Diagnosis and treatment of bulbar symptoms in amyotrophic lateral sclerosis

All-in-one wearable drug efficacy assessment systems for bulbar muscle function using amyotrophic lateral sclerosis animal models

Preclinical studies are crucial for developing amyotrophic lateral sclerosis drugs. Current FDA-approved drugs have been created by monitoring limb muscle function and histological analysis of amyotrophic lateral sclerosis model animals. Drug candidates for this disease have yet to be tested for bulbar-onset type due to the limitations of traditional preclinical tools: excessive animal use and discrete detection of disease progress. Here, our study introduces an all-in-one, wireless, integrated wearable system for facilitating continuous drug efficacy assessment of dysphagia-related muscles in animals during natural eating behaviors. By incorporating a kirigami-based strain-isolation mechanism, this device mounted on the skin of animals mitigates electromyography signal contamination caused by unpredictable animal movements. Our findings indicate this system, measuring the progression of motor neuron denervation, offers high precision in monitoring drug effects on dysphagia-responsible bulbar muscles. This study paves the way for more humane and efficient approaches to developing treatment solutions for degenerative neuromuscular diseases.

Sensory Changes Related to Swallowing in Motor Neurone Disease

Dysphagia is common in motor neurone disease (MND) and associated with negative health and psychosocial outcomes. Although largely considered a motor disease, a growing body of evidence suggests that MND can also affect the sensory system. As intact sensation is vital for safe swallowing, and sensory changes can influence the clinical management of dysphagia in people living with MND, this review evaluated and summarised the current evidence for sensory changes related to swallowing in MND. Of 3,481 articles originally identified, 29 met the inclusion criteria. Of these, 20 studies reported sensory changes, which included laryngeal sensation, taste, gag reflex, cough reflex, tongue sensation, smell, palatal and pharyngeal sensation, silent aspiration, and undefined sensation of the swallowing mechanism. Sensory changes were either described as decreased (n = 16) or heightened (n = 4). In the remaining nine studies, sensory function was reported as unaffected. The presence of changes to sensory function related to swallowing in MND remains inconclusive, although an increasing number of studies report sensory changes in some sensory domains. Future research is needed to evaluate the prevalence of sensory changes in MND and how such changes may influence dysphagia and its management.

Guggulsterone Selectively Modulates STAT-3, mTOR, and PPAR-Gamma Signaling in a Methylmercury-Exposed Experimental Neurotoxicity: Evidence from CSF, Blood Plasma, and Brain Samples

Amyotrophic lateral sclerosis (ALS) is a paralytic disease that damages the brain and spinal cord motor neurons. Several clinical and preclinical studies have found that methylmercury (MeHg+) causes ALS. In ALS, MeHg+-induced neurotoxicity manifests as oligodendrocyte destruction; myelin basic protein (MBP) deficiency leads to axonal death. ALS development has been connected to an increase in signal transducer and activator of transcription-3 (STAT-3), a mammalian target of rapamycin (mTOR), and a decrease in peroxisome proliferator-activated receptor (PPAR)-gamma. Guggulsterone (GST), a plant-derived chemical produced from Commiphorawhighitii resin, has been found to protect against ALS by modulating these signaling pathways. Vitamin D3 (VitD3) deficiency has been related to oligodendrocyte precursor cells (OPC) damage, demyelination, and white matter deterioration, which results in motor neuron death. As a result, the primary goal of this work was to investigate the therapeutic potential of GST by altering STAT-3, mTOR, and PPAR-gamma levels in a MeHg+-exposed experimental model of ALS in adult rats. The GST30 and 60 mg/kg oral treatments significantly improved the behavioral, motor, and cognitive dysfunctions and increased remyelination, as proven by the Luxol Fast Blue stain (LFB), and reduced neuroinflammation as measured by histological examinations. Furthermore, the co-administration of VitD3 exhibits moderate efficacy when administered in combination with GST60. Our results show that GST protects neurons by decreasing STAT-3 and mTOR levels while increasing PPAR-gamma protein levels in ALS rats.

Speech-Swallow Dissociation of Velopharyngeal Incompetence with Pseudobulbar Palsy: Evaluation by High-Resolution Manometry

Patients with pseudobulbar palsy often present with velopharyngeal incompetence. Velopharyngeal incompetence is usually observed during expiratory activities such as speech and/or blowing during laryngoscopy. These patients typically exhibit good velopharyngeal closure during swallowing, which is dissociated from expiratory activities. We named this phenomenon "speech-swallow dissociation" (SSD). SSD on endoscopic findings can help in diagnosing the underlying disease causing dysphagia. This endoscopic finding is qualitative, and the quantitative characteristics of SSD are still unclear. Accordingly, the current study aimed to quantitatively evaluate SSD in patients with pseudobulbar palsy. We evaluated velopharyngeal pressure during swallowing and expiratory activity in 10 healthy subjects and 10 patients with pseudobulbar palsy using high-resolution manometry, and compared the results between the two groups. No significant differences in maximal velopharyngeal contraction pressure (V-Pmax) were observed during dry swallowing between the pseudobulbar palsy group and healthy subjects (190.5 mmHg vs. 173.6 mmHg; P = 0.583). V-Pmax during speech was significantly decreased in the pseudobulbar palsy group (85.4 mmHg vs. 34.5 mmHg; P < 0.001). The degree of dissociation of speech to swallowing in V-Pmax, when compared across groups, exhibited a larger difference in the pseudobulbar palsy group, at 52% versus 80% (P = 0.001). Velopharyngeal pressure during blowing was similar to that during speech. Velopharyngeal closure in patients with pseudobulbar palsy exhibited weaker pressure during speech and blowing compared with swallowing, quantitatively confirming the presence of SSD. Pseudobulbar palsy often presents with SSD, and this finding may be helpful in differentiating the etiology of dysphagia.

A large-scale comparison of two voice synthesis techniques on intelligibility, naturalness, preferences, and attitudes toward voices banked by individuals with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) commonly results in the inability to produce natural speech, making speech-generating devices (SGDs) important. Historically, synthetic voices generated by SGDs were neither unique, nor age- or dialect-appropriate, which depersonalized SGD use. Voices generated by SGDs can now be customized via voice banking and should ideally sound uniquely like the individual's natural speech, be intelligible, and elicit positive reactions from communication partners. This large-scale 2 x 2 mixed between- and within-participants design examined perceptions of 831 adult listeners regarding custom synthetic voices created for two individuals diagnosed with ALS via two synthesis systems in common clinical use (waveform concatenation and statistical parametric synthesis). The study explored relationships among synthesis system, dysarthria severity, synthetic speech intelligibility, naturalness, and preferences, and also provided a preliminary examination of attitudes regarding the custom synthetic voices. Synthetic voices generated via statistical parametric synthesis trained on deep neural networks were more intelligible, natural, and preferred than voices produced via waveform concatenation, and were associated with more positive attitudes. The custom synthetic voice created from moderately dysarthric speech was more intelligible than the voice created from mildly dysarthric speech. Clinical implications and factors that may have contributed to the relative intelligibilities are discussed.

Diagnosis and differential diagnosis of MND/ALS: IFCN handbook chapter

•Accurate and rapid diagnosis of amyotrophic lateral sclerosis (ALS) is important to prevent erroneous interventions. •The recent Gold Coast criteria are easily applicable and have high sensitivity and specificity. •Future developments will help to distinguish ALS as a specific clinical-pathologic entity.

Accurate and rapid diagnosis of amyotrophic lateral sclerosis (ALS) is essential in order to provide accurate information for patient and family, to avoid time-consuming investigations and to permit an appropriate management plan. ALS is variable regarding presentation, disease progression, genetic profile and patient reaction to the diagnosis. It is obviously important to exclude treatable conditions but, in most patients, for experienced neurologists the diagnosis is clear-cut, depending on the presence of progressive upper and lower motor neuron signs. Patients with signs of restricted lower motor neuron (LMN) or upper motor neuron (UMN) dysfunction may present diagnostic difficulty, but electromyography (EMG) is often a determinant diagnostic test since it may exclude other disorders. Transcranial magnetic stimulation may aid detection of UMN dysfunction, and brain and spinal cord MRI, ultrasound and blood neurofilament measurements, have begun to have clinical impact, although none are themselves diagnostic tests. Several sets of diagnostic criteria have been proposed in the past; all rely on clinical LMN and UMN signs in different anatomic territories, EMG changes, exclusion of other disorders, and disease progression, in particular evidence of spreading to other anatomic territories. Fasciculations are a characteristic clinical feature and increased importance is now attached to fasciculation potentials detected by EMG, when associated with classical signs of denervation and reinnervation. The Gold Coast diagnostic criteria rely on the presence of UMN and LMN signs in one (or more) anatomic territory, or LMN signs in two (or more) anatomic territories, recognizing the fundamental clinical requirements of disease progression and exclusion of other diseases. Recent studies confirm a high sensitivity without loss of specificity using these Gold Coast criteria. In considering the diagnosis of ALS a critical question for future understanding is whether ALS should be considered a syndrome or a specific clinico-pathologic entity; this can only be addressed in the light of more complete knowledge.

