Mylohyoid motor evoked potentials can effectively predict persistent dysphagia 3 months poststroke

Background The purpose of this study was to investigate the association between mylohyoid motor‐evoked potentials ( MH ‐ MEP ) and swallowing function and determine the value of MH ‐ MEP for predicting aspiration 3 months poststroke. Methods Subacute patients within a month of their first stroke were enrolled up for 2 consecutive years. Videofluoroscopic swallowing studies ( VFSS ) were performed twice. Patients were evaluated during VFSS using the penetration aspiration scale ( PAS ) and videofluoroscopic dysphagia scale ( VDS ). MH ‐ MEP was recorded in the mylohyoid muscles. The active electrode was positioned submentally, 2 cm lateral to midline. Magnetic stimulation was performed on the contralateral motor cortex, 2‐4 cm anterior and 4‐6 cm lateral to the cranial vertex. The resting motor threshold ( rMT ), latency, and amplitude stimulation at 120% (amp120) and 150% (amp150) of the rMT were assessed. The ratio of each parameter was also estimated. The relationship between MH ‐ MEP and VFSS findings was analyzed. Key Results Sixty‐eight patients completed the study. On VFSS at 3 months poststroke, 24 (35.3%) patients showed aspiration. The rMT , rMT ratio, amp120 and amp120 ratio were significantly correlated with the PAS and VDS ( P  <   .05). The rMT ratio ( OR  = 1.208, P  =   .001) and amp120 ratio ( OR   =   0.821, P  =   .002) were independent predictors of aspiration at 3 months. The optimal cut‐off value of the rMT ratio was 126.1 ( AUC   =   0.94, sensitivity   =   0.92, specificity   =   0.89); that of the amp120 ratio was 66.5 ( AUC   =   0.89, sensitivity   =   0.88, specificity   =   0.86). Conclusions and Inferences MH ‐ MEP was well‐correlated with dysphagia severity assessed by VFSS . The rMT ratio and amplitude ratio of MH ‐ MEP can effectively predict persistent dysphagia 3 months poststroke.