Two single cases treated by a new pseudoelastic upper-limb orthosis for secondary dystonia of the young.

The study proposes a new treatment for dystonia based on a dynamic wearable orthosis equipped with metallic materials of non-linear mechanical characteristics. Two boys with upper-limb dystonia were enrolled, as well as six healthy children. Fully-customised devices were made for the patients. They used the orthosis for one month and their performances were evaluated before and after the treatment. The assessment was done with clinical scales (Modified Ashworth Score, Melbourne Upper Limb Assessment, PedsQL), interviews and optoelectronic kinematic analysis. Normal kinematics was obtained from the healthy group for comparison. Kinematic analysis showed modifications in motor patterns for both patients, with increases in the ranges of motion of initially stiff segments, improvements in posture, emergence of multi-joint strategies. Clinical scales did not always show similar trends in the two cases. The changes in control strategies could be linked to the force field dynamically applied by the device and appear to be learnable. This interpretation will be further tested with larger groups and longer treatments.