Abnormalities in white matter connections between orbitofrontal cortex and anterior cingulate cortex and their associations with negative symptoms in schizophrenia: A DTI study

Abstract

Introduction The medial orbitofrontal cortex (mOFC) and rostral part of the anterior cingulate cortex (rACC) are brain regions that are important in the neural network involving emotional processing and decision making, as well as playing an important role in social behavior and interaction. Considering the schizophrenia dysconnectivity hypothesis, observed abnormalities in emotional response and social behavior in schizophrenia might be associated with connectivity abnormalities between mOFC and rACC. Methods Twenty-seven patients with chronic schizophrenia and 26 healthy controls were examined using Diffusion Tensor Imaging (DTI). White matter properties in bilateral mOFC-rACC connections were examined using stochastic tractography, which has been shown to be among the most effective DTI methods for examining tracts between adjacent gray matter regions. Results Reductions in fractional anisotropy (FA) were observed in left anterior mOFC-rACC connections (p<0.0001), and bilateral posterior mOFC-rACC connections (left: p<0.0001; right: p<0.0001) in patients compared to controls. In addition, reduced FA in left posterior mOFC-rACC connections were associated with more severe anhedonia-asociality (R=−0.396, P=0.041) and avolition-apathy (R=−0.426, p=0.027) using the Scale for the Assessment of Negative Symptoms. Discussion White matter abnormalities within connections between mOFC and rACC are associated with more severe anhedonia-asociality and avolition-apathy, which suggest that these brain regions may be important in understanding abnormal emotional responses and social behavior in patients with schizophrenia.

Brain activation induced by psychological stress in patients with schizophrenia

“…Deficits in activation of this structure in patients with schizophrenia could result not only in a lack of inhibition of stress pattern, but it could also contribute to explain their deficits in decision-making and other negative symptoms (de Achával et al, 2012(de Achával et al, , 2013Wible et al, 2001). In fact, patients showed an inverse correlation between negative symptom severity and activation of anterior cingulum and orbitofrontal cortex, which is in agreement with the burgeoning evidence on the role of prefrontal cortex in clinical symptoms of schizophrenia (Wible et al, 2001;Ohtani et al, 2014).…”

Abnormal white matter connections between medial frontal regions predict symptoms in patients with first episode schizophrenia

“…Among the measures that reflect the WM properties, Fractional Anisotropy (FA) reduction has been reported to occur in response to axon death, myelin damage, damage to the axon membrane, and reduced “fiber coherence” (Kubicki et al, 2007), and reduced FA is most commonly reported in schizophrenia (Gasparotti et al, 2009; Zhang et al, 2010; Ohtani et al, 2014). Patients with schizophrenia exhibit abnormalities in integrity of both myelin sheaths as well as axon membranes (Uranova et al, 2007; Davis et al, 2003).…”

A combined VBM and DTI study of schizophrenia: bilateral decreased insula volume and cerebral white matter disintegrity corresponding to subinsular white matter projections unlinked to clinical symptomatology

“…Most of the DTI studies focused on FA values conducting voxel-based analysis of FA only (30,31). In whole brain analysis studies, even early cases of schizophrenia showed bilaterally decreased FA values, which may be associated with illness duration (32,33).…”