Swallowing characteristics in Amyotrophic Lateral Sclerosis

Analysis of Feeding Behavior Characteristics in the Cu/Zn Superoxide Dismutase 1 (SOD1) SOD1G93A Mice Model for Amyotrophic Lateral Sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is a progressive disease affecting upper and lower motor neurons. Feeding disorders are observed in patients with ALS. The mastication movements and their systemic effects in patients with ALS with feeding disorders remain unclear. Currently, there is no effective treatment for ALS. However, it has been suggested that treating feeding disorders and improving nutritional status may prolong the lives of patients with ALS. Therefore, this study elucidates feeding disorders observed in patients with ALS and future therapeutic agents. We conducted a temporal observation of feeding behavior and mastication movements using an open-closed mouth evaluation artificial intelligence (AI) model in an ALS mouse model. Furthermore, to determine the cause of masticatory rhythm modulation, we conducted electrophysiological analyses of mesencephalic trigeminal neurons (MesV). Here, we observed the modulation of masticatory rhythm with a prolonged open phase in the ALS mouse model from the age of 12 weeks. A decreased body weight was observed simultaneously, indicating a correlation between the prolongation of the open phase and the decrease observed. We found that the percentage of firing MesV was markedly decreased. This study partially clarifies the role of feeding disorders in ALS.

Prevalence of Sialorrhea Among Amyotrophic Lateral Sclerosis Patients: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative motor neuron disease (MND), and sialorrhea is a known symptom in patients with ALS, which may cause a social embarrassment and discomfort. However, people do not pay attention to sialorrhea up to now. This study is aimed at conducting a systematic review and meta-analysis of the pooled prevalence of sialorrhea in ALS patients all around the world and raising awareness of salivation.

METHODS

We searched PubMed and EMBASE databases to obtain the comprehensive literatures which reported the prevalence of sialorrhea. We used AHRQ and NOS to evaluate the literature quality. Subgroup analyses were performed based on screening instruments and severity of sialorrhea. At the meantime, sensitivity analyses was also conducted to identify the source of heterogeneity.

RESULTS

A total of 17 eligible studies which included 21 groups of data reported prevalence of sialorrhea. The pooled prevalence of sialorrhea among ALS patients was 30.8% (95% CI: 20.0%-44.2%). For studies using ALSFRS-R, direct questioning, postal survey, and ALSSoL average and ALSFRS-R, the pooled prevalence of sialorrhea was 22.7%, 25.8%, 29.8% and 52.0% respectively. According to the severity of sialorrhea, the prevalence of mild, moderate, and severe sialorrhea were 25.1%, 11.2%, and 10.5%, respectively. And none of the studies alone had a significant effect on the overall prevalence of sialorrhea after we eliminated each study separately in sensitivity analyses.

CONCLUSIONS

Sialorrhea is a relatively common symptom in ALS patients with a comparatively high prevalence. In our study, we found that the prevalence of sialorrhea in ALS patients is relatively higher than the results based on direct questioning or postal survey. Therefore, we deduced that sialorrhea should be evaluated by more complex professional assessment scales to improve the quality of life and improve early prognosis of disease.

Case Report: Event-Related Desynchronization Observed During Volitional Swallow by Electroencephalography Recordings in ALS Patients With Dysphagia

Dysphagia is a severe disability affecting daily life in patients with amyotrophic lateral sclerosis (ALS). It is caused by degeneration of both the bulbar motor neurons and cortical motoneurons projecting to the oropharyngeal areas. A previous report showed decreased event-related desynchronization (ERD) in the medial sensorimotor areas in ALS dysphagic patients. In the process of degeneration, brain reorganization may also be induced in other areas than the sensorimotor cortices. Furthermore, ALS patients with dysphagia often show a longer duration of swallowing. However, there have been no reports on brain activity in other cortical areas and the time course of brain activity during prolonged swallowing in these patients. In this case report, we investigated the distribution and the time course of ERD and corticomuscular coherence (CMC) in the beta (15–25 Hz) frequency band during volitional swallow using electroencephalography (EEG) in two patients with ALS. Case 1 (a 71-year-old man) was diagnosed 2 years before the evaluation. His first symptom was muscle weakness in the right hand; 5 months later, dysphagia developed and exacerbated. Since his dietary intake decreased, he was given an implantable venous access port. Case 2 (a 64-year-old woman) was diagnosed 1 year before the evaluation. Her first symptom was open-nasal voice and dysarthria; 3 months later, dysphagia developed and exacerbated. She was given a percutaneous endoscopic gastrostomy. EEG recordings were performed during volitional swallowing, and the ERD was calculated. The average swallow durations were 7.6 ± 3.0 s in Case 1 and 8.3 ± 2.9 s in Case 2. The significant ERD was localized in the prefrontal and premotor areas and lasted from a few seconds after the initiation of swallowing to the end in Case 1. The ERD was localized in the lateral sensorimotor areas only at the initiation of swallowing in Case 2. CMC was not observed in either case. These results suggest that compensatory processes for cortical motor outputs might depend on individual patients and that a new therapeutic approach using ERD should be developed according to the individuality of ALS patients with dysphagia.

