Submental Muscle Activity is Delayed and Shortened During Swallowing Following Stroke

Dynamic suprahyoid muscle ultrasound in assessing oropharyngeal dysphagia in neurological disorders

BACKGROUND

Appropriate evaluation and management of dysphagia are essential in neurological disorders. However, there is currently a lack of a simple yet reliable method for dysphagia evaluation.

AIM

This study aimed to investigate the usefulness of new dynamic M-mode ultrasonography (US) parameters of suprahyoid muscle (SHM) to evaluate dysphagia.

DESIGN

Prospective observational, cross-sectional study.

SETTING

Inpatient setting at neurology department of tertiary medical center.

POPULATION

A total of 89 patients with dysphagia and 175 healthy volunteers were enrolled in the study. Patients were subdivided into mild and severe dysphagia groups depending on the need for dietary changes and disease classification, which included amyotrophic lateral sclerosis, peripheral neuromuscular diseases, and stroke.

METHODS

Dynamic M-mode US was performed during swallowing to obtain the SHM thickness (the baseline thickness of the SHM), SHM displacement (peak-to-peak amplitude of SHM movement), SHM difference (SHM displacement - SHM thickness), SHM ratio (SHM displacement/SHM thickness), peak-to-peak time, and total duration. A videofluoroscopic swallowing study (VFSS) was performed.

RESULTS

Significant differences were found in SHM displacement and SHM difference according to dysphagia severity (P<0.001). The SHM ratio, total duration (P<0.001), and peak-to-peak time (P=0.001) differed significantly according to the patients' underlying diseases. The pharyngeal delay time and penetration-aspiration scale from the VFSS demonstrated significant negative correlations with SHM displacement and difference (P<0.001). By combining SHM difference and total duration, patients with dysphagia could be distinguished from healthy controls, with the highest negative predictive value of 95.6%.

CONCLUSIONS

Dynamic M-mode US of the SHM provided added value in evaluating the severity of dysphagia and differentiating swallowing mechanics of dysphagia related to underlying neurological disorders.

CLINICAL REHABILITATION IMPACT

Dynamic M-mode US of the SHM can serve as a supportive tool for rapid screening and repetitive follow-up of patients with dysphagia, which would contribute to dysphagia rehabilitation in patients with various neurological disorders.

A robust HD-sEMG sensor suitable for convenient acquisition of muscle activity in clinical post-stroke dysphagia

Objective.A flexible high-density surface electromyography (HD-sEMG) sensor combined with an adaptive algorithm was used to collect and analyze the swallowing activities of patients with Post-stroke dysphagia.Approach.The electrode frame, modified electrode, and bonded substrate of the sensor were fabricated using a flexible printed circuit process, controlled drop coating, and molding, respectively. The adaptation algorithm was achieved by using Laplace and Teager-Kaiser energy operators to extract active segments, a cross-correlation coefficient matrix (CCCM) to evaluate synergy, and multi-frame real-time dynamic root mean square (RMS) to visualize spatiotemporal information to screen lesions and level of dysphagia. Finally, support vector machines (SVM) were adopted to explore the classification accuracy of sex, age, and lesion location with small sample sizes.Main results.The sensor not only has a basic low contact impedance (0.262 kΩ) and high signal-to-noise ratio (37.284 ± 1.088 dB) but also achieves other characteristics suitable for clinical applications, such as flexibility (747.67 kPa) and durability (1000 times) balance, simple operation (including initial, repeated, and replacement use), and low cost ($ 15.2). The three conclusions are as follows. CCCM can be used as a criterion for judging the unbalanced muscle region of the patient's neck and can accurately locate unbalanced muscles. The RMS cloud map provides the time consumption, swallowing times, and unbalanced areas. When the lesion location involves the left and right hemispheres simultaneously, it can be used as an evidence of relatively severely unbalanced areas. The classification accuracy of SVM in terms of sex, age, and lesion location was as high as 100%.Significance.The HD-sEMG sensor in this study and the adaptation algorithm will contribute to the establishment of a larger-scale database in the future to establish more detailed and accurate quantitative standards, which will be the basis for developing more optimized screening mechanisms and rehabilitation assessment methods.