A critical view of the use of predictive energy equations for the identification of hypermetabolism in motor neuron disease: A pilot study

BACKGROUND AND AIMS

People living with motor neuron disease (MND) frequently struggle to consume an optimal caloric intake. Often compounded by hypermetabolism, this can lead to dysregulated energy homeostasis, prompting the onset of malnutrition and associated weight loss. This is associated with a poorer prognosis and reduced survival. It is therefore important to establish appropriate nutritional goals to ensure adequate energy intake. This is best done by measuring resting energy expenditure (mREE) using indirect calorimetry. However, indirect calorimetry is not widely available in clinical practice, thus dietitians caring for people living with MND frequently use energy equations to predict resting energy expenditure (pREE) and estimate caloric requirements. Energy prediction equations have previously been shown to underestimate resting energy expenditure in over two-thirds of people living with MND. Hypermetabolism has previously been identified using the metabolic index. The metabolic index is a ratio of mREE to pREE, whereby an increase of mREE by ≥110% indicates hypermetabolism. We aim to critically reflect on the use of the Harris-Benedict (1919) and Henry (2005) energy prediction equations to inform a metabolic index to indicate hypermetabolism in people living with MND.

METHODS

mREE was derived using VO₂ and VCO₂ measurements from a GEMNutrition indirect calorimeter. pREE was estimated by Harris-Benedict (HB) (1919), Henry (2005) and kcal/kg/day predictive energy equations. The REE variation, described as the percentage difference between mREE and pREE, determined the accuracy of pREE ([pREE-mREE]/mREE) x 100), with accuracy defined as ≤ ± 10%. A metabolic index threshold of ≥110% was used to classify hypermetabolism. All resting energy expenditure data are presented as kcal/24hr.

RESULTS

Sixteen people living with MND were included in the analysis. The mean mREE was 1642 kcal/24hr ranging between 1110 and 2015 kcal/24hr. When REE variation was analysed for the entire cohort, the HB, Henry and kcal/kg/day equations all overestimated REE, but remained within the accuracy threshold (mean values were 2.81% for HB, 4.51% for Henry and 8.00% for kcal/kg/day). Conversely, inter-individual REE variation within the cohort revealed HB and Henry equations both inaccurately reflected mREE for 68.7% of participants, with kcal/kg/day inaccurately reflecting 41.7% of participants. Whilst the overall cohort was not classified as hypermetabolic (mean values were 101.04% for HB, 98.62% for Henry and 95.64% for kcal/kg/day), the metabolic index ranges within the cohort were 70.75%-141.58% for HB, 72.82%-127.69% for Henry and 66.09%-131.58% for kcal/kg/day, indicating both over- and under-estimation of REE by these equations. We have shown that pREE correlates with body weight (kg), whereby the lighter the individual, the greater the underprediction of REE. When applied to the metabolic index, this underprediction biases towards the classification of hypermetabolism in lighter individuals.

CONCLUSION

Whilst predicting resting energy expenditure using the HB, Henry or kcal/kg/day equations accurately reflects derived mREE at group level, these equations are not suitable for informing resting energy expenditure and classification of hypermetabolism when applied to individuals in clinical practice.

Exploring Advancements in the Treatment of Amyotrophic Lateral Sclerosis: A Comprehensive Review of Current Modalities and Future Prospects

Amyotrophic lateral sclerosis (ALS) is a fatal and incurable disease requiring a multidisciplinary treatment approach and a collaborative therapeutic effort. A combination of both upper and lower motor neuron degeneration ultimately leads to respiratory failure, similar to other dementia-type neurodegenerative diseases. The aim of this paper is to pioneer current ALS research by carrying out a narrative literature review of the current treatment modalities of the disease. Through these efforts, we hope to condense the most pertinent information regarding current treatments and enhance the management of ALS patients as a whole, giving these patients a better quality of life as the search for a cure continues. We used a Pubmed search strategy and specific MeSH terms for the selection of the literature articles using the keywords "ALS," "new treatment," "treatment," and "symptomatic treatment." A combination of pharmaceutical interventions, psychological support, and physical rehabilitation has been most effective in enhancing the quality of life of patients with ALS (PALS). Among potential pharmacological therapies, only a few have been approved by the US Food and Drug Administration(FDA) to be used to treat ALS and its symptoms. Other treatment modalities being considered include gene therapy, cellular therapy, psychological therapy, physical therapy, and speech therapy, alongside robotics, alternative feeding methods, and communication devices.

Acoustic Voice Analysis as a Useful Tool to Discriminate Different ALS Phenotypes

Approximately 80-96% of people with amyotrophic lateral sclerosis (ALS) become unable to speak during the disease progression. Assessing upper and lower motor neuron impairment in bulbar regions of ALS patients remains challenging, particularly in distinguishing spastic and flaccid dysarthria. This study aimed to evaluate acoustic voice parameters as useful biomarkers to discriminate ALS clinical phenotypes. Triangular vowel space area (tVSA), alternating motion rates (AMRs), and sequential motion rates (SMRs) were analyzed in 36 ALS patients and 20 sex/age-matched healthy controls (HCs). tVSA, AMR, and SMR values significantly differed between ALS and HCs, and between ALS with prevalent upper (pUMN) and lower motor neuron (pLMN) impairment. tVSA showed higher accuracy in discriminating pUMN from pLMN patients. AMR and SMR were significantly lower in patients with bulbar onset than those with spinal onset, both with and without bulbar symptoms. Furthermore, these values were also lower in patients with spinal onset associated with bulbar symptoms than in those with spinal onset alone. Additionally, AMR and SMR values correlated with the degree of dysphagia. Acoustic voice analysis may be considered a useful prognostic tool to differentiate spastic and flaccid dysarthria and to assess the degree of bulbar involvement in ALS.

Dextromethorphan/quinidine for the treatment of bulbar impairment in amyotrophic lateral sclerosis

OBJECTIVE

No efficacious treatments exist to improve or prolong bulbar functions of speech and swallowing in persons with amyotrophic lateral sclerosis (pALS). This study evaluated the short-term impact of dextromethorphan/quinidine (DMQ) treatment on speech and swallowing function in pALS.

METHODS

This was a cohort trial conducted between August 2019 to August 2021 in pALS with a confirmed diagnosis of probable-definite ALS (El-Escorial Criteria-revisited) and bulbar impairment (ALS Functional Rating Scale score ≤ 10 and speaking rate ≤ 140 words per minute) who were DMQ naïve. Efficacy of DMQ was assessed via pre-post change in the ALS Functional Rating Scale-Revised bulbar subscale and validated speech and swallowing outcomes. Paired t-tests, Fisher's exact, and χ2 tests were conducted with alpha at 0.05.

RESULTS

Twenty-eight pALS enrolled, and 24 participants completed the 28-day trial of DMQ. A significant increase in ALSFRS-R bulbar subscale score pre- (7.47 ± 1.98) to post- (8.39 ± 1.79) treatment was observed (mean difference: 0.92, 95% CI: 0.46-1.36, p < 0.001). Functional swallowing outcomes improved, with a reduction in unsafe (75% vs. 44%, p = 0.003) and inefficient swallowing (67% vs. 58%, p = 0.002); the relative speech event duration in a standard reading passage increased, indicating a greater duration of uninterrupted speech (mean difference: 0.33 s, 95% CI: 0.02-0.65, p = 0.035). No differences in diadochokinetic rate or speech intelligibility were observed (p > 0.05).

INTERPRETATION

Results of this study provide preliminary evidence that DMQ pharmacologic intervention may have the potential to improve or maintain bulbar function in pALS.

