IMPLANTED FUNCTIONAL ELECTRICAL-STIMULATION HAND SYSTEM IN ADOLESCENTS WITH SPINAL-INJURIES - AN EVALUATION

Objective: To study the utility and functional benefits of an implante d functional electrical stimulation (FES) system for hand grasp and re lease in adolescents with tetraplegia secondary to spinal cord injurie s. Design: Intervention study with before-after trial measurement with each subject as his or her own control. Setting: Nonprofit pediatric orthopedic rehabilitation facility specializing in spinal cord injury. Participants: A convenience sample of five adolescents between 16 and 18 years of age with C5 or C6 level tetraplegia at least 1 year after traumatic spinal cord injury. Key muscles for palmar and lateral gras p and release were excitable by electrical stimulation. Interventions: A multichannel stimulator/receiver and eight electrodes were surgical ly implanted to provide stimulated palmar and lateral grasp and releas e. In conjunction with implantation of the FES hand system, surgical r econstruction in the form of tendon transfers, tendon lengthenings and releases, and joint arthrodeses was performed to augment stimulated h and function. Rehabilitation of the tendon transfers and training in t he use of the FES hand system were provided. Main Outcome Measures: Me asurements of pinch and grasp force, the Grasp and Release Test (GRT), and an assessment of six activities of daily living (ADL) were admini stered before implantation of the FES hand system and at regular follo w-up intervals. Results of the stimulated response of individual muscl es and surgical reconstruction were evaluated using standard and stimu lated muscle testing techniques and standard assessment of joint range of motion. All subjects completed followup testing. Results: Lateral and palmar forces were significantly greater than baseline forces (p = .043). Heavy objects on the GRT could only be manipulated with FES, a nd FES increased the level of independence in 25 of 30 ADL comparisons (5 subjects, 6 activities) as compared to baseline. After training, F ES was preferred in 21 of 30 comparisons over the typical means of tas k completion. Of the 40 electrodes implanted, 37 continue to provide e xcellent stimulated responses and all of the implanted stimulators hav e functioned without problems. The surgical reconstruction procedures greatly enhanced FES hand function by either expanding the workspace i n which to utilize FES (deltoid to triceps transfer), stabilizing the wrist (brachioradialis to wrist extensor transfer), or stabilizing joi nts (intrinsic tenodesis transfer, FPL split transfer). Conclusion: Fo r five adolescents with tetraplegia, the combination of FES and surgic al reconstruction provided active palmar and lateral grasp and release . Laboratory-based assessments demonstrated that the FES system increa sed pinch force, improved the manipulation of objects, and typically i ncreased independence in six standard ADL as compared to pre-FES hand function. The study also showed that the five adolescents generally pr eferred FES for most of the ADL tested. Data on the benefits of the im planted FES hand system outside of the laboratory are needed to unders tand the full potential of FES. (C) 1997 by the American Congress of R ehabilitation Medicine and the American Academy of Physical Medicine a nd Rehabilitation.