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.