The role of lung volume recruitment therapy in neuromuscular disease: a narrative review

Respiratory muscle weakness results in substantial discomfort, disability, and ultimately death in many neuromuscular diseases. Respiratory system impairment manifests as shallow breathing, poor cough and associated difficulty clearing mucus, respiratory tract infections, hypoventilation, sleep-disordered breathing, and chronic ventilatory failure. Ventilatory support (i.e., non-invasive ventilation) is an established and key treatment for the latter. As survival outcomes improve for people living with many neuromuscular diseases, there is a shift towards more proactive and preventative chronic disease multidisciplinary care models that aim to manage symptoms, improve morbidity, and reduce mortality. Clinical care guidelines typically recommend therapies to improve cough effectiveness and mobilise mucus, with the aim of averting acute respiratory compromise or respiratory tract infections. Moreover, preventing recurrent infective episodes may prevent secondary parenchymal pathology and further lung function decline. Regular use of techniques that augment lung volume has similarly been recommended (volume recruitment). It has been speculated that enhancing lung inflation in people with respiratory muscle weakness when well may improve respiratory system "flexibility", mitigate restrictive chest wall disease, and slow lung volume decline. Unfortunately, clinical care guidelines are based largely on clinical rationale and consensus opinion rather than level A evidence. This narrative review outlines the physiological changes that occur in people with neuromuscular disease and how these changes impact on breathing, cough, and respiratory tract infections. The biological rationale for lung volume recruitment is provided, and the clinical trials that examine the immediate, short-term, and longer-term outcomes of lung volume recruitment in paediatric and adult neuromuscular diseases are presented and the results synthesised.

A meta-analysis of post-exercise outcomes in people with amyotrophic lateral sclerosis

Objective

To systematically evaluate post-exercise outcomes related to function and quality of life in people with ALS.

Methods

PRISMA guidelines were used for identifying and extracting articles. Levels of evidence and quality of articles were judged based on The Oxford Centre for Evidence-based Medicine Levels of Evidence and the QualSyst. Outcomes were analyzed with Comprehensive Meta-Analysis V2 software, random effects models, and Hedge's G. Effects were examined at 0-4 months, up to 6 months, and > 6 months. Pre-specified sensitivity analyses were performed for 1) controlled trials vs. all studies and 2) ALSFRS-R bulbar, respiratory, and motor subscales. Heterogeneity of pooled outcomes was computed with the I² statistic.

Results

16 studies and seven functional outcomes met inclusion for the meta-analysis. Of the outcomes explored, the ALSFRS-R demonstrated a favorable summary effect size and had acceptable heterogeneity and dispersion. While FIM scores demonstrated a favorable summary effect size, heterogeneity limited interpretations. Other outcomes did not demonstrate a favorable summary effect size and/or could not be reported due to few studies reporting outcomes.

Conclusions

This study provides inconclusive guidance regarding exercise regimens to maintain function and quality of life in people with ALS due to study limitations (e.g., small sample size, high attrition rate, heterogeneity in methods and participants, etc.). Future research is warranted to determine optimal treatment regimens and dosage parameters in this patient population.

Current State and Future Directions in the Therapy of ALS

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder affecting upper and lower motor neurons, with death resulting mainly from respiratory failure three to five years after symptom onset. As the exact underlying causative pathological pathway is unclear and potentially diverse, finding a suitable therapy to slow down or possibly stop disease progression remains challenging. Varying by country Riluzole, Edaravone, and Sodium phenylbutyrate/Taurursodiol are the only drugs currently approved in ALS treatment for their moderate effect on disease progression. Even though curative treatment options, able to prevent or stop disease progression, are still unknown, recent breakthroughs, especially in the field of targeting genetic disease forms, raise hope for improved care and therapy for ALS patients. In this review, we aim to summarize the current state of ALS therapy, including medication as well as supportive therapy, and discuss the ongoing developments and prospects in the field. Furthermore, we highlight the rationale behind the intense research on biomarkers and genetic testing as a feasible way to improve the classification of ALS patients towards personalized medicine.

How to increase noninvasive ventilation effectiveness in bulbar amyotrophic lateral sclerosis patients

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease in which the respiratory muscles are also affected, leading to respiratory failure. Bulbar impairment develops in almost all cases during the course of the disease, becoming severe in the late stages of disease. Noninvasive ventilation (NIV) has been shown to increase survival in ALS; however, severe bulbar dysfunction has a negative impact on NIV tolerance and effectiveness. Therefore, certain steps should be taken to improve NIV outcomes in these patients including optimal ventilatory parameters, adequate interface selection, effective respiratory secretion management and control of bulbar symptoms.

Ultrasonographic and manometric study of the tongue as biomarkers of dysphagia in patients with amyotrophic lateral sclerosis

BACKGROUND

The possibility of having methods to assess dysphagia in amyotrophic lateral sclerosis (ALS) patients in a minimally invasive manner could facilitate follow-up and allow performing of therapeutic interventions at earlier stages of the disease. The aim of the study was to analyze the role of tongue strength and thickness in ALS patients and their correlation with dysphagia and bulbar function.

METHODS

A sample of outpatients with ALS was evaluated for demographic and clinical features. Tongue thickness and strength have been measured for each patient, and quantitative and qualitative data of the videofluoroscopy swallow study have been analyzed.

RESULTS

Of the 38 ALS patients studied, 47.4% were women, and 26.3% had bulbar onset. The median time between symptom onset and the study was 24 months (IQR 11.5-48), and 55.3% of the patients were carriers of non-invasive mechanical ventilation. Tongue strength identified patients with impaired oral and pharyngeal transit and those with bolus residue scale (BRS) > 1 or penetration-aspiration scale (PAS) ≥ 3. In contrast, tongue thickness is only associated with impaired oral transit. Finally, anterior tongue strength ≤ 34 kPa and posterior tongue strength ≤ 34.5 kPa detected ALS penetrators/aspirators (PAS ≥ 3) and patients with ALS with post-swallow residue (BRS > 1).

CONCLUSIONS

Our results suggest that measures that assess the functionality (strength) of the tongue are more valuable than morphological measurements (thickness) for the follow-up of patients with ALS. Alterations of the anterior and posterior lingual strength correlate with the presence of bronchoaspiration and post-swallowing residue (BRS > 1).

Iron quantitative analysis of motor combined with bulbar region in M1 cortex may improve diagnosis performance in ALS

OBJECTIVES

To explore whether the combined analysis of motor and bulbar region of M1 on susceptibility-weighted imaging (SWI) can be a valid biomarker for amyotrophic lateral sclerosis (ALS).

METHODS

Thirty-two non-demented ALS patients and 35 age- and gender-matched healthy controls (HC) were retrospectively recruited. SWI and 3D-T1-MPRAGE images were obtained from all individuals using a 3.0-T MRI scan. The bilateral posterior band of M1 was manually delineated by three neuroradiologists on phase images and subdivided into the motor and bulbar regions. We compared the phase values in two groups and performed a stratification analysis (ALSFRS-R score, duration, disease progression rate, and onset). Receiver operating characteristic (ROC) curves were also constructed.

RESULTS

ALS group showed significantly increased phase values in M1 and the two subregions than the HC group, on the all and elderly level (p < 0.001, respectively). On all-age level comparison, negative correlations were found between phase values of M1 and clinical score and duration (p < 0.05, respectively). Similar associations were found in the motor region (p < 0.05, respectively). On both the total (p < 0.01) and elderly (p < 0.05) levels, there were positive relationships between disease progression rate and M1 phase values. In comparing ROC curves, the entire M1 showed the best diagnostic performance.

CONCLUSIONS

Combining motor and bulbar analyses as an integral M1 region on SWI can improve ALS diagnosis performance, especially in the elderly. The phase value could be a valuable biomarker for ALS evaluation.

KEY POINTS

• Integrated analysis of the motor and bulbar as an entire M1 region on SWI can improve the diagnosis performance in ALS. • Quantitative analysis of iron deposition by SWI measurement helps the clinical evaluation, especially for the elderly patients. • Phase value, when combined with the disease progression rate, could be a valuable biomarker for ALS.

A clinical bulbar assessment scale (CBAS) for amyotrophic lateral sclerosis

INTRODUCTION/AIMS

Comprehensive and valid bulbar assessment scales for use within amyotrophic lateral sclerosis (ALS) clinics are critically needed. The aims of this study are to develop the Clinical Bulbar Assessment Scale (CBAS) and complete preliminary validation.

METHODS

The authors selected CBAS items from among the literature and expert opinion, and content validity ratio (CVR) was calculated. Following consent, the CBAS was administered to a pilot sample of English-speaking adults with El Escorial defined ALS (N = 54) from a multidisciplinary clinic, characterizing speech, swallowing, and extrabulbar features. Criterion validity was assessed by correlating CBAS scores with commonly used ALS scales, and internal consistency reliability was obtained.

RESULTS

Expert raters reported strong agreement for the CBAS items (CVR = 1.00; 100% agreement). CBAS scores yielded a moderate, significant, negative correlation with ALS Functional Rating Scale-Revised (ALSFRS-R) total scores (r = -0.652, p < .001), and a strong, significant, negative correlation with ALSFRS-R bulbar subscale scores (r = -0.795, p < .001). There was a strong, significant, positive correlation with Center for Neurologic Studies Bulbar Function Scale (CNS-BFS) scores (r = 0.819, p < .001). CBAS scores were significantly higher for bulbar onset (mean = 38.9% of total possible points, SD = 22.6) than spinal onset (mean = 18.7%, SD = 15.8; p = .004). Internal consistency reliability (Cronbach's alpha) values were: (a) total CBAS, α = 0.889; (b) Speech subscale, α = 0.903; and (c) Swallowing subscale, α = 0.801.

