Feeding and Swallowing Disorders in Pediatric Neuromuscular Diseases: An Overview

Translation, Cross-Cultural Adaptation and Validation of the Karaduman Chewing Performance Scale for the Italian Paediatric Population

BACKGROUND

Chewing is a fundamental motor activity, but there is no specific assessment tool in Italian for paediatric rehabilitation. The Karaduman Chewing Performance Scale (KCPS) is a performance-based assessment tool that allow to classify chewing performance in childhood.

OBJECTIVE

To translate, culturally adapt and assess reliability, criterion validity and cross-cultural validity of the KCPS into Italian in a paediatric population.

METHODS

Following international guidelines, the KCPS was translated and culturally adapted into Italian. Inter-rater reliability was measured using the intraclass correlation coefficient (ICC), the criterion validity using the Pearson correlation coefficient comparing KCPS score with the Paediatric Screening-Priority Evaluation Dysphagia (PS-PED), and cross-cultural validity was examined across diagnostic groups.

RESULTS

The study included 165 children with a mean age of 6.33 with different health conditions, namely autism spectrum disorder, cerebral palsy and genetic syndromes. The analysis revealed that KCPS was reliable measure with a ICC 0.93, and a moderate positive linear correlation with the PS-PED (Pearson 0.48) was found. In each diagnostic group, chewing performance disorders were found, highlighting specific characteristics.

CONCLUSIONS

Despite limited sample in reliability analysis and the need of exploring the relationship with chewing abilities and severity of diseases, the KCPS was found a reliable and valid tool for determining the level of chewing performance in paediatric population. Now Italian clinicians can use it with more confidence in their clinical practice and research.

Swallowing Assessment in a Pediatric Case of Allan-Herndon-Dudley Syndrome (MCT8 Deficiency): Advanced Insights into Dysphagia via Flexible Endoscopic Evaluation of Swallowing

Patients with MCT8 deficiency often present with underweight and are prone to frequent pulmonary infections, including aspiration pneumonia. Despite commonly reported swallowing difficulties in this population, specific dysphagia symptoms have not been well-documented. We conducted a flexible endoscopic evaluation of swallowing (FEES) on a young boy diagnosed with MCT8 deficiency, who exhibited recurrent pulmonary infections and failed to achieve substantial weight gain despite an oral energy intake appropriate for his age and height. The FEES revealed generally weakened swallowing mechanisms, characterized by prolonged swallow and cough sequences, along with penetration and aspiration of both fluid and semi-solid test boluses. Given the considerable effort associated with oral intake, we hypothesize that dysphagia contributes to his underweight status, alongside peripheral thyrotoxicosis. In conclusion, FEES proved to be an invaluable tool in identifying underlying swallowing impairments and assessing the need for gastrostomy in this patient. For MCT8 deficiency, patients presenting with underweight, frequent pulmonary infections, and swallowing difficulties, it is recommended that diagnostic evaluations include FEES to thoroughly assess their swallowing function and airway protection.

Validation and cultural adaptation of a Greek Version of Pediatric Eating Assessment Tool 10 (PEDI - EAT - 10) in Greek-Cypriot Parents

PURPOSE

The Pediatric Eating Assessment Tool (PEDI-EAT-10) is a parents/caregivers screening tool that assesses pediatric patients at risk of penetration and/or aspiration symptoms. The aim of this study was the validation of PEDI-EAT-10 in the Greek language.

MATERIALS AND METHODS

This cross-sectional study included 222 parents/caregivers of children with (n = 122) and without (n = 100) feeding and/or swallowing disorders, with age range 3 - 12 years. The children were selected from Cypriot schools and health settings. All parents filled out the PEDI-EAΤ-10 questionnaire and after its initial completion, it was re-administered after 2 weeks.

RESULTS

A statistically significant difference was observed in the PEDI-EAT-10 total mean scores between the study's two groups [t (220) = 9.886, p < 0.001]. Internal consistency was high (Cronbach's alpha= 0.801) with very good split-half reliability equal to 0.789. A significant and strong test-retest reliability was computed (r = 0.998, p < 0.001). The PEDI-EAT-10 cutoff point was 11.00 (AUC: 0.869, p < 0.001) for children with feeding and/or swallowing disorders in accordance with the PAS scale.

CONCLUSIONS

In conclusion, the Greek version of PEDI-EAT-10 is shown to be a valid and reliable screening tool for the assessment of the pediatric population with a risk of dysphagia.

Ndufs4 inactivation in glutamatergic neurons reveals swallow-breathing discoordination in a mouse model of Leigh Syndrome

Swallowing, both nutritive and non-nutritive, is highly dysfunctional in children with Leigh Syndrome (LS) and contributes to the need for both gastrostomy and tracheostomy tube placement. Without these interventions aspiration of food, liquid, and mucus occur resulting in repeated bouts of respiratory infection. No study has investigated whether mouse models of LS, a neurometabolic disorder, exhibit dysfunctions in neuromuscular activity of swallow and breathing integration. We used a genetic mouse model of LS in which the NDUFS4 gene is knocked out (KO) specifically in Vglut2 or Gad2 neurons. We found increased variability of the swallow motor pattern, disruption in breathing regeneration post swallow, and water-induced apneas only in Vglut2 KO mice. These physiological changes likely contribute to weight loss and premature death seen in this mouse model. Following chronic hypoxia (CH) exposure, swallow motor pattern, breathing regeneration, weight, and life expectancy were not changed in the Vglut2-Ndufs4-KO CH mice compared to control, indicating a rescue of phenotypes. These findings show that like patients with LS, Ndufs4 mouse models of LS exhibit swallow impairments as well as swallow-breathing dyscoordination alongside the other phenotypic traits described in previous studies. Understanding this aspect of LS will open roads for the development of future more efficacious therapeutic intervention for this illness.

Development of eating skills in infants and toddlers from a neuropediatric perspective

Early infant feeding and swallowing are complex motor processes involving numerous muscles in coordination, e.g. the orofacial muscles as well as the muscles of the pharynx, larynx and esophagus. The newborn's reflexive drinking develops into the ability to ingest pureed complementary food as infancy progresses. Finally, in the last part of the first year of life, a differentiated eating, chewing and swallowing process develops allowing the voluntary intake of different foods of the family diet. The dietary schedule for the first year of life, which describes the recommended nutrition of infants in Germany, corresponds to these milestones in eating development. Disturbances in gross motor development, sensory processing issues, and organic and behavioral problems are known to interfere with the development of eating skills. Swallowing disorders (dysphagia) in children can have a detrimental effect on food intake and pose a serious risk to growth and development. Their prevention treatment requires a multidisciplinary approach with the aim of enabling the child to eat independently in the long term.

