Electrophysiological patterns of oropharyngeal swallowing in multiple sclerosis

Surface Electromyographic Activities of Submental and Infrahyoid Muscles: Comparisons Based on Residue, Penetration and Aspiration

BACKGROUND

Surface electromyography (sEMG) has been used in a wide range of studies conducted in the field of dysphagia.

OBJECTIVES

The main aim of this case-control study is to obtain how submental and infrahyoid sEMG signals differ based on residue, penetration and aspiration.

METHODS

A total of 100 participants (50 patients with suspected dysphagia and 50 healthy controls) were enrolled in the present study. Participants with suspected dysphagia underwent a detailed fibreoptic endoscopic evaluation of swallowing (FEES) to observe the efficiency and safety of swallowing using the Yale Pharyngeal Residue Severity Rating Scale (YPRSRS) and the Penetration-Aspiration Scale (PAS), respectively. Afterward, sEMG parameters, including submental muscle activity duration (SMM-AD), infrahyoid muscle activity duration (IM-AD), amplitude of submental muscles (A-SMM) and amplitude of infrahyoid muscles (A-IM) were obtained during three consecutive dry swallows from all study cohorts.

RESULTS

There were significantly higher SMM-AD values in patients with a YPRSRS score of 1-2 and a YPRSRS score of 3-5 for residue in vallecula compared to the controls (p < 0.001 and p = 0.001, respectively). Both subgroups of patients with a YPRSRS score of 1-2 and a YPRSRS score of 3-5 for residue in piriforms showed significantly higher SMM-AD values compared to the controls (p < 0.001 and p = 0.048, respectively). The same prolongation of SMM-AD was also evident for the patients with airway invasion (penetration or aspiration) compared to the controls (p = 0.042 and p < 0.001, respectively). The other measured sEMG parameters (IM-AD, A-SMM and A-IM) did not differ significantly based on FEES outcomes (p > 0.05).

CONCLUSION

Since the availability of instrumental swallowing assessment methods in clinical practice is quite challenging, specific sEMG parameters may be useful to predict possible residue, penetration, or aspiration events in patients with dysphagia. SMM-AD can be considered as a first-line assessment parameter for possible residue, penetration, and aspiration events before referring patients for further instrumental methods.

Can Voice Parameters Provide Cutoff Values to Predict Dysphagia in Individuals with Multiple Sclerosis?

In dysphagia assessment, along with well-defined measurements and signs, voice parameters can potentially support clinical decision as a marker, but more evidence is needed. This study aims to determine the voice parameters that can predict the risk of dysphagia and to determine optimal cutoff values in individuals with multiple sclerosis (IwMS). Seventy-six adults participated in the study, including 39 IwMS and 37 healthy individuals (HI). The study used the Dysphagia in Multiple Sclerosis Questionnaire (DYMUS), Gugging Swallowing Screen (GUSS), and Voice Handicap Index (VHI-10) and recorded voice samples using Praat programme. Voice recordings were taken pre- and post-swallowing. The voice parameters analysed are fundamental frequency (F0), standard deviation F0 (SD F0), jitter (local), shimmer (local), and harmonic-to-noise ratio (HNR). Roc analysis was performed to examine the diagnostic accuracy performance of the risk for dysphagia/penetration. The parameters of IwMS pre-swallowing differed significantly from those of HI on the VHI-10, DYMUS, GUSS scores, and jitter (local), shimmer (local), and HNR. IwMS but not HI exhibited significant differences in shimmer (local) and HNR between the pre- and post-swallowing measurements. In IwMS, GUSS revealed significant differences in shimmer (local) pre- and post-swallowing between the groups with and without dysphagia/penetration. In the ROC analysis results, the area under the curve (AUC) for shimmer (local) pre-swallowing was 73.1% (cutoff = 1.69); post-swallowing, it was 78.6% (cutoff = 1.57). In conclusion, IwMS can be associated with differences in shimmer (local) and HNR parameters, low quality of life-related to voice, and dysphagia/penetration risk. The AUC values for shimmer (local) in IwMS pre- and post-swallowing may help to strengthen diagnostic decisions of dysphagia risk.

