Anterior and posterior cingulum abnormalities and their association with psychopathology in schizophrenia: a diffusion tensor imaging study

Evidence suggests that a disruption in limbic system network integrity and, in particular, the cingulate gyrus may play a role in the pathophysiology of schizophrenia. The cingulum bundles (CBs; posterior and anterior) are the most prominent white matter tracts in the limbic system, furnishing both input and output to the cingulate gyrus . In previous diffusion tensor imaging (DTI) studies, abnormal integrity has been demonstrated in the anterior CB portion, but not the posterior, in schizophrenia. As well, the relationships between the abnormalities of CB integrity and the psychopathology of schizophrenia remain to be elucidated. Using DTI acquired on a 3 T MRI machine, we examined fractional anisotropy (FA) in the anterior and posterior CBs of 42 patients with schizophrenia and 24 group-matched controls. Moreover, we investigated the relationships between CB abnormalities and the psychopathology of schizophrenia. Bilaterally reduced FA was demonstrated in both anterior and posterior CBs in schizophrenia patients. However, the pattern of FA reduction was different between anterior and posterior CBs: the reduction in FA was left-accentuated in anterior CBs, while no such lateralized abnormality was found in posterior ones. Finally, FA in posterior CBs correlated with positive symptom scores in patients with schizophrenia. These findings suggest that CB abnormalities in schizophrenia are not restricted to the anterior CB, but include the posterior as well. Pathology in the posterior CB would be one of the possible neural underpinnings of positive symptoms in schizophrenia.