Dept. of Stereotactic Neurosurgery, Otto-von-Guericke University, University Hospital Magdeburg, Germany
Long-term outcomes of semi-implantable functional electrical stimulation for central drop foot
Central drop foot is a common problem in patients with stroke or multiple sclerosis (MS). For decades, it has been treated with orthotic devices, keeping the ankle in a fixed position. It has been shown recently that semi-implantable functional electrical stimulation (siFES) of the peroneal nerve can lead to a greater gait velocity increase than orthotic devices immediately after being switched on. Little is known, however, about long-term outcomes over 12 months, and the relationship between quality of life (QoL) and gait speed using siFES has never been reported applying a validated tool. We provide here a report of short (3 months) and long-term (12 months) outcomes for gait speed and QoL.
Forty-five consecutive patients (91% chronic stroke, 9% MS) with central drop foot received siFES (Actigait®). A 10 m walking test was carried out on day 1 of stimulation (T1), in stimulation ON and OFF conditions, and repeated after 3 (T2) and 12 (T3) months. A 36-item Short Form questionnaire was applied at all three time points.
We found a main effect of stimulation on both maximum (p < 0.001) and comfortable gait velocity (p < 0.001) and a main effect of time (p = 0.015) only on maximum gait velocity. There were no significant interactions. Mean maximum gait velocity across the three assessment time points was 0.13 m/s greater with stimulation ON than OFF, and mean comfortable gait velocity was 0.083 m/s faster with stimulation ON than OFF. The increase in maximum gait velocity over time was 0.096 m/s, with post hoc testing revealing a significant increase from T1 to T2 (p = 0.012), which was maintained but not significantly further increased at T3. QoL scores showed a main effect of time (p < 0.001), with post hoc testing revealing an increase from T1 to T2 (p < 0.001), which was maintained at T3 (p < 0.001). Finally, overall absolute QoL scores correlated with the absolute maximum and comfortable gait speeds at T2 and T3, and the increase in overall QoL scores correlated with the increase in comfortable gait velocity from T1 to T3. Pain was reduced at T2 (p < 0.001) and was independent of gait speed but correlated with overall QoL (p < 0.001).
Peroneal siFES increased maximal and comfortable gait velocity and QoL, with the greatest increase in both over the first three months, which was maintained at one year, suggesting that 3 months is an adequate follow-up time. Pain after 3 months correlated with QoL and was independent of gait velocity, suggesting pain as an independent outcome measure in siFES for drop foot.
Miller Renfrew L, Lord AC, Warren J, Hunter R.
Evaluating the Effect of Functional Electrical Stimulation Used for Foot Drop on Aspects of Health-Related Quality of Life in People with Multiple Sclerosis: A Systematic Review.
Multiple sclerosis (MS) is a common degenerative neurologic condition resulting in walking difficulties. Foot drop is a common walking impairment in MS that can affect health-related quality of life (HRQOL). Functional electrical stimulation (FES) can improve walking in people with MS, but its effect on HRQOL is not well established. This review investigated the effect of FES used for foot drop on HRQOL in adults with MS.
A systematic search was performed using CINAHL, MEDLINE, Cochrane Library, PubMed, and PEDro online databases. Inclusion and exclusion criteria were applied to select eligible studies. Data were extracted, and two reviewers independently rated the quality of the studies using the Effective Public Health Practice Project assessment tool.
Eight studies were eligible for review; seven were of moderate-to-strong methodological quality and one was weak. Seven studies demonstrated significant positive effects of FES on different aspects of HRQOL as measured by the 29-item Multiple Sclerosis Impact Scale, 36-item Short Form Health Status Survey, Canadian Occupational Performance Measure, and Psychosocial Impact of Assistive Devices Scale.
This review provides preliminary evidence that FES has a positive effect on aspects of HRQOL in people with MS; however, the variety of HRQOL outcomes used makes it difficult to determine definitive conclusions. Future larger-scale randomized studies with long-term follow-up are recommended to better understand the effect of FES on HRQOL. This will inform prescribing decisions and support compliance with FES over the longer-term.