Assessment of dysphagia and its associations in patients with secondary progressive multiple sclerosis

In this cross-sectional study in patients with secondary progressive multiple sclerosis receiving anti-CD20 monoclonal antibodies, we assessed complaint of dysphagia and evaluated their association with sex, age, disease duration, disability severity, and disease-modifying therapies (DMTs). The validated Persian version of Dysphagia in Multiple Sclerosis (DYMUS) questionnaire was used. A total of 66 patients were included. The median DYMUS score was 1.0 [interquartile range: 0.0-2.3] and 40 (60.6%) had positive DYMUS. Only DMT showed a significant association with DYMUS score, with patients receiving reituximab exhibiting higher scores (mean estimated difference: 0.96 (±0.39), p = 0.014). Grouping patients into positive and negative DYMUS scores, no significant associations were observed (p > 0.05).

Dysphagia in multiple sclerosis: pathophysiology, assessment, and management-an overview

Dysphagia is a frequent and life-threatening complication of multiple sclerosis (MS). Swallowing disturbances may be present at all stages of MS, although their prevalence increases with age, with disease duration, and in progressive phenotypes. The pathophysiology of dysphagia in MS is likely due to a combination of factors, including the involvement of corticobulbar tracts, the cerebellum, and the brainstem. Accurate diagnosis and early management of swallowing disorders improve quality of life and may delay complications or invasive therapeutic interventions. Here we provide an overview of the pathophysiology, the assessment, and the management of MS dysphagia, also examining the possible role of novel therapeutic strategies. Although studies using imaging and neurophysiological techniques have contributed to better characterize swallowing alterations in MS, the treatment of dysphagia is still challenging. Rehabilitation represents the main therapeutic approach for swallowing disorders. Recently, some innovative neurophysiological approaches, such as pharyngeal electrical stimulation (PES), repetitive transcranial magnetic stimulation (rTMS), and transcranial direct current stimulation (tDCS), have been proposed as a supplement to swallowing therapy in different neurological conditions. However, only few studies have explored the role of neuromodulation for MS dysphagia.

Drooling may be Associated with Dysphagia Symptoms in Multiple Sclerosis

During the process of the multiple sclerosis (MS), persons with multiple sclerosis (PwMS) may experience drooling (sialorrhea) issues that are frequently disregarded. The exact cause of drooling in PwMS is poorly understood. This study aims to assess potential risk factors for drooling seen in PwMS. The study included 20 PwMS with drooling and 19 PwMS without drooling. The participants' sociodemographic data and clinical parameters were noted. To evaluate dysphagia, fatigue, and hypersalivation, the Dysphagia in Multiple Sclerosis Questionnaire (DYMUS), the Fatigue Severity Scale (FSS), and objective saliva flow rate measurement with cottons placed in Stensen ducts and under the tongue (swab test) were used, respectively. The study employed univariate and multivariate logistic regression models to identify the risk factors linked to drooling. Gender, age, disease duration, MS type, and Expanded Disability Status Scale scores did not differ between the two groups. There was a significant increase in the DYMUS and submandibular/sublingual (SM/SL) saliva flow rate values in PwMS with drooling (p = 0.009 and p = 0.019, respectively). However, in our study, hypersalivation was not observed in PwMS with or without drooling. In the univariate model, DYMUS, SM/SL saliva flow rate, and FSS were found to be risk factors for drooling in PwMS. But only DYMUS was shown to be a significant risk factor in the multivariate model obtained by the backward (Wald) elimination method (p = 0.023). Finally, our research is the first to demonstrate the relationship between drooling and the presence of dysphagia symptoms in PwMS. This is a very important study to determine the nature of drooling in PwMS. This finding shows that our study will serve as a reference for choosing the best method for drooling treatment.

The impact of physical therapy on dysphagia in neurological diseases: a review

A neurogenic dysphagia is dysphagia caused by problems with the central and peripheral nervous systems, is particularly prevalent in conditions such as Parkinson's disease and stroke. It significantly impacts the quality of life for affected individuals and causes additional burdens, such as malnutrition, aspiration pneumonia, asphyxia, or even death from choking due to improper eating. Physical therapy offers a non-invasive treatment with high efficacy and low cost. Evidence supporting the use of physical therapy in dysphagia treatment is increasing, including techniques such as neuromuscular electrical stimulation, sensory stimulation, transcranial direct current stimulation, and repetitive transcranial magnetic stimulation. While initial studies have shown promising results, the effectiveness of specific treatment regimens still requires further validation. At present, there is a lack of scientific evidence to guide patient selection, develop appropriate treatment regimens, and accurately evaluate treatment outcomes. Therefore, the primary objectives of this review are to review the results of existing research, summarize the application of physical therapy in dysphagia management, we also discussed the mechanisms and treatments of physical therapy for neurogenic dysphagia.

