The effects of different frequencies of repetitive transcranial magnetic stimulation on post-stroke dysphagia / 中华物理医学与康复杂志

ABSTRACT

Objective:To explore the effect of high-frequency and low-frequency transcranial magnetic stimulation (rTMS) on the unaffected pharyngeal motor cortex of dysphagic stroke survivors.Methods:Forty-two stroke survivors with dysphagia were enrolled and randomly divided into a high-frequency stimulation group ( n=14), a low-frequency stimulation group ( n=13), and a sham group ( n=15). All received conventional swallowing training. The high- and low-frequency stimulation groups additionally received 250 pulses of 5Hz or 1Hz rTMS over the cortical representation of the mylohyoid muscle on the unaffected side daily for 2 consecutive weeks. In the sham group, sham rTMS was applied with identical protocols. Before and after the intervention, all subjects were subjected to a videofluoroscopic swallowing study and surface electromyography (sEMG). They were also evaluated using the fuctional dysphagia scale (FDS) and the penetration aspiration scale (PAS). Results:After the intervention, a significant improvement was observed in the average PAS, FDS and sEMG results in both rTMS groups compared with the sham control group. The average FDS score of the high-frequency stimulation group had improved significantly more than that of the low-frequency group.Conclusions:rTMS of the contra-lesional cortical representation of the mylohyoid muscle at either 5Hz or 1Hz can effectively improve dysphagia post-stroke. The higher frequency gives superior results.