Anodal tDCS of the swallowing motor cortex for treatment of dysphagia in multiple sclerosis: a pilot open-label study

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.

Adaptation and validation of the Greek version of the Speech Pathology-Specific Questionnaire for Persons with Multiple Sclerosis (SMS)

PURPOSE

The aim of the present study was to adapt and validate the Speech Pathology-Specific Questionnaire for Persons with Multiple Sclerosis (SMS) into the Greek language.

METHOD

The study sample consisted of 124 people with multiple sclerosis (PwMS) and 50 healthy controls (HCs). All PwMS underwent cognitive assessment using the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS). Both PwMS and HCs completed the SMS, the Eating Assessment tool (EAT-10), the Voice Handicap Index (VHI), and the Stroke and Aphasia Quality of Life Scale-39 (SAQOL-39).

RESULT

Significant difference was found between PwMS and HCs for the EAT-10, SAQOL-39, the total SMS, and the SMS subscales. Discriminant validity analyses revealed a statistically significant difference between PwMS and HCs for the total and subscales SMS. Convergent validity analyses between the total SMS and the SMS subscales, and scores on the BICAMS, EAT-10, SAQOL-39, and VHI in PwMS were significantly correlated, with exception of the SMS Speech/Voice with the Symbol Digit Modalities Test (SDMT) and the Greek Verbal Learning Test-II (GVLT-II). Scores on the EAT-10, SAQOL-39, and VHI in PwMS were also correlated with the total SMS and the SMS subscales in PwMS, HCs, and the total sample. Construct validity analyses revealed that the total SMS and the SMS subscales were significantly correlated with the Expanded Disability Status Scale (EDSS) and years of education, while no associations were found with regards to age, MS subtype (relapsing-remitting MS [RRMS] vs progressive MS [PMS]), disease duration, or sex. The internal consistency of all items was excellent in PwMS and the total sample (Cronbach's alpha was >0.7 after deletion of one item), with the exception of two items, which still fell within the acceptable range (>0.6) for PwMS and the total sample.

CONCLUSION

The Greek version of the SMS is a reliable and valid patient-reported outcome measure to assess speech-language and swallowing pathology related symptoms in PwMS, and can be used for research and clinical purposes.

Evaluating the Therapeutic Application of Neuromodulation in the Human Swallowing System

In the last two decades, the focus of neurogenic dysphagia management has moved from passive compensatory strategies to evidence-based rehabilitative approaches. Advances in technology have enabled the development of novel treatment approaches such as neuromodulation techniques, which target the promotion of neurological reorganization for functional recovery of swallowing. Given the rapid pace of development in the field, this review aims to summarize the current findings on the effects of neuromodulation techniques on the human swallowing system and evaluate their therapeutic potential for neurogenic dysphagia. Implications for future clinical research and practical considerations for using neuromodulation in clinical practice will also be discussed.

Neurorehabilitation in Multiple Sclerosis-A Review of Present Approaches and Future Considerations

Multiple sclerosis is an increasingly prevalent disease, representing the leading cause of non-traumatic neurological disease in Europe and North America. The most common symptoms include gait deficits, balance and coordination impairments, fatigue, spasticity, dysphagia and an overactive bladder. Neurorehabilitation therapeutic approaches aim to alleviate symptoms and improve the quality of life through promoting positive immunological transformations and neuroplasticity. The purpose of this study is to evaluate the current treatments for the most debilitating symptoms in multiple sclerosis, identify areas for future improvement, and provide a reference guide for practitioners in the field. It analyzes the most cited procedures currently in use for the management of a number of symptoms affecting the majority of patients with multiple sclerosis, from different training routines to cognitive rehabilitation and therapies using physical agents, such as electrostimulation, hydrotherapy, cryotherapy and electromagnetic fields. Furthermore, it investigates the quality of evidence for the aforementioned therapies and the different tests applied in practice to assess their utility. Lastly, the study looks at potential future candidates for the treatment and evaluation of patients with multiple sclerosis and the supposed benefits they could bring in clinical settings.