Advancements and Challenges in Non-Invasive Sensor Technologies for Swallowing Assessment: A Review

Dysphagia is a pervasive health issue that impacts diverse demographic groups worldwide, particularly the elderly, stroke survivors, and those suffering from neurological disorders. This condition poses substantial health risks, including malnutrition, respiratory complications, and increased mortality. Additionally, it exacerbates economic burdens by extending hospital stays and escalating healthcare costs. Given that this disorder is frequently underestimated in vulnerable populations, there is an urgent need for enhanced diagnostic and therapeutic strategies. Traditional diagnostic tools such as the videofluoroscopic swallowing study (VFSS) and flexible endoscopic evaluation of swallowing (FEES) require interpretation by clinical experts and may lead to complications. In contrast, non-invasive sensors offer a more comfortable and convenient approach for assessing swallowing function. This review systematically examines recent advancements in non-invasive swallowing function detection devices, focusing on the validation of the device designs and their implementation in clinical practice. Moreover, this review discusses the swallowing process and the associated biomechanics, providing a theoretical foundation for the technologies discussed. It is hoped that this comprehensive overview will facilitate a paradigm shift in swallowing assessments, steering the development of technologies towards more accessible and accurate diagnostic tools, thereby improving patient care and treatment outcomes.

DYMUS-Hr self-assessment questionnaire (Croatian version) for dysphagia in multiple sclerosis-validity, reliability, and cross-cultural adaptation

BACKGROUND

The prevalence of dysphagia in the early phases of multiple sclerosis is 30-40%, with an estimated of 30% of cases going undiagnosed cases. Such complications can lead to malnutrition, dehydration, and aspiration pneumonia and have a great impact on the quality of life and psychosocial status of a person with MS. The aim of this study was the validation of dysphagia in multiple sclerosis self-assessment questionnaire (DYMUS) in the Croatian language.

METHODS AND PATIENTS

The cross-cultural adaptation process included a back-forward translation technique of the English language version of DYMUS to the Croatian language, with pilot testing on 30 participants. The validity and reliability of the Croatian version of DYMUS (DYMUS-Hr) was applied to 106 MS patients, with comparison to the Eating Assessment Tool (EAT10), the Water Swallowing Test (WST), and a dichotomous self-assessment question. In the assessment of test-retest reliability, 99 MS patients were included.

RESULTS

Internal consistency of DYMUS-Hr was very good (Cronbach's alpha-0.837); Cronbach's alpha was 0.819 for the "dysphagia for solids", and 0.562 for "dysphagia for liquids" subscale. A significant correlation (p < 0.001) was found between DYMUS-Hr and EAT10 (Spearman's rho-0.787), and WST (Spearman's rho-0.483). Construct validity was assessed with the self-assessment question and interpreted with the Mann-Whitney U test. Test-retest reliability showed moderate to substantial Cohen's Kappa reliability for each item.

CONCLUSION

DYMUS-Hr is a valid and reliable screening assessment tool for patients with MS. There is a general lack of awareness about dysphagia symptoms among patients with MS; consequently, this disorder receives inadequate attention and often goes untreated.

Electrokinesiographic Study of Oropharyngeal Swallowing in Neurogenic Dysphagia

Electrokinesiographic study of swallowing (EKSS) can be useful for the assessment of patients with suspected or overt neurogenic dysphagia. EKSS consists of multichannel recording of the electromyographic (EMG) activity of the suprahyoid/submental muscle complex (SHEMG), the EMG activity of the cricopharyngeal muscle (CPEMG), and the laryngopharyngeal mechanogram (LPM). The LPM is an expression of the mechanical changes that the laryngopharyngeal structures undergo during the pharyngeal phase of swallowing. This method allows detailed evaluation of the magnitude, duration and temporal relations of the different events that characterize oropharyngeal swallowing, and thus in-depth exploration both of physiological deglutition mechanisms and of pathophysiological features of swallowing in neurogenic dysphagia. Furthermore, EKSS can guide dysphagia treatment strategies, allowing identification of optimal solutions for single patients. For instance, CPEMG recording can identify incomplete or absent relaxation of the upper esophageal sphincter during the pharyngeal phase of swallowing, thus suggesting a therapeutic approach based on botulinum toxin injection into the cricopharyngeal muscle. More recently, the 'shape' of SHEMG and the reproducibility of both SHEMG and LPM over repeated swallowing acts have been implemented as novel electrokinesiographic parameters. These measures could be valuable for straightforward non-invasive investigation of dysphagia severity and response to dysphagia treatment in clinical practice.

