Neuroradiological facets of cognitive abnormality in schizophrenia

Cognitive abnormality has long been regarded as a core feature of schizophrenia, but its nature and etiopathology have been poorly understood. Predicated on new tests that characterize fundamental cognitive impairments, we investigated their relationship to four neuroradiological markers that have been previously implicated in schizophrenia: choroid plexus calcification, cerebellar atrophy, third ventricle enlargement, and pineal calcification. Twenty-three chronic schizophrenic inpatients meeting RDC and DSM-III diagnostic criteria were stabilized on chlorpromazine and assessed independently on a cognitive battery and on CT scan. The results indicated that all four neuroradiological variables were independent of one another and of demographic, historical, and general intellectual measures. The neuroradiological assessments, however, correlated significantly with different cognitive parameters, implying separate pathophysiological bases for distinct profiles of cognitive abnormality. The findings support a "dual-process model" of cognitive dysfunction that posits developmental and arousal-related components which may, more generally, underlie the positive-negative dimension of schizophrenia.