Characteristics of submental muscles function and hyoid bone movement in patients with dysphagia after stroke

BACKGROUND

Dysphagia is one of the common complications after stroke. Dysphagia significantly increases the probability of serious adverse consequences. The purpose of this study was to compare the characteristics of submental muscles electromyography and hyoid motion parameters between patients with dysphagia after stroke and healthy controls, and whether there is a synergistic effect between the function of the submental muscles and the movement of the hyoid.

METHODS

Fifteen patients with post-stroke dysphagia and fifteen healthy adults simultaneously underwent the videofluoroscopic and surface electromyography of the submental muscles while swallowing 5 ml of concentrated liquid barium sulphate. The electromyographic signal of the submental muscles was analysed along with parameters of hyoid movement.

FINDINGS

Stage transition duration and duration of surface electromyographic activity were extended significantly in post-stroke dysphagia patients(P < 0.05). Surface electromyography amplitude and hyoid movement were significantly reduced in patients (P < 0.05). There was a significant correlation between the maximum hyoid movement distance and the peak sEMG amplitude in healthy controls (r = 0.660, P = 0.014), but not in patients with dysphagia after stroke (r = 0.425, P = 0.148).

INTERPRETATION

Submental muscles electromyographic signal changes in patients may be the result of uncoordinated muscle contractions and decreased muscle strength. Furthermore, the reduced hyoid movement distance may be due to impaired function of the submental muscles. In addition, the submental muscles and hyoid movement or other swallowing structures functions were impaired to varying degrees, resulting in the disappearance of the correlation between the maximum movement distance of the hyoid and the peak amplitude.

Effects of Carbonated Water Concentration on Swallowing Function in Healthy Adults

In this study, we investigated the effects of carbonated water concentration on swallowing function using surface electromyography (sEMG). Healthy subjects (n = 52, 26.77 ± 3.21 years old) were asked to perform two swallows each of noncarbonated water, low-concentration carbonated water, medium-concentration carbonated water, and high-concentration carbonated water. Onset time, the mean sEMG activity amplitude, and duration of muscle activity in each swallow were measured and analyzed for orbicularis oris, masseter, submental muscle complex and infrahyoid muscles. Onset time significantly decreased and mean sEMG activity amplitude significantly increased with carbonation concentration. Therefore, stimulation with carbonation can be effective for modulating a faster and stronger swallow in the oral and pharyngeal phases of swallowing, and its effect on amplitude was greater in the oral phase than in the pharyngeal phase.Clinical Trials Registration This study is registered with Clinical Research Information Service (KCT0005925).

Electromyographic study assessing swallowing function in subacute stroke patients with respiratory muscle weakness

BACKGROUND

Dysphagia has been reported to be associated with the descent of the hyolaryngeal complex. Further, suprahyoid muscles play a greater role than infrahyoid muscles in elevation of the hyolarngeal complex. Respiratory muscle training (RMT) can improve lung function, and expiratory muscle strength training can facilitate elevation of the hyoid bone and increase the motor unit recruitment of submental muscles during normal swallowing. This study aimed to investigate the surface electromyography (sEMG) of the swallowing muscles, bilaterally, and the effect of RMT on swallowing muscles in stroke patients with respiratory muscle weakness.

METHODS

Forty patients with first episode of unilateral stroke were included in this retrospective controlled trial. After exclusion of 11 patients with respiratory muscle strength stronger than 70% of the predicted value, 15 were allocated to the RMT group and 14 to the control group. However, eventually, 11 patients in RMT group and 11 patients in control group completed the study. The sEMG of the orbicularis oris, masseter, submental, and infrahyoid muscles were recorded during dry swallowing, water swallowing (2 mL), and forced exhalation against a threshold breathing trainer set at different intensities, at baseline and after 6-week RMT.

RESULTS

Regarding the sEMG of submental muscles, there were significant between-group differences on the latency of the unaffected side (P = .048), significant change from baseline force on the unaffected side (P = .035), and significant between-side difference (P = .011) in the RMT group during dry swallowing. Significant change in the duration from baseline was observed on the affected side of the RMT group when blowing was set at 50% maximal expiratory pressure (MEP; P = .015), and on the unaffected side of the control group when blowing set at 15% MEP (P = .005). Significant difference was observed in the duration between 50% MEP and 15% MEP after 6-week program in the control group (P = .049).

