Suprahyoid Muscle Group Research Articles

Comparison of Two Types of Electrodes for Measuring Submental Muscle Activity During Swallowing.

This study aimed to investigate the potential of a newly developed small electrode to accurately record muscle activity during swallowing. This study included 31 healthy participants. The participants underwent swallowing trials with three types of material. The recordings involved the following conditions: 1) swallowing saliva, 2) swallowing 3 mL water, and 3) swallowing 5 mL water. Two types of electrodes, a conventional electrode (CE) and a newly developed small electrode (NE), were symmetrically positioned on the skin over the suprahyoid muscle group, starting from the center. From the surface electromyography data, the swallowing duration (s), peak amplitude, and rising time (duration from swallowing onset to peak amplitude: s) were measured. Additionally, the equivalence of characteristics of the waveform of muscle activities was calculated by using the variance in both the upper and lower confidence limits in duration and rising time. No significant differences in baseline, swallowing duration or rising time between the CE and NE were observed for any swallowing material. The peak amplitude was significantly higher for the NE than for the CE for all swallowing materials. The CE and NE displayed no significant difference in the equivalence of characteristics of the waveform of muscle activities for any swallowing material. The gold-plated small electrodes utilized in this study indicated the ability to record the same characteristics of muscle activity as conventional electrodes. Moreover, it was able to capture the muscle activity of each muscle group with improved sensitivity in a narrow area, such as under the submandibular region, with more precision than that of conventional electrodes.

Sincronización entre la videodeglución y la electromiografía de superficie en pacientes con afectación neurológica y síntomas de disfagia

Introducción. La disfagia se define como la dificultad para movilizar la comida desde la boca hasta el estómago. La prueba diagnóstica para esta condición es la videofluoroscopia, la cual no es totalmente inocua pues utiliza radiación ionizante. La electromiografía de superficie registra la actividad eléctrica de los músculos de manera no invasiva, por lo que puede considerarse como una alternativa para evaluar la deglución y estudiar la disfagia. Objetivo. Evaluar la relación entre los tiempos relativos de activación de los músculos implicados en la fase oral y faríngea de la deglución, con los movimientos registrados durante la videofluoroscopia. Materiales y métodos. Se analizaron las señales de la electromiografía de superficie de 10 pacientes neurológicos con síntomas de disfagia, captadas en forma simultánea con la videofluoroscopia. Se suministraron 5 ml de yogur y 10 ml de agua, y 3 g de galleta. Se estudiaron bilateralmente los grupos musculares maseteros, suprahioideos e infrahioideos. Se analizó el paso del bolo por la línea mandibular, las valleculas y el músculo cricofaríngeo, correlacionándolo con el tiempo inicial y el final de la activación de cada uno de los grupos musculares. Resultados. El tiempo promedio de la fase faríngea fue de 0,89 ± 0,12 s. En la mayoría de los casos, hubo activación muscular antes del paso por la línea mandibular y las valleculas. La terminación de la actividad muscular parece corresponder al momento en que se completa el paso del bolo alimenticio por el músculo cricofaríngeo. Conclusión. Se determinaron los tiempos de actividad muscular, la duración de la fase faríngea y la secuencia de la activación de los grupos musculares involucrados en la deglución, mediante electromiografía de superficie, validada con la videofluoroscopia.

Swallowing disorders analysis using surface EMG biomarkers and classification models

The swallowing process involves complex muscle coordination mechanisms, whose alterations are known as dysphagia. Its instrumental diagnosis is performed by invasive and expensive methods. The surface electromyography (sEMG) emerges as an alternative for automated and objective evaluations of dysphagia symptoms. In this paper we consider thirty-one healthy and 29 dysphagic patients who performed swallowing tasks with water, yogurt, saliva and crackers. The sEMG activity was recorded using bilateral channels for masseter, suprahyoid and infrahyoid muscle groups. Two main analyses were performed. Features in time, frequency, time-frequency, and nonlinear dynamics domains were analyzed to find biomarkers suitable to model dysphagia. Additionally, the automatic discrimination of dysphagia was evaluated with three classification scenarios using: (1) individual features, (2) individual muscle groups, and (3) the combination of muscle groups. Time-features domain exhibited a well-defined representation pattern of swallowing, and achieved the highest individual classification performance (AUC>0.8). The two scenarios with muscle groups yielded the best results along the experiments (AUC>0.85). The best classification results are found with the suprahyoid and masseter muscles, in water and saliva intake. As the main result of the study, we proposed a set of sEMG related biomarkers and classification approaches suitable for automatic dysphagia screening, a step forward in the implementation of non-invasive and objective strategies for swallowing evaluation.

