Hippocampus and amygdala in schizophrenia: assessment of the relationship of neuroanatomy to psychopathology.

The hippocampus and amygdala are believed to be involved in the pathology of schizophrenia. In this study, we attempted to replicate the reported bilateral volume reduction of the hippocampus and amygdala and to study the relationship of the volumes of these structures to the symptoms of schizophrenia. The hippocampus-amygdala complex (HAC) was manually traced on 3-mm coronal T(1)-weighted MRIs, resampled into 1-mm coronal slices, from 20 male patients with schizophrenia and 20 age-matched male controls. The complex was divided into three parts: anterior one-third representing the amygdala and middle and posterior thirds representing the anterior and posterior halves of the hippocampus. Positive and negative symptoms and severity of hallucinations and thought disorder (conceptual disorganization) were quantified using the Brief Psychiatric Rating Scale (BPRS). None of the above structures, controlled for brain volume, differed significantly in patients compared with normal controls. When the relationship between volumes and symptoms was examined, the left HAC was found to inversely correlate with thought disorder and negative symptoms. Specifically, significant inverse correlations were found between (i) left amygdala and thought disorder, (ii) left hippocampus and negative symptoms, and (iii) left anterior and posterior hippocampus volumes and positive and negative symptoms, respectively. Our findings further support the role of the HAC in the pathophysiology of schizophrenia and suggest unique associations between individual structures and specific symptoms of the illness.

Prevalence of cavum septum pellucidum in schizophrenia studied with MRI.

OBJECTIVE: To study the prevalence of cavum septum pellucidum (CSP), a midline developmental anomaly, in patients with schizophrenia. METHODS: Three-millimeter coronal T1 weighted MRI images of 43 normal controls and 73 patients with schizophrenia were examined. The images were resampled into 1-mm slices and CSP was measured by the number of slices in which it appeared. RESULTS: Patients had significantly higher incidence of CSP (Fisher's exact test 0.042; one-sided). Eighteen (41.9%) of the controls and 44 (60.3%) of patients had a CSP, and one of 46 controls and three of 73 patients had a large CSP of six slices or more. There was no relationship between the presence or size of CSP and regional brain volumes or volumes of hippocampus-amygdala complex, caudate, superior temporal gyrus or ventricular CSF. CONCLUSION: Higher incidence of CSP may reflect a neurodevelopmental disturbance in schizophrenia.