Practical recommendations for swallowing and speaking during NIV in people with neuromuscular disorders

Objectives

The functions of eating, drinking, speaking, and breathing demand close coordination of the upper airway musculature which may be challenged by the long-term use of daytime non-invasive ventilation (NIV). This rapid review explores the challenges and practicalities of these interactions in people with neuromuscular disorders.

Methods

A search was performed on PubMed (period 2000-2023) using generic terms to refer to eating, drinking, and speaking related to people with neuromuscular disorders on NIV. A narrative approach was used to summarize the available literature.

Results

Our review shows only a small number of studies exist exploring the use of NIV on swallowing and speaking in people with neuromuscular disorders. We summarize study findings and provide practical advice on eating, drinking and speaking with NIV.

Conclusions

By understanding breathing, NIV mechanics and upper airway interactions, it is possible to optimize swallowing and speaking whilst using NIV. There is a lack of specific guidelines, and concerns regarding aspiration warrant further research and guideline development.

Translation and validation of traditional Chinese version of the pediatric eating assessment Tool-10

BACKGROUND

/Purpose: The Pediatric Eating Assessment Tool-10 (Pedi-EAT-10) is a caregiver-administrated subjective questionnaire for evaluating swallowing and feeding disorders among children. This study translated the Pedi-EAT-10 into Traditional Chinese and tested the translated version's reliability and validity.

METHODS

Pedi-EAT-10 was translated into Traditional Chinese by experts and finalized after discussion and testing. A total of 168 participants, consisting of 32 children with dysphagia from a tertiary medical center and 136 healthy controls from its Children Care Center for Employees, were recruited. All participants were assessed by an otolaryngologist and speech-language pathologist. The reliability, validity, and efficacy of the translated Pedi-EAT-10 were analyzed to ensure it could be used to identify pediatric dysphagia and feeding problems.

RESULTS

The Traditional Chinese version of the Pedi-EAT-10 had significant clinical discriminative validity between the dysphagia group and the control group (total score = 9.6 vs. 2.6, P < 0.001), acceptable test-retest reliability (intraclass correlation = 0.63), and excellent internal consistency (Cronbach's α = 0.91 for the entire cohort). The overall performance of the test for distinguishing children with dysphagia from normal controls was acceptable, and the area under the curve was 74.8% (sensitivity = 71.9%; specificity = 69.9%). The optimal cutoff score was ≥3 on the Youdex index.

CONCLUSIONS

The Traditional Chinese version of the Pedi-EAT-10 has fair reliability and validity and can be quickly and easily completed by caregivers. The translated Ped-EAT-10 can be used as a first-line tool for assessing the need for further referral and instrumental examination.

Best practice recommendations for speech-language pathology in children with neuromuscular disorders: A Delphi-based consensus study

PURPOSE

Speech-language pathology (SLP) is considered an essential intervention due to the high prevalence of dysphagia and dysarthria in paediatric neuromuscular disorders (pNMD). Evidence-based guidelines for SLP in pNMD are missing and children could be deprived the best of care. This study aimed to achieve consensus and present best practice recommendations on SLP intervention in pNMD.

METHOD

A modified Delphi technique was used with a panel of experienced Dutch speech-language pathologists. In two online survey rounds and a face-to-face consensus meeting, the SLP experts proposed intervention items for cases of four types of pNMD (congenital myopathy, Duchenne muscular dystrophy, myotonic dystrophy type 1, and spinal muscular atrophy type 2), covering symptoms of dysphagia, dysarthria, drooling, and oral hygiene problems. They rated the level of agreement.

RESULT

Intervention items that achieved consensus were incorporated into best practice recommendations. These recommendations cover six core intervention components (wait and see, explanation and advice, training and treatment, aids and adjustments, referral to other disciplines, and monitoring) suitable for the described symptoms.

CONCLUSION

Insight into treatment options is essential to facilitate speech-language pathologists in clinical decision-making. The current study led to best practice recommendations for speech-language pathologists working within the field of pNMD.

A Systematic Literature Review of the Natural History of Respiratory, Swallowing, Feeding, and Speech Functions in Spinal Muscular Atrophy (SMA)

Background

Respiratory and bulbar dysfunctions (including swallowing, feeding, and speech functions) are key symptoms of spinal muscular atrophy (SMA), especially in its most severe forms. Demonstrating the long-term efficacy of disease-modifying therapies (DMTs) necessitates an understanding of SMA natural history.

Objective

This study summarizes published natural history data on respiratory, swallowing, feeding, and speech functions in patients with SMA not receiving DMTs.

Methods

Electronic databases (Embase, MEDLINE, and Evidence-Based Medicine Reviews) were searched from database inception to June 27, 2022, for studies reporting data on respiratory and/or bulbar function outcomes in Types 1-3 SMA. Data were extracted into a predefined template and a descriptive summary of these data was provided.

Results

Ninety-one publications were included: 43 reported data on respiratory, swallowing, feeding, and/or speech function outcomes. Data highlighted early loss of respiratory function for patients with Type 1 SMA, with ventilatory support typically required by 12 months of age. Patients with Type 2 or 3 SMA were at risk of losing respiratory function over time, with ventilatory support initiated between the first and fifth decades of life. Swallowing and feeding difficulties, including choking, chewing problems, and aspiration, were reported in patients across the SMA spectrum. Swallowing and feeding difficulties, and a need for non-oral nutritional support, were reported before 1 year of age in Type 1 SMA, and before 10 years of age in Type 2 SMA. Limited data relating to other bulbar functions were collated.

Conclusions

Natural history data demonstrate that untreated patients with SMA experience respiratory and bulbar function deterioration, with a more rapid decline associated with greater disease severity. This study provides a comprehensive repository of natural history data on bulbar function in SMA, and it highlights that consistent assessment of outcomes in this area is necessary to benefit understanding and approval of new treatments.