Effects of Comprehensive Swallowing Intervention on Obstructive Sleep Apnea and Dysphagia After Stroke: A Randomized Controlled Trial

ObjectiveThis study aims to explore the effects of comprehensive swallowing intervention on obstructive sleep apnea (OSA) and dysphagia in stroke patients. MethodsWe performed a randomized controlled trial in stroke patients with obstructive sleep apnea (OSA) complicated by dysphagia, divided into treatment group and control group. The treatment group underwent comprehensive swallowing intervention and received swallowing care for 4 weeks, while the control group received only swallowing care. Outcome measurements were obtained at baseline and after the 4-week intervention, evaluated by polysomnography (PSG), videoendoscopic swallowing study (VFSS) synchronized surface electromyography (sEMG), oropharyngeal magnetic resonance imaging (MRI) and swallowing assessment scales. ResultsSixty patients with stroke (30 treatment and 30 control) were eligible to participate in this study. There were no significant differences in any assessment between two groups at baseline. After a 4-week intervention, compared with to control group, there was a significant decrease in the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI), and increased mean and minimal oxygen saturation (SaO2), amplitudes of suprahyoid muscle group (ASUPMG) and subhyoid muscle group (ASUBMG). Moreover, the posterior palatal distance (PPD), posterior lingual distance (PLD) and minimal cross-sectional area (MCSA) were obviously elevated in the treatment group. Additionally, the scores of Gugging swallowing screen (GUSS) and VFSS were significantly increased in the treatment group, compared to control group. ConclusionsThe comprehensive swallowing intervention had therapeutic effects on OSA and dysphagia after stroke, and the mechanism was related to enhancing oropharyngeal muscle strength and changing upper airway structure.

Ultrasound-guided electroacupuncture at suprahyoid muscle group for pharyngeal dysphagia after stroke: a randomized controlled trial

To compare the effect among ultrasound-guided electroacupuncture (EA) at suprahyoid muscle group, conventional acupuncture and conventional EA at suprahyoid muscle group on pharyngeal dysphagia after stroke, and to explore its biomechanical mechanism. A total of 120 patients with pharyngeal dysphagia after stroke were randomly divided into an observation group, a control-1 group and a control-2 group, 40 cases in each group. The patients in the observation group were treated with ultrasound-guided EA at suprahyoid muscle group; the patients in the control-1 group were treated with EA at Lianquan (CV 23), Wangu (GB 12) and Fengchi (GB 20), etc.; the patients in the control-2 group were treated with EA at suprahyoid muscle group according to anatomical location. The EA in the three groups were discontinuous wave, with frequency of 5 Hz and current intensity of 1 mA. The EA was given for 30 minutes, once a day, 6 times were taken as a course of treatment, and 4 courses of treatment were provided. The video floroscopic swallowing study (VFSS) was performed before and after treatment. The Rosenbek penetration-aspiration scale (PAS) score, the forward and upward movement distance of hyoid bone and thyroid cartilage, Ichiro Fujima ingestion-swallowing function score were recorded in the three groups, and the incidences of subcutaneous hematoma were recorded after treatment. Compared before treatment, the PAS scores were reduced and the Ichiro Fujima ingestion-swallowing function scores were increased after treatment in the three groups (P<0.05); the PAS scores in the observation group were lower than those in the control-1 group and the control-2 group, and the Ichiro Fujima ingestion-swallowing function scores in the observation group were higher than those in the control-1 group and the control-2 group (P<0.05). After treatment, the forward and upward movement distance of hyoid bone and thyroid cartilage in the observation group and the control-2 group was increased (P<0.05), and the forward and upward movement distance of hyoid bone was increased in the control-1 group (P<0.05); the forward and upward movement distance of hyoid bone and thyroid cartilage in the observation group was longer than that in the control-1 group and the control-2 group (P<0.05). The incidence of subcutaneous hematoma in the observation group was 0% (0/40), which was lower than 20.0% (8/40) in the control-1 group and 47.5% (19/40) in the control-2 group (P<0.05). Ultrasound-guided EA at suprahyoid muscle group could improve the swallowing function in patients with pharyngeal dysphagia after stroke by increasing the motion of hyoid laryngeal complex. Its effect and safety are better than conventional acupuncture and conventional EA at suprahyoid muscle group.

