Effects of synchronized neuromuscular electrical stimulation (NMES) on the submental muscles during ingestion of a specified volume of soft food in patients with mild-to-moderate dysphagia following stroke

Abstract

Background: Neuromuscular electrical stimulation (NMES) is a method for producing regular contractions of muscles that have been paralyzed. This study aimed to evaluate the effects of synchronized NMES on the submental muscles during ingestion of a specified volume of soft food in patients with mild-to-moderate dysphagia following stroke. Material/Methods: Eighty-three patients with mild-to-moderate dysphagia following stroke were enrolled and randomly divided into 3 groups: conventional training (CT) (n=28), eating training (ET) (n=28), and intensive swallowing training (IST) (n=27). The CT group received conventional swallow training, the ET group was given additional individual feedings with a specified volume of soft food, and the IST group received intensive swallowing training with synchronized NEMS. All of the patients were evaluated before and after the treatment with a modified barium swallow, and the Dysphagia Outcome and Severity Scale (DOSS); the numbers of patients with Stroke-Associated Pneumonia (SAP) and wet voice also were assessed. Results: After 6 weeks, DOSS scores improved in patients in all 3 groups, and there were significant differences among the groups in their scores (P<0.001 for both measures). In the CT and ET groups, there was a statistically significant difference in the number of patients with SAP before and after treatment (P=0.010 and P<0.001, respectively). There also were fewer cases in the IST group than in the CT (P=0.042) and ET groups (P=0.011). After completion of treatment, compared with the first treatment, there were significantly fewer patients with wet voices in the CT (P<0.001) and IST groups (P<0.001). Conclusions: Feeding a specified volume of soft food plus synchronized NMES of the submental muscles can improve the swallowing function of patients with mild-to-moderate dysphagia following stroke and it reduces their risk of food aspiration.