The neuropathology of schizophrenic diseases: historical aspects and present knowledge.

In the first half of the century, histological abnormalities in the cortex and thalamus of schizophrenics were described. These findings, however, remained controversial and finally were widely forgotten. More recently, a large number of structural imaging studies convincingly showed subtle structural changes such as ventricular enlargement, cortical sulcal enlargement, and smaller hippocampi in a considerable proportion of schizophrenic patients. Many studies reported minor tissue abnormalities in limbic structures. Since the limbic system is anatomically and functionally interposed between the neocortical association areas and phylogenetically old hypothalamic and brain stem systems, limbic dysfunction may lead to a dissociation between cognitive activities and basic emotional reactions, thus, explaining some aspects of the psychopathology of schizophrenia. Reduced cortical asymmetry, lack of gliosis, and other findings support the idea of a disorder of early brain development; however, a progressive component also might be inherent.