P.11.6 Functional motor changes in Duchenne Muscular Dystrophy (DMD) patients on long term daily glucocorticoid (GC) treatment

Abstract

Longitudinal review of motor outcomes for a cohort of DMD patients on GC would offer insight into the altered natural history of DMD, provide anticipatory guidance for care management and inform the study designs of future clinical trials. To report the motor outcomes of a cohort of DMD patients on long term daily GC. Longitudinal retrospective review of timed function tests (TFT) – Timed Gower maneuver (G) (i.e. sit to stand ¨C measure of pelvic girdle weakness), 10 m walk/run (W/R), North Star Ambulatory Assessment (NSAA); and lower extremity contractures. 110 males aged 7 to ⩽13 y were treated with daily GC for 4.8 ± 1.5 y and followed at our clinic for 4.8 ± 1.6 y. Slope changes were 9.0 y for G, 8.5 y for W/R and 8.5 y for NSAA. TFTs were highly correlated regardless of time point. Times for G and W / R were correlated at first ( r = 0.76) and most recent visit ( r = 0.83). Times for G and NSAA scores were correlated at first ( r = 0.76) and most recent visit ( r = 0.66). W / R times and NSAA scores were strongly correlated at first ( r = 0.82) and most recent visit ( r = 0.83). Knee contractures (KC) were not observed in ambulatory boys, but ankle contractures (AC) negatively impacted motor function as the disease progressed. Subjects with AC performed worse on all TFTs at most recent visit compared to those without AC. Linear regression analysis suggests motor function declines faster in subjects with AC compared to those without. Our slope changes for all three TFTs were >7 years (Mazzone, 2011). Given the strong correlation, the easily executed W / R test may be a clinical surrogate for NSAA in a busy clinic. Our results indicate that early intervention for AC may improve motor outcomes and prolong ambulation in DMD boys.