Neuroleptic-induced parkinsonism in older schizophrenics.

The association of neuroleptic drug-induced parkinsonism (DIP) with factors related to brain structure and function are poorly understood. Twenty-one medicated schizophrenics over age 55 years were evaluated for parkinsonism, tardive dyskinesia, psychiatric symptoms, ventricular/brain ratio (VBR), and neuropsychological function. Sixteen (76%) of the patients had DIP, whereas 10 (48%) had tardive dyskinesia. Increased severity of parkinsonism was significantly associated with larger VBR and the severity of negative symptoms. Severity of parkinsonism predicted poor visual-spatial function, whereas negative symptoms were modestly predictive of impairment in both verbal ability and cognitive flexibility. These findings suggest that brain atrophy may be a risk factor for DIP. The pattern of cognitive dysfunction associated with DIP in this sample is similar to that found in idiopathic Parkinson's disease. Dopaminergic dysfunction may underlie the pattern of pathology described in this report.