The purpose of this study is to evaluate safety and efficacy of anti-cholinesterase therapy on the motor function in SMA type 3 patients with impaired neuromuscular junction (NMJ).

Spinal muscular atrophy (SMA) is the second neuromuscular disease meet in children. SMA is a genetically transmitted disease inducing muscular weakness predominating on shoulders and hips. Currently, there is no effective therapy to slow the progression of the disease. SMA is due to a neuron motor attempt of the spinal cord and recently it has been demonstrated a neuromuscular junction (NMJ) involvement, according to recent studies.

EMOTAS study aim to understand if NMJ abnormalities could have an impact on motor performance and fatigue in SMA type 3 ambulatory patients by electromyogram and to improve by non-invasive therapy quality of life of patients.

Inclusion Criteria:

• Spinal muscular atrophy type 3, genetically confirmed

  • Age higher than 6 years old
  • Ambulatory patient
  • Informed consent signed
  • More than 100 meters of walking at 6-minute walk test at screening
  • Value at screening and baseline in a range of 20% of the highest value at 6-minute walk test

Exclusion Criteria:

• Patient who had surgical intervention or suffer from a recent traumatism (less than 6 months)

  • Associated pathology such as endocrinopathy, infectious disease, allergy, myopathy, chronic or acute inflammatory pathology, during 3 weeks preceding the inclusion.
  • Other therapeutics than food supplements or those frequently prescribed in spinal muscular atrophy or its complications
  • Non tolerance of electromyography
  • Limited collaboration due to trouble in information comprehension
  • Pathology inducing contra-indication for pyridostigmine treatment (allergy at molecule, asthma, Parkinson disease, mechanic obstruction of urinary or digestive tracts)