Background
FSHD is an autosomal dominant muscular dystrophy characterized by slowly progressive descending weakness and accumulation of physical disability. Patients consistently rank mobility issues including difficulty getting up from bed, standing up and walking as serious impairments. The Timed Up and Go (TUG) test is an objective assessment of mobility, but is insensitive to muscle weakness outside the legs. We hypothesized that a TUG that includes a supine-to-sit and sit-to-supine component could provide an optimized TUG (oTUG) to measure changes in mobility in FSHD clinical trials
Objectives
To develop a new clinical outcome assessment of mobility in FSHD
Approach
22 FSHD patients were categorized by Ricci’s clinical severity scores (CSS range 0-5) into four groups (CSS 1-1.5: 6; CSS 2-2.5: 4; CSS 3-3.5:6 and CSS 4:6) and compared to 20 healthy controls. Each group performed the traditional TUG and oTUG on two visits one-week apart
Results
FSHD patients are significantly slower compared to healthy controls to complete TUG and oTUG at both visit 1 (p=0.0025, p=0.0003) and visit 2 (p=0.0073, p=0.0002) based on two-sample t-test. FSHD patients are also significantly slower compared to healthy controls to complete the supine-to-sit and sit-to-supine component of oTUG at both visit 1 (p=0.0001, p<0.0001) and visit 2 (p<0.0001, p<0.0001) based on two-sample t-test. FSHD patients with CSS 4 took significantly longer to complete TUG, oTUG, and supine-to-sit comparing to those with CSS 1-1.5 and CSS 2-2.5 (p<0.05). The test-retest reliability of TUG, oTUG, TUG part within oTUG between visit 1 and visit 2 is excellent for FSHD patients (ICC=0.92, 0.94, and 0.97)
Conclusions
Both TUG and oTUG show clear differences in FSHD from healthy controls. We have developed a modified TUG that is optimized for FSHD, and has the potential to show better responsiveness to therapeutic intervention in FSHD clinical trials by incorporating mobility of the trunk