T.P.10: 6 min walk test and Performance of Upper Limb in ambulant DMD boys

Abstract

The 6min walk test (6MWT) has been recently chosen as the primary outcome measure in several international multicenter clinical trials in Duchenne muscular dystrophy (DMD) patients. In the last few years there has been increasing attention to the assessment of upper limbs. The Performance of Upper Limb (PUL) has been specifically developed for the assessment of upper limbs in DMD providing information of three domains (shoulder, elbow and distal). The first published data have shown that involvement of upper limb is present not only in non ambulant patients and early signs of involvement can also be found in younger ambulant DMD boys. The aim of this longitudinal Italian multicentric study was to evaluate the correlation between the 6MWT and the PUL in ambulant DMD boys. As part of this study all boys are assessed using both measures. The preliminary results in over 100 DMD boys show that early signs of shoulder involvement can already be found after the age of 8 and become increasingly more marked with age. Boys with 6MWT results above 400m generally have full scores or one or two points below the full score. Their scores slightly decrease between 350 and 400m with a more obvious fall in scores below the cut off point of 350 that become increasingly more marked with the decrease in meters on the 6MWT. Our results suggest that upper limb involvement can already be found in DMD boys even in the ambulant phase and the scores on the PUL reflect to some extent the overall impairment observed on the 6MWT.