1Department of Neurology, Case Western Reserve University School of Medicine;2Research Service, VA Medical Center, Cleveland, OH, USA3Neurology Service, VA, Medical Center, Cleveland, OH, USA
Stance and swing phase gait deficits post stroke are both common and debilitating. Functional neuromuscular stimulation (FNS) with intramuscular (IM) electrodes (FNS-IM) is an innovative and effective method for restoring gait. The intramuscular electrode was used in conjunction with a multi-channel, portable stimulator worn on the subject's belt and controlled via a finger switch.
The electrode was constructed using a double helical coil for flexibility and a polypropylene core for durability. The electrode was tested in 17 stroke subjects with a total of 124 electrodes during 1413 electrode-months of use. The electrode had a 99 percent survival rate; no infections; and 97 percent of the electrodes produced a comfortable, therapeutic stimulus.
Feasibility of FNS-IM was tested in eight subjects with stroke onset three weeks -three months prior to FNS-IM treatment. There was 100 percent subject satisfaction with the system, no discomfort during use, and 75 percent of subjects used the system independently at home. Therapists used the system for six months with each subject for strengthening, endurance, coordination, and gait training. There were significant pre/post treatment gains in impairment (p < 0.022) and in disability (p < 0.029).
Efficacy of FNS-IM was pilot tested in six subjects with chronic stroke (> 12 months post stroke, in order to control for spontaneous recovery). Subjects demonstrated restoration of volitional motor function and volitional gait (pre/post treatment comparisons, p < 0.001); resolution of pain during walking; resolution of wheelchair or brace dependence; resumption of leisure activities; and resumption of self-care, housework, and outdoor work.
We are currently testing FNS-IM in conjunction with body weight supported treadmill training (BWS) and other innovative combination protocols in order to more fully restore stance and swing phase within a practical time frame. Early pilot data in these studies indicates significant gains in swing phase limb flexion and stance phase knee control (p < 0.001), which occur within a shorter time frame than was obtainable with FNS-IM alone.