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

Assessing Swallowing and Mastication Using the Swallowing Proficiency for Eating and Drinking Protocol Among Healthy Adults

BACKGROUND

Objective evaluation of swallowing using single bolus consistency are popular among Speech-Language Pathologists (SLPs) but has limited generalization to other bolus consistencies. The Swallowing Proficiency for Eating and Drinking (SPEAD) test assesses the oral and pharyngeal phases of swallowing using three different consistencies.

OBJECTIVES

The aim of this study was to establish normative data for the SPEAD test among healthy individuals aged 20-79 years.

METHOD AND MATERIALS

One hundred and twelve healthy adults recruited from the community were divided into three age groups (20-39.11, 40-59.11, & 60-79.11 years). Participants swallowing 100 g of water and thickened Electral, and 6.67 g of Parle Monaco was video recorded for data analysis.

RESULTS

Cronbachs Alpha test indicated good to excellent internal consistency and inter-class correlation test revealed a high level of inter-rater reliability for all SPEAD parameters. Older adults exhibited a higher number of bites, chews, and swallows, and required more time to swallow compared to younger and middle adults. Similarly, speed of ingestion and SPEAD rate were lowest in older adults. SPEAD indices also showed significant differences across the three consistencies at p < 0.01.

CONCLUSION

In summary, the SPEAD test was found to be feasible, reliable, and valid in healthy adults of India between 20 and 79 years of age. The age and sex based normative data established in this study will enable SLPs in assessing the presence and / or absence of swallowing difficulties in the oral and pharyngeal phases across different consistencies using one test.

Natural History of Mandibular Function in Spinal Muscular Atrophy Types 2 and 3

Background

Hereditary proximal spinal muscular atrophy (SMA) is characterized by abnormal alpha motor neuron function in brainstem and spinal cord. Bulbar dysfunction, including limited mouth opening, is present in the majority of patients with SMA but it is unknown if and how these problems change during disease course.

Objective

In this prospective, observational, longitudinal natural history study we aimed to study bulbar dysfunction in patients with SMA types 2 and 3.

Methods

We included 44 patients with SMA types 2 and 3 (mean age was 33.6 (95% CI 28.4;38.9) and re-examined them after on average 4 years. None were treated with SMN-modulating treatments before or during the course of this study. Longitudinal assessments included a questionnaire on mandibular and bulbar function, the Mandibular Function Impairment Questionnaire (MFIQ), and a clinical examination of masticatory performance, maximum voluntary bite force, and mandibular movements including the active maximal mouth opening.

Results

We found significant higher MFIQ scores and a significant decrease of all mandibular movements in patients with SMA type 2 (p < 0.001), but not in SMA type 3. Masticatory performance and maximum voluntary bite force did not change significantly. Mean reduction of active maximal mouth opening at follow-up was 3.5 mm in SMA type 2 (95% CI: 2.3; 4.7, p < 0.001). SMA type 2 was an independent predictor for a more severe reduction of the mouth opening (β= -2.0 mm (95% CI: -3.8; -0.1, p = 0.043)).

Conclusions

Bulbar functions such as mandibular mobility and active maximum mouth opening decrease significantly over the course of four years in patients with SMA type 2.

Measuring Fatigue and Fatigability in Spinal Muscular Atrophy (SMA): Challenges and Opportunities

Fatigue, a common symptom, together with the characteristic of performance fatigability, are well-documented features of SMA that impact quality of life and function. Importantly, establishing associations between multidimensional self-reported fatigue scales and patient performance has proven difficult. This review was conducted to evaluate the various patient-reported fatigue scales applied in SMA, with the objective of considering the limitations and advantages of each measure. Variable use of fatigue-related nomenclature, including conflicting terminology interpretation, has affected assessment of physical fatigue attributes, specifically perceived fatigability. This review encourages the development of original patient-reported scales to enable perceived fatigability assessment, providing a potential complementary method of evaluating treatment response.

Mastication in Patients with Spinal Muscular Atrophy Types 2 and 3 is Characterized by Abnormal Efficiency, Reduced Endurance, and Fatigue

Mastication problems can have a negative impact on the intake of food and quality of life. This cross-sectional study characterizes mastication problems using clinical and instrumental assessments in patients with spinal muscular atrophy (SMA) types 2 and 3 with self-reported bulbar problems. We included 27 patients (aged 13–67 years), 18 with SMA type 2 and 9 patients with SMA type 3 (of whom three were still ambulant) and applied a questionnaire, clinical mastication tests (TOMASS and 6-min mastication test), and muscle ultrasound of the mastication muscles. Non-ambulant patients demonstrated inefficient mastication as reflected by median z scores for masticatory cycles (z = 1.8), number of swallows (z = 4.3) and time needed to finish the cracker (z = 3.4), and limited endurance of continuous mastication as demonstrated by the median z scores of the 6-min mastication test (z = − 1.5). Patients reported increased fatigue directly after the 6-min mastication test as well as 5 min after completing the test (p < 0.001; p = 0.003). Reduced maximal mouth opening was associated with mastication problems (p < 0.001). Muscle ultrasound of the mastication muscles showed an abnormal muscle structure in 90% of both ambulant and non-ambulant patients. This study aims to understand the nature and underlying mechanisms of mastication problems in patients with SMA types 2 and 3 with reported bulbar problems.

