Study on rTMS's therapeutic effect on constipation in Parkinson's disease via the brain-gut axis theory

This study investigates the therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) on constipation in Parkinson's disease (PD) patients, based on the brain-gut axis theory.

Fifty-eight PD patients with constipation (aged 52-68 years) were randomly assigned to the treatment group (receiving high-frequency 10 hz rTMS targeting the left dorsolateral prefrontal cortex (DLPFC), n = 29) and control group (receiving sham stimulation, n = 29). Both patients and outcome assessors were blinded to the allocation. Constipation severity was assessed using the Constipation Severity Scale (CSS), and bowel movements were evaluated with the Spontaneous Bowel Movement (SBM) and Complete Spontaneous Bowel Movement (CSBM) frequencies. Depression severity was assessed using the Hamilton Depression Rating Scale (HAMD). Brain-gut peptides, serotonin (5-HT), brain-derived neurotrophic factor (BDNF), and inflammatory cytokines (IL-6, IL-8, IFN-γ) were measured via ELISA. Patient quality of life was assessed using the Patient Assessment of Constipation Quality of Life (PAC-QOL) instrument. Daily sessions were administered consecutively over a 14-day period.

The rTMS group showed significantly lower CSS scores and HAMD scores, and higher SBM and CSBM frequencies compared to the control group (p < 0.05). The rTMS group also exhibited higher levels of 5-HT, BDNF, and brain-gut peptides, with reduced IL-6, IL-8, and IFN-γ levels (p < 0.05). Clinical outcomes showed higher cure and efficacy rates in the rTMS group, with improved quality of life (p < 0.05).

rTMS targeting the left dorsolateral prefrontal cortex, combined with conventional drug therapy, significantly improves constipation and depressive symptoms in PD patients over a short-term period, potentially through mechanisms involving the brain-gut axis.