined. Sixty eight patients with Parkinson's disease and 28 age and education matched normal controls were evaluated using neuropsychological procedures that included assessment of language, memory, cognition, visuospatial skills and mood. Twenty three patients (34%) were found to have developed significant impairment in at least three of the five areas, thus meeting criteria for a dementia syndrome. Eleven patients (16%) had no intellectual impairment and thirty four patients (50%) had a mild to moderate intellectual disturbance. Patients with (n = 10) and without dementia (n = 20), matched for severity of Parkinson's disease, and normal controls (n = 10) matched for age with the two patients groups, were evaluated by MRI. MRI scans were analysed for evidence of generalised cerebral atrophy, ventricular enlargement, visualisation of the substantia nigra and severity of focal brain lesions. Results indicated that the presence of dementia in patients with Parkinson's disease was not associated with any specific pattern of MRI abnormalities.