DISCUSSION

The CBAS represents a novel means of standardized bulbar data collection using measures of speech, swallowing, respiratory, and cognitive-linguistic skills. Preliminary evidence suggests the CBAS is a valid, reliable scale for clinical assessment of bulbar dysfunction.

Discriminant Ability of the Eating Assessment Tool-10 to Detect Swallowing Safety and Efficiency Impairments

OBJECTIVES/HYPOTHESIS

Quick, sensitive dysphagia screening tools are necessary to identify high-risk patients for further evaluation in busy multidisciplinary amyotrophic lateral sclerosis (ALS) clinics. We examined the relationship between self-perceived dysphagia using the validated Eating Assessment Tool-10 (EAT-10) and videofluoroscopic analysis of swallowing safety and efficiency.

STUDY DESIGN

Prospective, observational, longitudinal study.

METHODS

Individuals with ALS completed the EAT-10 and a videofluoroscopic swallowing study. Duplicate, independent, blinded analyses of the validated Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) scale were performed to index swallowing safety and efficiency (mild dysphagia: DIGEST ≥ 1, moderate dysphagia: DIGEST ≥ 2). A between-groups analysis of variance with Games-Howell test for post-hoc pairwise comparisons was performed to examine EAT-10 scores across dysphagia severity levels. Receiver operator characteristic curve analysis, area under the curve (AUC), sensitivity, specificity, positive-negative predictive values (PPV, NPV), and odds ratios (OR) were derived.

RESULTS

Four hundred and thirty five paired EAT-10 and DIGEST scores were analyzed. Mean EAT-10 score was 8.48 (95% confidence interval [CI]: 7.63-9.33). Individuals with dysphagia demonstrated higher EAT-10 scores (mild: 4.1 vs. 11.3, moderate: 6.0 vs. 17.5, P < .001). Mean EAT-10 scores increased across DIGEST levels (D0: 4.1, D1: 7.9, D2: 15.1, D3: 20.4, D4: 39.0). For mild dysphagia, an EAT-10 cut score of 3 was optimal: AUC 0.74 (95% CI: 0.69-0.78; sensitivity: 77%; specificity: 53%; PPV: 71%; NPV: 60%; OR: 3.5). An EAT-10 cut score of 7 optimized detection of moderate dysphagia: AUC 0.83 (95% CI: 0.78-0.87; sensitivity: 81%; specificity: 66%; PPV: 39%; NPV: 93%; OR: 8.1).

CONCLUSION

The EAT-10 is an easy-to-administer dysphagia screening tool with good discriminant ability for use in ALS clinics.

LEVEL OF EVIDENCE

2 Laryngoscope, 132:2319-2326, 2022.

Characteristics of Dysphagia Based on the Type of ALS in Korean Patients Evaluated Using Videofluoroscopic Study: A Retrospective Analysis

Dysphagia is one of the main serious issues for amyotrophic lateral sclerosis (ALS) patients because of causing malnutrition and aspiration pneumonia. Early detection and management of dysphagia are essential for the long-term survival. In this study, videofluoroscopic swallowing study (VFSS) results of bulbar and spinal onset ALS patients were compared. VFSS results and revised ALS Functional Rating Scale (ALSFRS-R) score were also analyzed to assess the correlation between dysphagia and functional status of patients. ALS patients with swallowing difficulties who underwent VFSS were recruited retrospectively. Two oral, seven pharyngeal, and two esophageal components of VFSS were evaluated. An ALSRFRS-R bulbar subtype score < 9 was used to divide the groups with severe bulbar symptoms. Total 109 Korean ALS patients (39 bulbar vs 70 spinal) were included. Bulbar ALS patients exhibited a significantly longer oral transit time (OTT) then spinal ALS patients, especially in severe bulbar patients with low ALSRFRS-R bulbar subscale. In bulbar ALS patients, penetration (thick liquid), aspiration, OTT, and Penetration-Aspiration Scale (PAS) were significantly correlated with ALSFRS-R bulbar subscale score. However, in spinal ALS patients, only OTT (thin liquid) and aspiration (thick liquid) were significantly correlated with ALSFRS-R bulbar subscale score. Bulbar ALS patients demonstrated significantly longer OTT than spinal ALS patients, and ALSFRS-R bulbar subscale score also correlated well with bulbar ALS patients. Therefore, high vigilance and aggressive treatment for dysphagia especially in bulbar ALS patients rather than spinal ALS patients are mandatory.

Comparison of Slow and Forced Vital Capacity on Ability to Evaluate Respiratory Function in Bulbar-Involved Amyotrophic Lateral Sclerosis

Background and Objective

The percent-predicted forced vital capacity (FVC%) in the pulmonary function test (PFT) is generally used to evaluate the respiratory function in amyotrophic lateral sclerosis (ALS). The slow vital capacity (SVC) is another method to evaluate the respiratory function. Some neurologists found that the FVC% was not reflective of respiratory symptoms and the percent-predicted SVC (SVC%) was found to be higher in some patients with bulbar-onset ALS. We aimed to compare the percent predicted SVC (SVC%) with FVC% in evaluating the respiratory function and investigate the associations between the associations between clinical characteristics and the difference between the SVC% and the FVC% (SVC%-FVC%) in bulbar-involved ALS patients.

Method

This prospective study included patients with bulbar-involved ALS who visited the Peking University Third Hospital between October 2020 and November 2021. They underwent comprehensive clinical assessments, including bulbar symptom assessments, revised ALS functional rating scale (ALSFRS-R), Rasch-Built Overall Amyotrophic Lateral Sclerosis Disability Scale (Roads), and PFTs. The group differences were analyzed using parametric and non-parametric tests.

Results

A total of 59 participants were initially enrolled, and 51 of them were included in the final analysis. In patients with bulbar-involved ALS, the SVC% (73.82 ± 21.95%) was significantly higher (p = 0.013) than the FVC% (71.42 ± 23.15%). After controlling for other relevant variables, a partial correlation analysis showed a significant correlation (r = −0.352, p = 0.041) between ALSFRS-R1 score and SVC%-FVC%.

Conclusion

Our prospective study found that the SVC% was significantly higher and more reflective of actual respiratory function than the FVC% in patients with bulbar-involved ALS. Furthermore, the severity of dysarthria was found to be positively correlated with SVC%-FVC%, providing a clinical marker for predicting SVC%-FVC%.

An Automated Tongue Tracker for Quantifying Bulbar Function in ALS

Introduction

Bulbar symptoms, including difficulty swallowing and speaking, are common in amyotrophic lateral sclerosis (ALS) and other neurological disorders, such as stroke. The presence of bulbar symptoms provides important information regarding clinical outcomes, such as survival time after diagnosis. Nevertheless, there are currently no easily accessible, quantitative methods to measure bulbar function in patients.

Methods

We developed an open-source tool called Tongue Tracker (TT) to quantify bulbar function by training a neural network to track kinematic tongue features of short video clips of lateral tongue movements. We tested 16 healthy controls and ten patients with ALS, of whom two patients were clinically diagnosed with bulbar-onset type and eight patients were clinically diagnosed with limb-onset type. Of the limb-onset patients, five patients also showed symptoms of bulbar impairment.

Results

We validated TT by comparing the results with manual delineation of tongue movements in the clips. We demonstrate an early-stage bulbar-onset patient who showed fewer and slower tongue sweeps compared to healthy controls and limb-onset patients and we show that five bulbar-impaired limb-onset patients have a different tongue kinematic profile compared to healthy controls.

Discussion

TT may serve to detect quantitative markers of bulbar dysfunction in ALS and other motor disorders, such as stroke, by identifying signatures of spasticity or muscle weakness that affects tongue movement speed and/or tongue movement topography.

