Clinical effectiveness of the sequential 4-channel NMES compared with that of the conventional 2-channel NMES for the treatment of dysphagia in a prospective double-blind randomized controlled study.

The study was a pilot with a very small sample size (23 completers), limiting the generalizability of the findings. Baseline scores differed between groups for the functional oral intake scale, with the 4-channel group starting with worse oral intake function. Treatment duration and daily session frequency varied across the five participating hospitals and among patients. The study did not verify whether the electrical stimulation actually induced the intended muscle contractions. Stimulation intensity differed between groups, with the 4-channel group often requiring lower amplitude due to tolerance issues. Both groups received conventional swallowing therapies simultaneously, so the contribution of the NMES device alone cannot be separated from the effect of the exercises.

The study was funded by the National Research Foundation of Korea and the Korea Health Industry Development Institute. No commercial conflicts of interest were declared.

Do not assume the 4-channel device is superior for reducing aspiration. While the 4-channel group improved significantly on the penetration-aspiration scale, the 2-channel group did not, but the direct comparison of improvement between the two groups was not statistically significant (p=0.21). Furthermore, all patients received concurrent swallowing exercises, so the benefit may be due to the combined treatment rather than the specific electrical stimulation pattern.