Prevalence of dysphagia in patients with multiple sclerosis: A systematic review and meta-analysis

BACKGROUND

Dysphagia is a major disorder observed in patients with multiple sclerosis (MS), yet different prevalence rates are reported for it. Therefore, we designed this study to estimate the pooled prevalence of dysphagia in patients with MS.

METHOD

We searched PubMed, Scopus, EMBASE, Web of Science, and gray literature including references from the identified studies, reviews studies, and conference abstracts which were published up to May 2022. Articles that were relevant to our topic and could provide information regarding the prevalence of dysphagia among MS patients were included; however, articles with self-report screening strategies were excluded.

RESULTS

The literature search found 997 articles. After eliminating duplicates, 672 articles remained. Two conference abstracts were included for final analysis. A total of 11,266 MS cases and 5047 MS patients with dysphagia were included in the meta-analysis. The overall prevalence of dysphagia across all 54 studies was 44.8 % (95 % CI: [40.4 %-49.2 %]), with a high level of heterogeneity between countries (Q=; I² = 94.96 %; p < 0.001).

CONCLUSION

The results of this systematic review shows that the prevalence of dysphagia in MS patients is 45% which is greatly higher compared to the general population.

The comparison of tone and viscoelastic properties of superior orbicularis oris muscle in multiple sclerosis patients to healthy individuals

BACKGROUND

The orbicularis oris muscle is an important muscle for oral perception in mouth and swallowing rehabilitation. The muscle can be affected in patients with multiple sclerosis for many reasons. It is important to understand the quantitative changes in this muscle to determine the many problems associated with the cranio-facial region in multiple sclerosis. Therefore, this study aimed to compare the mechanical properties of the orbicularis oris muscle between MS patients and healthy individuals.

METHODS

A total of 55 individuals (28 with multiple sclerosis and 27 healthy) who met the inclusion criteria were evaluated. The tone and viscoelastic properties (elasticity and stiffness) of the superior orbicularis oris muscle of both groups were evaluated bilaterally in the supine position with the MyotonPro® (Myoton AS, Estonia) device. The reference point of the muscle is accepted as the right and left paramedial philtrum dimple.

RESULTS

It was observed that there was no difference in terms of stiffness values of the right and left orbicularis oris muscles of both groups (p>0.05). The tone and the elasticity of the muscle on both sides were higher in the HI group than MS group (p<0.05).

CONCLUSION

We think that the orbicularis oris muscle has a central location in the facial region, and that this muscle may be the key muscle for the symptoms arising from many neurological mechanisms. The decrease in muscle tone and elasticity may be the beginning of the changes in MS patients. We believe that the data from this muscle will be useful for comparative studies.

Validation of the DYALS (dysphagia in amyotrophic lateral sclerosis) questionnaire for the evaluation of dysphagia in ALS patients

BACKGROUND

Dysphagia is a common symptom during the trajectory of ALS, and it can significantly impact on the quality of life and prognosis of patients. Nowadays, no specific tool for the screening of dysphagia in ALS is validated, and the approach is heterogeneous across the Italian centres.

OBJECTIVE

To validate the DYALS (dysphagia in amyotrophic lateral sclerosis) questionnaire, adapting the DYMUS (dysphagia in multiple sclerosis) questionnaire, for the assessment of dysphagia in ALS patients, in order to uniform the evaluations across the Italian ALS network.

METHODS

We included 197 patients diagnosed with ALS following the El Escorial criteria, in sixteen Italian ALS centres between 1st December 2019 and 1st July 2020. For each patient, we collected clinical and demographic data and obtained ALSFRS-r score, ALSAQ-5 score, DYMUS score, and EAT-10 score.

RESULTS

Across the 197 patients, the ratio M/F was 113/84, and the median age was 64 years (IQR 56-72.5). Bulbar patients were 20%, and spinal patients 80%. The median ALSFRSr total score of patients was 35 (IQR 28-39). DYALS score was statistically higher in bulbar ALS than in spinal ALS (median = 6, IQR 4.5-9 vs median = 1, IQR 0-5, z = 6.253, p < 0.0001). DYALS questionnaire showed a high internal consistency (Cronbach's alpha = 0.88). There was a statistically significant correlation between DYALS and EAT-10 (rho = 0.90, p < 0.0001).

CONCLUSIONS

DYALS scale is reliable, manageable, and easily usable for the screening of dysphagia in ALS. It can be shared with all the Italian ALS centres in order to collect uniform data for therapeutic strategies and clinical trials.

