Altered Spontaneous Activity in Patients with Persistent Somatoform Pain Disorder Revealed by Regional Homogeneity

Abstract

Persistent somatoform pain disorder (PSPD) is a mental disorder un-associated with any somatic injury and can cause severe somatosensory and emotional impairments in patients. However, so far, the neuro-pathophysiological mechanism of the functional impairments in PSPD is still unclear. The present study assesses the difference in regional spontaneous activity between PSPD and healthy controls (HC) during a resting state, in order to elucidate the neural mechanisms underlying PSPD. Resting-state functional Magnetic Resonance Imaging data were obtained from 13 PSPD patients and 23 age- and gender-matched HC subjects in this study. Kendall’s coefficient of concordance was used to measure regional homogeneity (ReHo), and a two-sample t-test was subsequently performed to investigate the ReHo difference between PSPD and HC. Additionally, the correlations between the mean ReHo of each survived area and the clinical assessments were further analyzed. Compared with the HC group, patients with PSPD exhibited decreased ReHo in the bilateral primary somatosensory cortex, posterior cerebellum, and occipital lobe, while increased ReHo in the prefrontal cortex (PFC) and default mode network (including the medial PFC, right inferior parietal lobe (IPL), and left supramarginal gyrus). In addition, significant positive correlations were found between the mean ReHo of both right IPL and left supramarginal gyrus and participants’ Self-Rating Anxiety Scale (SAS) scores, and between the mean ReHo of the left middle frontal gyrus and Visual Analogue Scale (VAS) scores. Our results suggest that abnormal spontaneous brain activity in specific brain regions during a resting state may be associated with the dysfunctions in pain, memory and emotional processing commonly observed in patients with PSPD. These findings help us to understand the neural mechanisms underlying PSPD and suggest that the ReHo metric could be used as a clinical marker for PSPD.

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.…”

Frequency‐specific alterations of regional homogeneity in subcortical stroke patients with different outcomes in hand function

“…ReHo abnormalities within regions of the brain reflect alterations in the synchronization of temporal neural activities (Zhong et al, 2011), which suggests that there is unbalanced local functionality or noncompensatory reactions in the whole-brain network (Dai et al, 2012). This approach has been used to identify specific pathophysiological functional signatures and to reveal the neural mechanisms underlying dysfunctions in various brain disorders (Huang et al, 2016;Wang et al, 2014;Wu et al, 2011).…”

<p>Aberrant Thalamic-Centered Functional Connectivity in Patients with Persistent Somatoform Pain Disorder</p>

“…For instance, it was found that somatoform pain disorder patients exhibited higher regional homogeneity (ReHo) in the left precentral gyrus, the prefrontal cortex and default-mode network, but decreased ReHo in the bilateral primary somatosensory cortex, the posterior cerebellum, and the occipital lobe comparing with healthy controls. 8,9 Further, using independent component analysis to isolate intrinsic connectivity networks (ICNs) and to calculate the functional network connectivity (FNC) such as intra-and inter-ICNs, Zhao and his colleagues found altered FNCs between the sensorimotor network, the audio network, the visual network, the default-mode network, the executive control network, the salience network, the right-frontoparietal network, the left-frontoparietal network, and the cerebellum network in PSPD patients. 10 A resting-state EEG study revealed that somatoform pain disorder patients exhibited hyperexcitability resting-state cortical oscillations at the parietal region.…”