Sexual Dimorphism in Volume of the Cerebral Hemispheres and Lateral Ventricles in Schizophrenia Using Magnetic Resonance Imaging

Purpose: This study is designed to determine the sexual dimorphism pattern in volume of the cerebral hemispheres and lateral ventricles in schizophrenia using magnetic resonance imaging (MRI) and to compare it with normal sexual dimorphism pattern in healthy brains. Materials and Methods: This study is performed on 29 healthy volunteers (21 males, 8 females) and 29 patients suffered from schizophrenia (21 males, 8 females) after exact psychiatric examinations based on DSM-IV criteria. Males and females in each group were in the same age. The brains of patients and controls serially sectioned in full coronal series of 1.5 mm thickness by a 1.5 tesla MRI. The volumes of whole brain, hemispheres, and lateral ventricles and the ventricular - Brain Ratios (VBRs) were estimated by Cavalieri's principle. Finally the sex difference for each parameter was evaluated by t-student and non – parametrical Mann- Whitney tests. Results: The volumes of the whole brain and each of its hemispheres were significantly smaller in healthy females than those males (P<0.005). The volume of the right ventricle was also smaller in healthy females than those males (P<0.05). The volume of both lateral ventricles was tended to be smaller in females than males (0.05<P <0.1). However, the volume of the left ventricle was similar between two sexes in healthy controls. In schizophrenics, the volume of the whole brain and each of its hemispheres were significantly smaller in females than males (P < 0.005), but there were not any significant sex difference in ventricular volumes. VBRs were similar between two sexes in healthy controls. In schizophrenics, the- VBRL and the YBRW were significantly higher in females than males. Conclusion: The lateral ventricular volumes, particularly in left, are larger in schizophrenic females than those males. On the other word, since the VBRL and the VBRw are higher in schizophrenic females than those males, it is concluded that the internal cerebral atrophy in schizophrenia is more severe in females than males, particularly in the left hemisphere.