Surface Electromyography Quantification Methods for Evaluating Muscle Activity in Dysphagia

Quantitative evaluation of stroke patients with the risk of swallowing disorder or dysphagia is required to support diagnosis and further rehabilitation planning. Fluoroscopy X-ray imaging usually is used for swallowing diagnosis, though it gives radiation exposure to patients. Therefore, quantification of muscle coordination patterns involved in swallowing based on surface electromyography (sEMG) was introduced. However, an adequate quantification of sEMG for dysphagia diagnosis still lacks standardization. In this work, potential sEMG signal features, namely the contraction duration (DUR), the time to peak of maximum contraction (TTP), and the total RMS power (TP), were further investigated to evaluate the swallowing processes in healthy subjects and post-stroke patients. The experimental scheme instructed the participant, i.e. 20 healthy subjects and 20 patients, to swallow 3 mL of water in normal swallowing mode and swallow saliva in dry swallowing mode. The proposed signal processing procedure helps to establish the feature extraction of the three features mentioned earlier. For dysphagia assessment, with the support of our proposed signal processing procedure, DUR and TTP can be used together to improve diagnosis reliability. The characteristic of both features in healthy subjects was shorter than in post-stroke patients. Also, the TP feature is useful as additional information to evaluate the role of suprahyoid (SUP) and infrahyoid (INF) muscle groups which are very important in the swallowing process. These results are promising to provide a reliable set of features in the time domain for swallowing analysis. Notably, this can also be utilized as a feature for supporting the automatic classification of dysphagia diagnosis.

A comparison of the head lift exercise and recline exercise in patients with chronic head and neck cancer post-radiation.

Patients who undergo surgery and adjuvant radiation treatment for head and neck cancer often develop dysphagia as a result of this treatment. Improvements in swallow function may be achieved with exercise. The goal of this pilot study was to compare the effectiveness and perceived difficulty of using the head lift exercise and the recline exercise to activate the suprahyoid musculature in 8 individuals with a history of head and neck cancer. Muscle activation using surface electromyography was examined to determine if the recline exercise activates the suprahyoid muscle groups to the same degree as the head lift exercise. Participants also rated the exertion they experienced to assess how easily patients are able to complete the exercises. The majority of participants completed both exercises in their entirety on their first attempt. However, ratings of perceived exertion were significantly lower for the recline exercise than the head lift exercise. The head lift exercise activated the suprahyoid musculature to a significantly greater degree than the recline exercise. The recline exercise, in comparison with the head lift exercise, is easier for participants to complete and results in significantly reduced perceptions of fatigue. Results of this study indicate that the recline exercise may be a good potential substitute for the head lift exercise in patient populations that are incapable of performing the head lift exercise, but that the head lift exercise should be prescribed whenever it is viable as it activates target musculature more effectively than the recline exercise.

Effects of age and gender on swallowing activity assessed by electromyography and laryngeal elevation.

Quantitative assessment of swallowing function is necessary to prevent swallowing impairment due to ageing. Though surface electromyography (EMG) has been widely used to measure swallowing activity, the relationship between EMG results and swallowing function is unclear. This study examined the relationship between the temporal characteristics of muscle activity and laryngeal elevation (LE) during swallowing. This study analysed 60 healthy volunteers in two age groups (young, between 20 and 38years; old, between 65 and 75years), each containing the same number of male and female participants. Surface EMG signals were recorded from the suprahyoid and infrahyoid muscle groups (SH-EMG and IH-EMG, respectively). LE was measured using an array of pressure sensors. The participants swallowed 3mL of water under three swallowing speed conditions: fast, normal and slow swallowing. The EMG duration, EMG time intervals before and after the onset of LE (pre-LE and post-LE intervals, respectively), and the LE velocity were analysed. Both EMG duration and the post-LE interval of IH-EMG were significantly longer in the older group. As for the gender effect, the pre-LE interval of SH-EMG was significantly longer and the LE velocity was significantly higher in men than in women. Furthermore, there was a negative correlation between pre-LE interval and LE velocity in the fast swallowing condition. Though ageing slightly prolonged the muscle activity time, gender influenced swallowing activity in a more complex manner. Therefore, it is important to take gender into account when examining swallowing function with increasing age.

