Normal Asymmetry of the Planum Temporale in Patients with Schizophrenia

Abstract

Background: Abnormal cerebral anatomical lateralisation has been reported in schizophrenia and may implicate anomalous neurodevelopment in the aetiology of this disease. A popular recent hypothesis has predicted that such disturbances in normal lateralisation should be especially apparent in the morphology of the temporal lobes.Method: A temporal cortical region lying in the plane of the Sylvian fissure – known as the planum temporale – exhibits pronounced leftward asymmetry in normal right-handed males. We compared lateralisation of the planum temporale in schizophrenic and control males using MRI surface-rendering morphometry of the supratemporal cortex.Results: Contrary to the lateralisation hypothesis, normal patterns of leftward planum asymmetry were detected in both the schizophrenic and control groups. Schizophrenics and controls also exhibited a predicted symmetry in the bilateral areas of Heschl's gyrus, a supratemporal cortical structure immediately anterior to the planum.Conclusion: These data do not support the notion that neurodevelopmental mechanisms of cerebral asymmetry are abnormal in schizophrenia.