Advances in the Treatment of Dysphagia in Neurological Disorders: A Review of Current Evidence and Future Considerations

Dysphagia, which refers to difficult and/or disordered swallowing, is a common problem associated with various neurological diseases such as stroke, motor neuron diseases and neurodegenerative diseases. Traditionally, dysphagia treatments are either compensatory, which includes modifications of bolus texture or feeding posture, or rehabilitative, which includes behavioral exercises and sensory stimulation. Despite being widely adopted in clinical practice, recent views have challenged the clinical efficacy of these treatments due to the low level of evidence supported by mainly non-controlled studies. As such, with advancements in technology and scientific research methods, recent times have seen a surge in the development of novel dysphagia treatments and an increasing number of robust randomized controlled clinical trials. In this review, we will review the clinical evidence of several newly introduced treatments for dysphagia in the last two decades, including rehabilitative exercises, biofeedback, pharmacological treatments, neuromodulation treatments and soft robotics. Despite the recent improvements in the quality of evidence for the efficacy of dysphagia treatments, several critical issues, including heterogeneity in treatment regimens, long-term treatment effects, underlying mechanisms of some neuromodulation treatments, and the effects of these techniques in non-stroke dysphagia, remain to be addressed in future clinical trials.

Multiple sclerosis: Inflammation, autoimmunity and plasticity

In recent years, experimental studies have clarified that immune system influences the functioning of the central nervous system (CNS) in both physiologic and pathologic conditions. The neuro-immune crosstalk plays a crucial role in neuronal development and may be critically involved in mediating CNS response to neuronal damage. Multiple sclerosis (MS) represents a good model to investigate how the immune system regulates neuronal activity. Accordingly, a growing body of evidence has demonstrated that increased levels of pro-inflammatory mediators may significantly impact synaptic mechanisms, influencing overall neuronal excitability and synaptic plasticity expression. In this chapter, we provide an overview of preclinical data and clinical studies exploring synaptic functioning noninvasively with transcranial magnetic stimulation (TMS) in patients with MS. Moreover, we examine how inflammation-driven synaptic dysfunction could affect synaptic plasticity expression, negatively influencing the MS course. Contrasting CSF inflammation together with pharmacologic enhancement of synaptic plasticity and application of noninvasive brain stimulation, alone or in combination with rehabilitative treatments, could improve the clinical compensation and prevent the accumulating deterioration in MS.

Efficacy of transcranial direct current stimulation in people with multiple sclerosis: a review

BACKGROUND AND PURPOSE

Multiple sclerosis (MS) is a chronic inflammatory disease causing a wide range of symptoms including motor and cognitive impairment, fatigue and pain. Over the last two decades, non-invasive brain stimulation, especially transcranial direct current stimulation (tDCS), has increasingly been used to modulate brain function in various physiological and pathological conditions. However, its experimental applications for people with MS were noted only as recently as 2010 and have been growing since then. The efficacy for use in people with MS remains questionable with the results of existing studies being largely conflicting. Hence, the aim of this review is to paint a picture of the current state of tDCS in MS research grounded on studies applying tDCS that have been done to date.

METHODS

A keyword search was performed to retrieve articles from the earliest article identified until 14 February 2021 using a combination of the groups (1) 'multiple sclerosis', 'MS' and 'encephalomyelitis' and (2) 'tDCS' and 'transcranial direct current stimulation'.

RESULTS

The analysis of the 30 articles included in this review underlined inconsistent effects of tDCS on the motor symptoms of MS based on small sample sizes. However, tDCS showed promising benefits in ameliorating fatigue, pain and cognitive symptoms.

CONCLUSION

Transcranial direct current stimulation is attractive as a non-drug approach in ameliorating MS symptoms, where other treatment options remain limited. The development of protocols tailored to the individual's own neuroanatomy using high definition tDCS and the introduction of network mapping in the experimental designs might help to overcome the variability between studies.

Diagnosis and treatment of neurogenic dysphagia - S1 guideline of the German Society of Neurology

Introduction

Neurogenic dysphagia defines swallowing disorders caused by diseases of the central and peripheral nervous system, neuromuscular transmission, or muscles. Neurogenic dysphagia is one of the most common and at the same time most dangerous symptoms of many neurological diseases. Its most important sequelae include aspiration pneumonia, malnutrition and dehydration, and affected patients more often require long-term care and are exposed to an increased mortality. Based on a systematic pubmed research of related original papers, review articles, international guidelines and surveys about the diagnostics and treatment of neurogenic dysphagia, a consensus process was initiated, which included dysphagia experts from 27 medical societies.

Recommendations

This guideline consists of 53 recommendations covering in its first part the whole diagnostic spectrum from the dysphagia specific medical history, initial dysphagia screening and clinical assessment, to more refined instrumental procedures, such as flexible endoscopic evaluation of swallowing, the videofluoroscopic swallowing study and high-resolution manometry. In addition, specific clinical scenarios are captured, among others the management of patients with nasogastric and tracheotomy tubes. The second part of this guideline is dedicated to the treatment of neurogenic dysphagia. Apart from dietary interventions and behavioral swallowing treatment, interventions to improve oral hygiene, pharmacological treatment options, different modalities of neurostimulation as well as minimally invasive and surgical therapies are dealt with.