A Novel Method for Triggering the Swallowing Reflex in Patients with Amyotrophic Lateral Sclerosis: the Ishizaki Press Method

This study describes the identification of specific maxillofacial points triggering the swallowing reflex by finger pressure in a patient with severe amyotrophic lateral sclerosis. This method has been named as the "Ishizaki Press Method." The first point was identified in a serendipitous encounter during training sessions to aid communication. This led to the search for such additional points, after obtaining informed consent from the patient and his relatives. Seven effective points were identified: the depressions in front of the left and right tragus (Ting gong points), bilateral points over the parotid and submandibular glands, and a point over the mentum in the midline of the face. The efficacy of these trigger points was noted to be ≥ 70%. The mean time taken for swallowing to occur in response to the stimulation at each of these points was less than 10 s, and the induction of a rapid swallowing reflex was recognized. Alternating left and right stimulations of the Ting gong points and the parotid points triggered the swallowing reflex significantly faster than unilateral stimulations alone. The Ishizaki Press Method may improve the management of dysphagia in patients with amyotrophic lateral sclerosis.

A Swallowing Decoder Based on Deep Transfer Learning: AlexNet Classification of the Intracranial Electrocorticogram

To realize a brain-machine interface to assist swallowing, neural signal decoding is indispensable. Eight participants with temporal-lobe intracranial electrode implants for epilepsy were asked to swallow during electrocorticogram (ECoG) recording. Raw ECoG signals or certain frequency bands of the ECoG power were converted into images whose vertical axis was electrode number and whose horizontal axis was time in milliseconds, which were used as training data. These data were classified with four labels (Rest, Mouth open, Water injection, and Swallowing). Deep transfer learning was carried out using AlexNet, and power in the high-[Formula: see text] band (75-150[Formula: see text]Hz) was the training set. Accuracy reached 74.01%, sensitivity reached 82.51%, and specificity reached 95.38%. However, using the raw ECoG signals, the accuracy obtained was 76.95%, comparable to that of the high-[Formula: see text] power. We demonstrated that a version of AlexNet pre-trained with visually meaningful images can be used for transfer learning of visually meaningless images made up of ECoG signals. Moreover, we could achieve high decoding accuracy using the raw ECoG signals, allowing us to dispense with the conventional extraction of high-[Formula: see text] power. Thus, the images derived from the raw ECoG signals were equivalent to those derived from the high-[Formula: see text] band for transfer deep learning.

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.

Cohort Study on Laryngeal Cough Reflex, Respiratory Disease, and Death: A Mediation Analysis

OBJECTIVE

To estimate quantitatively whether the presence of cough associated with dysphagia (laryngeal cough reflex) increased mortality through respiratory disease among community-dwelling older Japanese.

DESIGN

A 6-year follow-up prospective cohort study (from 2010 to 2017).

SETTING

Thirteen municipalities in Japan.

PARTICIPANTS

Community-dwelling individuals aged 65 years or older (N = 32,682).

MEASURES

The baseline survey was conducted through self-reported questionnaire. Exposure was experience of laryngeal cough reflex while drinking. The outcome was all-cause mortality. All covariates were selected from demographic, socioeconomic variables, baseline health and functional status, smoking, alcohol drinking, number of remaining teeth, and stroke. The mediator variable was respiratory disease. Cox proportional hazards regression was used to estimate hazard ratios (HRs) for mortality. Parametric mediation analysis was conducted to estimate the effect of laryngeal cough reflex on the mean residual time to death mediated through respiratory disease.

RESULTS

Among the 32,682 participants (mean age = 74.1 years, standard deviation = 5.9 years), 5550 (17.0%) experienced laryngeal cough reflex at baseline. A total of 4037 deaths occurred. Crude mortality rates of the participants with or without laryngeal cough reflex were 16.3% and 11.6%, respectively. After adjusting for covariates, laryngeal cough reflex [HR = 1.10; 95% confidence interval (CI) = 1.02 to 1.19] and respiratory disease (HR = 1.80; 95% CI = 1.62 to 2.00) were associated with mortality. The mediation analysis showed that respiratory disease significantly (P < .001) and partially mediated the association between laryngeal cough reflex, an indicator of 1 or more conditions such as chronic aspiration and mortality.

CONCLUSIONS/IMPLICATIONS

Laryngeal cough reflex was a prevalent condition, and it was associated with all-cause mortality in community-dwelling older Japanese individuals. Clinicians could contribute to reduce mortality risk by addressing swallowing function problems using their interprofessional collaboration team (speech-language pathologist, dentist, rehabilitation doctor, otolaryngologist, respiratory physician, and gerontologist).

Screening and evaluation tools of dysphagia in adults with neuromuscular diseases: a systematic review

Background:

The purpose of this systematic review was to summarize the different dysphagia screening and evaluation tools, and to identify their measurement properties in adults with neuromuscular diseases (NMDs).

