Instrumental motor predictors of neuroleptic-induced parkinsonism in newly medicated schizophrenia patients.

Previous studies suggest that many untreated schizophrenia patients exhibit motor disturbances. On the basis of these findings, the authors hypothesized that preexisting extrapyramidal movement disorders may increase the risk of developing neuroleptic-induced parkinsonism (NIP). Thirty-five newly medicated psychotic patients underwent pretreatment clinical and instrumental motor and psychiatric assessments. Posttreatment ratings of parkinsonism were conducted at monthly intervals for the first 3 months and every 3 months thereafter. Thirteen patients (37%) developed NIP. Advanced age and pretreatment extrapyramidal disturbances predicted NIP. Life-table survival curves indicated that patients with pretreatment instrumental rigidity developed clinically significant NIP earlier than those without rigidity. These findings suggest that pretreatment motor dysfunction may be a risk factor for drug-induced parkinsonism, especially among older patients.