Monitoring changes and predicting loss of ambulation in Duchenne muscular dystrophy with the Motor Function Measure

AimTo assess changes in motor function in patients with Duchenne muscular dystrophy using the Motor Function Measure (MFM).MethodThree studies were performed. Two studies included only physiotherapy-treated patients, with 13 patients (males mean age 11y 7mo, SD 1y 10mo, range 8-14y) in the 3-month study and 41 patients (males mean age 14y 1mo, SD 5y 5mo, range 6-32y) in the 1-year study. A third study compared 12 patients treated with steroids with 12 age- and motor-function-matched untreated patients (males mean age of treated patients 10y 2mo, SD 2y 2mo range 6-14) over a 12-month period.ResultsOver 3 months, the MFM D1 subscore (standing and transfers) decreased significantly (-4.7%; p < 0.01). Over 1 year, all MFM subscores decreased significantly: -4.9% for D1 (p < 0.01); -7.7% for D2 (axial and proximal motor capacity; p < 0.01); -4.3% for D3 (distal motor capacity; p=0.03); and -5.8% for the total score (p < 0.01). A threshold value for loss of ambulation and a predictive value 1 year before loss were estimated (total score 70% and D1 subscore 40%). Compared with the controls, patients treated with steroids had more stable total scores (-0.59 vs -5.87; p=0.02) and D2 subscores (0.98 vs -8.50; p < 0.01).InterpretationThese results support the use of the MFM in everyday patient management to prepare for loss of ambulation and in clinical trials to follow up patients receiving various treatments.