Analysis of 54 cases of thyroglossal duct cyst resection with hyoid bone preservation

Objective:To investigate the efficacy, complications and recurrence rate of thyroglossal duct cyst resection with hyoid preservation in children. Method:Fifty-four children with thyroglossal duct cyst underwent cervical color Doppler ultrasound, CT and/or MRI before operation to make a definite diagnosis.Hyoid-preserving thyroglossal cyst resection was performed in all children.In 51 cases, the cyst wall was close to the hyoid bone, and the thin layer of the hyoid bone surface was removed, while the other 3 cases had no definite association with hyoid bone, only cysts and branches were resected.In the cases where the cyst was close to the hyoid bone, fistula tissue was found in the suprahyoid muscle group in 4 cases, which were carefully separated and excised. Result:All patients had no complications after operation, and the incision healed in the first stage. Postoperative pathology: 51 cases were thyroglossal duct cysts and 3 cases were epidermoid cysts.Follow-up for 1 years to 3 years showed that only 1 case had recurrence（2.0%,1/51）. Conclusion:Postoperative recurrence of thyroid hyoid cysts does not depend on whether the hyoid bone is removed, but on the residue of its branches.The significance of hyoid bone preservation is to narrow the scope of operation, reduce trauma and complications, and avoid the impact of hyoid bone loss on vocal and swallowing function.

Formant-Estimated Vocal Tract Length and Extrinsic Laryngeal Muscle Activation During Modulation of Vocal Effort in Healthy Speakers.

Purpose The goal of this study was to explore the relationships among vocal effort, extrinsic laryngeal muscle activity, and vocal tract length (VTL) within healthy speakers. We hypothesized that increased vocal effort would result in increased suprahyoid muscle activation and decreased VTL, as previously observed in individuals with vocal hyperfunction. Method Twenty-eight healthy speakers of American English produced vowel-consonant-vowel utterances under varying levels of vocal effort. VTL was estimated from the vowel formants. Three surface electromyography sensors measured the activation of the suprahyoid and infrahyoid muscle groups. A general linear model was used to investigate the effects of vocal effort level and surface electromyography on VTL. Two additional general linear models were used to investigate the effects of vocal effort on suprahyoid and infrahyoid muscle activities. Results Neither vocal effort nor extrinsic muscle activity showed significant effects on VTL; however, the degree of extrinsic muscle activity of both suprahyoid and infrahyoid muscle groups increased with increases in vocal effort. Conclusion Increasing vocal effort resulted in increased activation of both suprahyoid and infrahyoid musculature in healthy adults, with no change to VTL.

Effects of Transcutaneous Neuromuscular Electrical Stimulation on Swallowing Disorders: A Systematic Review and Meta-Analysis.

The aim of the study was to evaluate the efficacy of transcutaneous neuromuscular electrical stimulation on swallowing disorders. MEDLINE/PubMed, Embase, CENTRAL, Web of science, and PEDro were searched from their earliest record to August 1, 2019. All randomized controlled trials and quasi-randomized controlled trial were identified, which compared the efficacy of neuromuscular electrical stimulation plus traditional therapy with traditional therapy in swallowing function. The Grading of Recommendations Assessment, Development and Evaluation approach was applied to evaluate the quality of evidence. Eight randomized controlled trials and three quasi-randomized controlled trials were included. These studies demonstrated a significant, moderate pooled effect size (standard mean difference = 0.62; 95% confidence interval = 0.06 to 1.17). Studies stimulating suprahyoid muscle groups revealed a negative standard mean difference of 0.17 (95% confidence interval = -0.42, 0.08), whereas large effect size was observed in studies stimulating the infrahyoid muscle groups (standard mean difference = 0.89; 95% confidence interval = 0.47 to 1.30) and stimulating the suprahyoid and infrahyoid muscle groups (standard mean difference = 1.4; 95% confidence interval = 1.07 to 1.74). Stimulation lasting 45 mins or less showed a large, significant pooled effect size (standard mean difference = 0.89; 95% confidence interval = 0.58 to 1.20). The quality of evidences was rated as low to very low. There is no firm evidence to conclude on the efficacy of neuromuscular electrical stimulation on swallowing disorders. Larger-scale and well-designed randomized controlled trials are needed to reach robust conclusions.