Alternative splicing events as peripheral biomarkers for motor learning deficit caused by adverse prenatal environments

Severity of neurobehavioral deficits in children born from adverse pregnancies, such as maternal alcohol consumption and diabetes, does not always correlate with the adversity's duration and intensity. Therefore, biological signatures for accurate prediction of the severity of neurobehavioral deficits, and robust tools for reliable identification of such biomarkers, have an urgent clinical need. Here, we demonstrate that significant changes in the alternative splicing (AS) pattern of offspring lymphocyte RNA can function as accurate peripheral biomarkers for motor learning deficits in mouse models of prenatal alcohol exposure (PAE) and offspring of mother with diabetes (OMD). An aptly trained deep-learning model identified 29 AS events common to PAE and OMD as superior predictors of motor learning deficits than AS events specific to PAE or OMD. Shapley-value analysis, a game-theory algorithm, deciphered the trained deep-learning model's learnt associations between its input, AS events, and output, motor learning performance. Shapley values of the deep-learning model's input identified the relative contribution of the 29 common AS events to the motor learning deficit. Gene ontology and predictive structure-function analyses, using Alphafold2 algorithm, supported existing evidence on the critical roles of these molecules in early brain development and function. The direction of most AS events was opposite in PAE and OMD, potentially from differential expression of RNA binding proteins in PAE and OMD. Altogether, this study posits that AS of lymphocyte RNA is a rich resource, and deep-learning is an effective tool, for discovery of peripheral biomarkers of neurobehavioral deficits in children of diverse adverse pregnancies.

Evaluation and Management of Pediatric Feeding Disorder

Feeding disorders are increasingly common in children, especially as medical advancements improve the life expectancy of children born with prematurity and complex medical conditions. The most common symptoms include malnutrition, refusal to eat and drink, food pocketing, disruptive feeding behavior, slow feeding, food selectivity or rigid food preferences, limited appetite, and delayed feeding milestones. A unifying diagnostic definition of pediatric feeding disorder has been proposed by a panel of experts to improve the quality of health care and advance research. Referral to specialized care should be considered when feeding problems are complex or difficult to resolve. In this review, we provide an overview of the evaluation and management of pediatric feeding disorders and information that may be useful when considering whether referral to specialized care may be beneficial.

Protective Effect of Breastfeeding Against Febrile Seizure: A Nationwide Study in Korea

BACKGROUND

Breastfeeding is known to protect against febrile seizure (FS). Whether its impact continues throughout the childhood period is still controversial. Our objective was to investigate the protective effect of breastfeeding against FS stratified by age.

METHODS

We included children who participated in the National Health Screening Program for Infants and Children (NHSPIC) aged between four and six months between 2008 and 2014. Feeding type was confirmed based on the NHSPIC questionnaire, and data from the Korean National Health Insurance Service were used to determine FS cases during a five-year follow-up period.

RESULTS

Among the 1,791,335 children, the most prevalent feeding type was exclusive breastfeeding (EB) (42.3%). FS occurred most frequently in the exclusive formula feeding (EF) group (12.2%), followed by the partial breastfeeding (PB) (11.3%) and EB groups (10.7%). Compared with the EF group, the adjusted odds ratio for FS was 0.87 (95% confidence interval, 0.86 to 0.88, P < 0.001) and 0.93 (0.92 to 0.94, P < 0.001) in the EB and PB groups, respectively. The protective effect by age 2.5 years was significant in both the EB (0.85; 0.84 to 0.86, P < 0.001) and PB (0.92; 0.90 to 0.93, P < 0.001) groups. In contrast, the protective effect was not significant in the PB group and inconsistent in the EB group after 2.5 years.

CONCLUSION

Breastfeeding has a protective effect against FS in the most prevalent age period, from 0 to 2.5 years. Despite the limited effect after age 2.5 years, we support the current recommendation for prolonged breastfeeding to promote childhood health.

Assessing Bulbar Function in Spinal Muscular Atrophy Using Patient-Reported Outcomes

BACKGROUND

Novel Spinal Muscular Atrophy (SMA) treatments have demonstrated improvements on motor measures that are clearly distinct from the natural history of progressive decline. Comparable measures are needed to monitor bulbar function, which is affected in severe SMA.

OBJECTIVE

To assess bulbar function with patient-reported outcome measures (PROs) and determine their relationships with clinical characteristics.

METHODS

We recruited 47 non-ambulatory participants (mean (SD) age = 29.8 (13.7) years, range = 10.3-73.2) with SMA. PROs including Voice Handicap Index (VHI) and Eating Assessment Tool-10 (EAT-10) were collected alongside clinical characteristics and standardized motor assessments. Associations were assessed using Spearman correlation coefficients and group comparisons were performed using Wilcoxon rank sum tests.

RESULTS

A majority of the 47 participants were SMA type 2 (70.2%), non-sitters (78.7%), 3 copies of SMN2 (77.5%), and using respiratory support (66.0%). A majority (94%) reported voice issues primarily in 8/30 VHI questions. Problems included: difficulty understanding me in a noisy room (87.2%); difficult for people to hear me (74.5%); and people ask me to repeat when speaking face-to-face (72.3%). A majority (85.1%) reported swallowing issues primarily in 3/10 EAT-10 questions: swallowing pills (68.1%); food sticks to my throat (66.0%); and swallowing solids (61.7%). The two PROs were moderately associated (rs = 0.66).

CONCLUSIONS

Weaker individuals with SMA experience bulbar problems including difficulties with voice and swallowing. Further refinement and assessment of functional bulbar scales will help determine their relevance and responsiveness to changes in SMA. Additional study is needed to quantify bulbar changes caused by SMA and their response to disease-modifying treatments.

The Quality, Reliability, and Accuracy of Videos Regarding Exercises and Management for Dysphagia in Pediatric Populations Uploaded on YouTube

Objectives: YouTube is well known for providing easy access to various kinds of video content. In this study, we investigated the quality and reliability of videos on YouTube addressing exercise or dysphagia management in the pediatric population. Methods: Video quality and reliability were assessed by using the Global Quality Scale (GQS) and a modified DISCERN tool, respectively. The accuracy of the information in each video was also evaluated. Other information, including the video source, length, date of upload, as well as the number of views, likes, dislikes, and comments were investigated, and statistical significance was determined. Results: In total, 22 videos on exercises and dysphagia management in pediatric populations were evaluated; 36.4% and 72.7% of these videos did not have high quality or reliability, respectively. Moreover, half of the videos did not contain accurate information. Even when videos were created by medical specialists, many of these YouTube videos were of low quality, reliability, and accuracy. Conclusions: The reliability, quality, and accuracy of many videos on exercise or dysphagia management in the pediatric population were low. Video creators, especially medical specialists, should strive to create videos with high quality, reliability, and accuracy.

