Effect of electromyography‐triggered peripheral magnetic stimulation on voluntary swallow in healthy humans

Abstract

Background: Electrical stimulation therapy is effective for patients with dysphagia. However, because of the pain, strong stimulation cannot be applied. Although magnetic stimulation induces less pain, there are no reports on magnetic stimulation being synchronised with a swallowing reflex.Objective: This study aimed to determine whether it is possible to induce magnetic stimulation during a voluntary swallowing using electromyography (EMG)-triggered peripheral magnetic stimulation and to evaluate its effect on healthy individuals.Methods: A total of 20 healthy adults in seated position were instructed to swallow saliva and 10 ml of barium under videofluoroscopy. For concomitant use of magnetic stimulation, a magnetic stimulus for suprahyoid muscles at 30 Hz frequency was applied for 2 s when the EMG level in the sternohyoid muscle exceeded the threshold. During the voluntary swallowing, the movement of the hyoid bone and opening width of the upper oesophageal sphincter (UES) were measured. Furthermore, pressure topography was evaluated in 6 subjects using high-resolution manometry. Results:The magnetic stimulation significantly extended the movement time of the hyoid bone (p < 0.001). During liquid deglutition, significant increases were observed in the anterior maximum movement distance of the hyoid bone (p < 0.05), opening width of the UES (p < 0.001) and anterior movement distance of the hyoid bone at the maximum UES opening (p < 0.01). In the pressure topography, the maximum pressure immediately after UES closure significantly decreased with magnetic stimulation (p < 0.05). Conclusion:EMG-triggered peripheral magnetic stimulation made it possible to apply magnetic stimulation during a voluntary swallowing.

Effect of Peripheral Magnetic Stimulation for Dysphagia Rehabilitation: A Systematic Review

“…Active rPMS was applied directly to the submental suprahyoid muscle. One [28] of the seven studies performed the EMG-triggered rPMS. The included studies used varied protocols of rPMS.…”

“…Regarding the frequency of rPMS, all studies applied 30 Hz for 2 s. One study [25] compared the outcomes of 30 Hz for 2 s and 20 Hz for 3 s. Rest time (stimulation off) ranged from 8 s [22] to 27-28 s [23,25,26]. While four studies conducted outcome measurements during on and off stimulation [27,28] or performed immediate measurements on the day of the intervention [23,25], multiple sessions of rPMS were conducted with an intervention period of 6 days or longer in three studies [22,24,26]. The number of intervention sessions ranged from 2-3 [24] to 30 [22].…”

“…The number of intervention sessions ranged from 2-3 [24] to 30 [22]. The intensity ranged from pain-inducing minimum intensity (90% of maximum stimulus output) [23,25,26] to non-painful intensity (70-80% of maximum intensity) [22,28]. Co-exercises were per-…”

“…The number of intervention sessions ranged from 2-3 [24] to 30 [22]. The intensity ranged from pain-inducing minimum intensity (90% of maximum stimulus output) [23,25,26] to non-painful intensity (70-80% of maximum intensity) [22,28]. Co-exercises were performed as conventional dysphagia rehabilitation (oral stretching, tongue push-up exercise, and isokinetic HLE) after stimulation in two studies [24,26].…”

Exposure to 10 Hz Pulsed Magnetic Field Induced Slight Apoptosis and Reactive Oxygen Species in Primary Human Gingival Fibroblasts

“…In recent years, electromagnetic fields (EMFs) stimulation had been increasingly used as an effective, noninvasive and economical method in clinical treatment, such as dysphagia, implant osseointegration, wound repair, and so on [Showkatbakhsh et al, 2010; Abdelrahim et al, 2011; Costantini et al, 2019; Mohajerani et al, 2019; Nayak et al, 2020; Nagashima et al, 2021; Nunes et al, 2021]. Although, many investigations had mentioned the beneficial effect of EMFs treatment, the potential hazards were paid little attention to [Saliev et al, 2019].…”