Efficacy of a hybrid upper limb neuromuscular electrical stimulation system in lessening selected impairments and dysfunctions consequent to cerebral damage

Abstract

Objective: The purpose of this study was to test the efficacy of a new computerized neuromuscular electric stimulation system (HandmasterTM) in improving selected impairments and functional measures of patients who survived stroke and traumatic brain injury (TBI). Methods: Survivors of stroke (n = 13) and TBI (n = 7) with chronic paralysis lasting 6.8 ± 7.8 years (range 1 to 29 years) participated in a home program of electrical stimulation. The device is a hybrid of a hand-forearm splint that incorporates five surface electrodes and a computerized electrical stimulator. The patterned stimulation elicits finger flexion and extension, lateral pinch, and grasp of the paralyzed hand. Patients practiced daily for 3.4 ± 0.5 hours over a mean duration of 13.1 ± 6.6 weeks. Assessment included goniometric measurements of wrist and elbow resting posture, passive and active joints motion, linear distance of fingers to palm, Ashworth scale, and the ability to hold a 1 kg load in the affected hand. The Frenchay arm test represented hand function. Results: ANOVA tests and Wilcoxon signed rank test were employed. There were significant improvements (p = 0.01) in elbow, wrist, and fingers posture; Ashworth scale; volitional active elbow flexion (32.5 ± 12.7°); wrist extension (12.7 ± 11.1°) and flexion (9.03 ± 4.5°). Passive wrist extension improved 13.7 ± 3.6°. Thirteen patients (65 percent) had active wrist extension post stimulation compared with only three (15 percent) before study commencement. Partial completion of the Frenchay tasks were observed before stimulation in only three patients compared with partial completion of tasks by nine patients at study conclusion. Post stimulation, 16 of 20 patients were able to hold a 1 kg weight with the NESS system active, compared with only three patients without it. Conclusions: Application of the NESS system for three to four hours daily improves selected impairments and may help to restore partial hand functions of patients with chronic stroke or head injury. © 1998 Demos Medical Publishing.