Abstract 17: Motor Relearning Effects of Functional Electrical Stimulation in Lower Limb Hemiparesis

Abstract

Objective: The primary objective of this study was to assess the effect of peroneal nerve stimulation (PNS) on lower limb motor impairment among chronic stroke survivors. The secondary objective was to assess the effect of PNS on lower limb functional mobility (disability) and overall quality of life. Design: A single-blinded randomized controlled trial, which enrolled 110 chronic hemiparetic stroke survivors (>90 days post-stroke), compared the effect of ambulation training with a PNS device to ambulation training with usual care (ankle foot orthosis or no device). Subjects were treated for 12-wks (Device Usage period) and followed for a total of 6-mos post-treatment. Outcome assessments were performed at baseline, end of the Device Usage period, and 3-mos and 6-mos post-treatment. The primary outcome measure was the Fugl-Meyer Motor Impairment scale. Secondary outcome measures were the Modified Emory Functional Ambulation Profile (mEFAP) and the Stroke Specific Quality of Life scale (SSQOL). Change scores were analyzed via repeated measure ANOVA with treatment and baseline dorsiflexion status (absence or presence of partial dorsiflexion) as independent factors and the baseline measure as a covariate. Results: Change in Fugl-Meyer scores was not significantly influenced by either treatment group (PNS or usual care) or by the presence (DP) or absence (DA) of volitional dorsiflexion at baseline. However, there was a significant treatment group by dorsiflexion status interaction (F=13.46, p=.00) on change in mEFAP scores. Post-hoc subset analysis of the DP and DA subjects using treatment group as an independent factor and baseline mEFAP score as covariate showed a significant treatment group effect (DP subjects: F=6.57, p=0.012 and DA subjects: F=4.24, p=.05) on mEFAP changes scores. A series of independent t-tests which compared the mean mEFAP change in the DP subjects relative to treatment group showed significant differences in favor of the usual care group. However, the same series of independent t-tests in the DA subjects showed the opposite effect with significant differences in favor of the PNS group. SSQOL change scores were not significantly influenced by treatment group or dorsiflexion status. Conclusions: Ambulation training for 12 weeks with either PNS or usual care had similar effects on lower limb motor impairment and overall quality of life in chronic stroke survivors. However, post-hoc analysis found that while PNS enhanced functional mobility in chronic stroke survivors with absent dorsiflexion, usual care was superior in chronic stroke survivors who demonstrated preservation of volitional ankle dorsiflexion.