2025 American Academy of Neurology Abstract Website

Objective:

To describe the effect of Risdiplam on a cohort of 6 adult SMA patients using Motor Function Measure (MFM32) score as standardized scale to quantify motor improvements induced by therapy.

Background:

Risdiplam is a validated treatment for adult SMA patients. To date there is a lack of clear guidelines concerning functional assessment at baseline and during the follow-up, especially in terms of sensible and validated outcome measure able to capture minimal changes in motor performances induced by therapy.

Design/Methods:

We included six patients (4F;2M) with SMA type 2 (N=4) and non ambulant SMA type 3 (N=2) aged 21-65 years (mean age of 40.5 years). At baseline all patients received: i) a neuromuscular evaluation focusing on residual motor abilities and MRC muscle testing; ii) motor performance status was evaluated by an expert physiotherapist (CAI) using Motor Function Measurement 32 (MFM32). After starting Risdiplam we evaluated neuromuscular assessment; ii) MFM32 with clinically significant improvement considered as a score >3% compared to the baseline iii) patients reported outcomes (PROs) and side effects. The mean period of follow-up is 16 months, ranging 7-27 months.

Results:

MFM32 showed an increased score ranging from +2.16% to +7.29% in 4 patients. The improvement was maintained overtime, with two patients presenting the
longest follow-up period of 24 and 27 months respectively. Subdomain D3 was ameliorated in 66.6% of patients. Two patients previously treated with Nusinersen maintained the pre-Risdiplam scores. All patients reported subjective ameliorations. The commonest PROs were improvements in breath fatigue, voice’s intelligibility, hand strength and dexterity. Adverse effects were mild and decreased over time.

Conclusions:

Risdiplam was well -tolerated and resulted in improvement or stabilization of motor functions. MFM32 proved to be sensitive to detect changes induced by therapy. Subjective meaningful improvements were sustained overtime especially in bulbar functions, breath fatigue and distal motor abilities.