Mirror therapy combined with defecation motor imagery and repetitive transcranial magnetic stimulation improves post-stroke constipation: a retrospective study with EEG biomarker analysis.

BACKGROUND

Post-stroke constipation is prevalent after frontal lobe infarction and may reflect disrupted cortical-autonomic regulation. Neurorehabilitation strategies targeting cortical plasticity may offer therapeutic benefit.

OBJECTIVE

To evaluate whether mirror therapy combined with defecation motor imagery and repetitive transcranial magnetic stimulation (rTMS) improves bowel function, and to explore associated cortical changes using EEG-derived event-related desynchronization (ERD).

METHODS

In this single-center retrospective study, 98 patients with frontal lobe infarction and Rome IV-defined constipation were analyzed. Forty-eight received mirror therapy + motor imagery + rTMS in addition to routine rehabilitation, and 50 received routine care alone. Primary outcomes included Wexner Constipation Score, weekly bowel frequency, and PAC-QOL. EEG μ/β-band ERD during defecation motor imagery was quantified. Between-group differences and correlations were analyzed.

RESULTS

After 8 weeks, the intervention group showed significantly greater improvement in Wexner score, bowel frequency, and PAC-QOL compared with controls (all P < 0.01; Cohen's d 0.60-0.82). Enhanced μ/β ERD was observed only in the intervention group. ERD changes correlated moderately with Wexner improvement (r = 0.56).

CONCLUSIONS

Combined mirror therapy, motor imagery, and rTMS were associated with improved bowel function and increased task-related cortical activation. EEG-derived ERD may serve as a candidate biomarker for bowel-focused neurorehabilitation.