Third-ventricle enlargement and neuropsychological deficit in schizophrenia

Cerebral ventricular enlargement is present in a substantial subgroup of schizophrenic patients. Most, but not all studies examining neuropsychological performance and ventricular size in schizophrenics show more severe cognitive impairment in those patients with greatest ventricular enlargement. Inconsistencies in this literature have been attributed to different neuroimaging techniques, variation in patient characteristics across studies, and the variety of neuropsychological batteries used. In the present study, schizophrenic patients (n = 49 men, n = 23 women) and normal controls (n = 13 men, n = 18 women) underwent magnetic resonance (MR) imaging of the brain and extensive neuropsychological testing including measures of frontal and temporal lobe function. A complete coronal set of MR images was used to calculate volumetric estimates of lateral and third cerebral ventricles. Highly significant associations were found between cognitive deficits and third-ventricle volume, with measures of frontal functioning, attention, and concentration showing the most robust correlations. In contrast, neuropsychological performance was not highly associated with lateral ventricular size. These findings further support the pathophysiological relevance of ventricular enlargement in schizophrenia. More specifically, third, but not lateral, ventricular enlargement was associated with greater cognitive disturbance in this sample. Results are consistent with pathological involvement of periventricular diencephalic structures resulting in dysfunctional frontal and limbic processing in a subgroup of patients.