Article

OBJECTIVE: To measure muscle strength in patients with spinal muscular atrophy
using a handheld dynamometer as an objective tool to evaluate the progression of
disease and the outcome of therapeutic trials. DESIGN: Maximum voluntary
isometric contraction was measured in a group of 24 patients aged 5-38 years with
types II and III spinal muscular atrophy. Four muscle groups were examined. Data
were grouped according to age and sex. Comparison was made between spinal
muscular atrophy types; ambulatory vs non-ambulatory, and survival motor neuron
(SMN)2 copies. The results were compared with those of a healthy reference
population. RESULTS: Muscle strength was much lower in patients with spinal
muscular atrophy than in the healthy population. The walkers group yielded higher
values than patients who were non-walkers. Knee extensors were the weakest
muscles in both groups, regardless of the ability to walk. The greatest
differences were found between ambulatory and non-ambulatory patients.
Non-walkers type III patients showed lower values, similar to those for type II
patients. Patients with 3 and 4 SMN2 copies showed higher strength with respect
to those with 2 SMN2 copies, although not statistically significant. CONCLUSION:
The handheld dynamometer is a valid tool for measuring muscle strength in
patients with spinal muscular atrophy. It can be used to measure disease
progression and to evaluate changes in therapeutic trials.

Langue : ANGLAIS