Autoimmune Neurogenic Dysphagia

Autoimmune neurogenic dysphagia refers to manifestation of dysphagia due to autoimmune diseases affecting muscle, neuromuscular junction, nerves, roots, brainstem, or cortex. Dysphagia is either part of the evolving clinical symptomatology of an underlying neurological autoimmunity or occurs as a sole manifestation, acutely or insidiously. This opinion article reviews the autoimmune neurological causes of dysphagia, highlights clinical clues and laboratory testing that facilitate early diagnosis, especially when dysphagia is the presenting symptom, and outlines the most effective immunotherapeutic approaches. Dysphagia is common in inflammatory myopathies, most prominently in inclusion body myositis, and is frequent in myasthenia gravis, occurring early in bulbar-onset disease or during the course of progressive, generalized disease. Acute-onset dysphagia is often seen in Guillain–Barre syndrome variants and slowly progressive dysphagia in paraneoplastic neuropathies highlighted by the presence of specific autoantibodies. The most common causes of CNS autoimmune dysphagia are demyelinating and inflammatory lesions in the brainstem, occurring in patients with multiple sclerosis and neuromyelitis optica spectrum disorders. Less common, but often overlooked, is dysphagia in stiff-person syndrome especially in conjunction with cerebellar ataxia and high anti-GAD autoantibodies, and in gastrointestinal dysmotility syndromes associated with autoantibodies against the ganglionic acetyl-choline receptor. In the setting of many neurological autoimmunities, acute-onset or progressive dysphagia is a potentially treatable condition, requiring increased awareness for prompt diagnosis and early immunotherapy initiation.

Conformable AlN Piezoelectric Sensors as a Non-invasive Approach for Swallowing Disorder Assessment

Deglutition disorders (dysphagia) are common symptoms of a large number of diseases and can lead to severe deterioration of the patient's quality of life. The clinical evaluation of this problem involves an invasive screening, whose results are subjective and do not provide a precise and quantitative assessment. To overcome these issues, alternative possibilities based on wearable technologies have been proposed. We explore the use of ultrathin, compliant, and flexible piezoelectric patches that are able to convert the laryngeal movement into a well-defined electrical signal, with extremely low anatomical obstruction and high strain resolution. The sensor is based on an aluminum nitride thin film, grown on a soft Kapton substrate, integrated with an electrical charge amplifier and low-power, wireless connection to a smartphone. An ad-hoc designed laryngeal motion simulator (LMS), which is able to mimic the motions of the laryngeal prominence, was used to evaluate its performances. The physiological deglutition waveforms were then extrapolated on a healthy volunteer and compared with the sEMG (surface electromyography) of the submental muscles. Finally, different tests were conducted to assess the ability of the sensor to provide clinically relevant information. The reliability of these features permits an unbiased evaluation of the swallowing ability, paving the way to the creation of a system that is able to provide a point-of-care automatic, unobtrusive, and real-time extrapolation of the patient's swallowing quality even during normal behavior.

Prevalence and Risk Factors of Dysphagia in Patients with Multiple Sclerosis

Dysphagia is one of the most common symptoms in multiple sclerosis (MS) patients. It can reduce the quality of life and increase the risk of mortality by developing complications such as aspiration pneumonia. The present study was conducted to estimate the prevalence of dysphagia in MS patients and investigate the associations between dysphagia and disease characteristics. The Persian version of the DYMUS questionnaire was used to assess dysphagia in 865 patients with MS, including 738 (85.3%) relapsing-remitting MS (RRMS), 106 (12.3%) secondary progressive MS (SPMS), and 21 (2.4%) primary progressive MS (PPMS). Also, demographic and clinical data, including age, sex, smoking status, Expanded Disability Status Scale (EDSS) score, disease duration, disease-modifying therapies exposure, initial symptoms of MS, were recorded. The mean (SD) age was 37.95(9.25) years, and 83.1% of the participants were female. The prevalence of dysphagia was estimated to be 25.4% among all patients. According to the DYMUS questionnaire results, the prevalence of dysphagia in RRMS, SPMS, and PPMS patients was 22.2%, 44.3%, and 42.9%, respectively. After multivariate analysis the current EDSS score (OR = 1.197, CI: 1.062, 1.350, p = 0.003), cerebellar impairment (OR = 1.335, CI: 1.450, 4.716, p = 0.004) and motor dysfunction (OR = 1.651, CI: 1.004, 2.715, p = 0.048) emerged as the risk factors for dysphagia. Since dysphagia, as previously mentioned, is a common symptom in multiple sclerosis, particularly in SPMS and PPMS courses, active screening for this condition is recommended in all patients, particularly those with identified risk factors.

