Effortful swallowing training combined with electrical stimulation in post-stroke dysphagia: a randomized controlled study

Abstract

We tested the effect of effortful swallow combined with surface electrical stimulation used as a form of resistance training in post-stroke patients with dysphagia. Twenty post-stroke dysphagic patients were randomly divided into two groups: those who underwent effortful swallow with infrahyoid motor electrical stimulation (experimental group, n = 10) and effortful swallow with infrahyoid sensory electrical stimulation (control group, n = 10). In the experimental group, electrical stimulation was applied to the skin above the infrahyoid muscle with the current was adjusted until muscle contraction occurred and the hyoid bone was depressed. In the control group, the stimulation intensity was applied just above the sensory threshold. The patients in both groups were then asked to swallow effortfully in order to elevate their hyolaryngeal complex when the stimulation began. A total of 12 sessions of 20 min of training for 4 weeks were performed. Blinded biomechanical measurements of the extent of hyolaryngeal excursion, the maximal width of the upper esophageal sphincter (UES) opening, and the penetration-aspiration scale before and after training were performed. In the experimental group, the maximal vertical displacement of the larynx was increased significantly after the intervention (p < 0.05). The maximal vertical displacement of the hyoid bone and the maximal width of the UES opening increased but the increase was not found to be significant (p = 0.066). There was no increase in the control group. Effortful swallow training combined with electrical stimulation increased the extent of laryngeal excursion. This intervention can be used as a new treatment method in post-stroke patients with dysphagia.