Primary Outcome Measures:
Secondary Outcome Measures:
- Walking Speed During 10 Meter Gait Test [ Time Frame: Baseline, 6 and 12 weeks post-implantation ]
The test assesses walking speed in meters per second over a short duration. At baseline this test was done with subject's conventional walking aid. At 6 and 12 weeks post-implantation this was done with and without stimulation.
- Canadian Occupational Performance Measure (COPM) Score [ Time Frame: Baseline,12 weeks post-implantation ]
A semi-structured interview is conducted in order to identify subject's limitations with daily occupations of importance in categories self-care, productivtiy or leisure. The subject is then asked to rate the imporance of each of the occupations using a 10-point rating scale. Afterwards the subject chooses up to 5 of the most important occupations (problems) (basis for identifying intervention goals). The subject is asked to use a 10 point scale to rate level of performance and satisfaction with performance for each of the five identified problems. Average COPM performance score and satisfaction score are calculated. The scores range between 1 and 10, where 1 indicates poor performance and low satisfaction, respectively, while 10 indicates very good performance and high satisfaction.
- Four Square Step Test (FSST) [ Time Frame: Baseline, week 12 post-implantation ]
It is a test of dynamic balance that clinically assesses the person's ability to step over objects forward, sideways, and backwards. The patient's time to perform the test is measured which shorter time representing better performance. At baseline this test was done with subject's conventional walking aid. At 12 weeks post-implantation it was done with and without stimulation.
- Nerve Conduction Velocity of the Peroneal Nerve [ Time Frame: Baseline, week 12 post-implantation ]
Measured: Nervus peroneus communis (CPN) and Nervus peroneus superficialis (SPN)
- Change in MRI of Affected Leg and Implant Post-implantation [ Time Frame: Week 3 post-implantation ]
MRI will be conducted to evaluate the impact of the implant on the common peroneal nerve (e.g. positioning of the nerve cuff along the nerve, path of the lead wire and the common peroneal nerve, estimation of the cross-sectional area of the common peroneal nerve compared to the pre-operative MRI recording, etc.)
Stroke is the third leading cause of death in the United States and other developed countries and a major source of disability. Prognosis for regaining the ability to walk is good, with 64% of those initially dependent in walking regaining independence by 3 months. However, many gait abnormalities persist. A conservative estimate suggests that 20% of stroke survivors have a drop foot. Drop foot following stroke is caused by paresis of the ankle dorsiflexor muscles. It prevents the patient from effectively swinging the leg during walking, causing an abnormal gait characterized by hip hitching and circumduction and toe catch. Walking speed in people with drop foot is often significantly reduced and the risk of stumbling or falling is high. The conventional treatment for drop foot is an ankle-foot orthosis (AFO). While AFOs are appropriate for many patients, in certain patient groups AFOs have significant limitations (e.g. in patients with strong spasticity, suffering from pronounced inversion, suffering from volume changes in the lower extremity, etc). An alternative way of treating drop foot is by means of functional electrical stimulation. Clinical studies evaluating the effectiveness of drop foot stimulation suggest that it provides many benefits to patients, such as an improved confidence in walking, increased walking speed and endurance, less effort during walking and reduced spasticity. Implantable systems such as ActiGait are considered therapeutic alternatives specifically for those patients for whom conventional treatments have failed. ActiGait system consists of an external module (antenna and control module), a foot switch transmitting to the external module and an implanted assembly (receiver, pulse train generator, electrodes). The objective of this study is to obtain additional evidence on safety of ActiGait implantation procedure and on its efficacy. The study will enrol 5 subjects that will be implanted and followed for 12 weeks. Efficacy outcomes will be assessed at the baseline and during two follow-up visits (week 6 and 12). Subjects will be asked to walk with and without their preferred walking at the baseline and with and without stimulation at follow-up visits.