Effect of Repetitive Transcranial Magnetic Stimulation on Patients with Brain Injury and Dysphagia

Objective To investigate the effect of repetitive transcranial magnetic stimulation (rTMS) on recovery of the swallowing function in patients with a brain injury. Method Patients with a brain injury and dysphagia were enrolled. Patients were randomly assigned to sham, and low and high frequency stimulation groups. We performed rTMS at 100% of motor evoked potential (MEP) threshold and a 5 Hz frequency for 10 seconds and then repeated this every minute in the high frequency group. In the low frequency group, magnetic stimulation was conducted at 100% of MEP threshold and a 1 Hz frequency. The sham group was treated using the same parameters as the high frequency group, but the coil was rotated 90 degrees to create a stimulus noise. The treatment period was 2 weeks (5 days per week, 20 minutes per session). We evaluated the Functional Dysphagia Scale (FDS) and the Penetration Aspiration Scale (PAS) with a videofluoroscopic swallowing study before and after rTMS. Results Thirty patients were enrolled, and mean patient age was 68.2 years. FDS and PAS scores improved significantly in the low frequency group after rTMS, and American Speech-Language Hearing Association National Outcomes Measurements System Swallowing Scale scores improved in the sham and low frequency groups. FDS and PAS scores improved significantly in the low frequency group compared to those in the other groups. Conclusion We demonstrated that low frequency rTMS facilitated the recovery of swallowing function in patients with a brain injury, suggesting that rTMS is a useful modality to recover swallowing function.