In the first half of the century, histological abnormalities in the cortex
and thalamus of schizophrenics were described. These findings, however, rem
ained controversial and finally were widely forgotten. More recently, a lar
ge number of structural imaging studies convincingly showed subtle structur
al changes such as ventricular enlargement, cortical sulcal enlargement, an
d smaller hippocampi in a considerable proportion of schizophrenic patients
. Many studies reported minor tissue abnormalities in limbic structures. Si
nce the limbic system is anatomically and functionally interposed between t
he neocortical association areas and phylogenetically old hypothalamic and
brain stem systems, limbic dysfunction may lead to a dissociation between c
ognitive activities and basic emotional reactions, thus, explaining some as
pects 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
.