Conclusions

The diagnosis and treatment of neurogenic dysphagia is challenging and requires a joined effort of different medical professions. While the evidence supporting the implementation of dysphagia screening is rather convincing, further trials are needed to improve the quality of evidence for more refined methods of dysphagia diagnostics and, in particular, the different treatment options of neurogenic dysphagia. The present article is an abridged and translated version of the guideline recently published online (https://www.awmf.org/uploads/tx_szleitlinien/030-111l_Neurogene-Dysphagie_2020-05.pdf).

[Dysphagia in Multiple Sclerosis - an underestimated symptom?]

BACKGROUND

It is estimated that 240,000 people suffer from multiple sclerosis in Germany. In addition to sensory, motor, vegetative, and neuropsychological functional deficits, dysphagia is a highly relevant and disabling, although not well studied symptom of MS.

OBJECTIVES

The purpose of this article is to provide an overview of the scientific background, increase awareness of the symptoms of dysphagia, and to introduce diagnostic tools for its management, overall aiming at alleviating symptoms of dysphagia in persons with MS, and improving their quality of life.

METHODS

A structured literature review was conducted of what is currently known on the development, manifestation, diagnosis and treatment options for MS-related dysphagia. Due to the lack of class 1 evidence, in particular for diagnosis and treatment options of dysphagia, also smaller studies or pilot projects were included and discussed in this review.

RESULTS

Data from imaging methods such as Flexible Endoscopic Evaluation of Swallowing and Videofluoroscopic Swallowing Evaluation enabled the diagnosis. There was a high variablity in the reported frequency of dysphagia in published studies, largely related to differences in methodology to evaluate the swallowing (from 38 % up to 81 %). Overall, dysphagia as a symptom of multiple sclerosis was underestimated at the patient and the physician level. According to current data from the German MS register, specific treatments were only carried out in 30% of the affected patients.

Advances in the Use of Neuromodulation for Neurogenic Dysphagia: Mechanisms and Therapeutic Application of Pharyngeal Electrical Stimulation, Transcranial Magnetic Stimulation, and Transcranial Direct Current Stimulation

Purpose The swallowing motor system and, specifically, its cortical substrates appear to have certain unique properties that make it highly susceptible to brain plasticity, both driven and following injury. Furthermore, neurogenic dysphagia is a common complication of brain disease, associated with poor outcomes, and yet treatment options remain limited. Therefore, translating the physiology of neurostimulation into clinical populations becomes imperative. In this review, we describe therapeutic application of neuroplasticity in the human swallowing motor system by initially examining the role of pharyngeal electrical stimulation from a mechanistic perspective and then reporting on clinical studies using this approach. Thereafter, we explore the application of noninvasive brain stimulation, which has previously been used to treat nervous system disorders such as depression, pain modulation, and cognitive impairment. Transcranial brain stimulations, in particular, transcranial magnetic stimulation and transcranial direct current stimulation, have been utilized by a number of investigators for rehabilitation in early-stage clinical trials, including dysphagia after neurological disease. In this review, we assess its usefulness in neurogenic dysphagia. Conclusion Early studies indicate these emerging neurostimulatory techniques hold future therapeutic promise. However, both a greater number of and larger clinical trials are required to provide evidence delineating their efficacy and scope of application.

The effects of spaced transcranial Direct Current Stimulation combined with conventional dysphagia therapy in Parkinson's disease: A case report

Parkinson's disease (PD) is a neurodegenerative disease of the central nervous system that is characterized by a set of motor and non-motor symptoms. Impaired swallowing or dysphagia is one relatively common motor symptom in patients with PD. We investigated whether neuroplasticity induction by spaced transcranial Direct Current Stimulation (tDCS) combined with conventional swallowing therapy leads to long-lasting effects on swallowing ability in patients with PD. We present a case of a 61-year-old male PD patient with dysphagia. Conventional Swallowing Therapy (CDT) combined with tDCS (bilateral anodal, 1 mA, 20 min, 10 online sessions, twice daily with a 20 min interval in between for five days over two weeks) was applied over the pharyngeal motor cortex. Our findings suggest that anodal tDCS combined with CDT is feasible, safe, and well-tolerated, and leads to a clinically relevant improvement of swallowing functions.

Anodal transcranial direct current stimulation and intermittent theta-burst stimulation improve deglutition and swallowing reproducibility in elderly patients with dysphagia

BACKGROUND

Dysphagia in the elderly, known as presbydysphagia, has become a relevant public health problem in several countries. Swallowing disorders may be a consequence of different neurological disorders (secondary presbydysphagia) or the expression of the aging process itself (primary presbydysphagia). We aimed to test the therapeutic potential of two different non-invasive brain stimulation (NIBS) techniques in subjects with primary or secondary presbydysphagia.