Modification of Masticatory Rhythmicity Leading to the Initiation of the Swallowing Reflex in Humans.

Modification of movements by proprioceptive feedback during mastication has an important role in shifting from the oral to the pharyngeal phase of swallowing. The aim of this study was to investigate the kinetics of masticatory muscles throughout a sequence of oropharyngeal swallowing and to present a hypothetical model of the involvement of the nervous system in the transition from mastication to the swallowing reflex. Surface electromyographic signals were recorded from the jaw-closing masseter muscles and the jaw-opening suprahyoid muscle group when a piece of bread (3-5g) was ingested. Participants were not provided any additional instruction regarding how to chew and swallow. In the final stage of mastication, compared with other stages of mastication, the duration between sequential peak times of rhythmic activity of the masseter muscles was prolonged. Electromyography revealed no significant change in the suprahyoid muscle group. Accordingly, contraction of the jaw-closing muscles and the jaw-opening muscles altered from out-of-phase to in-phase. We have presented a hypothetical model based on the results of the present study, in which mastication shifts to the swallowing reflex when feed-forward inputs from rhythm generators for the jaw-closing and the jaw-opening muscles converge onto an assumed "convertor" neuron group concurrently. This model should contribute to understanding the pathophysiology of dysphagia.

Effects of expiratory muscle strength training on oropharyngeal dysphagia in subacute stroke patients: a randomised controlled trial.

Expiratory muscle strength training (EMST) involves forcible blowing as a means of generating high expiratory pressure, against adjustable resistance. EMST has recently been introduced as a potential treatment for dysphagia. This study was performed to investigate the effects of EMST on the activity of suprahyoid muscles, aspiration and dietary stages in stroke patients with dysphagia. Twenty-seven stroke patients with dysphagia were randomly divided into two groups. The experimental group performed EMST with a 70% threshold value of maximal expiratory pressure, using an EMST device, 5 days a week for 4 weeks. The placebo group trained with a sham device. The EMST regime involved 5 sets of 5 breaths through the EMST device for a total of 25 breaths per day. Activity in the suprahyoid muscle group was measured using surface electromyography (sEMG). Further, the penetration-aspiration scale (PAS) was used to assess the results of the videofluoroscopic swallowing study (VFSS). In addition, dietary stages were evaluated using the Functional Oral Intake Scale (FOIS). The experimental group exhibited improved suprahyoid muscle group activity and PAS results, when compared to the placebo group. Following intervention, statistical analysis indicated significant differences in measured suprahyoid muscle activity (P = 0·01), liquid PAS outcomes (P = 0·03) and FOIS results (P = 0·06), but not semisolid type PAS outcomes (P = 0·32), between the groups. This study confirms EMST as an effective treatment for the development of suprahyoid muscle activity in stroke patients with dysphagia. Additionally, improvements in aspiration and penetration outcomes were observed.

New Swallowing Evaluation Using Piezoelectricity in Normal Individuals.

This study aimed to elucidate the relationship between the piezoelectric waveform latency, hyoid bone movement, surface electromyogram (sEMG), and the pharyngeal transit time (PTT) during swallowing. Forty-one healthy subjects were divided into three age groups: younger (20-39years, n=8), middle-aged (40-59years, n=9), and older (60-79years, n=24). Motion analysis of the hyoid bone using videofluorography (VF), waveform analysis of the front neck using piezoelectric films, and sEMG of the suprahyoid muscle group were performed simultaneously. Latencies of the three movement phases were defined as upward (VFS1), forward (VFS2), and returning to starting position (VFS3). The three phases of the piezoelectric waveform-from wave initiation of the negative wave to the start of the second deep negative wave; from the start of the second deep negative wave to the start of the last positive wave (SLPW); and from the SLPW to the end of the last positive wave-were defined as PS1, PS2, and PS3, respectively. VFS1-3 and PS1-3 were significantly correlated. VFS1 and PS1 latencies were significantly longer with thick liquid than with thin liquid. VFS2, PS1, and PS2 latencies were longer in the older group than in the other two groups. The start of PS1 was nearly equal to those of sEMG and VFS1. Bolus arrival time in the valleculae was statistically equal to the end of the PS1 with both thin and thick liquids. To establish the swallowing screening using Piezoelectric film, further investigation is necessary in the dysphagia patients.

