SMA CLINICAL DATA, OUTCOME MEASURES AND REGISTRIES: P.89More than just fun and games: ACTIVE workspace volume video game quantifies meaningful change in function in individuals with spinal muscular atrophy

Abstract

This study explored the utility of ACTIVE scaled workspace volume scores to quantify meaningful change in individuals with spinal muscular atrophy (SMA) due to disease progression or treatment. ACTIVE, a 65-second custom designed video game, uses a skeletal tracking algorithm to quantify the volume of space (m3) the player can interact with while reaching in three dimensions to squish spiders or dig for jewels. Sixty-two individuals with SMA type 2 or 3 (age 10.5y +/-5y) and 362 age-matched controls (age 10.7y +/-3.5y) participated. Individuals seen in our clinic (n=37) also completed traditional assessments including the PROMIS self-report of upper extremity function, Hammersmith Functional Motor Scale Expanded (HFMSE), and revised upper limb module (RULM). The remainder were tested at a CureSMA meeting (ACTIVE only n=25). ACTIVE differentiated between patients with varying severity of SMA, as defined by their Brooke level, and from healthy controls (Jonckheere-Terpstra test for trend P<0.0001). ACTIVE significantly correlated with the HFMSE and the RULM (Rho=0.8-0.9, p<0.01). Relevance to patients and families was established by strong correlations to self and parent measures of upper extremity ability (Rho=0.6-0.7, p<0.01). Nine individuals (age 9.4y +/- 4.8y) in this cohort received Spinraza. Responsiveness to change was demonstrated by significant changes pre and post treatment (Median change = 28 pts, Wilcoxon signed rank test p=0.02). Two methods were used to calculate a minimal clinically important difference (MCID). Using the more conservative of the 2 estimates (14.5 pts), all but one Spinraza-treated patient exceeded the MCID, suggesting a robust change not due to random fluctuation. In contrast, no SMA patients in our natural history cohort improved greater than the MCID. Our results validate ACTIVE for use in an SMA cohort and suggest meaningful functional change post-treatment can be readily detected using ACTIVE in individuals with SMA types 2 and 3.