Clinical aspects of comorbid schizophrenia and idiopathic Parkinson's disease.

The comorbidity of schizophrenia and idiopathic Parkinson's disease (IPD) is illustrated by a case description of a schizophrenic patient who develops motor symptoms finally diagnosed and treated as comorbid IPD. Several aspects of the clinical challenges of this comorbidity are discussed and an overview of earlier reported cases is presented. IPD must be distinguished from neuroleptic-induced parkinsonism by clinical course and characteristics. A SPECT scan is helpful for diagnosis. We recommend antiparkinsonian treatment to be prescribed only with the protection of antipsychotic agents, of which clozapine and quetiapine are the best choices.