The motor function measure to study limitation of activity in children and adults with Charcot-Marie-Tooth disease

Psychometric Characteristics of the Motor Function Measure in Neuromuscular Diseases: A Systematic Review1

BACKGROUND

Recent pharmaceutical breakthroughs in neuromuscular diseases may considerably change the prognosis and natural history these diseases. The ability to measure clinically relevant outcomes such as motor function is critical for the assessment of therapeutics and the follow up of individuals. The Motor Function Measure (MFM) is a quantitative scale designed to measure motor function in adult and children with neuromuscular disease (NMD).

OBJECTIVE

The objective of this study is to assess the quality and level of evidence of the MFM's published measurement properties by completing a systematic review of the validation and responsiveness studies of the MFM20 (a 20-item version of MFM adapted for children 2 to 6 years of age) and the MFM32 (the original 32 item version), in all NMDs and in specific diseases.

METHODS

A search for MFM responsiveness and MFM validation studies was completed in February 2023 in EMBASE, MEDLINE, SCOPUS and Web of Science databases. The PRISMA guidelines and the COSMIN manual for systematic reviews were followed for databases searches, articles screening and selection, study quality and measurement properties evaluation.

RESULTS

49 studies were included in analysis. In studies including individuals with all NMDs, MFM's internal consistency, reliability, convergent validity, construct validity and responsiveness were rated as sufficient with a high quality of evidence. Structural validity was rated sufficient with a moderate quality of evidence In SMA in particular, MFM's reliability, internal consistency, convergent validity, discriminant validity and responsiveness are sufficient with a high quality of evidence. More studies would be required to assess specific measurement properties in different diseases. MFM32's minimal clinically relevant difference has been defined between 2 and 6%.

CONCLUSION

MFM's structural validity, internal consistency, reliability, construct validity, convergent validity and responsiveness have been verified with moderate to high level of evidence.

Instruments to assess upper-limb function in children and adolescents with neuromuscular diseases: a systematic review

AIM

To synthesize clinical and scientific evidence regarding the instruments available to assess upper-limb function in paediatric patients with neuromuscular disease (NMD).

METHOD

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidelines (Prospective Registry of Systematic Reviews no. CRD42020140343). Two independent reviewers searched the PubMed/MEDLINE, LILACS, Embase, and Scopus databases. Inclusion criteria were cross-sectional or longitudinal studies or randomized controlled trials that used scales or questionnaires to assess upper-limb function in paediatric patients with NMDs. The COSMIN Risk of Bias checklist and criteria for good measurement properties were applied to assess the methodological quality of the instruments.

RESULTS

In total, 34 articles and 12 instruments were included. The Brooke Upper Extremity (n=16) and Performance of Upper Limb (PUL) (n=12) instruments were the most used tools. The PUL and Duchenne muscular dystrophy (DMD) Upper Limb patient-reported outcome measures (PROMs) tested more measurement properties and provided higher methodological quality scores for patients with DMD. Likewise, the Revised Upper Limb Module (RULM) was the most suitable instrument for patients with spinal muscular atrophy. No instrument has been devised to assess upper-limb function in patients with Charcot-Marie-Tooth disease and no other disease-specific instruments were found.

INTERPRETATION

The PUL, DMD Upper Limb PROM, and RULM are the most suitable instruments to assess upper-limb function in the two most prevalent paediatric NMDs. The identified gaps and methodological flaws of the available instruments indicate a need to develop high-quality instruments to assess other types of paediatric NMDs. What this paper adds The most suitable observer-rater instrument to assess upper-limb function in Duchenne muscular dystrophy (DMD) is the Performance of Upper Limb. The most suitable observer-rater instrument to assess upper-limb function in spinal muscular atrophy is the Revised Upper Limb Module. The DMD Upper Limb patient-reported outcome measure is recommended to assess the upper-limb performance of patients with DMD. Literature gaps and methodological flaws indicate the need to develop high-quality instruments to assess other types of paediatric neuromuscular disease.

Physical function and performance measures of children and adolescents with Charcot-Marie-Tooth disease

This study aimed to verify whether there are differences in foot type, physical function, and performance between children and adolescents with Charcot-Marie-Tooth disease (CMT) and their healthy counterparts, and whether an interval of 6 months, from the initial assessment, reveals any significant changes on physical performance and other specific physical measures of the lower limbs. Subjects and Methods: Participants between 6 and 17 years of age, with CMT (CMT group n = 40), were compared to healthy participants (Control group, n = 49). Twenty participants with CMT completed the follow-up. We collected anthropometric, goniometric (ankle and knee), and dynamometric (inversion, eversion, plantar flexors, dorsiflexors, knee, hip extensors) measures, agonist/antagonist ratios, feet alignment (Foot Posture Index - FPI), muscle power (Long Jump), Pediatric Balance Scale (PBS), and 10-meter walk test (10MWT). Results: Compared to Control, CMT showed reduced passive range of motion (ROM), weakness in all evaluated muscles, increased agonist/antagonist ratios, predominance of varus and lower performance (PBS and Long Jump). After 6 months, CMT measures did not change. Conclusion: The cross-sectional analysis showed reduced ROM, strength, power, and distal muscle imbalance, as well as secondary limitations (PBS and 10MWT) in children and adolescents with CMT. These biomechanical and functional alterations did not change at the 6-month follow-up.

