Gray matter heterotopias in schizophrenia.

Gray matter heterotopias (GMHs) are a type of neuronal migration anomaly in which collections of normal neurons are abnormally located secondary to an arrest of radial migration. They are often manifested clinically by seizures and cognitive, motor, and language deficits. Through magnetic resonance imaging, we have observed two cases in patients presenting with symptoms of schizophrenia, but no neurological abnormalities, and otherwise normal scans. While the incidence of GMH among normal individuals is unknown, it is possible that this particular anomaly may occur in schizophrenic patients at a higher rate than in the normal population. Furthermore, neuronal migration abnormalities may be involved in the pathogenesis of the disorder among a small subset of patients with schizophrenia.