Aerobic capacities and exercise tolerance in neuromuscular diseases: a descriptive study

Up until now, there has been little description of the test exercises carried out in patients with neuromuscular diseases. However, prescription of physical therapy by exercise requires rigorous individualized assessment of the patient's physical endurance parameters.

To describe exercise tolerance and external limitation factors in a sample group of adult patients suffering from neuromuscular diseases.

A descriptive retrospective study of exercise tests realized at the Reims university hospital for patients divided into three groups according to their pathologies: CMT hereditary neuropathies, muscular dystrophies, metabolic myopathies.

Forty-four (44) tests were analyzed. Cessation was occasioned on 63.6% of the cases by muscular symptomatology, with no possibility of maintaining the cycling frequency in 29.5% of the overall population. Insufficient lung volume recruitment was involved in 61.4% of the patients, final oxygen pulse (VO2/heart rate) was 80% lower than the theoretical pulse in 50% of the patients, and there existed an early first ventilatory threshold in 54.5% of the cases. Peripheral deconditioning was highly severe in 18% of the population and significantly greater in the subjects suffering from dystrophies (VT1 at 31% of the maximum theoretical O2, P<0.001).

The main limitation factor in exercise tests is peripheral. Ventilatory and cardiovascular limitations can nonetheless be added on; while they are absent when the patient is at rest, they are unmasked in effort situations. Exercise tests could be of great interest in screening and managing the relevant pathologies. Multicenter studies on homogeneous populations could facilitate definition of the procedures specific to exercise tests for patients suffuring from neuromuscular diseases.