Electrophysiological Evaluation of Dysphagia in the Mild or Moderate Patients with Multiple Sclerosis: A Concept of Subclinical Dysphagia

Abstract

Swallowing mechanism and neurogenic dysphagia in MS have been rarely studied by electromyographical (EMG) methods. This study aims to evaluate the presence of subclinical dysphagia in patients with mild multiple sclerosis (MS) using electrophysiological methods. A prospective study of 51 patients with relapsing remitting multiple sclerosis and 18 age-matched healthy adults was investigated. We used electromyography to measure the activity of the submental muscles during swallowing. Electrophysiological recordings of patients were obtained during relapse, after relapse, and at any time in remission period. Clinical dysphagia was found in 12% of MS patients, while electrophysiological swallowing abnormalities were encountered in 33% of patients. Subclinical dysphagia was determined in 35% of patients during an MS relapse, in 20% of patients after a relapse, and in 25% of all 51 patients in the remission period based on EMG findings. Duration of swallowing signal of submental muscles in all MS patients was found to be longer than in normal subjects (p = 0.001). During swallowing of 50 ml of sequential water, the compensatory respiratory cycles occurred more often in MS patients than normal subjects, especially during a relapse (p = 0.005). This is the first study investigating swallowing abnormalities and subclinical dysphagia from the electrophysiological aspect in MS patients with mild disability. The electrophysiological tests described in this study are useful to uncover subclinical dysphagia since they have the advantage of being rapid, easy to apply, non-invasive, and without risk for the patients.

Effects of Resistive Jaw-Opening Exercise with Elastic Bands on Suprahyoid Muscle Activation in Normal Subjects

“…During the examination, the participants were instructed to sit upright in a chair and hold his or her trunk in a neutral, upright position. Prior to the measurement, the submental skin of each participant was cleansed with an alcohol wipe and allowed to dry for approximately 30 s. To record the activity of the suprahyoid muscle complex (a conglomerate signal from the mylohyoid, geniohyoid, anterior belly of digastric muscle) [17], disposable Ag/AgCl surface electrodes (1 cm in diameter) were placed bilaterally under the chin, 1 cm apart, lateral to the midline [18] (Fig. 2).…”

Effect of partial head extension swallowing exercise on the strength of the suprahyoid and tongue muscles in healthy subjects: A feasibility study

“…The sEMG signals were amplified, band‐pass filtered (10 and 500 Hz) and notch filtered (60 Hz) before being digitally recorded at 1000 Hz and processed into the root mean square. To record muscle activation in the suprahyoid muscle complex (mylohyoid, geniohyoid and anterior digastric muscle), wireless sEMG electrodes (electrode diameter: 1 cm) were attached at a distance of 1 cm on the skin on both sides of the midline under the chin . Reference isometric voluntary contraction (RVC) was used to normalise the EMG data.…”

“…To record muscle activation in the suprahyoid muscle complex (mylohyoid, geniohyoid and anterior digastric muscle), wireless sEMG electrodes (electrode diameter: 1 cm) were attached at a distance of 1 cm on the skin on both sides of the midline under the chin. 7 Reference isometric voluntary contraction (RVC) was used to normalise the EMG data. RVCs were used instead of maximum voluntary contraction to decrease the risk of injury.…”

Neurogenic Dysphagia in Brainstem Disorders and EMG Evaluation

“…SWS is technically similar to the "3 ounce test" and "timed test, " but these two SW tests are performed by clinical observation during which 90-150 mL of water should be swallowed as fast as possible without interruption (60,61). SWS is assessed either by the collection of radiological (57,62) or physiological recordings (16,63,64). During SWS, there are rhythmic or pseudorhythmic SW sequences with- When recordings of SWS are collected while using a nasal airway sensor for respiration and SM-EMG, we can observe approximately 1 sec interswallow intervals between each couple of swallow deflections in the SM-EMG, during which the respiratory recordings demonstrate breath holding that results in a swallow apnea period in normal subjects.…”

“…The physiological method of SWS was previously described (16,63,64). Briefly, subjects are instructed to drink 50 mL of water from a cup continuously as "in daily life. "…”