Motor Function Changes in Duchenne Muscular Dystrophy: A Case Series Using Conventional and Spinal Muscular...

Area of Science:

• Neurology
• Pediatrics
• Genetics

Background:

• Motor function tests (MFTs) for Duchenne muscular dystrophy (DMD) face floor effects in advanced stages and may not detect distal function.
• Spinal muscular atrophy (SMA)-based fine motor assessments like CHOP-INTEND show promise in detecting changes in severely affected patients.

Purpose of the Study:

• To evaluate viltolarsen's treatment response in DMD patients using both DMD-specific and SMA-based MFTs.
• To determine the utility of CHOP-INTEND in assessing treatment efficacy in advanced DMD.

Main Methods:

• Retrospective evaluation of three DMD patients (two nonambulatory, one ambulatory) treated with viltolarsen.
• Assessment using conventional DMD MFTs (time to stand, 10-meter walk/run, Brooke scale) and SMA-based CHOP-INTEND.

Main Results:

• The ambulatory patient showed minimal improvement in time to stand and decline in walk/run.
• Nonambulatory patients demonstrated significant CHOP-INTEND score improvements, with no change in conventional MFTs.

Conclusions:

• CHOP-INTEND may identify subtle, clinically meaningful improvements in advanced DMD not detected by standard tests.
• Selecting stage-appropriate MFTs is crucial for evaluating treatment effects in DMD patients.