Assessing upper limb function in nonambulant SMA patients: development of a new module.

We report the development of a module specifically designed for assessing upper limb function in nonambulant SMA patients, including young children and those with severe contractures. The application of the module to a preschool cohort of 40 children (age 30-48 months) showed that all the items could be completed by 30 months. The module was also used in 45 nonambulant SMA patients (age 30 months to 27 years). Their scores were more variable than in the preschool cohort, ranging from 0 to 18. The magnitude of scores was not related to age (r=-0.19). The upper limb scores had a good correlation with the Hammersmith Functional Motor Scale, r=0.75, but the upper limb function did not always strictly follow the overall gross motor function. These findings suggest that even some of the very weak nonambulant children possess upper limb skills that can be measured.