Esophageal dysphagia in neuromuscular disorder patients with validity and reliability study of the brief esophageal dysphagia questionnaire

Esophageal dysphagia (ED) is often underestimated in neuromuscular disorders (NMD) and it is important to evaluate the esophageal phase of swallowing with an easy and rapid screening test. We aimed both to assess the prevalence of ED in NMD and to perform validity and reliability study of the brief easophageal dysphagia questionnaire (BEDQ) screening test in NMD patients. This prospective cross-sectional clinical study was performed on NMD patients. Demographic features and disease characteristics were recorded. Endoscopic evaluation for oropharyngeal dysphagia (OD) and high-resolution esophageal manometry for ED were performed. In addition, the BEDQ and the 10-item eating assessment tool (EAT-10) were used to all subjects. Cronbach's α and principle components factor analysis (PFCA) with varimax rotation were used for reliability. The Chicago Classification version 3 (CCv3) level (high-resolution esophageal manometry) and EAT-10 was used for validity. A total of 50 patients were included in the study. Thirty-four (68%) patients were diagnosed with myasthenia gravis and 16 (32%) patients were diagnosed with myopathy. Esophageal dysphagia according to the CCv3 was found in 33 (66%) of patients. While the Cronbach's α was excellent as 0.937 for test overall the T-BEDQ scale. The PCFA included all scale items and resulted in a single factor (eigenvalue = 5.72, 71.5%). The all BEDQ scores were demonstrated good correlation with EAT-10 score and very good correlation with CCv3 level. Evaluation of swallowing in patients with NMD should include not only the oropharyngeal phase of swallowing, but also esophageal phase. For this purpose, the BEDQ can be used as a rapid, valid, and reliable test for the evaluation of ED.

Validation and Cultural Adaptation of an Arabic Version of Pediatric Eating Assessment Tool (Pedi-EAT-10Arabic)

Pediatric eating assessment tool (Pedi-EAT-10_Arabic) is a validated and reliable caregiver administered outcome instrument designed for detection of children at high risk of penetration/aspiration. The objective of this study is to translate and validate the Arabic version of Pedi-EAT-10 and to correlate its results with pharyngeal residue and aspiration on fiber optic endoscopic examination of swallowing (FEES). A cross-sectional study including 202 children selected randomly from those attending the swallowing clinic in phoniatrics unit, Otorhinolaryngology department (ORL) at main university hospital between February 2019 and October 2020 complaining of dysphagia. For test-retest reliability, one hundred caregivers refilled the Pedi-EAT-10_Arabic after a 2-week period following their first visit. Validity was established by comparing the scores of dysphagia patients to healthy controls. Internal consistency of Pedi-EAT-10_Arabic was high (Cronbach's alpha 0.986). Intra class correlation showed excellent test-retest reliability (r = 0.968). The median Pedi-EAT 10_Arabic score was significantly higher in dysphagia group compared to healthy controls. (Median 27 IQR 21-34 for cases compared to median zero IQR 0-2 points for healthy controls, P less than 0.001). A strong correlation was found between Pedi-EAT 10_Arabic scores and PAS scores with Spearman's correlation coefficient r = 0.803 and P < 0.001. The ROC for evaluating the discriminatory capacity of Pedi-EAT 10 for aspiration showed an AUC of 0.92 (95% CI of 0.89 to 0.96)_. Conclusion: Pedi-EAT 10_Arabic was found to be a valid and reliable screening tool for further instrumental assessment of risk of dysphagia in pediatric population.

Body mass index in type 2 spinal muscular atrophy: a longitudinal study

The aim of this retrospective study was to review body mass index (BMI) in a large cohort of Italian pediatric type 2 spinal muscular atrophy (SMA) patients, aged between 0 and 20 years and to establish possible differences in relation to a number of variables such as ventilation, motor function, and survival motor neuron 2 gene copies. Cross-sectional data were collected from 102 patients for a total of 344 visits. Standard growth charts for height and weight were used as reference, with age adjusted BMI calculated using the Center for Disease and Prevention Children's BMI Tool. In the 344 visits, weight ranged between 3.90 and 83 kg, and the BMI between 8.4 and 31.6 with a BMI/age z-scores <  - 2SD present in 28% and BMI/age z-scores >  + 2SD in 9% of the measurements. The BMI/age z-scores were relatively stable < 5 years of age with an increasing number of patients <  - 2SD after the age of 5, and a wider range of BMI/age z-scores after the age of 13. A difference on the BMI/age z-scores was found among the different age subgroups (< 5, 5-12, ≥ 13 years). A multivariate analysis in 58 patients with longitudinal assessments showed that baseline BMI/age z-scores and gender were significantly contributing to the changes while other variables were not.

CONCLUSION

Our results confirm that careful surveillance of weight and BMI/age z-scores is needed in type 2 SMA. Further studies, including assessments of chewing and swallowing and of lean/fat body mass, will help to better understand the possible mechanisms underlying weight issues.

WHAT IS KNOWN

• Feeding difficulties have been reported in a few studies and were invariably found in patients with type 1 SMA. • Type 2 SMA patients often have low BMI with a relevant number of patients requiring tube feeding.

WHAT IS NEW

• Reduction in BMI/age z-score overtime appeared to depend on baseline BMI/age z-score and gender. • Patients with a low BMI/age z-score were at higher risk of developing further reduction.

Esophageal Dysphagia in Children: State of the Art and Proposal for a Symptom-Based Diagnostic Approach

Pediatric esophageal dysphagia (PED) is an infrequent condition that can be determined by a large number of disorders. The etiologic diagnosis is challenging due to overlapping clinical phenotypes and to the absence of pediatric diagnostic guidelines. This review aims to summarize the most relevant causes of ED during childhood, highlight the clinical scenarios of PED presentation and discuss the indications of available diagnostic tools. Available information supports that PED should always be investigated as it can underlie life-threatening conditions (e.g., foreign body ingestion, mediastinal tumors), represent the complication of benign disorders (e.g., peptic stenosis) or constitute the manifestation of organic diseases (e.g., eosinophilic esophagitis, achalasia). Therefore, the diagnosis of functional PED should be made only after excluding mucosal, structural, or motility esophageal abnormalities. Several clinical features may contribute to the diagnosis of PED. Among the latter, we identified several clinical key elements, relevant complementary-symptoms and predisposing factors, and organized them in a multi-level, hierarchical, circle diagram able to guide the clinician through the diagnostic work-up of PED. The most appropriate investigational method(s) should be chosen based on the diagnostic hypothesis: esophagogastroduodenoscopy has highest diagnostic yield for mucosal disorders, barium swallow has greater sensitivity in detecting achalasia and structural abnormalities, chest CT/MR inform on the mediastinum, manometry is most sensitive in detecting motility disorders, while pH-MII measures gastroesophageal reflux. Further studies are needed to define the epidemiology of PED, determine the prevalence of individual underlying etiologies, and assess the diagnostic value of investigational methods as to develop a reliable diagnostic algorithm.