Effect of aging on oral and swallowing function after meal consumption.

Background/purposeDysphagia may worsen due to fatigue of the infrahyoid and suprahyoid muscle groups as a result of repetitive swallowing during a meal. We investigated the hypothesis that meal consumption may reduce tongue strength and endurance in older adults (OAs).MethodsTongue–palate pressure, oral diadochokinesis, repetitive saliva swallowing, and surface electromyography activity before and after a meal were measured in 23 young adults (YAs) and 23 OA volunteers.ResultsThere was a statistically significant difference in both tongue pressure and the number of voluntary swallows between YAs and OAs. Peak tongue pressure was significantly lower in OAs than YAs both before and after meal consumption. The most notable finding was that the first time interval (the time from test initiation to the beginning of the first swallow) was prolonged after meal consumption only in OAs, whereas the first time interval showed no difference between YAs and OAs before meal consumption with reference to the repetitive saliva swallowing test. The initiation of swallowing was prolonged by both meal consumption and aging; there was a significant interaction between these two factors. The number of repetitions of the monosyllable/pa/was statistically similar between YAs and OAs before meal consumption, but it was significantly lower in OAs after meal consumption.ConclusionAging leads to declining tongue pressure and motor function of the lips. It is possible that swallowing function declines in older individuals when meal consumption is prolonged, especially at the end of mealtime, as a result of their efforts in mastication and swallowing.

The Relationship Between Limit of Dysphagia and Average Volume Per Swallow in Patients with Parkinson’s Disease

The goal of this study was to obtain the limit of dysphagia and the average volume per swallow in patients with mild to moderate Parkinson's disease (PD) but without swallowing complaints and in normal subjects, and to investigate the relationship between them. We hypothesize there is a direct relationship between these two measurements. The study included 10 patients with idiopathic PD and 10 age-matched normal controls. Surface electromyography was recorded over the suprahyoid muscle group. The limit of dysphagia was obtained by offering increasing volumes of water until piecemeal deglutition occurred. The average volume per swallow was calculated by dividing the time taken by the number of swallows used to drink 100ml of water. The PD group showed a significantly lower dysphagia limit and lower average volume per swallow. There was a significantly moderate direct correlation and association between the two measurements. About half of the PD patients had an abnormally low dysphagia limit and average volume per swallow, although none had spontaneously related swallowing problems. Both measurements may be used as a quick objective screening test for the early identification of swallowing alterations that may lead to dysphagia in PD patients, but the determination of the average volume per swallow is much quicker and simpler.

Vocal frequency estimation and voicing state prediction with surface EMG pattern recognition

The majority of laryngectomees use the electrolarynx as their primary mode of verbal communication after total laryngectomy surgery. However, the archetypal electrolarynx suffers from a monotonous tone and the inconvenience of requiring manual control. This paper presents the potential of pattern recognition to support electrolarynx use by predicting fundamental frequency (F0) and voicing state (VS) from surface EMG of the infrahyoid and suprahyoid muscles, as well as from a respiratory trace. In this study, surface EMG signals from the infrahyoid and suprahyoid muscle groups and respiratory trace were collected from 10 able-bodied, adult males (18–60years old). Participants performed three kinds of vocal tasks – tones, legatos and phrases. Signal features were extracted from the EMG and respiratory trace, and a Support Vector Machine (SVM) classifier with radial basis function kernels was employed to predict F0 and voicing state. An average root mean squared error of 2.81±0.6 semitones was achieved for the estimation of vocal frequency in the range of 90–360Hz. An average cross-validation (CV) accuracy of 78.05±6.3% was achieved for the prediction of voicing state from EMG and 65.24±7.8% from the respiratory trace. The proposed method has the advantage of being non-invasive compared with studies that relied on intramuscular electrodes (invasive), while still maintaining an accuracy above chance. Pattern classification of neck-muscle surface EMG has merit in the prediction of fundamental frequency and voicing state during vocalization, encouraging further study of automatic pitch modulation for electrolarynges and silent speech interfaces.

