Rizwan Kalani, MD
Stein C, Fritsch CG, Robinson C, Sbruzzi G, and Méa Plentz RD. Effects of Electrical Stimulation in Spastic Muscles After Stroke: Systematic Review and Meta-Analysis of Randomized Controlled Trials. Stroke. 2015
Spasticity occurs in 20-30% of individuals with prior stroke. Common management strategies include administration of GABAergic agents (baclofen), ankle-foot orthotics, physical therapy, and tendon surgeries. Given inconsistent results from prior randomized controlled trials (RCTs), Stein et al did a systematic review and meta-analysis of studies evaluating the effect of neuromuscular electrical stimulation (NMES) on post-stroke spasticity.
The authors reviewed the literature for RCTs that assessed the effect of NMES (with or without additional therapeutic intervention) for spasticity after stroke. Studies evaluating at least three days of NMES, regardless of dosage, and applied to the upper or lower extremities, were included. Two independent reviewers selected the studies, extracted relevant data, and assessed for risk of bias. The primary outcome was spasticity (per the modified ashworth scale) and secondary outcome was range of motion (ROM) (by goniometer).
Of the 29 RCTs (with 940 subjects) that met the inclusion criteria for the systematic review, 14 were included in the meta-analysis (the other 15 had missing data and used other scales to assess spasticity). Most studies used NMES frequencies of 18-50 Hz and pulse duration from 0.1-0.3 seconds. NMES (alone or combined with other treatment) was associated with reduction in spasticity (-0.30, 95% CI: -0.58 – -0.03) compared to the control group. The 12 studies that combined NMES with another therapeutic modality for spasticity significantly reduced spasticity (-0.35, 95% CI: -0.63 – -0.07) whereas the two studies that evaluated NMES alone did not. Interestingly, reports that used NMES on the legs showed a significant reduction in spasticity (-0.78, 95% CI: -1.02 – -0.54) but those with NMES applied to the upper extremity did not. NMES (alone or with other intervention) was associated with an increase in ROM (2.87, 95% CI: 1.18-4.56). Again, when NMES was combined another modality, a significant increase in ROM was noted (2.73, 95% CI: 1.07-4.39); this did not hold true when NMES was used alone. Application to the leg and elbow improved ROM, whereas use on the wrist did not.
NMES combined with other therapeutic interventions improves spasticity and increases ROM after stroke. RCTs evaluated varied in the time the intervention was started after stroke, treatment duration, stimulation parameters used, degree of spasticity and functional deficit, as well as comparative treatments evaluated in certain studies; these factors may affect response to NMES. Establishing efficacy would be best assessed by a large, high-quality RCT. However, based on this analysis, it is worth considering this option in conjunction with a physiatrist and the patient.