METHODS

A blinded randomized controlled trial with crossover design was carried out in 42 patients, randomly assigned to anodal transcranial direct current stimulation (tDCS) or intermittent theta-burst stimulation (TBS) group. Both tDCS and TBS were applied for 5 consecutive days over the right swallowing motor cortex. The swallowing function was assessed before and 1 and 3 months after the stimulation using the Dysphagia Outcome and Severity Scale (DOSS), scored based on clinical assessment and fiberoptic endoscopic evaluation of swallowing. An electrophysiological method was also applied to evaluate changes in the reproducibility of the swallowing behavior.

KEY RESULTS

Both real tDCS and TBS had beneficial effects on the swallowing function in patients with primary and secondary presbydysphagia. Anodal tDCS resulted in an improvement of 0.5 points in DOSS at 1-month follow-up (P = .014), whereas intermittent TBS induced an increase of 0.7 and 0.6 points at 1- and 3-month follow-up evaluations, respectively (P = .0001 and P = .005, respectively). Reproducibility of both the oral and pharyngeal phases of swallowing significantly increased at 1-month follow-up.

CONCLUSIONS AND INFERENCES

Our results suggest that non-invasive cortical stimulation may be useful for dysphagia recovery in elderly patients.

Dysphagia In Multiple Sclerosis Patients: Diagnostic And Evaluation Strategies

Dysphagia after multiple sclerosis (MS) is a common disabling symptom which can lead to serious complications. Regular screening and assessment of dysphagia in patients with MS are important. Using valid and reliable instruments to measure dysphagia in MS patients is a crucial component in clinical practice and of research quality. There are various strategies to diagnose and assess the dysphagia in patients with MS. Screening strategies are for early diagnosis of the dysphagia. Clinical, non-instrumental strategies are used to verify the presence and to determine the severity and cause of dysphagia. Instrumental strategies are complementary to clinical examination to provide objective data on the various aspects of swallowing dysfunctions. This review revealed a few validated tools for dysphagia assessment in MS. The Dysphagia in Multiple Sclerosis Questionnaire (DYMUS) and the Mann Assessment of Swallowing Ability (MASA) are the only validated MS-specific dysphagia tools. Further development of valid and reliable MS-specific screening and assessment tools that can be administered rapidly and scored easily to detect dysphagia and evaluate clinical outcomes in adults with MS is imperative. Until then, validation and metric evaluation of the screening and assessment tools currently available are required.

Beyond rehabilitation in MS: Insights from non-invasive brain stimulation

Although the number of disease-modifying treatments for people with multiple sclerosis (pwMS) has meaningfully increased in the past years, targeting repair or compensation for central nervous system damage associated with the disease process remains an important clinical goal. With this aim, neurorehabilitation is a powerful approach targeting central nervous system plasticity. Another driver of brain plasticity is non-invasive brain stimulation (NIBS), receiving recent attention in neurology, particularly for its potential synergy with neurorehabilitation and as add-on treatment for several neurological conditions, from pain to fatigue to sensorimotor and cognitive deficits. In this review, we will resume the evidence exploring the neurobiological basis of NIBS and its applications to MS-related conditions.

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.

The place of transcranial direct current stimulation in the management of multiple sclerosis-related symptoms

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system, characterized by chronic inflammation, demyelination, synaptopathy and neurodegeneration. Patients may exhibit sensory, motor, cognitive, emotional and behavioral symptoms throughout their disease process. Nowadays, the challenge is to find optimal treatment for MS symptoms, especially that available pharmacological interventions are faced by modest therapeutic outcomes and numerous side effects. Thus, finding alternative strategies might be of help in this context. The aim of this report is to visit the effects of transcranial direct current stimulation - a noninvasive brain stimulation technique - in the context of MS symptoms, namely fatigue, cognitive deficits, psychiatric complaints, neuropathic pain and some sensorimotor manifestations.

Transcranial Direct Current Stimulation (tDCS) in Mice

Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique proposed as an alternative or complementary treatment for several neuropsychiatric diseases. The biological effects of tDCS are not fully understood, which is in part explained due to the difficulty in obtaining human brain tissue. This protocol describes a tDCS mouse model that uses a chronically implanted electrode allowing the study of the long-lasting biological effects of tDCS. In this experimental model, tDCS changes the cortical gene expression and offers a prominent contribution to the understanding of the rationale for its therapeutic use.