CONCLUSIONS

A 6-week RMT can improve the electric signal of the affected swallowing muscles with more effect on the unaffected side than on the affected side during dry swallowing. Furthermore, RMT with 50% MEP rather than 15% MEP can facilitate greater submental muscle activity on the affected side in stroke patients with respiratory muscle weakness.

Detection of swallowing disorders using a multiple channel surface electromyography sheet: A preliminary study

Background/purpose

We invented a sensor sheet with multiple electromyogram electrodes, which can be easily attached to the front of the neck, to evaluate surface electromyograms (sEMG) during swallowing function. In this paper, we evaluated sEMG in healthy volunteers and dysphagia patients using the sensor sheet and discussed its potential to evaluate swallowing function.

Materials and methods

Ten healthy volunteers (age, 29.5 ± 3.9 years) and 18 clinically diagnosed dysphagia patients (age, 67.8 ± 12.1 years) were included. The sensor sheet had four pairs of electrodes, and sEMG at the suprahyoid muscles (positions A and B) and the infrahyoid muscles (positions C and D) were recorded while swallowing water, thickened water, yogurt, and jelly; sEMG findings were compared between these positions.

Results

Significant differences in the duration of muscle activity was observed when swallowing yogurt at position D and when swallowing jelly, thickened water, and water at position B (Mann–Whitney U test, p < 0.05). In healthy volunteers, muscle activation typically began from positions A or B to position D, whereas in dysphagia patients, it sometimes began from position D.

Conclusion

There were significant differences in duration and sequence patterns of four sEMG activities between healthy young volunteers and dysphagia patients in the assessment using the sensor sheet, although some technical and scientific problems remained unresolved. These results indicate that swallowing function could be evaluated using the sensor sheet.

What Happens to Swallowing Muscles after Stroke?: A Prospective Randomized Controlled Electrophysiological Study

Background

Stroke is the most frequent reason of neurological dysphagia Electrophysiological studies can be used to evaluate oral, pharyngeal and initial phase of esophageal phase.

Aims

This study aims to noninvasively evaluate mastication, mimic, and tongue muscles of stroke patients, which play an important role in the oral phase of swallowing process and compare them with healthy individuals.

Setting and Design

This study was conducted at the Physical Medicine and Rehabilitation Clinic of our hospital between January 2014 and December 2016.

Materials and Methods

Fifty-one patients who were admitted to our clinic with stroke and 51 healthy individuals were evaluated for the study. Demographic features of individuals were recorded. The swallowing intervals and motor action potentials (MAPs) of trigeminal, facial and hypoglossal nerves were measured. After four weeks of treatment schedule, patients were re-evaluated.

Statistical Analysis

The Wilcoxon Signed Rank test, the Mann-Whitney U test and Fisher exact test were used in this study.

Results

The all swallowing intervals were found prolonged compared to the healthy controls (P < 0.05). The MAPs of the masseter, orbicularis oculi, and intrinsic tongue muscles were significantly lower in patient group (P < 0.05). After treatment, we found significant improvement for all parameters in patient group, but the swallowing intervals were still significantly prolonged, and MAPs of these muscles were still lower (P < 0.05).

Conclusion

Although swallowing is examined as different phases, the process is complicated and should be evaluated totally. In post-stroke dysphagia, oral phase of swallowing process is as important as phayngeal phase and perioral, mastication, and tongue muscles are influenced even in an early period as a month.

Swallowing changes related to chronic temporomandibular disorders

OBJECTIVES

To investigate whether chronic temporomandibular disorder (TMD) patients showed any changes in swallowing compared to a control group. Moreover, it was examined whether swallowing variables and a valid clinic measure of orofacial myofunctional status were associated.

