A pilot study to investigate the feasibility of electrical stimulation to assist gait in Parkinson's disease

Objectives. This study aims to investigate the effect of functional electrical stimulation (FES) on gait in people with Parkinson's disease. Materials and Methods. Seven subjects with idiopathic Parkinson's disease received single-channel electrical stimulation for eight weeks to the common peroneal nerve to improve heel strike and provide sensory stimulus during the swing phase of gait. Stride length, time, and number of steps to complete a 20-m walk and distance completed in 3 min were assessed. Episodes of freezing and incidence of falls were recorded. Statistical analysis of the walking test data was analyzed using the nonparametric Wilcoxon signed ranks test. Results. An immediate improvement was demonstrated with FES on distance and average stride length during a 3-min walk during the treatment period but not on number of steps and walking speed during a 20-m walk. A training effect was observed for all parameters of gait measured over the eight-week treatment period, which was mostly maintained four weeks after treatment was stopped. Fewer falls and episodes of freezing occurred during the treatment period. The number of falls returned to pretreatment levels when treatment was stopped. Conclusions. This study has shown that FES can improve some parameters of gait over an eight-week period of use with a carryover effect that is maintained without stimulation during that time and an immediate reduction in the frequency of falls. An immediate effect of FES was demonstrated over a 3-min walk but not over a 20-m walk. Improvements in gait largely persisted on reassessment four weeks after stopping use of FES although the frequency of falls returned to pretreatment levels. A larger study is required to support these findings, to understand the mechanisms of the effects of electrical stimulation on gait and to identify those most likely to benefit from it.