Comparison of brain activity within the sensorimotor network between sports players and patients with somatic symptom...

We aimed to identify differences in brain functional connectivity (FC) and characteristics of body sensation between sports players and patients with somatic symptom disorder (SSD), in order to investigate the neurobiological basis of SSD.

Thirty-five sports players (SPORTS group), 36 patients with SSD (SOM group), and 33 healthy control participants (HC group) underwent resting-state functional magnetic resonance imaging. We used a seed-based FC analysis.

Both groups showed increased brain activity in the left precuneus. The level of body intelligence in the SPORTS group and the level of somatosensory amplification in the SOM group were positively correlated with brain activity in the left precuneus. The SPORTS group showed increased FC between the left precuneus and the right/left insula compared to the HC group. The SOM group showed increased FC between the left precuneus and the right parahippocampal gyrus compared to the HC group. The SPORTS group showed increased FC between the left precuneus and left posterior cingulate gyrus compared to the SOM group.

Increased FC between the precuneus within the default mode network (DMN) and the insula connected to the sensorimotor network in sports players may be related to better somatosensory functions. In contrast, increased FC between the precuneus of the DMN and the parahippocampal gyrus of the affective network in SSD may be associated with dysfunctional processing and misconception of information. Future studies should examine whether treatments for improving affective processing normalize the affective network, and if this is correlated with somatic symptom improvement.