Evidence of a smaller left hippocampus and left temporal horn in both patients with first episode schizophrenia and normal control subjects

Findings from cerebral magnetic resonance imaging (MRI) studies in schizoph renia indicating temporal lobe involvement have been inconsistent and contr oversial. In a prospective study, we quantified the volumes of temporal lob e structures in 20 male patients with first episode schizophrenia (FES; mea n +/- S.D. = 27.4 +/- 4.8 years) and 20 healthy age-matched male control su bjects (27.7 +/- 3.1 years). Measurements were performed on contiguous 2.2- mm coronal MRI slices, which included, as well as the temporal lobe, the am ygdala, the hippocampal formation, and the temporal horn of the lateral ven tricle. The definition of the borders of the structures relied on measureme nt guidelines derived from mutual comparisons of MRI and histological data. The definition of the hippocampus-amygdala interface was also validated in a correlated triplanar display. We did not detect any significant volume r eductions of the measured structures in the FES group, as compared with hea lthy control subjects, on either side. Comparisons within groups, however, revealed that in both the patients and the healthy volunteers the hippocamp al formations showed a significant right-sided bias (+9%, P = 0.004, in the FES group; + 12%, P = 0.0003 in the control subjects). A significant volum e difference in favor of the right hemisphere was also observed in the temp oral horns of the lateral ventricles (+ 17%, P = 0.02 in the patients with FES; + 34%, P = 0.003, in the control group). There was only a nonsignifica nt trend for a larger temporal horn on the left side in patients with schiz ophrenia as compared with the control subjects. Our findings do not indicat e a loss ol reversal of the normal volume asymmetry pattern in the FES grou p. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.