Oral and Swallowing Abilities Tool (OrSAT) for Type 1 SMA Patients: Development of a New Module

We describe the development of a new tool specifically designed to record oral abilities, swallowing and, more generally, feeding in young type 1 SMA patients, to be used during the first 24 months of life.The tool is composed by a checklist and a separate section summarizing the functional abilities into levels of feeding/swallowing impairment. The checklist includes 12 questions assessing aspects thought to be clinically meaningful for a type 1 SMA population and developmentally appropriate for infants during the first months of life. Each item is graded with a score of 0 or 1, depending on the child's ability to perform the activity. As some items are age-dependent, the number of items to be used, and therefore the maximum score, changes with increasing age. The levels of feeding/swallowing impairment include four levels that can be identified using easily identifiable clinical criteria.In an attempt to validate the tool in an untreated population we applied it to 24 type 1 SMA patients (age range: 2.3-24.1 months, mean: 10.8) in whom the same information collected by the new tool had been previously recorded using a less-structured format.When patients were classified in three groups according to the Dubowitz decimal classification, there was a significant difference both at baseline and at follow-up (p < 0.001). The items assessing fatigue during the nursing sessions were the most frequently impaired even in infants who did not have any other obvious clinical sign of swallowing difficulties.

Assessing the ability of boys with Duchenne muscular dystrophy age 4-7 years to swallow softgel capsules: Clinical trial experience with edasalonexent

WHAT IS KNOWN AND OBJECTIVE

There is limited information on acceptability of solid dosage forms by young patients with neuromuscular disorders such as Duchenne muscular dystrophy (DMD). Capsule size selection and ability to swallow the NF-κB inhibitor edasalonexent were assessed in males 4-7 years of age with DMD enrolled in clinical trials for a new therapeutic.

METHODS

The Phase 3 PolarisDMD randomized, double-blind, placebo-controlled trial enrolled 131 patients from 8 countries. The Phase 2 MoveDMD trial enrolled 31 patients in the United States. As part of enrolment criteria, these trials assessed the ability to swallow softgel 100 mg (~10 mm) or 250 mg (~15 mm) capsules formulated with a phosphatidylcholine-containing coating. Supportive strategies included pill-swallowing techniques and aids.

RESULTS

Most (97%; 175/181) patients screened were able to swallow capsules. In Phase 2 and 3, respectively, 77% (24/31) and 61% (80/131) of enrolled patients selected the larger capsule and among those selecting the smaller capsule, most transitioned to the larger capsule. There were no obvious geographical differences in ability to swallow capsules and size selection was not correlated with age. Compliance was high (92%-98%) through 52 weeks of dosing with no discontinuations due to capsule burden.

WHAT IS NEW AND CONCLUSION

Swallowing of capsules was not a barrier for drug administration in young patients with DMD. Capsule formulations may be an acceptable alternative to liquid formulations for children as young as 4 years of age.

Nutritional, Gastrointestinal and Endo-Metabolic Challenges in the Management of Children with Spinal Muscular Atrophy Type 1

The management of patients with spinal muscular atrophy type 1 (SMA1) is constantly evolving. In just a few decades, the medical approach has switched from an exclusively palliative therapy to a targeted therapy, transforming the natural history of the disease, improving survival time and quality of life and creating new challenges and goals. Many nutritional problems, gastrointestinal disorders and metabolic and endocrine alterations are commonly identified in patients affected by SMA1 during childhood and adolescence. For this reason, a proper pediatric multidisciplinary approach is then required in the clinical care of these patients, with a specific focus on the prevention of most common complications. The purpose of this narrative review is to provide the clinician with a practical and usable tool about SMA1 patients care, through a comprehensive insight into the nutritional, gastroenterological, metabolic and endocrine management of SMA1. Considering the possible horizons opened thanks to new therapeutic frontiers, a nutritional and endo-metabolic surveillance is a crucial element to be considered for a proper clinical care of these patients.

Screening for oropharyngeal dysphagia in adult patients with neuromuscular diseases using the Sydney Swallow Questionnaire

INTRODUCTION/AIMS

Oropharyngeal dysphagia is common in patients with neuromuscular diseases (NMDs). Its early recognition is vital for proper management. We tested a large cohort of adult NMD patients for oropharyngeal dysphagia using the Sydney Swallow Questionnaire (SSQ). We also looked for possible differences in characteristics of oropharyngeal dysphagia in various NMD groups and diseases. Finally, we compared results of this screening with those from their corresponding medical records for eventual "clinical history" of dysphagia.

METHODS

We asked patients to fill in the SSQ during follow-up outpatient visits at our neuromuscular reference center. A total score above the cutoff score of 118.5 out of 1700 was indicative of oropharyngeal dysphagia.

RESULTS

Of the 304 adult patients assessed for eligibility, 201 NMD patients (96 women and 105 men, aged 49.0 ± 16.2 years) were included and tested in this study. Oropharyngeal dysphagia was detected in 45% of all the NMD patients when using the SSQ, whereas only 12% had a positive medical record for dysphagia. The median SSQ scores for patients with myotonic syndromes (including myotonic dystrophy type 1), with amyotrophic lateral sclerosis, and with facioscapulohumeral dystrophy were above the cutoff score. The SSQ scores obtained revealed distinct oropharyngeal dysphagia characteristics in the different NMD groups and diseases.

DISCUSSION

The SSQ tests positively for oropharyngeal dysphagia in a higher proportion of NMD patients compared with their medical records. The distinct oropharyngeal dysphagia characteristics we revealed in different NMD groups and diseases may help to elaborate adapted clinical approaches in the management of oropharyngeal dysphagia.

Dysphagia and Dysarthria in Children with Neuromuscular Diseases, a Prevalence Study

BACKGROUND

Dysphagia and dysarthria are frequently described in pediatric neuromuscular diseases (pNMD). The consequences can be substantial: failure to thrive, malnutrition, aspiration pneumonia, or communication problems. Early detection and identification of risk factors and etiology support preventing complications and morbidity, including impact on quality of life. Information about the prevalence of dysphagia and dysarthria in pNMD is scarce.

