Persons with C5 or C6 tetraplegia achieve selected functional gains using a neuroprosthesis

Objective: To test the efficacy and safety of the NESS Handmaster(TM) neuroprosthesis with subjects with C5 or C6 tetraplegia. Design: Interventional, nonrandomized case series. Setting: Subjects' residence and university research laboratory. Participants: Mien. 3 to 17 years after C5 (n=5) and C6 (n=2) spinal cord injury (SCI). Intervention: Subjects practiced with the neuroprosthesis daily to regain grasp. hold, and release ability and to restore selected functions of 1 of the 2 paralyzed hands. Subjects were observed 2 to 3 times weekly for 3 weeks. Main Outcome Measures: Three activities of daily living (ADL) tasks: (1) pick up a telephone, (2) eat food with a fork. and (3) perform I individually selected ADL task and 2 grasp. hold, and release tasks (lift a videocassette. lift a 150-g weight). Secondary outcomes were grip strength. electrically induced finger motion, and Fugl-Meyer spherical grasp, Noriparametric data were analyzed with the Wilcoxon signed-rank test. and parametric data (grip strength and finger motion) were analyzed by analysis of variance. All tests were considered significant at P equal to .01. Results: At study completion, all 7 subjects were 100% successful at using the Handmaster in the studied ADL and grasp, hold, and release tasks. Significant improvements occurred in grip strength (from .57+/-.98N at baseline to 16.5+/-4.4N), finger linear motion (from 0.0cm at baseline to 8.4+/-3.2cm), and Fugl-Meyer scores. No safety issues were encountered. Six of 7 subjects rated their overall performance as "excellent." Conclusions: The Handmaster is a safe. noninvasive neuroprosthesis that improves hand function of selected subjects with C5 or C6 SCI.