Use of Pharyngeal High-Resolution Manometry to Evaluate Dysphagia in Adults with Motor Neurone Disease: A Scoping Review

There has been a recent shift towards proactive dysphagia intervention in motor neurone disease (MND) to maintain physiological reserve. Pharyngeal high-resolution manometry (PHRM) can quantify swallowing pathophysiology to inform and evaluate proactive dysphagia intervention. This study aims to explore the current use of PHRM as a dysphagia evaluation in adults with MND. A scoping review based on the Joanna Briggs Framework was completed. Four electronic databases (PubMed, EMBASE, CINAHL and Web of Science core) were searched (inception to March 2021) by two independent researchers. Data were analysed according to (i) PHRM protocol and analysis methods and the feasibility of same, (ii) swallow biomechanics data and (iii) dysphagia intervention effects as measured by PHRM. Six studies with 78 people with MND (PwMND) were included. There was considerable variation in PHRM protocol and analysis methods. Five studies reported a 100% completion rate and three studies reported no adverse events. Swallow biomechanics data were reported across all studies. The effects of sensory stimulation, increased bolus consistency, effortful swallow and cricopharyngeal myotomy were evaluated using PHRM with 20 PwMND across four studies with varying effects. Literature on the use of PHRM in PwMND is limited. Variability in PHRM methods restricts comparison of metrics. PHRM appears to be a feasible tool for PwMND. PHRM can provide novel swallow physiology data in PwMND and quantify discrete effects of compensatory and surgical dysphagia interventions not detectable by videofluoroscopy or FEES. Further research on the effects of proactive dysphagia intervention as measured by PHRM is required.

[Dysphagia - from Pathophysiology to Treatment]

More than 5 million persons in Germany suffer from swallowing disorders (dysphagia), predominantly oropharyngeal dysphagia. Due to the demographic changes in our population, the prevalence rates are expected to increase. Multiple conditions may be the cause of dysphagia and dysphagia may lead to various symptoms. Esophageal dysphagia is predominantly accompanied by regurgitation, vomiting, pain and foreign body sensation in the esophageal region. Oropharyngeal dysphagia is characterized by cough, hawking and airway disease. In some patients with oropharyngeal dysphagia, symptoms may be completely absent or are not attributed to dysphagia. Both forms of dysphagia are regularly accompanied by difficulties with nutritional intake and consecutive malnutrition. Therefore, the diagnostic and therapy of dysphagia should always be accompanied by nutritional support.

Laryngospasm in amyotrophic lateral sclerosis

INTRODUCTION

Laryngospasm is an involuntary, sustained closure of sphincter musculature that leads to an unpleasant subjective experience of dyspnea and choking. It is an underreported symptom in amyotrophic lateral sclerosis (ALS). In this study we aimed to better characterize the prevalence and clinical characteristics of laryngospasm in ALS patients.

METHODS

The medical records of 571 patients with ALS followed between 2008 and 2018 were searched for evidence of laryngospasm. A total of 23 patients with laryngospasm were identified and the data related to patient and laryngospasm characteristics were extracted.

RESULTS

Laryngospasm was reported in 4% of ALS patients. Females comprised 57% of patients and their mean age was 63.4 years. Laryngospasm frequently manifested in patients with moderate bulbar dysfunction and seemed independent of respiratory function. Among laryngospasm patients, 26% were cigarette smokers and 13% had a history of gastroesophageal reflux. The most common reported trigger was excessive saliva irritating the vocal cords (35%) followed by eating a meal (17%). There was significant variation in laryngospasm frequency (up to 5 per hour) and duration (seconds to minutes). Most patients could not identify an effective coping mechanism, although 13% reported that drinking water was effective.

DISCUSSION

Despite its low prevalence in ALS, laryngospasm should be included in the symptom inquiry. The present findings may improve patient care through increased recognition of the clinical features of laryngospasm in ALS patients, identifying a link between laryngospasm and moderate bulbar dysfunction, and highlighting trigger avoidance as a management strategy. Additional research is required to understand the pathophysiology and optimal treatment.

Tongue measurements and pharyngeal residue in amyotrophic lateral sclerosis

Aim: We aimed to analyze the relationship between tongue measurements and vallecular residue in patients with amyotrophic lateral sclerosis (ALS). Materials & methods: Twenty-one patients with ALS were assessed for posterior maximum tongue isometric pressure (PMTIP) and posterior tongue isometric endurance (PTIE) by the Iowa Oral Performance Instrument; vallecular residue after 10 ml of moderately thickened consistency by Fiberoptic Endoscopic Evaluation of Swallowing; and tongue thickness (TT) by ultrasonography. Results: PMTIP, PTIE and TT were decreased compared with the reference values for healthy individuals and were not different between patients with and without vallecular residue. Conclusion: In ALS, PMTIP, PTIE and TT are not good predictors of vallecular residue in the tested volume and food consistency.

Case Report: Laryngospasm as Initial Manifestation of Amyotrophic Lateral Sclerosis in a Long-Survival Patient With Heterozygous p.D90A - SOD1 Mutation

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease affecting motor neurons. Although its etiology is still unknown, many genes have been found to be implicated in ALS pathogenesis. The Cu/Zn superoxide dismutase (SOD1) gene was the first to be identified. Currently, more than 230 mutations in the SOD1 gene have been reported. p.D90A (p. Asp90Ala) is the most common SOD1 mutation worldwide. It shows both autosomal and recessive inheritance in different populations. To date, five Italian patients with the heterozygous p.D90A mutation have been reported. None of them complained of laryngological symptoms as the initial manifestation of ALS, although they had atypical clinical features. We describe a long-survival patient carrying heterozygous p.D90A mutation who presented with severe laryngospasm due to bilateral vocal cord paralysis. We suggest that genetic analysis may help to diagnose ALS with insidious onset like hoarseness, laryngospasm, and other type of voice disturbances.

Metabolic Abnormalities, Dietary Risk Factors and Nutritional Management in Amyotrophic Lateral Sclerosis

Amyotrophic Lateral Sclerosis (ALS) is a devastating progressive neurodegenerative disease that affects motor neurons, leading to a relentless paralysis of skeletal muscles and eventual respiratory failure. Although a small percentage of patients may have a longer survival time (up to 10 years), in most cases, the median survival time is from 20 to 48 months. The pathogenesis and risk factors for ALS are still unclear: among the various aspects taken into consideration, metabolic abnormalities and nutritional factors have been the focus of recent interests. Although there are no consistent findings regarding prior type-2 diabetes, hypercholesterolemia and ALS incidence, abnormalities in lipid and glucose metabolism may be linked to disease progression, leading to a relatively longer survival (probably as a result of counteract malnutrition and cachexia in the advanced stages of the disease). Among potential dietary risk factors, a higher risk of ALS has been associated with an increased intake of glutamate, while the consumption of antioxidant and anti-inflammatory compounds, such as vitamin E, n-3 polyunsaturated fatty acids, and carotenoids, has been related to lower incidence. Poor nutritional status and weight loss in ALS resulting from poor oral intake, progressive muscle atrophy, and the potential hypermetabolic state have been associated with rapid disease progression. It seems important to routinely perform a nutritional assessment of ALS patients at the earliest referral: weight maintenance (if adequate) or gain (if underweight) is suggested from the scientific literature; evidence of improved diet quality (in terms of nutrients and limits for pro-inflammatory dietary factors) and glucose and lipid control is yet to be confirmed, but it is advised. Further research is warranted to better understand the role of nutrition and the underlying metabolic abnormalities in ALS, and their contribution to the pathogenic mechanisms leading to ALS initiation and progression.

The Effects of Symptom Onset Location on Automatic Amyotrophic Lateral Sclerosis Detection Using the Correlation Structure of Articulatory Movements

Purpose Kinematic measurements of speech have demonstrated some success in automatic detection of early symptoms of amyotrophic lateral sclerosis (ALS). In this study, we examined how the region of symptom onset (bulbar vs. spinal) affects the ability of data-driven models to detect ALS. Method We used a correlation structure of articulatory movements combined with a machine learning model (i.e., artificial neural network) to detect differences between people with ALS and healthy controls. The performance of this system was evaluated separately for participants with bulbar onset and spinal onset to examine how region of onset affects classification performance. We then performed a regression analysis to examine how different severity measures and region of onset affects model performance. Results The proposed model was significantly more accurate in classifying the bulbar-onset participants, achieving an area under the curve of 0.809 relative to the 0.674 achieved for spinal-onset participants. The regression analysis, however, found that differences in classifier performance across participants were better explained by their speech performance (intelligible speaking rate), and no significant differences were observed based on region of onset when intelligible speaking rate was accounted for. Conclusions Although we found a significant difference in the model's ability to detect ALS depending on the region of onset, this disparity can be primarily explained by observable differences in speech motor symptoms. Thus, when the severity of speech symptoms (e.g., intelligible speaking rate) was accounted for, symptom onset location did not affect the proposed computational model's ability to detect ALS.

