Effects of transcranial magnetic stimulation on the swallowing and brain-stem auditory evoked potentials of dysphagic stroke survivors / 中华物理医学与康复杂志

ABSTRACT

Objective:To observe any effects of contralateral repeated transcranial magnetic stimulation (rTMS) of the swallowing motor cortex on the swallowing and brainstem auditory evoked potentials (BAEPs) of stroke survivors with dysphagia.Methods:A total of 83 stroke survivors with dysphagia were randomly divided into an ipsilesional stimulation group ( n=22), a contralesional stimulation group ( n=21), a bilateral stimulation group ( n=20), and a control group ( n=20). In addition to their conventional dysphagia training, those in the three stimulation groups received 3Hz rTMS while the control group was given fake stimulation. The treatment was administered daily for 20 minutes, 6 days a week, for 5 consecutive weeks. Before and after the treatment, swallowing function was assessed videofluoroscopically and using the Dysphagia Outcome and Severity Scale (DOSS). The oral and pharyngeal stages of swallowing were evaluated using the videofluoroscopic dysphagia scale (VDS). Brain stem conduction was assessed using BAEPs. Results:After treatment the average DOSS scores of all 4 groups were significantly better than before the treatment. The average DOSS scores of the contralesional and bilateral sti-mulation groups were then significantly better than those of the other two groups. The sub-item and total VDS scores of all 4 groups had decreased significantly, but the average score of the bilateral stimulation group was significantly lower than the control group′s average. Ipsilesional stimulation significantly improved the VDS sub-item scores for the triggering of pharyngeal swallowing, laryngeal elevation, and pharyngeal transit time compared with the control group. In the contralesional stimulation group the average total score and the VDS sub-item scores for apraxia, premature bolus loss, oral transit times, the triggering of pharyngeal swallowing, vallecular residue, laryngeal elevation, coating on the pharyngeal wall, and pharyngeal transit time were significantly lower than those of the control group, on average. After the treatment the latencies of BAEP waves I, III and V and the I-III, III-V and I-V interpeak intervals had decreased significantly in all four groups, but the average latencies and intervals of the bilateral and contralesional groups were significantly shorter than those of the control group. The latencies and intervals of the bilateral stimulation group were then significantly shorter than those in the ipsilesional stimulation group on average. The average latency of wave V in the bilateral stimulation group (6.53±0.73ms) was significantly shorter than that in the contralesional stimulation group after the treatment.Conclusion:Bilateral rTMS over the swallowing motor cortex combined with conventional dysphagia training can significantly improve the swallowing of dysphagic stroke survivors.