Repetitive peripheral sensory stimulation (RPSS)

Abstract

Background: Repetitive peripheral sensory stimulation (RPSS) followed by 4- hour task-specific training improves upper limb motor function in subjects with stroke who experience moderate to severe motor upper limb impairments. Obectives: Here, we compared effects of RPSS versus sham followed by a shorter duration of training in subjects with moderate to severe motor impairments in the chronic phase after stroke. Design and setting: Single-center, randomized, placebo-controlled, parallelgroup clinical trial. Methods: We compared effects of 18 sessions of either 1.5 hours of active RPSS or sham followed by a supervised session of 30-minutes of functional electrical stimulation (FES) and 45-minutes of task-specific training (TST) of the paretic upper limb. In both groups, subjects were instructed to perform functional tasks at home, without supervision. The primary outcome measure was the Wolf Motor Function Test (WMFT) after six weeks of treatment. Grasp and pinch strength were secondary outcomes. Results: In intention-to-treat analysis, WMFT improved significantly in both active and sham groups at 3 and 6 weeks of treatment. Grasp strength improved significantly in the active, but not in the sham group, at 3 and 6 weeks. Pinch strength improved significantly in both groups at 3 weeks, and only in the active group at 6 weeks. Conclusions: RPSS enhanced hand strength in chronic stroke. Despite the short duration of supervised training (2.75 hours/session), changes in WMFT in both groups were comparable to those reported after longer, more intensive training protocols. These findings are relevant to settings that impose constraints in duration of direct contact between therapists and patients.