OBJECTIVE

To describe the pooled prevalence of dysphagia and dysarthria in pNMD in the Netherlands. In addition, we describe the prevalence of dysphagia and dysarthria each, and the prevalence of chewing (oral) and swallowing problems per diagnostic group, based on their anatomic origin.

METHODS

Data were collected from 295 children (mean age 11;0 years, range 2;6-18;0) with pNMD in 12 hospitals and rehabilitation centers in the Netherlands. A speech language therapist established whether dysphagia and dysarthria were present or not.

RESULTS

In almost all the 14 diagnostic groups of pNMD, dysphagia and dysarthria were present. Pooled overall prevalence of dysphagia and dysarthria was 47.2% and 31.5%, respectively. Of 114 children with dysphagia, 90.0% had chewing problems, 43.0% showed swallowing problems and 33.3% showed both chewing and swallowing problems.

CONCLUSIONS

The overall pooled prevalence of dysphagia and dysarthria was high in the population of pNMD. It can be argued that periodic monitoring of dysphagia and dysarthria and early referral to a speech language therapist should be a necessity from the start of the diagnosis in the whole pNMD population.

Feeding and Swallowing Problems in Infants with Spinal Muscular Atrophy Type 1: an Observational Study

BACKGROUND

Infantile hereditary proximal spinal muscular atrophy (SMA) type 1 is characterized by onset in the first 6 months of life and severe and progressive muscle weakness. Dysphagia is a common complication but has not been studied in detail.

OBJECTIVE

To study feeding and swallowing problems in infants with SMA type 1, and to explore the relation between these problems and functional motor scores.

METHODS

We prospectively included 16 infants with SMA type 1 between September 2016 and October 2018. Eleven infants received palliative care and five infants best supportive care in combination with nusinersen. We compiled and used an observation list with feeding related issues and observed feeding sessions during inpatient and outpatient visits. The Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND) was used as a measure of motor function.

RESULTS

All infants in the palliative care group (median onset of disease 14 days (range 1-56); median inclusion in the study 52 days (range 16-252) demonstrated symptoms of fatigue during feeding and unsafe swallowing. Symptoms were short nursing sessions (10-15 minutes), and not being able to finish the recommended feeding volumes (72%); increased frequency of feeding sessions (55%); coughing when drinking or eating (91%), and wet breathing during and after feeding (64%).Two out of five infants in the nusinersen group (median onset of disease 38 days (range 21-90); inclusion in the study at 63 days (range 3-218) were clinically pre-symptomatic at the start of treatment. The other three infants showed symptoms of fatigue and unsafe swallowing at inclusion in the study. These symptoms initially decreased after the start of the treatment, but (re)appeared in all five infants between the ages of 8 to 12 months, requiring the start tube of feeding. In the same period motor function scores significantly improved (median increase CHOP INTEND 16 points).

CONCLUSION

Impaired feeding and swallowing remain important complications in infants with SMA type 1 after the start of nusinersen. Improvement of motor function does not imply similar gains in bulbar function.

Characterization of Esophageal and Sphincter Reflexes across Maturation in Dysphagic Infants with Oral Feeding Success vs Infants requiring Gastrostomy

To test the hypothesis that esophageal and sphincteric sensory-motor reflexes are distinct across maturation in infants with dysphagia receiving gastrostomy-tube (G-tube). This is a retrospective review of 29 dysphagic infants (N = 15 study requiring gastrostomy, N = 14 age matched control achieving oral feeds) that underwent longitudinal pharyngeal-esophageal manometry at 42.3 (37-50.2) weeks postmenstrual age (PMA) and 48.9 (43.3-57.9) weeks PMA. Graded stimuli (0.1-5 mL) of varying media (air, water, and apple juice) tested esophageal peristaltic reflex, upper esophageal sphincter contractile reflex (UESCR), and lower esophageal sphincter relaxation reflex (LESRR). Comparisons were performed between study and controls and across maturation (time-1 vs time-2). Data represented as mean ± SE or OR (95% CI). Across maturation (time-1 vs time-2): Study infants did not exhibit significant differences across in peristaltic, UES, or LES reflexes (all p > 0.05). In contrast, controls exhibited increased UES resting pressure (13 ± 3 vs 17 ± 3 mmHg, p = 0.001), LES resting pressure (22 ± 3 vs 25 ± 3 mmHg, p < 0.009), LES nadir pressure (0.5 ± 1 vs 4.3 ± 1 mmHg, p = 0.001), and esophago-deglutition responses [2.5 (1.23-4.88), p = 0.04], and decreased secondary peristalsis [0.44 (0.31-0.61), p = 0.001], UESCR [0.4 (0.25-0.65), p = 0.001], LESRR [0.4 (0.24-0.75), p = 0.01], and symptoms [0.6 (0.45-0.83), p = 0.005]. Among infants with dysphagia, esophageal provocation induced peristaltic reflex, UESCR, and LESRR advance with longitudinal maturation when infants are oral-fed successfully, but not in those who received gastrostomy. Underlying mechanisms may be related to esophageal sensitivity, afferent or efferent transmission, and coordination of upstream excitation and downstream inhibition, which can be potential therapeutic targets for improving feeding capabilities after gastrostomy placement in infants with dysphagia.

A Multidisciplinary Evaluation of Patients with DMD in An Italian Tertiary Care Center

With more widespread prolonged survival, Duchenne muscular dystrophy patients progressively experience multisystem complications. We retrospectively reviewed the charts of 132 Duchenne patients (112 alive/20 dead, age 3.5÷32.3 years) with the aims: 1) to provide a comprehensive description of the clinical status considering different aspects of the disease; 2) to propose a new scoring tool able to consider and pool together heterogeneous different functional. Five functions were analyzed: cardiac, respiratory, nutritional, ambulation and scoliosis. For each function, different items were considered and classified according to clinical severity (as indicated by international guidelines) and an incremental scoring was assigned. In addition, a global score incorporating all functions was defined. The scoring system confirmed that despite the significant protective role of steroids, all functions deteriorated with age. The severity of the global score became significantly higher since the age of 13 years. The severity of cardiac, respiratory and nutritional dysfunction was higher since 18 years. Deceased patients were characterized by significantly worse cardiac function, absence of steroid therapy and later use of respiratory assistive devices. The index proposed in this pilot study is a promising tool able to aggregate and correlate heterogeneous functions. It could become either an individual prognostic indicator of decline or a global score to evaluate changes in clinical trials therefore allowing multicenter studies, optimizing the management of both the primary and the secondary complications of the disease and understanding their relative impact.

