DISTURBED PLANUM TEMPORALE ASYMMETRY IN SCHIZOPHRENIA - A QUANTITATIVE POSTMORTEM STUDY

The planum temporale of the temporal cortex was investigated post-mortem in 24 schizophrenic patients and 24 age- and sex-matched control subjects. Schizophrenic patients demonstrated a 20% volume reduction of the left planum temporale (p=0.032), whereas on the right side, there was a trend for increase in male schizophrenics (+22%, p=0.17), while in female patients the volume was moderately decreased (-6%, p=0.74). The mean anterior-posterior diameter of the planum temporale was significantly reduced in the left hemisphere (-20%, p=0.008), but unchanged on the right side. The asymmetry coefficients (Galaburda et al. (1987) Neuropsychologia 25, 853-868) for the planum temporale cortex volume (p=0.02) and anterior-posterior diameter (p=0.002) but not for mean area (p=0.61) were significantly different between schizophrenics and control subjects. These data support the idea of disturbed cerebral laterality in schizophrenia. The implications of methodology and patient samples are discussed.