Swallowing Safety and Efficiency Impairment Profiles in Individuals with Amyotrophic Lateral Sclerosis

Dysphagia is common in individuals with amyotrophic lateral sclerosis (ALS) and associated with reductions in quality of life and health-related outcomes. Despite the high prevalence of dysphagia in ALS, functional impairment profiles of swallowing safety and efficiency have not been comprehensively examined. We therefore aimed to determine the relative prevalence of unsafe and inefficient swallowing in a large cohort of individuals with ALS. We further sought to examine the impact of global and bulbar disease progression (Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised "ALSFRS-R" total and bulbar scores, respectively), disease duration, and onset type on swallowing impairment profiles. One hundred individuals with ALS completed a standardized videofluoroscopic swallowing examination Two independent and blinded raters performed validated ratings of safety (Penetration-Aspiration Scale, PAS) and efficiency (Analysis of Swallowing Physiology: Events, Kinematics, and Timing, ASPEKT % residue). Binary classifications of safety (unsafe: PAS ≥ 3), efficiency (inefficient: total residue ≥ 3% of C2-4²) and global swallowing status were derived. The ALSFRS-R was completed to derive ALSFRS-R total and bulbar subscale scores. Demographic data (disease duration and onset type) for each participant was also recorded.  Descriptives, 2 × 2 contingency tables with Fishers exact test, and independent samples t-tests were performed (α = 0.05). Prevalence of unsafe and inefficient swallowing was 48% and 73%, respectively. Global swallowing profiles were, in rank order: unsafe and inefficient (39%), inefficient but safe (34%), safe and efficient (18%), and unsafe but efficient (9%). There were no differences in global disease progression or disease duration across swallowing impairment profiles. ALSFRS-R bulbar subscale scores were significantly lower in unsafe versus safe swallowers, p < 0.05. Spinal onset patients had a greater proportion of safe swallowers as compared to bulbar onset patients (p = 0.000, Fisher's exact test). Both spinal and bulbar onset patients demonstrated a higher prevalence of inefficient swallowers as compared to efficient swallowers (p = 0.04, Fisher's exact test). Dysphagia was prevalent in this group of individuals with ALS. Approximately half demonstrated safety impairments and two-thirds had impairments in swallowing efficiency. Inefficient swallowing was approximately four times more likely to be the initial functional impairment in patients with one pathophysiologic functional impairment. A longitudinal study is needed to examine the temporal evolution of dysphagia in ALS.

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).

Ghrelin as a treatment for amyotrophic lateral sclerosis

Ghrelin is a gut hormone best known for its role in regulating appetite and stimulating the secretion of the anabolic hormone growth hormone (GH). However, there is considerable evidence to show wider-ranging biological actions of ghrelin that favour improvements in cellular and systemic metabolism, as well as neuroprotection. Activation of these ghrelin-mediated pathways may alleviate pathogenic processes that are assumed to contribute to accelerated progression of disease in patients with neurodegenerative disease. Here, we provide a brief overview on the history of discoveries that led to the identification of ghrelin. Focussing on the neurodegenerative disease amyotrophic lateral sclerosis (ALS), we also present an overview of emerging evidence that suggests that ghrelin and ghrelin mimetics may serve as potential therapies for the treatment of ALS. Given that ALS is a highly heterogeneous disease, where multiple disease mechanisms contribute to variability in disease onset and rate of disease progression, we speculate that the wide-ranging biological actions of ghrelin might offer therapeutic benefit through modulating multiple disease-relevant processes observed in ALS. Expanding on the well-known actions of ghrelin in regulating food intake and GH secretion, we consider the potential of ghrelin-mediated pathways in improving body weight regulation, metabolism and the anabolic and neuroprotective actions of GH and insulin-like growth factor-1 (IGF-1). This is of clinical significance because loss of body weight, impairments in systemic and cellular metabolism, and reductions in IGF-1 are associated with faster disease progression and worse disease outcome in patients with ALS.

CNS glucose metabolism in Amyotrophic Lateral Sclerosis: a therapeutic target?

Amyotrophic lateral sclerosis (ALS) is a fatal progressive neurodegenerative disorder primarily characterized by selective degeneration of both the upper motor neurons in the brain and lower motor neurons in the brain stem and the spinal cord. The exact mechanism for the selective death of neurons is unknown. A growing body of evidence demonstrates abnormalities in energy metabolism at the cellular and whole-body level in animal models and in people living with ALS. Many patients with ALS exhibit metabolic changes such as hypermetabolism and body weight loss. Despite these whole-body metabolic changes being observed in patients with ALS, the origin of metabolic dysregulation remains to be fully elucidated. A number of pre-clinical studies indicate that underlying bioenergetic impairments at the cellular level may contribute to metabolic dysfunctions in ALS. In particular, defects in CNS glucose transport and metabolism appear to lead to reduced mitochondrial energy generation and increased oxidative stress, which seem to contribute to disease progression in ALS. Here, we review the current knowledge and understanding regarding dysfunctions in CNS glucose metabolism in ALS focusing on metabolic impairments in glucose transport, glycolysis, pentose phosphate pathway, TCA cycle and oxidative phosphorylation. We also summarize disturbances found in glycogen metabolism and neuroglial metabolic interactions. Finally, we discuss options for future investigations into how metabolic impairments can be modified to slow disease progression in ALS. These investigations are imperative for understanding the underlying causes of metabolic dysfunction and subsequent neurodegeneration, and to also reveal new therapeutic strategies in ALS.

Hypothalamus and weight loss in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating progressive neurodegenerative disorder. While initially pathophysiology was thought to be restricted to motor deficits, it is increasingly recognized that patients develop prominent changes in weight and eating behavior that result from and mediate the underlying neurodegenerative process. These changes include alterations in metabolism, lipid levels, and insulin resistance. Emerging research suggests that these alterations may be mediated through changes in the hypothalamic function, with atrophy of the hypothalamus shown in both ALS patients and also presymptomatic genetic at-risk patients. This chapter reviews the evidence for hypothalamic involvement in ALS, including melanocortin pathways and potential treatment targets.

Tongue and hypoglossal morphology after intralingual cholera toxin B-saporin injection

INTRODUCTION

We recently developed an inducible model of dysphagia using intralingual injection of cholera toxin B conjugated to saporin (CTB-SAP) to cause death of hypoglossal neurons. In this study we aimed to evaluate tongue morphology and ultrastructural changes in hypoglossal neurons and nerve fibers in this model.

METHODS

Tissues were collected from 20 rats (10 control and 10 CTB-SAP animals) on day 9 post-injection. Tongues were weighed, measured, and analyzed for microscopic changes using laminin immunohistochemistry. Hypoglossal neurons and axons were examined using transmission electron microscopy.

RESULTS

The cross-sectional area of myofibers in the posterior genioglossus was decreased in CTB-SAP-injected rats. Degenerative changes were observed in both the cell bodies and distal axons of hypoglossal neurons.

DISCUSSION

Preliminary results indicate this model may have translational application to a variety of neurodegenerative diseases resulting in tongue dysfunction and associated dysphagia.

Evaluation and Management of Dysphagia in Amyotrophic Lateral Sclerosis: A Survey of Speech-Language Pathologists' Clinical Practice

Objectives:

The aim of this study was to determine the evaluation and management of dysphagia in amyotrophic lateral sclerosis (ALS) patients by speech-language pathologists (SLPs).

Methods:

A 15-question web-based survey sent to SLPs in general clinical practice.

Results:

Forty-nine SLPs responded. Although only 8 (17.0%) of the SLPs worked in ALS clinics, 46 (93.9%) had worked with ALS patients. A variety of dysphagia evaluation protocols were used by 43 (97.7%) SLPs. Most SLPs, 40 (88.9%), recommended instrumental assessments, but timing and indication varied greatly: 19 (42.2%) SLPs recommended this at baseline even without bulbar symptoms, whereas others recommended this based on symptoms and/or clinical assessments.

Conclusions:

There is currently no uniform approach as to the indication, timing, and specific methods to use in the evaluation of dysphagia in ALS patients among SLPs. There is need for further research to assist in the development of definitive guideline recommendations for this population.

Measuring vital capacity in amyotrophic lateral sclerosis: Effects of interfaces and reproducibility

BACKGROUND

Deterioration of vital capacity (VC) in amyotrophic lateral sclerosis (ALS) signifies disease progression and indicates need for non-invasive ventilation. Weak facial muscles consequent to ALS, with resulting poor mouth seal, may interfere with the accuracy of VC measurements.

OBJECTIVES

To determine whether different interfaces affect VC measurements in ALS patients and whether the interface yielding the largest VC produces an even higher VC when re-measured after one week (learning effect). To explore the relationship between optimal interface VC and sniff nasal pressure (SNIP), a measurement of global inspiratory muscle strength.

METHODS

Thirty-five patients (17 bulbar and 18 spinal ALS) were studied. Three interfaces (rigid-cylindrical, flanged, oronasal mask) were tested. One week after the first visit, VC was recorded using the optimal interface. SNIP recordings were also obtained.

