Effect of Repetitive Transcranial Magnetic Stimulation on Post-stroke Dysphagia in Acute Stage

Repetitive transcranial magnetic stimulation (rTMS) play a important role for rehabilitation in stroke. But therapeutic schedule of rTMS in dysphagia after acute stroke is still controversial. The purpose of this study was to investigate the therapeutic effect of rTMS with different frequencies on dysphagia after acute stroke. From August 2019 to December 2020, 45 patients with post-stroke dysphagia were selected as research subjects, and randomly divided into 3 groups: the high frequency stimulation on bilateral hemisphere group (High group), bilateral high frequency stimulation on the affected hemisphere and low frequency stimulation on the unaffected hemisphere group (High-low group), and sham stimulation group (Sham group). On the basis of routine swallowing training (30 min) for all patients, the high group received 5 Hz rTMS in both hemispheres, the high- low group received 5 Hz rTMS in the unaffected hemisphere, 1 Hz rTMS in the affected hemisphere, and the sham stimulation group received sham stimulation in bilateral hemisphere. All participants were assessed with dysphagia handicap index (DHI), functional oral intake scale (FOIS) and videofluoroscopic swallowing study (VFSS) before the intervention (T1), immediately after intervention (T2) and 1 month after the intervention (T3). Meanwhile, according to the results of VFSS, Rosenbek penetration aspiration scale (PAS), the moving distance of hyoid bone towards the superior side (H), and pharyngeal response time (T) were analyzed and evaluated. After intervention, all three groups showed significant improvement in post-treatment scores from baseline ( P = 0.000). The results of DHI, PAS and H showed that the improvement in high group and high-low group was significantly greater than sham group ( P = 0.000). The results of FOIS and T showed that the improvement of bilateral high-frequency group was significantly greater than that of high-low group and sham group ( P = 0.000), and the difference lasted until 1 month after the end of treatment. Therefore, bilateral pharyngeal cortex high frequency rTMS and affected side high frequency/unaffected side low frequency rTMS can effectively improve swallowing disorder after acute stroke. However, the effect of bilateral high frequency rTMS is significantly higher than high-low in improving oral feeding function and pharyngeal response time.