Electrode position and hyoid movement in surface electrical stimulation of the suprahyoid muscle group

Shimizu S, Metani H, Hiraoka T, Seki S, Hanayama K, Tsubahara A. Electrode position and hyoid movement in surface electrical stimulation of the suprahyoid muscle group. Jpn J Compr Rehabil Sci 2014; 5: 97-​ 101. Objective: To determine the relationship between electrode position and hyoid movement for effective surface electrical stimulation in the treatment of dysphagia. Methods: Surface electrode pairs targeted on the suprahyoid muscle group were placed in mesial, distal, or pervasive placement patterns on the skin anterior to the suprahyoid muscle group of five healthy subjects, and the vertical and horizontal movements of the hyoid induced by electrical stimulation in the three pattern groups were measured and compared. Results: The mesial electrode-pair pattern induced significant anterior movement of the hyoid. The distal pattern showed a tendency to induce upward hyoid movement. The distance of hyoid movement induced by the electrical stimulation was about half of that found for actual water swallowing. No significant difference in electrical stimulus intensity was found among the electrode patterns. Conclusion: Surface electrical stimulation with mesial electrode-pair placement anterior to the hyoid presumably induces contraction of the digastric muscle anterior belly and the geniohyoid muscle, and was found to pull the hyoid forward. This information and further elucidation of the relationship between surface electrode position and hyoid movement is expected to increase the range of clinical applications.

Evaluating Swallowing Muscles Essential for Hyolaryngeal Elevation by Using Muscle Functional Magnetic Resonance Imaging

Reduced hyolaryngeal elevation, a critical event in swallowing, is associated with radiation therapy. Two muscle groups that suspend the hyoid, larynx, and pharynx have been proposed to elevate the hyolaryngeal complex: the suprahyoid and longitudinal pharyngeal muscles. Thought to assist both groups is the thyrohyoid, a muscle intrinsic to the hyolaryngeal complex. Intensity modulated radiation therapy guidelines designed to preserve structures important to swallowing currently exclude the suprahyoid and thyrohyoid muscles. This study used muscle functional magnetic resonance imaging (mfMRI) in normal healthy adults to determine whether both muscle groups are active in swallowing and to test therapeutic exercises thought to be specific to hyolaryngeal elevation. mfMRI data were acquired from 11 healthy subjects before and after normal swallowing and after swallowing exercise regimens (the Mendelsohn maneuver and effortful pitch glide). Whole-muscle transverse relaxation time (T2 signal, measured in milliseconds) profiles of 7 test muscles were used to evaluate the physiologic response of each muscle to each condition. Changes in effect size (using the Cohen d measure) of whole-muscle T2 profiles were used to determine which muscles underlie swallowing and swallowing exercises. Post-swallowing effect size changes (where a d value of >0.20 indicates significant activity during swallowing) for the T2 signal profile of the thyrohyoid was a d value of 0.09; a d value of 0.40 for the mylohyoid, 0.80 for the geniohyoid, 0.04 for the anterior digastric, and 0.25 for the posterior digastric-stylohyoid in the suprahyoid muscle group; and d values of 0.47 for the palatopharyngeus and 0.28 for the stylopharyngeus muscles in the longitudinal pharyngeal muscle group. The Mendelsohn maneuver and effortful pitch glide swallowing exercises showed significant effect size changes for all muscles tested, except for the thyrohyoid. Muscles of both the suprahyoid and the longitudinal pharyngeal muscle groups are active in swallowing, and both swallowing exercises effectively target muscles elevating the hyolaryngeal complex. mfMRI is useful in testing swallowing muscle function.

Swallowing in Patients with Parkinson’s Disease: A Surface Electromyography Study

Our goal was to study deglutition of Parkinson's disease (PD) patients and normal controls (NC) using surface electromyography (sEMG). The study included 15 patients with idiopathic PD and 15 age-matched normal controls. Surface electromyography was collected over the suprahyoid muscle group. Conditions were the following: swallow at once 10 and 20ml of water and 5 and 10ml of yogurt of firm consistency, and freely drink 100ml of water. During swallowing, durations of sEMG were significantly longer in PD patients than in normal controls but no significant differences of amplitudes were found. Eighty percent of the PD patients and 20% of the NC needed more than one swallow to consume 20ml of water, while 70% of the PD patients and none of the NC needed more than one swallow to consume 5ml of yogurt. PD patients took significantly more time and needed significantly more swallows to drink 100ml of water than normal controls. We conclude that sEMG might be a simple and useful tool to study and monitor deglutition in PD patients.