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

BACKGROUND

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.

OBJECTIVE

This study examined the relationship between the temporal characteristics of muscle activity and laryngeal elevation (LE) during swallowing.

METHODS

This study analysed 60 healthy volunteers in two age groups (young, between 20 and 38 years; old, between 65 and 75 years), 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 3 mL 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.

RESULTS

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.

CONCLUSION

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.

The Dysphagia in Multiple Sclerosis Questionnaire Correlates with Fiber-Optic Endoscopic Examination for Detecting Swallowing Deficits in MS

Multiple sclerosis (MS) refers to chronic inflammation of the central nervous system including the brain and spinal cord. Assessing for the presence of dysphagia in subjects with MS represents a challenge for neurologists in clinical practice. The aim of the present study was to verify the relationship between DYMUS scores, a patient-reported scale, and objective symptoms using the Dysphagia Outcome Severity Score (DOSS), based on fiber-optic endoscopy. Data were collected in a multicenter study. Two hundred and fifteen MS patients were enrolled, irrespective of self-reported dysphagia. DOSS revealed dysphagia in 122 subjects (56.7%). Compared with non-dysphagic subjects, the presence of dysphagia was related to more severe disability, longer disease duration, and a progressive form of the disease. A DYMUS score of 0 strongly correlated with a DOSS of 6 (sensitivity 100%) while DYMUS score of > 2 correlated with a DOSS < 7 (specificity 82%) of the self-reported scale. The DYMUS questionnaire can be a useful clinical tool for red-flagging patients who should undergo objective testing and referral to a otorhinolaryngologist.

Effects of the head lift exercise and neuromuscular electrical stimulation on swallowing muscles activity in healthy older adults: a randomized pilot study

PURPOSE

Swallowing physiology exhibits several changes in advanced ages. The present study aimed to investigate and compare effects of a period of the head lift exercise (HLE) and neuromuscular electrical stimulation (NMES) on swallowing muscles activity in healthy elderly.

PATIENTS AND METHODS

A total of 23 older adults were randomized to either the HLE or NMES group for ten therapy sessions. They received pre- and post-therapy surface electromyography (sEMG) during water swallowing.

RESULTS

For the HLE group, duration of suprahyoid muscles activity was significantly reduced at post-intervention compared to pre-intervention (p=0.036). Moreover after treatments, duration and latency between onset and peak amplitude of suprahyoid muscles activity was significantly shorter in the HLE group compare to the NMES group (respectively, p=0.007 and p=0.003).

CONCLUSION

Our findings suggest that the HLE, against the NMES, may be effective in reducing some aging effects on the suprahyoid muscles activity, especially in elders who demonstrate prolonged duration and latency between onset and peak of the suprahyoid muscles activity during swallowing.

A pilot study on the efficacy of transcranial direct current stimulation applied to the pharyngeal motor cortex for dysphagia associated with brainstem involvement in multiple sclerosis

OBJECTIVE

we investigated the effect of anodal transcranial direct current stimulation (tDCS) applied over the pharyngeal motor area in dysphagia associated with multiple sclerosis (MS).

METHODS

Eighteen MS patients with dysphagia associated with brainstem involvement were randomized to receive either "real" or "sham" tDCS.

PRIMARY OUTCOME

The Penetration/Aspiration Scale (PAS).

SECONDARY OUTCOMES

changes in electromyographic (EMG) parameters and pharyngeal cortical motor evoked potentials (MEPs). Patients were evaluated at baseline (T₀), at the end of 5-session cycle of tDCS stimulations (T₁), after two (T₂), and four (T₃) weeks.

RESULTS

the PAS values were significantly lower in the active group than in "sham" group at T₁, and at T₃. Over the post-stimulation periods, PAS significantly improved only in the "real" group. As regards the secondary outcomes, we observed a statistically significant difference between the 2 groups only in the MEPs amplitude at T₁. The comparison between baseline and each of the post-stimulation times showed significant differences only of the "real" group across all the secondary parameters.

CONCLUSIONS

Our findings support a beneficial effect of anodal tDCS applied to the pharyngeal motor cortex in MS-associated dysphagia.

SIGNIFICANCE

Considering its safety and efficacy, tDCS may represent an important resource in MS-associated dysphagia.

