White Matter Integrity of the Corpus Callosum and Psychopathological Dimensions in Deficit and Non-Deficit Schizophrenia Patients

Abstract

Deficit syndrome (DS) is a subtype of schizophrenia characterized by primary persistent negative symptoms. The corpus callosum (CC) appears to be related to psychopathology in schizophrenia. This study assessed white matter integrity in the CC using diffusion tensor imaging (DTI) in deficit and non-deficit schizophrenia (NDS) patients. We also investigated the psychopathological dimensions of schizophrenia and their relationship to CC integrity. Fifteen DS patients, 40 NDS patients, and 30 healthy controls (HC) underwent psychiatric evaluation and neuroimaging. We divided the CC into five regions and assessed their fractional anisotropy (FA) and mean diffusivity (MD). Psychopathology was assessed with the Positive and Negative Syndrome Scale. DS patients had lower FA than NDS patients and HC, and higher MD in Region 5 of the CC than did HC. NDS patients had higher MD in Region 4 of the CC. The patient groups differed in terms of negative symptoms. After differentiating clinical groups and HC, no significant correlations were observed between DTI measures and psychopathological symptoms. Our results suggest that DS and NDS are characterized by minor impairments of the posterior CC. We confirmed that DS patients have greater negative psychopathology than NDS patients. Our results are preliminary, and further studies are needed.

Investigating the Relationship between White Matter Connectivity and Motivational Circuits in Subjects with Deficit Schizophrenia: A Diffusion Tensor Imaging (DTI) Study

“…Our study has several strengths. Indeed, previous studies that investigated WM alterations in DS did not search for abnormalities of motivational circuits, since this was not the primary objective of these studies [ 4 , 39 , 40 , 75 , 76 , 77 , 78 , 79 , 80 ]. Furthermore, in our study, the assessment of deficit schizophrenia was made using the SDS, which is regarded as the gold-standard instrument in this field.…”

“…Furthermore, in our study, the assessment of deficit schizophrenia was made using the SDS, which is regarded as the gold-standard instrument in this field. In some of the previously mentioned studies [ 77 , 79 , 80 ], deficit schizophrenia was assessed using a proxy derived from the PANSS. The latter method for categorizing patients as DS and NDS has some problems in terms of face validity and temporal stability [ 14 ].…”

“…In subjects with deficit schizophrenia, white matter (WM) abnormalities in the superior longitudinal fasciculus [ 75 ], left uncinate fasciculus [ 76 , 77 ], right inferior longitudinal fasciculus, right arcuate fasciculus [ 77 ], postcentral area, left forceps minor [ 78 ], right posterior thalamic radiation [ 79 ] and posterior corpus callosum [ 80 ] have been reported.…”

“…However, these studies did not investigate abnormalities of motivational circuits in subjects with deficit schizophrenia, since this was not the primary objective of these studies. Furthermore, some of the above-mentioned studies [ 77 , 79 , 80 ] did not use the Schedule for the Deficit Syndrome (SDS), which represents the gold standard to assess deficit schizophrenia, but they instead used a proxy from the Positive and Negative Syndrome Scale (PANSS) [ 81 ]. However, it has been demonstrated that the proxy for categorizing patients in subjects with deficit and non-deficit schizophrenia has some problems in terms of face validity and temporal stability [ 14 ].…”

Relationship of Corpus Callosum Integrity with Working Memory, Planning, and Speed of Processing in Patients with First-Episode and Chronic Schizophrenia

“…Five single projections with ROIs on a sagittal plane ((A) = Region 1, (B) = Region 2, (C) = Region 3, (D) = Region 4, (E) = Region 5), (F) = whole region of CC, and (G) = all regions of CC (based on Hofer and Frahm's [16] segmentation: I = Region 1, II = Region 2, III = Region 3, IV = Region 4, V = Region 5). The methodology and segmentation scheme are discussed in our previous publication[80].…”