RESULTS

In the bulbar ALS group, median (interquartile range) VC with the flanged mouthpiece was 8.4% (3.9-15.5) larger than with the cylindrical mouthpiece (p < 0.001). VC values with oronasal mask were intermediate to VC with the other two interfaces. In spinal ALS, flanged mouthpiece VC was 4.6% (2.3-7.5) larger than with oronasal mask (p < 0.0006). The latter was 4.5% (0.6-5.2) smaller than with the cylindrical mouthpiece (p = 0.002). In both groups, VC during the second visit was greater than during the first visit (p < 0.025). SNIPs were logarithmically related to VC values recorded with the flanged mouthpiece.

CONCLUSION

A flanged mouthpiece yields the largest values of VC in patients with bulbar and spinal ALS.

Esophageal Peristalsis Disorders in ALS Patients with Dysphagia

To detect the variations of esophageal peristalsis in amyotrophic lateral sclerosis (ALS) patients with predominantly bulbar or predominantly pseudobulbar clinical presentation by using esophageal manometry (EM). Fifteen ALS patients with pseudobulbar clinical presentation (PBP) and 13 patients with bulbar presentation (BP), fulfilling WFN Criteria, were studied. EM was performed in all subjects using a flexible catheter with solid-state transducers. Swallowing was initiated with 5 to 10 mL of water (wet swallows) and saliva (dry swallows) and repeated at 30 s intervals. The manometric parameters were measured automatically and visualized by the computer system. The tracings were analyzed using Synectics software. In PBP patients, an increase of resting pressure value in the upper esophageal sphincter (UES) >45 mmHg, a wave-like course of resting pressure, and toothed peristaltic waves were observed. In BP patients, a low amplitude of peristaltic waves <30 mmHg (mean: 17 ± 5) was recorded, without signs of esophageal motility disturbance at onset or during progression. EM procedure allows objectively distinguishing dysphagia in ALS patients due to bulbar syndrome from the dysphagia due to pseudobulbar syndrome. It is important to identify PBP patients because of their high risk of aspiration.

Defining novel functions for cerebrospinal fluid in ALS pathophysiology

Despite the considerable progress made towards understanding ALS pathophysiology, several key features of ALS remain unexplained, from its aetiology to its epidemiological aspects. The glymphatic system, which has recently been recognised as a major clearance pathway for the brain, has received considerable attention in several neurological conditions, particularly Alzheimer's disease. Its significance in ALS has, however, been little addressed. This perspective article therefore aims to assess the possibility of CSF contribution in ALS by considering various lines of evidence, including the abnormal composition of ALS-CSF, its toxicity and the evidence for impaired CSF dynamics in ALS patients. We also describe a potential role for CSF circulation in determining disease spread as well as the importance of CSF dynamics in ALS neurotherapeutics. We propose that a CSF model could potentially offer additional avenues to explore currently unexplained features of ALS, ultimately leading to new treatment options for people with ALS.

Riluzole Oral Suspension for the Treatment of Amyotrophic Lateral Sclerosis: Texture and Compatibility with Food Thickeners Evaluation

Riluzole 5 mg/mL oral suspension is the only licensed liquid medicine to treat Amyotrophic Lateral Sclerosis (ALS) orally. As more than 80% of ALS patients develop dysphagia, an oral liquid formulation provides an important therapeutic option. The Riluzole 5 mg/mL oral suspension is administered by means of the graduated oral dosing syringe included in the medicine package. Its concentration (5 mg/mL) is consistent with a small and easy to measure volume (10 mL) to deliver the prescribed 50-mg dose twice daily. This work had a dual objective. The first was to evaluate the texture of the Riluzole 5 mg/mL oral suspension according to the International Dysphagia Diet Standardisation Initiative (IDDSI) flow test. Results of this experiment indicated that Riluzole 5 mg/mL oral suspension would basically fall under the “mildly thick” IDDSI descriptors. This is an important feature because thick fluids facilitate a safer swallow in patients with dysphagia. As a second objective, we evaluated for scientific purposes the compatibility of Riluzole 5 mg/mL oral suspension with some of the most common food thickeners available on the market. Intimate mixtures of the Riluzole 5 mg/mL oral suspension with thickeners were evaluated for appearance, pH, Riluzole assay and Riluzole related substances immediately after preparation and after two hours at room temperature. Riluzole 5 mg/mL oral suspension resulted to be compatible with all the marketed thickeners tested.

Diagnostic utility of the amyotrophic lateral sclerosis Functional Rating Scale-Revised to detect pharyngeal dysphagia in individuals with amyotrophic lateral sclerosis

Objective

The ALS Functional Rating Scale–Revised (ALSFRS-R) is the most commonly utilized instrument to index bulbar function in both clinical and research settings. We therefore aimed to evaluate the diagnostic utility of the ALSFRS-R bulbar subscale and swallowing item to detect radiographically confirmed impairments in swallowing safety (penetration or aspiration) and global pharyngeal swallowing function in individuals with ALS.

Methods

Two-hundred and one individuals with ALS completed the ALSFRS-R and the gold standard videofluoroscopic swallowing exam (VFSE). Validated outcomes including the Penetration-Aspiration Scale (PAS) and Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) were assessed in duplicate by independent and blinded raters. Receiver operator characteristic curve analyses were performed to assess accuracy of the ALSFRS-R bulbar subscale and swallowing item to detect radiographically confirmed unsafe swallowing (PAS > 3) and global pharyngeal dysphagia (DIGEST >1).

Results

Although below acceptable screening tool criterion, a score of ≤ 3 on the ALSFRS-R swallowing item optimized classification accuracy to detect global pharyngeal dysphagia (sensitivity: 68%, specificity: 64%, AUC: 0.68) and penetration/aspiration (sensitivity: 79%, specificity: 60%, AUC: 0.72). Depending on score selection, sensitivity and specificity of the ALSFRS-R bulbar subscale ranged between 34–94%. A score of < 9 optimized classification accuracy to detect global pharyngeal dysphagia (sensitivity: 68%, specificity: 68%, AUC: 0.76) and unsafe swallowing (sensitivity:78%, specificity:62%, AUC: 0.73).

Conclusions

The ALSFRS-R bulbar subscale or swallowing item did not demonstrate adequate diagnostic accuracy to detect radiographically confirmed swallowing impairment. These results suggest the need for alternate screens for dysphagia in ALS.

Association between maximum tongue pressure and swallowing safety and efficacy in amyotrophic lateral sclerosis

BACKGROUND

Oropharyngeal dysphagia (OD) is common in amyotrophic lateral sclerosis (ALS), leading to a reduction of swallowing safety and efficacy. The tongue has an important role in swallowing function for oral processing and bolus propulsion through the pharynx. The study aims to analyze the association between instrumental findings of OD and tongue pressure.

METHODS

Patients with ALS referred for fiberoptic endoscopic evaluation of swallowing (FEES) were recruited. FEES was conducted to test swallowing function with liquid (5, 10, and 20 ml), semisolid (5, 10, and 20 ml), and solid. FEES recordings were assessed for swallowing safety, using the penetration-aspiration scale (PAS), and for swallowing efficacy, using the Yale Pharyngeal Residue Severity Rating Scale (YPRSRS). PAS scores >2 were suggestive of penetration, PAS scores >5 of aspiration, and YPRSRS scores >2 of residue. Maximum tongue pressure (MTP) and tongue endurance were measured using the Iowa Oral Performance Instrument. Tongue pressure measurements were compared between patients with and without penetration, aspiration, or residue.

KEY RESULTS

Fifty-five patients with ALS were included. Mean MTP was 29.7 kPa, and median tongue endurance was 10 seconds. Patients with residue in the pyriform sinus had a significantly lower MTP than patients without residue in the pyriform sinus with semisolids 10 ml (P = .011) and 20 ml (P = .032). Patients with a tongue endurance <10 seconds exhibited higher frequency of penetration with liquids 5 ml (P = .046), liquids 10 ml (P = .015), and solids (P = .22).

CONCLUSION AND INFERENCES

In patients with ALS, MTP is significantly associated with an impairment of swallowing efficacy and tongue endurance was significantly associated with an impairment of swallowing safety.