Nutritional practices in pediatric patients with neuromuscular disorders

Children with neuromuscular disorders (NMDs) may experience a spectrum of nutritional issues with adverse health consequences. This review summarizes the current understanding of nutritional care in pediatric NMDs, recognizing disease-specific aspects of nutrition alongside the challenges and needs in dietetic care. General or disease-related nutritional issues for children with NMDs include being underweight, overweight, or obese and having swallowing difficulty, gastroesophageal reflux, diarrhea, and/or constipation. Specific challenges in NMD nutritional assessment include alterations in body composition and energy requirements and difficulties in measuring anthropometry. Multidisciplinary dietetic intervention focuses on optimizing nutrient intakes to avert growth failure or obesity and managing feeding difficulties and gastrointestinal problems. Care guidelines are disease specific and vary in approach and detail. To promote best clinical practice across diverse settings, a standardized approach to assessing growth and nutrition across all pediatric NMDs is needed to direct optimal care centered on individual requirements. Future studies should focus on determining the prevalence of specific nutritional issues and the effectiveness of specific interventions among various pediatric NMD populations.

Early detection of dysphagia and dysarthria in children with neuromuscular disorders: Diagnostic accuracy of a Screeninglist for Physicians

PURPOSE

Regardless of age or disease stage, children with neuromuscular disorders (NMD) are at risk of developing dysphagia and/or dysarthria. It is important to screen these children regularly in order to detect and treat problems as soon as possible. To date, there are no standardized tools for screening for dysphagia and dysarthria in children with NMD (pNMD). Thus, children are not always referred for assessment by a speech language therapist (SLT). A new screening instrument for dysphagia and dysarthria has been developed, the Screeninglist Physician of the Diagnostic list for Dysphagia and Dysarthria in pediatric NMD (DDD-pNMD). The diagnostic accuracy was estimated in this study.

METHODS

Sensitivity and specificity were assessed in 131 children aged 2.0-18.0 years by comparing the outcome of the Screeninglist Physician with the diagnosis of dysphagia and/or dysarthria established by an SLT.

RESULTS

The sensitivity of the Screeninglist Physician was 88% and its specificity was 63%. The AUC was 0.83. The prevalence of dysphagia and/or dysarthria was 53%.

CONCLUSION

The Screeninglist Physician of the DDD-pNMD is the first valid screening tool for physicians to identify children with NMD with possible dysphagia and/or dysarthria, thereby enabling timely referral to an SLT.

Where is my mouth? Rapid experience-dependent plasticity of perceived mouth position in humans

Several neural and behavioural studies propose that movements of the hand to the mouth are a key motor primitive of the primate sensorimotor system. These studies largely focus on sensorimotor coordination required to reach the mouth with the hand. However, hand-to-mouth movement depends on representing the location of the mouth. We report 5 experiments using a novel dental model illusion (DMI) that investigates the neural representation of mouth position. When participants used their right index finger to touch the teeth of an unseen dental model in synchrony with the experimenter's tactile stimulation of the participant's own teeth, participants felt that the position of their own teeth was shifted towards the dental model and stated that their right index finger was touching their actual teeth. This result replicated across four experiments and provides an oral analogue to the rubber hand illusion. Synchrony between the two tactile motions was necessary condition to elicit DMI (Experiment 3). DMI was moderately affected by manipulating the macrogeometric or microgeometric tactile properties of the dental model, suggesting cognitive images of one's own oral morphology play a modest role (Experiments 4 and 5). Neuropsychological theories often stress that hand-to-mouth movement emerges early in development or may even be innate. Our research suggests that general, bottom-up principles of multisensory plasticity suffice to provide spatial representation of the egocentric core, including mouth position.

Novel Missense Variants in ADAT3 as a Cause of Syndromic Intellectual Disability

Autosomal recessive variants in the adenosine deaminase, tRNA specific 3 ( ADAT3 ) gene cause a syndromic form of intellectual disability due to a loss of ADAT3 function. This disorder is characterized by developmental delay, intellectual disability, speech delay, abnormal brain structure, strabismus, microcephaly, and failure to thrive. A small subset of individuals with ADAT3 deficiency have other structural birth defects including atrial septal defect, patent ductus arteriosus, hypospadias, cryptorchidism, and micropenis. Here, we report a sibling pair with novel compound heterozygous missense variants that affect a conserved amino acid in the deaminase domain of ADAT3. These siblings have many of the features characteristic of this syndrome, including, intellectual disability, hypotonia, esotropia, failure to thrive, and microcephaly. Both had gastroesophageal reflux disease (GERD), feeding problems, and aspiration requiring thickening of feeds. Although they have no words, their communication abilities progressed rapidly when they began to use augmentative and alternative communication (AAC) devices. One of these siblings was born with an anterior congenital diaphragmatic hernia, which has not been reported previously in association with ADAT3 deficiency. We conclude that individuals with ADAT3 deficiency should be monitored for GERD, feeding problems, and aspiration in infancy. They may also benefit from the use of AAC devices and individualized educational programs that take into account their capacity for nonverbal language development. Additional studies in humans or animal models will be needed to determine if ADAT3 deficiency predisposes to the development of structural birth defects.

Dysphagia diagnosis with questionnaire, tongue strength measurement, and FEES in patients with childhood-onset muscular dystrophy

INTRODUCTION

Dysphagia in progressive muscle diseases is primarily due to muscle weakness. Objective of our study is to investigate the prevalence and phenotypes of dysphagia in patients with childhood onset muscular dystrophy (MD) with the use of a validated questionnaire, the measurement of tongue strength and Flexible Endoscopic Evaluation of Swallowing (FEES).

METHODS

Prospective observational longitudinal study of dysphagia in a cohort of 58 patients attending the Pediatric Department Center for Neuromuscular Diseases. Control participants were 56 age and sex matched healthy volunteers. Dysphagia was evaluated with the Eating Assessment Tool-10 (EAT-10), and the measurement of Maximal Isometric Tongue Pressure (MITP) and tongue endurance (Iowa Oral Performance Instrument-IOPI). Dysphagic patients were submitted to FEES. Recorded data included demographic and anthropometric characteristics, type of MD, feeding status, and spirometry.

RESULTS

Our patients' cohort consisted of 41 children, 11 adolescents, and 6 adults. Based on EAT-10, 20.7% of the patients were dysphagic: 14.63% of children, 27.3% of adolescents and 50% of adults. The main complain was solid food dysphagia. Spirometry parameters mean values for children and adolescent patients corresponded to lower than the fifth percentile. Means of FVC and FEV1 expressed as % predicted for adult patients were 27.8 (SD:25.05) and 28.8 (SD:28.44) respectively. Reduced tongue strength was measured to children aged 9-10, adolescent and adult MD patients. The main FEES findings were pharyngeal residue, spillage of food before the swallow, and supraglottal penetration.