Methods:

A systematic review was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search strategy was conducted across three databases (PubMed, CINAHL and ScienceDirect). Measurement properties of each tools and the Quality Index, developed by Downs and Black, were considered for the different investigated studies.

Results:

The search strategy produced 2221 articles. After removal of duplicates and full-text analysis, 19 studies were included. Most of the publications focused on amyotrophic lateral sclerosis (ALS; n = 10) and Duchenne muscular dystrophy (DMD; n = 4). A total of 12 tools, listed as instrumental and noninstrumental examinations, were retrieved. A total of five of them used videofluoroscopic swallow study (VFSS). Measurement properties of the tools are not completely described in detail in many studies. The neuromuscular disease swallowing status scale, a noninstrumental tool, is the only one that assessed all measurement properties in ALS patients. The median score reported for the Quality Index was 16.

Conclusions:

This systematic review identified 12 different tools for the screening and evaluation of dysphagia in adults with NMD. Majority of the studies presented VFSS as a valid and reliable examination to assess dysphagia in ALS and DMD. Other tools were mainly evaluated in ALS patients, but further studies are needed to complete their measurement properties. In other NMDs, no firm conclusion can be made because of insufficient data and heterogeneity of NMDs.

Hypoglossal Motor Neuron Death Via Intralingual CTB-saporin (CTB-SAP) Injections Mimic Aspects of Amyotrophic Lateral Sclerosis (ALS) Related to Dysphagia

Amyotrophic lateral sclerosis (ALS) is a devastating disease leading to degeneration of motor neurons and skeletal muscles, including those required for swallowing. Tongue weakness is one of the earliest signs of bulbar dysfunction in ALS, which is attributed to degeneration of motor neurons in the hypoglossal nucleus in the brainstem, the axons of which directly innervate the tongue. Despite its fundamental importance, dysphagia (difficulty swallowing) and strategies to preserve swallowing function have seldom been studied in ALS models. It is difficult to study dysphagia in ALS models since the amount and rate at which hypoglossal motor neuron death occurs cannot be controlled, and degeneration is not limited to the hypoglossal nucleus. Here, we report a novel experimental model using intralingual injections of cholera toxin B conjugated to saporin (CTB-SAP) to study the impact of only hypoglossal motor neuron death without the many complications that are present in ALS models. Hypoglossal motor neuron survival, swallowing function, and hypoglossal motor output were assessed in Sprague-Dawley rats after intralingual injection of either CTB-SAP (25 g) or unconjugated CTB and SAP (controls) into the genioglossus muscle. CTB-SAP treated rats exhibited significant (p ≤ 0.05) deficits vs. controls in: (1) lick rate (6.0 ± 0.1 vs. 6.6 ± 0.1 Hz; (2) hypoglossal motor output (0.3 ± 0.05 vs. 0.6 ± 0.10 mV); and (3) hypoglossal motor neuron survival (398 ± 34 vs. 1018 ± 41 neurons). Thus, this novel, inducible model of hypoglossal motor neuron death mimics the dysphagia phenotype that is observed in ALS rodent models, and will allow us to study strategies to preserve swallowing function.

Residue influences quality of life independently of penetration and aspiration in head and neck cancer survivors

OBJECTIVES/HYPOTHESIS

Dysphagia is one of the most significant side effects of the treatment of head and neck cancer. Residue and aspiration are two indicators of dysphagia, but aspiration is historically the only indicator of interest, because it may impact health outcomes. Clinicians have anecdotally used residue as another marker of swallowing dysfunction, but it is understudied. This project investigated the impact of aspiration versus residue on function and quality of life (QoL) in these patients.

STUDY DESIGN

Observational study.

METHODS

A total of 168 head and neck cancer survivors with moderate to severe dysphagia were enrolled in a randomized clinical trial comparing two swallow therapy interventions. Data at time of entry were used for the current study. A modified barium swallow study was done to compute Penetration-Aspiration Scale (PAS) scores, percentage oral residue, and percentage pharyngeal residue with three bolus consistencies (5 mL thin, nectar, and pudding). The Performance Status Scale (PSS) and the Head Neck Cancer Inventory (HNCI) questionnaires were administered. Data were analyzed to determine associations between aspiration and residue estimates with function and QoL scores.

RESULTS

Worsening aspiration and residue estimates were all correlated with decreased scores on the PSS functional scales (r = -0.190 to -0.324, P ≤ .031). However, only increasing residue estimates were significantly related to decreased patient-perceived QoL on the HNCI (r = -.178 to -.194, P < .046). This effect was more pronounced with oral versus pharyngeal residue.

CONCLUSIONS

In this group of head and neck cancer survivors, penetration/aspiration and residue show independent effects. PAS affects functional status only, but residue affects both functional status and QoL. This study supports that residue should be considered a primary measurement of swallowing function and be a target for identification, treatment, and evaluation of swallowing.

LEVEL OF EVIDENCE

2c. Laryngoscope, 127:1615-1621, 2017.