Dissociation of Regional Activity in Default Mode Network in Medication-Naive, First-Episode Somatization Disorder

Abstract

BackgroundPatients with somatization disorder (SD) have altered neural activity in the brain regions of the default mode network (DMN). However, the regional alteration of the DMN in SD remains unknown. The present study was designed to investigate the regional alterations of the DMN in patients with SD at rest.MethodsTwenty-five first-episode, medication-naive patients with SD and 28 age-, sex-, education- matched healthy controls underwent a resting-state functional magnetic resonance imaging (fMRI) scan. The fractional amplitude of low-frequency fluctuations (fALFF) was applied to analyze the data.ResultsPatients with SD showed a dissociation pattern of resting-state fALFF in the DMN, with increased fALFF in the bilateral superior medial prefrontal cortex (MPFC, BA8, 9) and decreased fALFF in the left precuneus (PCu, BA7). Furthermore, significantly positive correlation was observed between the z values of the voxels within the bilateral superior MPFC and somatization subscale scores of the Symptom Check List (SCL-90) in patients with SD.ConclusionsOur findings indicate that there is a dissociation pattern of the anterior and posterior DMN in first-episode, treatment-naive patients with SD. The results provide new insight for the importance of the DMN in the pathophysiology of SD.

Increased functional connectivity strength of right inferior temporal gyrus in first-episode, drug-naive somatization disorder

“…A recent review of neuroimaging studies suggested that the DMN may play an important role in the pathophysiology of SD (Browning et al, 2011). Furthermore, a recent fMRI study has shown that there was a dissociation pattern of the anterior and posterior DMN in SD (Su et al, 2014). Our findings of increased FCS in the right ITG regarded as a core region of DMN is of particular interest (Bullmore and Sporns, 2009;Greicius et al, 2003).…”

Prefrontal modulation during chewing performance in occlusal dysesthesia patients: a functional near-infrared spectroscopy study

“…Considering the functional convergence in prefrontal cognitions [53] and its deactivation in psychiatric patients [22,23], it is conceivable that the comprehensive cognitive and metacognitive capacities such as subjective evaluation of somatic sensory cognition might be modulated in OD patients. Furthermore, cortical modifications associated with somatoform states have been suggested in m-PFC function [9][10][11][12][13]. In the present study, we found not only prefrontal deactivation during chewing but also found associated deterioration of somatization scores in OD patients.…”

“…Neuropsychological evidence for somatization and somatoform disorders has shown cortical associations with the superior medial prefrontal cortex, temporal region, and parietal region [9][10][11][12][13]. For example, Su et al [13] reported a positive relationship between somatization subscale and bilateral superior medial prefrontal activities in patients with somatoform pain disorders.…”

“…For example, Su et al [13] reported a positive relationship between somatization subscale and bilateral superior medial prefrontal activities in patients with somatoform pain disorders. With regard to somatization in the oral region, Ono et al [14] recently examined prefrontal activity and tooth contact sensation in relation to tooth grinding, and they found that increased prefrontal hemodynamic responses may reflect top-down attention and/or self-regulation against uncomfortable somatosensory input induced in OD patients.…”

Dissociation of anatomical and functional alterations of the default-mode network in first-episode, drug-naive schizophrenia

“…VBM is capable of assessing structural differences in the whole brain and avoids operational bias toward particular brain regions (Honea et al, 2005;Meisenzahl et al, 2008;Ma et al, 2012;Hu et al, 2013;Guo et al, 2014a), and fALFF is designed to detect the regional intensity of spontaneous of blood oxygen level-dependent (BOLD) signals and provides a specific measure of low-frequency oscillatory phenomena (Zou et al, 2008). Increased fALFF might reflect neural hyperactivity in the area and vice versa Liu et al, 2013;Su et al, 2014). The two approaches have been widely used to explore anatomical and functional abnormalities in a bulk of psychiatric disorders, including schizophrenia.…”