Ultrasound: an emerging modality for the dysphagia assessment toolkit?

PURPOSE OF REVIEW

Videofluoroscopy (VFSS) and fibreoptic endoscopic evaluation of swallowing (FEES) are established instrumental techniques to support differential diagnosis and treatment of oropharyngeal dysphagia. Whilst their value is undisputed, each tool is not without limitations. The COVID-19 pandemic has restricted access to VFSS and FEES leading clinicians to explore alternative or augmentative tools to support swallowing assessment.Ultrasound (US) is an established tool for visualisation of head and neck anatomy, including structures implicated in swallowing. Although US has been utilised in swallowing research for many years, its application has not translated into common clinical practice. This review presents and debates the evidence for and against use of US for clinical swallowing assessment.

RECENT FINDINGS

Evaluation of swallowing muscle morphometry and measurement of isolated swallowing kinematics are two primary uses of US in swallowing assessment that have been identified in the literature. Use of US to detect bolus flow, aspiration and residues is in its early stages and needs further research.

SUMMARY

US shows promise as an adjunctive modality to support assessment of swallowing. With standardisation, these measurements may have potential for transition into clinical care. Reliability and validity testing and development of normative data are imperative to ensure its use as an evidence-based instrumentation.

Two mastication tests used in children with down syndrome: A feasibility study

BACKGROUND

Children with Down syndrome can have problems with chewing and swallowing. However, no objective tests are available that give information about the efficiency and endurance of mastication. In this study, the feasibility of two mastication tests is studied by answering two research questions: are the Test of Mastication and Swallowing of Solids and the 6-min mastication test feasible to use in children with Down syndrome? Do these tests give information about the mastication efficiency and endurance in these children?

METHOD

A total of 24 (4-18 years) children with Down syndrome participated. The collected variables in the Test of Mastication and Swallowing of Solids were masticatory time, discrete bites, masticatory cycles and number of swallows per cracker. The inter-rater reliability of these variables was tested. Collected variables in the 6-min mastication test were total masticatory cycles and percentage difference between minutes 1 and 6. Qualitative ratings of masticatory movements were made. In both tests, a comparison with a typically developing group was made.

RESULTS

In both tests, a total of 87.5% of the children completed the test. Both tests are feasible for children with Down syndrome with language comprehension skills of 3 years and over.

CONCLUSIONS

The tests give information about the function and endurance during mastication in children with Down syndrome. The results showed that children with Down syndrome do not have endurance problems during mastication, but there is a lack of efficiency in mastication.

Association of Body Composition, Physical Functioning, and Protein Intake in Adult Patients With Mitochondrial Diseases

BACKGROUND

Whether decreased physical functioning of patients with mitochondrial disease (MD) is related to altered body composition or low protein intake needs clarification at the background of the nutrition state.

METHODS

In this 2-site cross-sectional study, MD patients were age-, body mass index (BMI)-, and gender-matched to controls. Body composition was assessed by dual-energy x-ray absorptiometry. Physical functioning was measured by handgrip strength, 6-minute walking test, 30-second sit-to-stand test (30SCT), and 6-minute mastication test. Total daily protein intake was calculated by 3-day food records. Malnutrition was assessed by Patient-Generated Subjective Global Assessment and the Global Leadership Initiative on Malnutrition (GLIM) criteria and sarcopenia by the 2018 consensus. Data were analyzed using independent samples t-tests, Fisher exact test, and Spearman and Pearson correlation coefficients.

RESULTS

Thirty-seven MD patients (42 ± 12 years, BMI: 23 ± 4 kg/m² , 59% females) and 37 matched controls were included. Handgrip strength was moderate, inversely related to fat mass index in both MD patients and controls, whereas it correlated with fat-free mass index in controls solely. Protein intake was associated with muscle strength (handgrip strength and 30SCT) in MD patients but not in controls. Twenty-seven MD patients (73%) were malnourished, and 5 (14%) were classified as sarcopenic.

CONCLUSIONS

Muscle strength is related to body composition and protein intake in MD patients. This, in combination with the high incidence of both malnutrition and sarcopenia, warrants individual nutrition assessment in MD patients.

Feeding difficulties, a key feature of the Drosophila NDUFS4 mitochondrial disease model

Mitochondrial diseases are associated with a wide variety of clinical symptoms and variable degrees of severity. Patients with such diseases generally have a poor prognosis and often an early fatal disease outcome. With an incidence of 1 in 5000 live births and no curative treatments available, relevant animal models to evaluate new therapeutic regimes for mitochondrial diseases are urgently needed. By knocking down ND-18, the unique Drosophila ortholog of NDUFS4, an accessory subunit of the NADH:ubiquinone oxidoreductase (Complex I), we developed and characterized several dNDUFS4 models that recapitulate key features of mitochondrial disease. Like in humans, the dNDUFS4 KD flies display severe feeding difficulties, an aspect of mitochondrial disorders that has so far been largely ignored in animal models. The impact of this finding, and an approach to overcome it, will be discussed in the context of interpreting disease model characterization and intervention studies.This article has an associated First Person interview with the first author of the paper.