Brain activity during a public-speaking situation in virtual reality in patients with irritable bowel syndrome and functional dyspepsia.

Background: Psychosocial stress plays a central role in the pathophysiology of disorders of gut-brain interactions (DGBI), including functional dyspepsia (FD) and irritable bowel syndrome (IBS). Brain activity during psychosocial stress in patients with DGBI has not been adequately investigated. In this prospective study, we aimed to explore brain activity during psychosocial stress in patients with DGBI.

Methods: Situations in an unmanned room, public space without attention, and public speaking were simulated in a virtual reality (VR) environment. Subjective stress, emotional state, and gastrointestinal (GI) symptoms were assessed using a visual analog scale, the State-Trait Anxiety Inventory, and the GI Symptom Rating Scale, respectively. Electrocardiograms were recorded to evaluate autonomic function. Activity in the prefrontal cortex (PFC) was examined using functional near-infrared spectroscopy (fNIRS).

Results: Overall, 15 healthy controls, 15 patients with IBS, and 15 patients with FD were included. In the public-speaking scenario, subjective stress scores significantly decreased (indicating more stress) and sympathetic nervous activity increased equally among the three groups compared with those in an unmanned scene. Patients with IBS had higher activity in the left ventrolateral prefrontal cortex (VLPFC) and lower activity in the dorsolateral PFC (DLPFC) than those with FD and healthy controls.

Conclusions: Brain activity increased in the VLPFC and decreased in the DLPFC under stressful psychosocial situations created in the VR space in patients with IBS. Thus, the combination of VR and fNIRS is a viable option for evaluating brain activity under psychosocial stress in natural clinical settings.