Does surface neuromuscular electrical stimulation (sNMES) to the upper limb following acute stroke improve outcome?

Abstract

Does surface neuromuscular electrical stimulation (sNMES) to the upper limb following acute stroke Improve outcome? Introduction: Upper limb impairment affects 85% of stroke patients, half of whom still experience problems three months later('-3). The literature is unclear about the effectiveness of upper limb rehabilitation strategies, and there is a need to identify interventions that will improve upper limb function and reduce the incidence of shoulder pain. Surface neuromuscular electrical stimulation (sNMES) has been proposed as a safe method of improving outcome after stroke but further research is needed to evaluate the effect of this treatment on upper limb recovery and pain (4.5) Aims: We have undertaken a randornised controlled trial to evaluate a programme of upper limb sNMES following acute stroke. Methods: Patients admitted within 10 days of acute stroke were assessed against the following eligibility criteria: new upper limb impairment (motor and/or sensory and/or neglect); medically stable; no cognitive/language impairments or previous upper limb problem likely to influence assessments; no contraindication to sNIVIES. Participants were randomised via an independent telephone randomisation service to receive a 4-week programme of upper limb sNIVIES (11 hour three times daily) or placebo in addition to stroke unit care. The active stimulator produced a shoulder shrug. Outcome measures were undertaken by a researcher who was blinded to the randomisation group. The primary outcome measure was the Action Research Arm Test (ARAT)(6,7) 3 months after stroke. Secondary outcome measures included upper limb pain, disability and health status. One hundred and sixty eight subjects were required for 80% power to detect a clinically significant difference in ARAT (8 points)(6,7). Results: There were 176 study participants. The groups were well matched at baseline. There was no difference in arm function between groups in terms of the primary outcome measure. The median ARAT (6,7) score at 3 months was 50.0 in the intervention group (n=79) and 55.5 in the control group (n=74) (p=0.068). There were however significant differences in outcomes in favour of the control group when using other measures to assess arm function (the grasp and gross subsections of the ARAT(6. 7 ) , and the Frenchay Arm Test' (FAT)(8)). There was also a significant difference in favour of the control group when assessing impairment using the Arm subsection of the Motricity Index(g). There were no statistically significant differences between the groups at 3 months in terms of prevalence of upper limb pain, disability and global health status. No significant differences were seen between the groups at 4 weeks in any of the outcome measures. Secondary analysis revealed statistically significant differences in favour of the control group in those with more severe initial functional impairment. Subjects received 70% of intended stimulation or placebo with no significant difference between groups. Conclusions: A 4-week programme of sNMES to the shoulder does not improve functional outcome following acute stroke and may worsen arm function in certain stroke patients. 'Routine' use of sNMES to the proximal upper limb after acute stroke cannot be recommended.