DISCUSSION

This is the first study to use a validated questionnaire to evaluate dysphagia in childhood onset MD and report dyphagia prevalence at different patients' age. This is the first study reporting MITP in children and adults with generalised MD. Tongue pressures are reduced well before clinical signs of dysphagia are present.

CONCLUSION

Screening of potentially dysphagic MD patients can be based on a validated questionnaire. Patients with an EAT-10 score suggestive of dysphagia at regular follow-up can have the MITP measured and in the case of reduced values a thorough dysphagia evaluation with FEES is indicated.

"Everyone sees you sitting there struggling with your food": experiences of adolescents and young adults with cerebral palsy

Objective: The impact of difficulties with eating and drinking in adolescents and young adults with cerebral palsy is unknown. The purpose of this study is to find out which difficulties adolescents and young adults with cerebral palsy experience with eating and drinking in daily life and how they deal with these difficulties. The study also explores how they think about themselves with respect to eating and what does or does not help regarding social participation. Method: We collected the data from ten participants with spastic cerebral palsy (aged 15-23 years) living in the Netherlands. We used a qualitative study design with a conventional content analysis. Semi-structured in-depth interviews were used to identify meaningful factors related to eating and drinking difficulties. We coded relevant phrases from each interview and clustered and synthesized them into categories. Result: We derived four categories from the transcripts: (I) perceived eating and drinking difficulties (e.g., not managing to eat all food textures and/or choking); (II) challenges in physical and social context (e.g., accessibility of restaurants, menu supply, and/or needing assistance or not); (III) dealing with eating and drinking difficulties (e.g., adaptation, food avoidance, and/or giving up); (IV) Negative feelings about their eating and drinking (e.g., shame, frustration, fear for choking, and/or concerns about the future). One striking finding was that most participants had not recently received either monitoring or intervention for their feeding skills. Conclusion: This study shows that adolescents and young adults with cerebral palsy experience many restrictions in eating and drinking situations leading to negative feelings and lower participation levels, while little attention is directed towards these difficulties. Regular multidisciplinary rehabilitation programs should include evaluation, advice, and intervention regarding eating and drinking ability in order to increase social participation and self-management. Implications for Rehabilitation Adolescents and young adults with cerebral palsy experience difficulties with eating, drinking, and swallowing, and they encounter difficulties in participating in mealtimes with family and friends. Although adolescents and young adults with cerebral palsy rated their eating and drinking abilities as reasonable, they reported feelings of shame, frustration, fear, distress, and concerns for the future or unknown environments. Regular multidisciplinary involvement with eating and drinking is needed for purposes of evaluation, advice, and intervention throughout the life course, adjusted to living conditions and the latest evidence. Adolescents and young adults with cerebral palsy showed limited initiative in asking for personal assistance in eating and drinking activities.

Nutritional Challenges in Duchenne Muscular Dystrophy

Neuromuscular diseases (NMDs) represent a heterogeneous group of acquired or inherited conditions. Nutritional complications are frequent in NMDs, but they are sometimes underestimated. With the prolongation of survival in patients with NMDs, there are several nutritional aspects that are important to consider, including the deleterious effects of overnutrition on glucose metabolism, mobility, and respiratory and cardiologic functions; the impact of hyponutrition on muscle and ventilatory function; constipation and other gastrointestinal complications; chewing/swallowing difficulties with an increased risk of aspiration that predisposes to infectious diseases and respiratory complications; as well as osteoporosis with an associated increased risk of fractures. The aim of this review is to provide a comprehensive analysis of the nutritional aspects and complications that can start in children with Duchenne muscular dystrophy (DMD) and increase with ageing. These aspects should be considered in the transition from paediatric clinics to adult services. It is shown that appropriate nutritional care can help to improve the quality of life of DMD patients, and a multidisciplinary team is needed to support nutrition challenges in DMD patients. However, studies on the prevalence of overnutrition and undernutrition, gastrointestinal complications, infectious diseases, dysphagia, and reduced bone mass in the different types of NMDs are needed, and appropriate percentiles of weight, height, body mass index, and body composition appear to be extremely important to improve the management of patients with NMD.

Pediatric feeding and swallowing rehabilitation: An overview

Children with neurological disabilities frequently have problems with feeding and swallowing. Such problems have a significant impact on the health and well-being of these children and their families. The primary aims in the rehabilitation of pediatric feeding and swallowing disorders are focused on supporting growth, nutrition and hydration, the development of feeding activities, and ensuring safe swallowing with the aim of preventing choking and aspiration pneumonia. Pediatric feeding and swallowing disorders can be divided into four groups: transient, developmental, chronic or progressive.This article provides an overview of the available literature about the rehabilitation of feeding and swallowing disorders in infants and children. Principles of motor control, motor learning and neuroplasticity are discussed for the four groups of children with feeding and swallowing disorders.

The 6-min mastication test: a unique test to assess endurance of continuous chewing, normal values, reliability, reproducibility and usability in patients with mitochondrial disease

In patients with mitochondrial disease, fatigue and muscle problems are the most common complaints. They also experience these complaints during mastication. To measure endurance of continuous mastication in patients with mitochondrial diseases, the 6-min mastication test (6MMT) was developed. This study included the collection of normal data for the 6MMT in a healthy population (children and adults). During 6 min of continuous mastication on a chew tube chewing cycles per minute, total amount of chewing cycles and the difference between minute 1 (M₁ ) and minute 6 (M₂ ) were collected in 271 healthy participants (5-80 years old). These results were compared with those of nine paediatric and 25 adult patients with a mitochondrial disease. Visual analogue scale (VAS) scores were collected directly after the test and after 5 min. A qualitative rating was made on masticatory movements. The reproducibility of the 6MMT in the healthy population with an interval of approximately 2 weeks was good. The inter-rater reliability for the observations was excellent. The patient group demonstrated lower total amount of chewing cycles or had greater differences between M₁ and M₆ . The 6MMT is a reliable and objective test to assess endurance of continuous chewing. It demonstrates the ability of healthy children and adults to chew during 6 min with a highly stable frequency of mastication movements. The test may give an explanation for the masticatory problems in patient groups, who are complaining of pain and fatigue during mastication.