Abstract

Clozapine therapy for psychosis and Parkinsonism in a phenotypical case of Prader-Willi Syndrome

Psychosis with or without neurological abnormalities has only rarely been reported in association with Prader-Willi syndrome. A 52-year-old woman showed evidence of developmental and behavioural abnormalities typical of this syndrome, along with a history of schizophrenic psychosis with onset in young adulthood. She developed moderately severe Parkinsonism, which persisted after withdrawal of a low dose of a typical neuroleptic. Both the psychosis and Parkinsonism responded to a low dose of clozapine. Cytogenetic analysis failed to confirm a chromosomal anomaly. In patients with Prader- Willi syndrome, the neurodevelopmental abnormalities may increase vulnerability to both psychosis and drug-triggered Parkinsonism. Atypical neuroleptics such as clozapine may be more appropriate than a typical neuroleptic in treating a combination of Parkinsonism and psychosis, particularly when complicated by central nervous system disease.