Related Experiment Video
Updated: Aug 8, 2025
Measurements of Motor Function and Other Clinical Outcome Parameters in Ambulant Children with Duchenne Muscular Dystrophy
Published on: January 12, 2019
Longitudinal Assessment of Timed Function Tests in Ambulatory Individuals with SMA Treated with Nusinersen
Kristin J Krosschell1,2, Laurey Brown3,4, Katie Hoffman3,4
1Department of Physical Therapy and Human Movement Sciences, Northwestern University Feinberg School of Medicine, USA.
Background:
Ambulatory individuals with spinal muscular atrophy experience weakness and impairments of speed and endurance. This leads to decreased motor skill performance required for daily living including transitioning from floor to stand, climbing stairs, and traversing short and community distances. Motor function improvements have been reported in individuals receiving nusinersen, but changes in timed functional tests (TFTs) which assess shorter distance walking and transitions have not been well documented.
Objective:
To evaluate changes in TFT performance over the course of nusinersen treatment in ambulatory individuals with SMA and identify potential factors [age, SMN2 copy number, BMI, Hammersmith Functional Motor Scale Expanded (HFMSE score), Peroneal Compound Motor Action Potential (CMAP) amplitude] associated with TFT performance.
Methods:
Nineteen ambulatory participants receiving nusinersen were followed from 2017 through 2019 (range: 0-900 days, mean 624.7 days, median 780 days); thirteen of 19 (mean age = 11.5 years) completed TFTs. The 10-meter walk/run test, time-to-rise from supine, time-to-rise from sitting, 4-stair climb, 6-minute walk test (6MWT), Hammersmith Expanded and peroneal CMAP were assessed at each visit. Linear mixed-effects models were used to evaluate unadjusted and adjusted changes in these outcomes over time.
Results:
Apart from time to rise from sitting and from supine, all TFTs were found to improve over the course of treatment after adjusting for baseline age and BMI.
Conclusions:
Improvement in TFTs over time in patients with SMA treated with nusinersen suggests that shorter TFTs may have value to assess individuals with SMA who have or later gain ambulatory function during treatment.