How often should sitting and rising from a chair be evaluated in patients with Duchenne muscular dystrophy?

OBJECTIVE

To determine how often sitting/rising from a chair should be assessed in Duchenne muscular dystrophy (DMD) patients to avoid redundant/missing data.

METHODS

Sitting/rising from a chair was evaluated in 26 DMD children (5-12 yrs), in three-month intervals, over twelve months, with the Functional Evaluation Scale (domain sitting/rising from a chair). Scores were compared by effect sizes (ES) and standardized response means (SRM) (responsiveness analysis).

RESULTS

Sit-to-stand showed low-to-moderate responsiveness in three-month intervals (ES:0.23-0.32; SRM:0.36-0.68), moderate-to-high responsiveness in six-month intervals (ES:0.52-0.65; SRM:0.76-1.28), high responsiveness at nine-month (ES:0.84-0.91; SRM:1.26-1.64) and twelve-month intervals (ES:1.27; SRM:1.48). Stand-to-sit showed low responsiveness in three-month intervals (ES:0.26-0.49; SRM:0.37-0.42), moderate responsiveness in six-month intervals (ES:0.50-0.78; SRM:0.56-0.71), high responsiveness in nine-month (ES:0.94-1.00; SRM:0.84-1.02) and twelve-month intervals (ES:1.13; SRM:1.52).

CONCLUSION

Six months or longer intervals for reassessment are indicated to evaluate sitting/standing from a chair in DMD patients.

Reliability of home-based, motor function measure in hereditary neuromuscular diseases

Objective

To evaluate the reliability of the motor function measure (MFM) scale in the assessment of disease severity and progression when administered at home and clinic and assess its correlation with the Paediatric Outcomes Data Collection Instrument (PODCI).

Methods

In this prospective study, two assessors rated children with hereditary neuromuscular diseases (HNMDs) using the MFM at the clinic and then 2 weeks later at the patients’ home. Intraclass correlation coefficient (ICC) was calculated for the reliability of the MFM and its domains. The reliability of each item was assessed and the correlation between MFM and three domains of PODCI was evaluated.

Results

A total of 48 children (5–17 years of age) were assessed in both locations and the MFM scale demonstrated excellent inter-rater reliability (ICC, 0.98). Weighted kappa ranged from excellent to poor. Correlation of the home-based MFM with the PODCI domain ‘basic mobility and transfers’ was excellent, with the ‘upper extremity’ domain was moderate, but there was no correlation with the ‘happiness’ domain.

Conclusion

The MFM is a reliable tool for assessing patients with HNMD when used in a home-based setting.

Update on Charcot-Marie-Tooth disease

PURPOSE OF REVIEW

Charcot-Marie-Tooth disease (CMT) is the common terminology used to describe the hereditary neuropathies. This update reviews advances in the past year in our understanding of these diseases, including some important earlier references.

RECENT FINDINGS

In the past year, advances in next-generation sequencing continued to increase the number of genes associated with CMT. The connection between genotype and phenotype has become more complicated. New insights into the pathogenesis of the diseases are reviewed. Treatment and clinical trial updates coming from these new insights, as well as use of high-throughput screening to match potential treatments with targets, are moving the field forward. There is a discussion of potential next steps, including the use of patient-derived induced pluripotent stem cells, to enhance our understanding of individual genotypes and phenotypes.

SUMMARY

The use of high-throughput screens, and techniques such as RNAi and induced pluripotent stem cell continue to push forward other therapies for specific genetic forms of CMT and are potentially more generalizable to peripheral neuropathies. These developments, along with the development of improved outcome measures and longitudinal natural history data, advance CMT, making the future for finding treatments and/or cures closer than it has ever been.

Charcot-Marie-Tooth 1A: A narrative review with clinical and anatomical perspectives

Charcot-Marie-Tooth 1A (CMT1A) is regarded as the most common hereditary peripheral neurodegenerative disorder. This narrative review highlights perspectives around the historically well-established and characteristic anatomical manifestations of CMT1A seen in the feet, legs and hands, in addition to a clinical diagnosis that may be confirmed by electrophysiology, genetic or molecular markers together with the presence of a typical family history. A less well-known perspective is the potential for systemic manifestations and wider complication. The condition is characterised by a progressive clinical picture with unmistakable anatomical and neurological features that have been described since the late 19th century. There remains no cure although supportive, rehabilitative, and surgical regimes may provide helpful management or amelioration of symptoms. Most recently, the emergence of a pleotherapeutic approach suggests distinct promise. Future research focused on a detailed elucidation of the underlying molecular mechanisms underpinning myelin and axonal function may eventually hold the key to successful treatment of CMT1A. Genetic modification would potentially present a cure. Clin. Anat. 29:547-554, 2016. © 2015 Wiley Periodicals, Inc.