Long-term follow-up of patients using the ActiGait implanted drop-foot stimulator

The ActiGait drop foot stimulator has been shown to be an effective and safe device for the treatment of drop foot following stroke, showing comparable results with surface drop foot systems [1,2]. The device comprises an implant, a control unit and a wireless heel switch that triggers stimulation. Stimulation of the common Peroneal (CP) nerve is through a nerve cuff placed around the CP nerve just above the knee. The cuff has four tri-polar electrodes, orientated to activate different nerve fibres within the CP nerve. Each channel is programmed independently via a PC. Fifteen patients who had suffered a stroke at least six months prior to recruitment were implanted with the ActiGait drop-foot stimulator. Two subjects deviated from the study protocol and, at the 90 day assessment three subjects had technical problems. Fifteen months after the start of the study 13 subjects using the device have undergone a further assessment in which we repeated the walking tests with and without the stimulator. Results showed a statistically significant improvement in walking parameters when stimulation was applied. Mean increase in distance walked = 11.5m p=0.05 and increase in maximum walking speed 0.07 m/s p=0.01. Statistically significant improvements were also detected when walking parameters were compared with those at Baseline. In conclusion: when initial technical problems with the ActiGait implanted drop-foot stimulator were overcome the system was shown to be effective in improving walking and well accepted by users.