Assessing upper limb function in nonambulant SMA patients: development of a new module

Area of Science:

• Neurology
• Pediatrics
• Rehabilitation Medicine

Background:

• Assessing upper limb function in nonambulant pediatric patients with spinal muscular atrophy (SMA) presents unique challenges.
• Existing assessment tools may not adequately capture the functional abilities of severely affected individuals, including those with contractures.

Purpose of the Study:

• To develop and validate a novel module for assessing upper limb function in nonambulant patients with SMA.
• To evaluate the module's applicability across a wide age range and severity spectrum of SMA.

Main Methods:

• Development of a specialized assessment module targeting upper limb function.
• Application of the module to a cohort of 40 preschool-aged children (30-48 months) with SMA.
• Further application to a broader cohort of 45 nonambulant SMA patients (30 months to 27 years).

Main Results:

• The module proved feasible for use in children as young as 30 months.
• Scores in the broader SMA cohort showed variability (0-18) and were not age-dependent (r=-0.19).
• Upper limb scores correlated well with the Hammersmith Functional Motor Scale (r=0.75), though function didn't always mirror gross motor skills.

Conclusions:

• The developed module is a viable tool for assessing upper limb function in nonambulant SMA patients.
• It can identify measurable upper limb skills even in severely weakened individuals.
• Findings highlight the importance of specific upper limb assessments, as they may not directly correlate with overall gross motor function.