A continuous repetitive task to detect fatigability in spinal muscular atrophy

Area of Science:

• Neurology
• Motor Function Assessment
• Clinical Trials

Background:

• Spinal muscular atrophy (SMA) is a neuromuscular disorder affecting motor neurons.
• Impaired motor function and fatigability are characteristic of SMA, particularly in later disease types.
• Continuous repetitive tasks offer a potential method to quantify fatigability.

Purpose of the Study:

• To evaluate the utility of a continuous repetitive task in detecting and quantifying fatigability in patients with hereditary proximal SMA.
• To assess fatigability as an additional dimension of motor impairment in SMA.

Main Methods:

• A repeated measure case-control study involving 52 patients with SMA types 2-4, 17 healthy controls, and 29 disease controls.
• Participants performed five consecutive rounds of the Nine-Hole Peg test.
• Analysis focused on differences in test performance and associations with disease characteristics.

Main Results:

• Five patients with SMA type 2 (22%) and one disease control (3%) could not complete the task due to fatigue.
• SMA type 2 patients performed significantly slower than all other groups, with round five 27% slower than round one.
• Healthy controls performed round five 14% faster than round one, indicating a difference in fatigability.

Conclusions:

• Fatigability in arm function is a notable feature of SMA type 2.
• Continuous repetitive tasks, such as the Nine-Hole Peg test, can effectively detect and quantify fatigability in SMA.
• This assessment provides valuable insights into motor function impairment in SMA patients.