There is paucity of safety and efficacy data on nusinersen treatment of adults with SMA as well as the safety and tolerability of alternative methods for intrathecal delivery of the drug in patients with spinal fusions. Additionally, it is unknown whether restoring SMN levels will improve motor unit repair in adult SMA patients undergoing treatment with nusinersen. While there is dramatic improvement seen in infants with SMA, it is not clear whether restoring high levels of SMN in adult SMA patients will result in improved reinnervation capacity of the remaining motor units and thus improved muscle strength. 

To determine the tolerability and efficacy of nusinersen in adults with SMA and to explore its effect on motor unit physiology.

Adults with SMA were prospectively studied prior to and after initiation of nusinersen. Baseline and post treatment data included muscle strength  measured using maximum voluntary isometric contraction (MVICT), motor function assessed using six minute walk test, Hammersmith Functional Motor Scale Expanded (HFMSE), Revised Upper Limb Module (RULM), SMA-Function Rating scale (SMAFRS), pulmonary function, and Ulnar-CMAP and MUNE.   

A total of 40 patients were evaluated for nusinersen treatment. Treatment was decline by 17 % due to lack of data and concerns about the intrathecal procedure. The majority of those interested in treatment (80%) received insurance approval or enrolled in free drug program. Currently 25 patients (12 women, 13 men, mean age 38 ±12.5; range, 18-65) received total of 120 injections. Fluoroscopy guided C1-C2 lateral approach was used for 8 patients with spinal fusion who received 35 injections. 

We successfully administered nusinersen to a large cohort of adults with SMA. Data on outcome analysis will be presented at the meeting.  

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