Reduced frontal and occipital lobe asymmetry on the CT-scans of schizophrenic patients. Its specificity and clinical significance

Abstract

Frontal and occipital lobe width were determined in the computed tomographic (= CT) scans of 135 schizophrenic patients, 158 neuropsychiatrically healthy and 102 psychiatric control subjects, including patients with affective psychosis, neurosis and schizoaffective psychosis. Most healthy right handed subjects demonstrate a relative enlargement of the right frontal as well as left occipital lobe compared to the opposite hemisphere. These normal frontal and occipital lobe asymmetries were selectively reduced in schizophrenics (f.: 5%, p < .0005; o.: 3%, p < .05), irrespective of the psychopathological subgroup. Schizophrenic neuroleptic non-responders revealed a significant reduction of frontal lobe asymmetry (3%, p < .05), while no correlation between BPRS-subscores and disturbed cerebral laterality could be detected. In sum the present study demonstrates disturbed cerebral lateralisation in schizophrenic patients supporting the hypothesis of interrupted early brain development in schizophrenia.

Progressive loss of cortical gray matter in schizophrenia: a meta-analysis and meta-regression of longitudinal MRI studies

“…This may explain the finding of abnormalities in cerebral asymmetries frequently, but inconsistently reported in previous literature on the brain pathology of schizophrenia. 73, 74, 75, 76 The progression of cortical volume changes seems to affect especially the left hemisphere: this could justify the finding of abnormal asymmetries reported particularly in chronic, rather than first-episode cases, when this phenomenon may be less detectable. A reduced lateralization of cortical structures has been recently reported also at the onset of schizophrenia, before medical treatment is initiated, most prominent in the inferior frontal gyrus (part of Broca's area) and the STG (part of Wernicke's area).…”

Alterations of the occipital lobe in schizophrenia

“…Occipital lobe asymmetries in schizophrenic patients have also been found to be reduced. 82 More research is needed to explore occipital lobe functions and volumes across different stages of schizophrenia. More extensive data are necessary from the earliest phase of schizophrenia, to conclude the understanding of the alterations of the occipital lobe in schizophrenia.…”

The XY gene hypothesis of psychosis: Origins and current status

“…Selective decrease in volume in the left temporal and right frontal regions in patients with schizophrenia [Turetsky et al, 1995] and a reduction in left temporal lobe gray matter, and absence of normal left-greater-than-right asymmetry of the temporal pole gray volume [Kasai et al, 2003b] are consistent with the concept of Gratiolet and Leuret [1839] that the left frontal lobe, and right occipito-parietotemporal regions gyrify earlier than their contralateral counterparts. Apparent volume losses in right frontal and left temporal Crow et al [1989a] Lateral X-rays of radio-opaque filled ventricles of formalin-fixed post-mortem hemispheres Percentage enlargement greatest in temporal horn and selective to the left side "Schizophrenia as an anomaly of development of cerebral asymmetry-Á Á Á a proposal concerning the genetic-basis of the disease" Degreef et al [1992], Kawasaki et al [1993], and Yotsutsuji et al [2003] MRI: ventricular shape analysis Left temporal horn enlargement-selectively correlated with indices of clinical severity [Degreef et al, 1992]; with positive symptoms [Kawasaki et al, 1993]; greater than right (M > F) [Yotsutsuji et al, 2003] ?Arrest of development of left temporal pole Cerebral torque Crow et al [1989b] and Falkai et al [1995b] CT scan: hemisphere width measures Loss in early onset cases [Crow et al, 1989b]; overall loss of anterior and posterior asymmetries [Falkai et al, 1995b] Bilder et al [1994 MRI: coronal section volumes Loss of torque in schizophrenia [Bilder et al, 1994]; mood disorder pts intermediate between pts…”