Assessing Upper-Limb Function in Neuromuscular Diseases: Current Tools and Needs

In most neuromuscular diseases (NMDs), main clinical symptoms are progressive weakness and muscle fatigue due to the involvement of motor neurons, peripheral nerves, neuromuscular junctions, and skeletal muscle. Assessing upper-limb function in pediatric patients with NMDs is becoming more important as the treatment landscapes expand, and a systematic review published in Developmental Medicine & Child Neurology aims to synthesize the existing clinical and scientific evidence on the instruments available to do so.

Charcot-Marie-Tooth disease (CMT) =, Duchenne muscular dystrophy (DMD), and spinal muscular atrophy (SMA) are the most common NMDs, and they first appear in infancy or adolescence. Each disease has different clinical symptoms, and patients have varying degrees of disability.

Those with CMT tend to have weakness in distal muscles, whereas those with SMA or DMD first show weakness in proximal muscles. Patients with CMT rarely lose the ability to walk, but those with DMD typically become wheelchair dependent at around 12 years old. Motor abilities very depending on the type of SMA, ranging from patients who are unable to sit independently to those who can sit and those who can walk independently.

The study authors point out that, due to the severity of lower-extremity disability in these diseases, upper extremities historically get less attention. However, lower-extremity disability places more demand on the upper extremities in functions of daily life. Therefore, analyzing upper-limb function is critical as new therapies change the quality of life for patients with NMDs.

The review aimed to:

• synthesize evidence that can contribute to clinical and evidence-based practice by searching the current literature to identify the instruments most commonly used to assess upper-limb function in this patient group,
• suggest the most suitable disease-specific instruments, based on their methodological properties and methodological quality, and
• synthesize the available scientific evidence to detect literature gaps and methodological flaws in the available instruments to provide recommendations for the development of future studies.

Researchers had 2 independent reviewers search the PubMed/MEDLINE, LILACS, Embase, and Scopus databases for cross-sectional or longitudinal studies or randomized controlled trials that used scales or questionnaires to assess upper-limb function in pediatric patients with NMDs. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN).

A total of 34 articles met the criteria for inclusion in the review, and they included 12 tools. The most used instruments were the Brooke Upper Extremity (n = 16) and Performance of Upper Limb (PUL) (n = 12) tools. These included patient-reported and observed-rater assessments.

Overall, the following instruments were evaluated:

• Brooke Upper Extremity Scale to assess the upper-limb function of patients with NMDs
• Performance of Upper Limb (PUL) measure
• Dimension 3 of the Motor Function Measure (MFM) scale
• Upper Limb Module (ULM)
• Revised Upper Limb Module (RULM)
• Quality of Upper Extremity Skills
• Duchenne Muscular Dystrophy Functional Ability Self-Assessment Tool
• Escala de Evaluacion Funcional deExtremidades Superiores (EEFES)
• Web-based questionnaire (WBQ)
• Paediatric Outcomes Data Collection Instrument
• DMD Upper Limb PROM
• Capabilities of Upper Extremity (CUE) instrument

The methodological quality of the instruments chosen for the analysis was assessed using the COSMIN Risk of Bias checklist, which includes 10 sections to screen the risk of bias of studies included in systematic reviews of instruments.

In patients with DMD, the most commonly used tools were the Brooke Upper Extremity Scale and the PUL measure. The MFM scale was next, utilized in patients with DMD, SMA, and congenital muscular dystrophy. Patients with SMA were commonly assessed with the Brooke Upper Extremity Scale, ULM, and RULM instruments.

The RULM (an observed-rater assessment) was the best method to assess patients with SMA, according to the review. The ULM and RULM are exclusively designed to assess SMA. The PUL (observed-rater) and DMD Upper Limb PROM (patient-reported) scales were the best instruments for assessing upper-limb function in patients with DMD.

The authors note that despite CMT being the most prevalent pediatric NMD, there is no instrument specifically designed to assess upper-limb function in these patients. “This clinical gap should be addressed by developing a high-quality methodological instrument,” they wrote.

They also clarify, “Extrapolations from these recommendations should not be made for NMDs in general since the cited instruments were developed to evaluate specific diseases and require validation for other diseases and in different languages before their implementation in clinical practice and research.”

The review highlights the importance of developing more observed-rater and patient-reported tools to assess all aspects of upper-body function in specific NMDs, including CMT, in clinical and research settings.

“The gaps in the literature and methodological fragility of the available scales indicate a need to develop high-quality instruments that can assess patients with CMT, congenital muscular dystrophy, Becker muscular dystrophy, limb-girdle muscular dystrophy, facioscapulohumeral muscular dystrophy, and congenital myopathy,” the review concluded.

Reference

De Queiroz Davoli G, Cardoso J, Silva G, et al. Instruments to assess upper-limb function in children and adolescents with neuromuscular diseases: a systematic review. Dev Med Child Neurol. 2021;63(9):1030-1037. doi:10.1111/dmcn.14887