Cerebral ventricular enlargement in schizophrenia: Relationships to neuropsychological functioning, symptomatology, and disruptions in speech prosody
Cerebral ventricular enlargement is one of a number of structural brain abnormalities regularly found in populations of schizophrenics. Theories such as Crow's Type I/Type II model predict that ventricular enlargement will be associated with intellectual decline and specific types of schizophrenic symptomatology (e.g. "negative" symptoms), but the data to support these predictions has been inconsistent. Previous studies' reliance on ratings of symptomatology and behavior, rather than more specific quantitive assessments of behavior, may be contributing to these inconsistencies. The purpose of this study was to examine the associations between cerebral ventricular enlargement and a variety of clinical characteristics in a group of schizophrenics, and to assess clinical characteristics with both rating scales and more specific cognitive and behavioral measures. Subjects were thirty-four schizophrenic inpatients diagnosed by structured interview. Cerebral ventricular size was determined in these subjects using ventricle-to-brain ratios (VBR's) derived from computed tomography (CT) scans of schizophrenic patients' brains. Patients were then blindly administered a battery of neuropsychological tests, rating scales to assess positive and negative schizophrenic symptomatology, a voice recording procedure designed to assess disruptions in speech prosody (systematic pitch variability related to the expression of affect), and a set of acoustic perceptual measures. Results revealed that a larger VBR of one particular portion of the ventricular system (the frontal horns of the lateral ventricles) was consistently associated with poor performance on neuropsychological tests of reasoning and visual-spatial organization, and with poor acoustic perceptual accuracy. Ventricular measures were unrelated, though, to either clinical symptom ratings or to measures of disturbed speech prosody. Neuropsychological tests were found in this study to be sensitive indicators of structural brain abnormality. However, data do not support theoretical predictions of an association between cerebral ventricular enlargement and both intellectual impairment and negative symptomatology. Compared to subjects in other studies, subjects in this study were relatively unimpaired with respect to neuropathology and behavioral dysfunction. Further research using subjects with more severe schizophrenia-related neuropathology and greater functional disability is recommended to adequately test hypotheses of their association.
Keilp, John George, "Cerebral ventricular enlargement in schizophrenia: Relationships to neuropsychological functioning, symptomatology, and disruptions in speech prosody" (1989). ETD Collection for Fordham University. AAI9020013.