Effects of Biofeedback Training on Esophageal Peristalsis in Amyotrophic Lateral Sclerosis Patients with Dysphagia

Esophageal manometry (EM) could serve as an objective method for the detection of esophageal peristalsis in patients with amyotrophic lateral sclerosis (ALS). In this group of patients, biofeedback training (BT) using the EM procedure is a promising method for the rehabilitation of swallowing function. A total of 20 ALS patients with clinical evidence of dysphagia and who met WFN criteria were recruited for this study. The standard transnasal EM with solid-state transducers was performed, and swallows with water and saliva were initiated in all subjects and repeated at 30-s intervals. The median upper esophageal contractile amplitude, duration, and velocity results during the wet and dry swallows were evaluated and compared in both the ALS and the control groups. In ALS patients, in contrast to the control, significant abnormalities in all EM parameters were recorded, which implies a specific pattern of esophageal peristalsis. Twelve months after BT, the body mass index (BMI) of ALS patients who underwent BT (ALSBT) was compared to the BMI of those who did not (ALS1)—compared to the ALS1 group, ALSBT patients showed a slightly smaller drop in BMI value. We presume that BT using EM can be a promising tool for the improvement of the swallowing mechanism in ALS patients.

Intralingual Administration of AAVrh10-miRSOD1 Improves Respiratory But Not Swallowing Function in a Superoxide Dismutase-1 Mouse Model of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal disease characterized by degeneration of motor neurons and muscles, and death is usually a result of impaired respiratory function due to loss of motor neurons that control upper airway muscles and/or the diaphragm. Currently, no cure for ALS exists and treatments to date do not significantly improve respiratory or swallowing function. One cause of ALS is a mutation in the superoxide dismutase-1 (SOD1) gene; thus, reducing expression of the mutated gene may slow the progression of the disease. Our group has been studying the SOD1^G93A transgenic mouse model of ALS that develops progressive respiratory deficits and dysphagia. We hypothesize that solely treating the tongue in SOD1 mice will preserve respiratory and swallowing function, and it will prolong survival. At 6 weeks of age, 11 SOD1^G93A mice (both sexes) received a single intralingual injection of gene therapy (AAVrh10-miR^SOD1). Another 29 mice (both sexes) were divided into two control groups: (1) 12 SOD1^G93A mice that received a single intralingual vehicle injection (saline); and (2) 17 non-transgenic littermates. Starting at 13 weeks of age, plethysmography (respiratory parameters) at baseline and in response to hypoxia (11% O₂) + hypercapnia (7% CO₂) were recorded and videofluoroscopic swallow study testing were performed twice monthly until end-stage disease. Minute ventilation during hypoxia + hypercapnia and mean inspiratory flow at baseline were significantly reduced (p < 0.05) in vehicle-injected, but not AAVrh10-miR^SOD1-injected SOD1^G93A mice as compared with wild-type mice. In contrast, swallowing function was unchanged by AAVrh10-miR^SOD1 treatment (p > 0.05). AAVrh10-miR^SOD1 injections also significantly extended survival in females by ∼1 week. In conclusion, this study indicates that intralingual AAVrh10-miR^SOD1 treatment preserved respiratory (but not swallowing) function potentially via increasing upper airway patency, and it is worthy of further exploration as a possible therapy to preserve respiratory capacity in ALS patients.

Shifting Tides Toward a Proactive Patient-Centered Approach in Dysphagia Management of Neurodegenerative Disease

Purpose Persons with neurodegenerative disease frequently develop comorbid dysphagia as part of their disease process. Current "reactive" approaches to dysphagia management address dysphagia once it manifests clinically and consist of compensatory approaches. The purpose of this article is to propose a paradigm shift in dysphagia management of patients with neurodegenerative disease from a "reactive to proactive" approach by highlighting amyotrophic lateral sclerosis (ALS) and dementia as case examples. Method The authors present several areas of special consideration for speech-language pathologists (SLPs) treating dysphagia in patients with neurodegenerative disease. The drawbacks of historical "reactive" approaches to dysphagia management are described. Concepts of functional reserve for swallowing and homeostenosis are discussed. A "proactive" patient-centered paradigm of care for these patients is proposed with evidence to support its importance. A rationale for use of this approach in patients with ALS and dementia is provided with strategies for implementation. Results When treating dysphagia in patients with neurodegenerative disease, SLPs must balance a variety of factors in their decision making, including disease severity and expected progression, cultural considerations, goals of care, patient empowerment, and caregiver support. Reactive approaches to dysphagia management in these populations are problematic in that they disempower patients by focusing on use of compensatory techniques (e.g., diet modification, postural changes, feeding tube placement). Proactive approaches that employ rehabilitative interventions to increase functional reserve, such as resistance training, may result in improvement or maintenance of swallowing function longer into disease progression. An interdisciplinary team with early SLP involvement is necessary. Conclusions SLPs play a critical role in the management of dysphagia in patients with neurodegenerative disease and should be integrated early in the care of these patients. By focusing on a proactive patient-centered approach, patients with neurodegenerative conditions, such as ALS and dementia, will experience improved quality of life and health outcomes for a longer time.

An Experimental Swallow Evoked Potential Protocol to Investigate the Neural Substrates of Swallowing

Advancement in dysphagia intervention is hindered by our lack of understanding of the neural mechanisms of swallowing in health and disease. Evoking and understanding neural activity in response to normal and disordered swallowing is essential to bridge this knowledge gap. Building on sensory evoked potential methodology, we developed a minimally invasive approach to generate swallow evoked potentials (SwEPs) in response to repetitive swallowing induced by citric acid stimulation of the oropharynx in lightly anesthetized healthy adult rats. The SwEP waveform consisted of 8 replicable peaks within 10 milliseconds immediately preceding the onset of electromyographic swallowing activity. Methodology refinement is underway with healthy rats to establish normative SwEP waveform morphology before proceeding to models of advanced aging and age-related neurodegenerative diseases. Ultimately, we envision that this experimental protocol may unmask the pathologic neural substrates contributing to dysphagia to accelerate the discovery of targeted therapeutics.

Achados videoendoscópicos da deglutição em diferentes consistências de alimento na Esclerose Lateral Amiotrófica

RESUMO Objetivo Este estudo teve por objetivo comparar os achados videoendoscópicos da deglutição orofaríngea em distintas consistências de alimento na Esclerose Lateral Amiotrófica (ELA). Método Estudo clínico retrospectivo com amostra de conveniência. Foram incluídos 20 indivíduos com diagnóstico de ELA e disfagia orofaríngea confirmada por avaliação clínica e objetiva de deglutição, independentemente do tipo, bulbar ou esquelética, e tempo de diagnóstico neurológico, 13 do sexo masculino e sete do sexo feminino, faixa etária variando de 34 a 78 anos, média de 57 anos. Foram analisados os achados da videoendoscopia de deglutição (VED) nas consistências líquida (N=18), líquida espessada (N=19) e pastosa (N=20) no volume de cinco ml. Os achados sobre escape oral posterior, resíduos faríngeos, penetração laríngea e/ou aspiração foram comparados nas três consistências de alimento e a análise estatística utilizou o teste ANOVA de Friedman. Resultados Não foi encontrada alteração na sensibilidade laríngea nessa população. Não houve diferença estatística significativa entre as consistências de alimento na presença de escape oral posterior, penetração e/ou aspiração. Houve diferença estatística significativa somente com resíduos faríngeos na consistência líquida espessada e pastosa na ELA. Conclusão Dentre os achados videoendoscópicos da deglutição na ELA, somente o resíduo faríngeo teve maior frequência na dependência da consistência de alimento.

Size-Dependent Vulnerability of Lumbar Motor Neuron Dendritic Degeneration in SOD1G93A Mice

The motor neuron (MN) soma surface area is correlated with motor unit type. Larger MNs innervate fast fatigue-intermediate (FInt) or fast-fatiguable (FF) muscle fibers in type FInt and FF motor units, respectively. Smaller MNs innervate slow-twitch fatigue-resistant (S) or fast fatigue-resistant (FR) muscle fibers in type S and FR motor units, respectively. In amyotrophic lateral sclerosis (ALS), FInt and FF motor units are more vulnerable, with denervation and MN death occurring for these units before the more resilient S and FR units. Abnormal MN dendritic arbors have been observed in ALS in humans and rodent models. We used a Golgi-Cox impregnation protocol to examine soma size-dependent changes in the dendritic morphology of lumbar MNs in SOD1^G93A mice, a model of ALS, at pre-symptomatic, onset and mid-disease stages. In wildtype control mice, the relationship between MN soma surface area and dendritic length or dendritic spine number was highly linear (i.e., increased MN soma size correlated with increased dendritic length and spines). By contrast, in SOD1^G93A mice, this linear relationship was lost and dendritic length reduction and spine loss were observed in larger MNs, from pre-symptomatic stages onward. These changes correlated with the neuromotor symptoms of ALS in rodent models. At presymptomatic ages, changes were restricted to the larger MNs, likely to comprise vulnerable FInt and FF motor units. Our results suggest morphological changes of MN dendrites and dendritic spines are likely to contribute ALS pathogenesis, not compensate for it. Anat Rec, 303:1455-1471, 2020. © 2019 American Association for Anatomy.