Management of dysphagia in multiple sclerosis: current best practice

Multiple sclerosis (MS) is characterized by extreme variability in both severity and clinical course. It can show severe disabling symptoms, and among them dysphagia is frequently described. However, its management still represents a challenge in the daily care. Areas covered: In this review, we will focus on the clinical recognition and therapeutic strategies to identify and manage dysphagia in people with MS. In the view of a personalized approach, different interventions should be tailored to every single patient. Expert commentary: Multidisciplinary evaluation is mandatory in MS management, and dysphagia represents a perfect model of taking care of a disabling symptom in a chronic disease. Further research is required to better organize a personalized and long-term management of dysphagia phenomenon, through the different subtypes of MS.

Atividade elétrica dos músculos masseter e supra-hióideo durante a deglutição do paciente com esclerose múltipla

RESUMO Objetivo caracterizar a atividade eletromiográfica dos músculos da deglutição na EM. Método foram avaliados 60 indivíduos, sendo 30 com diagnóstico definitivo de EM e 30 sem alterações neurológicas. Foram levantados os dados pessoais dos voluntários e, em seguida, coletados em prontuário tempo de diagnóstico, forma clínica da doença e escore da escala EDSS. Em seguida foi administrado o questionário DYMUS. Todos foram submetidos à realização do Protocolo de Avaliação Eletromiográfica da Deglutição. Resultados na deglutição de saliva, deglutição de líquido com volume confortável e deglutição contínua, foram verificadas diferenças entre os grupos no músculo masseter, e as médias foram mais elevadas no grupo de comparação. Foram registradas diferenças entre masseter e supra-hióideo no repouso, na deglutição de saliva, na deglutição de líquido com volume confortável e na deglutição contínua, e em todas as situações as médias foram mais elevadas no supra-hióideo, sendo que a menor diferença ocorreu no repouso, e a maior na deglutição contínua. Foram registradas correlações do EDSS com a atividade do supra-hióideo na deglutição de saliva, na deglutição de líquido com volume confortável e na deglutição contínua. Com o DYMUS foram observadas correlações com a atividade do masseter e com o tempo de deglutição. As pontuações elevadas no DYMUS apresentaram correlações com o aumento da atividade elétrica do masseter. Conclusão quanto pior o estado clínico do paciente, menor será a atividade elétrica do supra-hióideo, e o aumento da atividade elétrica do masseter está relacionado com a dificuldade de deglutição.

Botulinum Toxin Is Effective in the Management of Neurogenic Dysphagia. Clinical-Electrophysiological Findings and Tips on Safety in Different Neurological Disorders

Background and Aims: Neurogenic dysphagia linked to failed relaxation of the upper esophageal sphincter (UES) can be treated by injecting botulinum toxin (BTX) into the cricopharyngeal (CP) muscle. We compared the effects of this treatment in different neurological disorders with dysphagia, to evaluate its efficacy over time including the response to a second injection. Materials and Methods: Sixty-seven patients with neurogenic dysphagia associated with incomplete or absent opening of the UES (24 with brainstem or hemispheric stroke, 21 with parkinsonian syndromes, 12 with multiple sclerosis, and 10 with spastic-dystonic syndromes secondary to post-traumatic encephalopathy) were treated with the injection of IncobotulinumtoxinA (dose 15-20 U) into the CP muscle under electromyographic guidance. The patients were assessed at baseline and after the first and second treatment through clinical evaluation and fiberoptic endoscopy of swallowing, while their dysphagia was quantified using the Dysphagia Outcome and Severity Scale (DOSS). An electrokinesiographic/electromyographic study of swallowing was performed at baseline. Results: Most patients responded to the first BTX treatment: 35 patients (52.2%) were classified as high responders (DOSS score increase >2 levels), while other 19 patients (28.4%) were low responders (DOSS score increase of ≤2 levels). The effect of the first treatment usually lasted longer than 4 months (67%), and in some cases up to a year. The treatment efficacy remained high also after the second injection: 31 patients (46.3%) qualified as high responders and other 22 patients (32.8%) showed a low response. Only in the parkinsonian syndromes group we observed a reduction in the percentage of high responders as compared with the first treatment. Side effects were mostly mild and reported in non-responders following the first injection. A severe side effect, consisting of ingestion pneumonia, was observed following the second BTX injection in two patients who had both been non-responders to the first. Non-responders were characterized electromyographically by higher values of the oropharyngeal interval. Conclusion: These findings confirm the effectiveness of IncobotulinumtoxinA injection in the treatment of neurogenic dysphagia due to hyperactivity and relaxation failure of the UES. Caution should be used as regards, the re-injection in non-responders to the first treatment.

