Stroke Gait Rehabilitation Using Functional Electrical Stimulation

Stroke is the number one cause of disability. Difficulty with walking affects most stroke
survivors. Walking deficits (e.g. reduced ankle flexion during swing phase, decreased forward
propulsion during terminal stance) can cause risks of falls, slow walking speed, increased
effort of walking, and difficulties with activities of daily living. Restoration of walking
ability can improve quality of life, and is perceived as a major goal of rehabilitation by
stroke survivors. Examples of interventions that are used to rehabilitate walking post-stroke
are functional electrical stimulation, fast treadmill walking, and bio- feedback. While
recent research has focused on comparing the effectiveness of different gait rehabilitation
interventions, the neural and biomechanical mechanisms underlying different gait
rehabilitation strategies are unknown.

The overall purpose of this protocol is to assess the magnitude and time course of
biomechanical and neurophysiologic effects of rehabilitative strategies and protocols that
are commonly used during physical therapy treatment of gait disorders post-stroke among 2
cohorts of people post-stroke - Cohort 1 and Cohort 2.

The study is being conducted in 2 phases. The Preliminary study phase involves enrolling 35
healthy young able bodied participants that undergo different gait training sessions using
electrical stimulation, walking speed, and biofeedback, or neurophysiologic evaluations
comprising measurement of corticospinal excitability and spinal excitability (to understand
neurophysiology in neurologically-unimpaired adults). This preliminary study helps to better
understand the feasibility and safety of the gait training sessions, and to develop
strategies for neurophysiologic evaluations (corticospinal and spinal excitability measures)
for post stroke subjects that are involved in next phase of the study. Post-stroke
individuals also participated in preliminary neurophysiologic testing.

The interventional study phase involves enrolling 55 post stroke subjects that will be
assigned to 2 cohorts. Both cohorts will receive identical training sessions involving
FastFES and FES but will differ in the number of training sessions. Subjects in Cohort 1 will
receive 3 training sessions with a repeated-measures crossover design, while the subjects in
Cohort 2 will receive up to 18 training sessions. For both cohorts, dependent variables will
include corticospinal and spinal neurophysiology measures, gait biomechanics, and gait
function.

Inclusion Criteria:

- Chronic stroke (>6 months post stroke)

- First (single) lesion

- Able to walk with or without the use of a cane or walker

- Sufficient cardiovascular health and ankle stability to walk for 6 minutes at a
self-selected speed without an orthoses

- Resting heart rate 40-100 beats per minute

- Resting blood pressure between 90/60-70/90.

Exclusion Criteria:

- Evidence of moderate/ severe chronic white matter disease or cerebellar stroke on MRI

- Cerebellar signs (ataxic ("drunken") gait or decreased coordination during rapid
alternating hand or foot movements

- Insulin dependent diabetes

- History of lower extremity joint replacement

- Score of >1 on question 1b and >0 on question 1c on NIH Stroke Scale

- Inability to communicate with investigators

- Neglect/hemianopia, or unexplained dizziness in last 6 months

- Neurologic conditions other than stroke

- Orthopedic problems in the lower limbs or spine (or other medical conditions) that
limit walking

- Contraindications to transcranial magnetic stimulation (TMS) are: history of seizures,
metal implants in the head or face, history of recurring or severe headaches/migraine,
headache within the past 24 hours, presence of skull abnormalities or fractures,
hemorrhagic stroke, history of dizziness, syncope, nausea, or loss of consciousness in
the past 12 months