MATERIAL AND METHODS

Twenty-three patients with chronic TMD, diagnosed with disc displacement with reduction (DDR) and pain, according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), and 27 healthy volunteers (control group) were compared. Surface electromyography (EMG) of the temporalis, masseter, sternocleidomastoid, and suprahyoid muscles was performed during swallowing tasks of thin liquid (10 and 15 mL) and spontaneous saliva. Data were normalized.

RESULTS

Compared to the control group, TMD patients showed a prolonged duration of swallowing for liquid and saliva and required a longer time to reach the activity peak and half the integral. While the overall mean value of the relative peaks was similar for the groups, the suprahyoid peak was significantly lower in the TMD group during swallowing of liquid. Moreover, TMD patients recruited the jaw elevator muscles proportionally more than controls. The orofacial myofunctional status was moderately correlated with EMG parameters.

CONCLUSION

Patients with chronic TMD showed temporal prolongation and changes in the relative activity of the muscles during the swallowing tasks.

CLINICAL RELEVANCE

The present results contribute additional evidence regarding the reorganization of muscle activity in patients with chronic TMD.

Evaluation of an Automated Swallow-Detection Algorithm Using Visual Biofeedback in Healthy Adults and Head and Neck Cancer Survivors

Mobile health (mHealth) technologies may offer an opportunity to address longstanding clinical challenges, such as access and adherence to swallowing therapy. Mobili-T^® is an mHealth device that uses surface electromyography (sEMG) to provide biofeedback on submental muscles activity during exercise. An automated swallow-detection algorithm was developed for Mobili-T^®. This study evaluated the performance of the swallow-detection algorithm. Ten healthy participants and 10 head and neck cancer (HNC) patients were fitted with the device. Signal was acquired during regular, effortful, and Mendelsohn maneuver saliva swallows, as well as lip presses, tongue, and head movements. Signals of interest were tagged during data acquisition and used to evaluate algorithm performance. Sensitivity and positive predictive values (PPV) were calculated for each participant. Saliva swallows were compared between HNC and controls in the four sEMG-based parameters used in the algorithm: duration, peak amplitude ratio, median frequency, and 15th percentile of the power spectrum density. In healthy participants, sensitivity and PPV were 92.3 and 83.9%, respectively. In HNC patients, sensitivity was 92.7% and PPV was 72.2%. In saliva swallows, HNC patients had longer event durations (U = 1925.5, p < 0.001), lower median frequency (U = 2674.0, p < 0.001), and lower 15th percentile of the power spectrum density [t(176.9) = 2.07, p < 0.001] than healthy participants. The automated swallow-detection algorithm performed well with healthy participants and retained a high sensitivity, but had lowered PPV with HNC patients. With respect to Mobili-T^®, the algorithm will next be evaluated using the mHealth system.

Non-invasive Assessment of Swallowing and Respiration Coordination for the OSA Patient

The objectives of this study are to investigate swallowing and its coordination with respiration in patients with obstructive sleep apnea (OSA). This is a prospective cohort study conducted in a tertiary referred Medical Center. A non-invasive method of assessing swallowing was used to detect the oropharyngeal swallowing parameters and the coordination with respiration during swallowing. The system used to assess swallowing detected: (1) movement of the larynx using a force-sensing resistor; (2) submental muscle activity using surface electromyography; and (3) coordination with respiration by measuring nasal airflow. Five sizes of water boluses (maximum 20 mL) were swallowed three times, and the data recorded and analyzed for each participant. Thirty-nine normal controls and 35 patients with OSA who fulfilled the inclusion criteria were recruited. The oropharyngeal swallowing parameters of the patients differed from the controls, including longer total excursion duration and shorter duration of submental muscles contraction. A longer swallowing respiratory pause (SRP), temporary coordination with respiration during swallowing, was demonstrated in the patients compared with the controls. The frequency of non-expiratory/expiratory pre- and postswallowing respiratory phase patterns of the patients was similar with the controls. There was significantly more piecemeal deglutition in OSA patients when clumping 10- and 20-mL water boluses swallowing together (p = 0.048). Oropharyngeal swallowing and coordination with respiration affected patients with OSA, and it could be detected using a non-invasive method. The results of this study may serve as a baseline for further research and help advance research methods in obstructive sleep apnea swallowing studies.