The importance of the reproducibility of oropharyngeal swallowing in amyotrophic lateral sclerosis. An electrophysiological study

OBJECTIVE

To investigate electrophysiologically the reproducibility of oropharyngeal swallowing in patients with ALS.

METHODS

We enrolled 26 ALS patients, both with and without clinical signs of dysphagia, and 30 age-matched controls. The reproducibility of the electrophysiological signals related to the oral phase (electromyographic activity of the submental/suprahyoid muscles) and the pharyngeal phase (laryngeal-pharyngeal mechanogram) of swallowing across repeated swallows was assessed. To do this we computed two similarity indexes (SI) by using previously described mathematical algorithms.

RESULTS

The reproducibility of oropharyngeal swallowing was significantly reduced both in patients with and in those without clinical signs of dysphagia, with more marked alterations being detected in the dysphagic group. The SI of both phases of swallowing, oral and pharyngeal, correlated significantly with dysphagia severity and disease severity.

CONCLUSIONS

In ALS different pathophysiological mechanisms can alter the stereotyped motor behaviors underlying normal swallowing, thus reducing the reproducibility of the swallowing act. A decrease in swallowing reproducibility could be a preclinical sign of dysphagia and, beyond a certain threshold, a pathological hallmark of oropharyngeal dysphagia.

SIGNIFICANCE

Electrophysiological assessment is a simple and useful tool for the early detection of swallowing abnormalities, and for the management of overt dysphagia in ALS.

The Relationship Between Submental Surface Electromyography and Hyo-Laryngeal Kinematic Measures of Mendelsohn Maneuver Duration

PURPOSE

The Mendelsohn Maneuver (MM) is a commonly prescribed technique that is taught to individuals with dysphagia to improve swallowing ability. Due to cost and safety concerns associated with videofluoroscopy (VFS) use, submental surface electromyography (ssEMG) is commonly used in place of VFS to train the MM in clinical and research settings. However, it is unknown whether ssEMG accurately reflects the prolonged hyo-laryngeal movements required for execution of the MM. The primary goal of this study was to examine the relationship among ssEMG duration, duration of laryngeal vestibule closure, and duration of maximum hyoid elevation during MM performance.

METHOD

Participants included healthy adults and patients with dysphagia due to stroke. All performed the MM during synchronous ssEMG and VFS recording.

RESULTS

Significant correlations between ssEMG duration and VFS measures of hyo-laryngeal kinematic durations during MM performance ranged from very weak to moderate. None of the correlations in the group of stroke patients reached statistical significance.

CONCLUSION

Clinicians and researchers should consider that the MM involves novel hyo-laryngeal kinematics that may be only moderately represented with ssEMG. Thus, there is a risk that these target therapeutic movements are not consistently being trained.

Electrophysiological Investigations of Shape and Reproducibility of Oropharyngeal Swallowing: Interaction with Bolus Volume and Age

Electrophysiological assessment provides valuable information on physiological and pathophysiological characteristics of human swallowing. Here, new electrophysiological measures for the evaluation of oropharyngeal swallowing were assessed: (1) the activation pattern of the submental/suprahyoid EMG activity (SHEMG); (2) the reproducibility of the oral and pharyngeal phases of swallowing, by calculating the similarity index (SI) of the SHEMG (SI-SHEMG) and of the laryngeal-pharyngeal mechanogram (SI-LPM) during repeated swallows; and (3) kinesiological measures related to the LPM. An electrophysiological-mechanical method for measuring the activation pattern of the SHEMG, the SI-SHEMG, and the SI-LPM, and maximal LPM velocity and acceleration during swallowing was applied in 65 healthy subjects divided into three age groups (18-39, 40-59, 60 years or over). All the measures were assessed during three trials of eight consecutive swallows of different liquid bolus volumes (3, 12, and 20 ml). A high overall reproducibility of oropharyngeal swallowing in healthy humans was recorded. However, while values of SI-SHEMG were similar in all the age groups, the SI-LPM was found to fall significantly in the older age group. Both the SI-SHEMG and the SI-LPM were found to fall with increasing bolus volumes. The activation pattern of the SHEMG and the LPM kinesiological measures were differently modified by bolus volume and age in the older subjects with respect to the others. We describe a new approach to the electrophysiological study of swallowing based on computed semi-automatic analyses. Our findings provide insight into some previously uninvestigated aspects of oropharyngeal swallowing physiology, considered in relation to bolus volume and age. The new electrophysiological measures here described could prove useful in the clinical setting, as it is likely that they could be differently affected in patients with different kinds of dysphagia.