Spinal Muscular Atrophy (SMA) is an autosomal recessive disease caused by a mutation of exon 7, in 95% of cases, encoding the gene for the motor neuron survival protein called SMN1 (Survival Motor Neuron) located on chromosome 5q. Patients with an SMA-5q mutation suffer from progressive muscle deficiency and subsequent atrophy induced by degeneration of motor neurons in the spinal cord. Gene therapy is now available for the management of spinal muscular atrophy and nusinersen is the first approved treatment. Nusinersen has been granted marketing authorization in France since May 30, 2017. Nusinersen has a high level of medical service rendered (MSR) for types I, II, and III, but the improvement in medical service rendered (IMSR) is assessed as moderate for types I and II. For Type III, IMSR is not known.

The aim of the study will be to evaluate the impact on functional motor abilities of intrathecally-injected nusinersen in adult 5q-SMA type 2 and type 3 persons.

If the efficacy of nusinersen protocol will demonstrate the positive impact for patient's, the results of this study would promote an improvement in the medical service rendered in this population in terms of disease stabilization, maintenance of functional capacities and social participation.

inclusion criteria :

• Adults (over 18 years of age)
• 5q-SMA type 2 or 3
• with indication for nusinersen treatment by the physician of the center of reference and competence for neuromuscular diseases
• accepting treatment by nusinersen
• Agreeing to participate in the study (signature of the informed consent form).
• living within a radius of 40 km of the investigation center (for logistical reasons related to the conduct of assessments in the patient's home).
• affiliated to a social security system.

exclusion criteria :

• minors (less than 18 years of age)
• with a contra-indication to the nusinersen: pregnancy, breast feeding, hypersensitivity to the nusinersen
• with a contraindication to lumbar puncture: hemostasis disorder, intracerebral mass
• benefiting from another gene therapy drug to treat spinal muscular atrophy.