Stroke
Conditions
Keywords
Chronic Stroke ( > 6 months), non-invasive brain stimulation, rehabilitation, walking, kinetics
Brief summary
This project will evaluate two different methods of normalizing the center of mass acceleration (COMa) in individuals post-stroke, specifically focusing on rates and pattern of recovery to analyze walking-specific adaptations as precursors to motor learning. In addition, the proposed project seeks to establish the optimal configuration of electrodes to activate neural circuits involved in post-stroke locomotion. Once the better method of training COMa and optimal parameters of electrode placement for tDCS are identified, the investigators will evaluate the effects of tDCS on locomotor adaptations during single sessions and over a five-day training period.
Detailed description
The project seeks to establish the optimal configuration of electrodes to change the excitability of neural circuits involved in post-stroke locomotion, identify effective strategies for training a specific locomotor adaptation, and improve adaptations via adjunctive non-invasive brain stimulation. Tools to improve neural excitability may increase potential for locomotor skill learning, thereby improving rehabilitation outcomes. Non-invasive brain stimulation with transcranial direct current stimulation (tDCS) has recently emerged as a simple to administer, low-cost, and low-risk option for stimulating brain tissue. Cortical excitability is increased after application and preliminary results imply a relationship to increases in motor activity in those post-stroke. However, inhibition of the contralesional hemisphere is also shown to improve paretic motor output through inhibition of excessive maladaptive strategies, and combining the two electrode configurations may provide additional benefit for locomotor tasks requiring interlimb coordination. Furthermore, the effects of tDCS on walking function in conjunction with physical intervention strategies aimed at improving locomotor ability post-stroke are yet unstudied.
Interventions
DEVICEtDCS
Constant non-invasive, low intensity, direct electrical current utilized to stimulate specific areas of the brain. Evaluating immediate effects of anodal/cathodal stimulation during 20 minutes of treadmill walking.
DEVICESham tDCS
Per published protocols, tDCS will be administered for 30 secs allowing for sensory adaptation to occur and then turned off, so that the remaining sham stimulation will include zero current. Evaluating immediate effects during 20 minutes walking on a treadmill.
Sponsors
Ralph H. Johnson VA Medical Center
Medical University of South Carolina
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 85 Years
Healthy volunteers
Yes
Inclusion criteria
Chronic Stroke 1. age 18-70 2. at least six month post-stroke 3. residual paresis in the lower extremity (Fugl-Meyer LE motor score \<34) 4. ability to sit unsupported for ≥ 30 sec 5. ability to walk at least 10 ft. 6. self-selected 10 meter gait speed \< 0.8 m/s 7. provision of informed consent.
Exclusion criteria
Acute Stroke 1. Unable to ambulate at least 150 feet prior to stroke, or experienced intermittent claudication while walking \< 200 meters 2. history of congestive heart failure, unstable cardiac arrhythmias, hypertrophic cardiomyopathy, severe aortic stenosis, angina or dyspnea at rest or during activities of daily living 3. History of COPD or oxygen dependence 4. Preexisting neurological disorders, dementia or previous stroke 5. History of major head trauma 6. Legal blindness or severe visual impairment 7. history of significant psychiatric illness 8. Life expectancy \<1 yr 9. Severe arthritis or orthopedic problems that limit passive ROM 10. post-stroke depression (PHQ-9 ≥10) 11. History of DVT or pulmonary embolism within 6 months 12. Uncontrolled diabetes with recent weight loss, diabetic coma, or frequent insulin reactions 13. Severe hypertension with systolic \>200 mmHg and diastolic \>110 mmHg at rest 14. presence of cerebellar stroke.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Center of Mass Acceleration Peak | Pre (same as initial session) and post (immediately following final session) conducted within 5-10 days apart according to subject availability. | Peak full body center of mass acceleration during gait, expressed as m/sec\^2, captured during 30 seconds of treadmill walking at a steady-state, self-selected walking speed. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Center of Mass Acceleration Impulse | Pre (directly prior to initial session) and post (immediately following final session) conducted within 5-10 days apart according to subject availability. | Positive integral of the full body center of mass acceleration during the gait cycle, expressed as an average over all strides captured during 30 seconds of data collection at a steady-state, self-selected walking speed (m/sec). |
Other
| Measure | Time frame | Description |
|---|---|---|
| Self-selected walking speed | Pre (directly prior to initial session) and post (immediately following final session) conducted within 5-10 days apart according to subject availability. | Walking speed overground for 10 meters, average of 3 timed trials, expressed as m/sec. |
| Paretic step ratio | Pre (directly prior to initial session) and post (immediately following final session) conducted within 5-10 days apart according to subject availability. | Percentage of the total stride completed by paretic step. This is a unit-less measure. Each stride is initiated by foot strike of the paretic leg, and the data are expressed as an average over all strides captured during 30 seconds of data collection at a steady-state, self-selected walking speed. |
Countries
United States
Outcome results
None listed