A prospective cohort study of Nusinersen in the treatment of spinal muscular atrophy in children with type 2 and 3 on quantitative muscle MRI

Motivation: A biomarker to assess the efficacy of Nusinersen is needed as it enhances motor function and prolongs survival in SMA patients. Goal(s): We investigated whether qMRI could monitor the efficacy of Nusinersen in the treatment of SMA. Approach: Patients underwent measurements of thigh qMRI (mDixon-Quant, T2 mapping and DTI) and Hammersmith Functional Motor Scale Expanded (HFMSE) before and after nusinersen treatment, X-ray exams to obtain Cobb angle were performed at baseline. Results: After treatment, the mean thigh FF and FA decreased over time, and the HFMSE increased, while T2 values and ADC remain stable. Impact: qMRI can evaluate the treatment outcomes of SMA patients. The younger patients with less scoliosis more likely to have minimumclinically significant difference at 6 months after treatment.