THE TEMPORAL LOBES, REVERSED ASYMMETRY AND THE GENETICS OF SCHIZOPHRENIA

MECHANISMS determining temporal lobe structural asymmetries may be inv olved in the pathogenesis of schizophrenia. To investigate the tempora l lobes in familial schizophrenia, computed tomographic scans were obt ained from 51 subjects (seven families). Enlargement of sylvian fissur es and temporal lobe sulcal spaces was observed in family members with schizophrenia. The posterior one-third of the sylvian fissure was lar ger on the left side in subjects with schizophrenia, and larger on the right side in unaffected individuals. This disturbed pattern of poste rior sylvian fissure asymmetry suggests that adjacent language regions may be affected in schizophrenia. An intermediate degree of disturban ce in subjects who had schizophrenia-related illnesses or were obligat e carriers suggests that genetic factors may be important determinants of temporal lobe asymmetries in familial schizophrenia.