Mechanisms of Walking Recovery After Stroke

Not Applicable

Completed

Interventions: Behavioral: No intervention
Behavioral: High-intensity interval training

Brief Summary: Subjects with stroke will have behavioral testing and brain imaging before and after a 4-week control period and a 4-week exercise intervention.

Detailed Description: Subjects with stroke will have behavioral testing and brain imaging before and after a 4-week control period and a 4-week exercise intervention using high-intensity interval training.

Recruitment & Eligibility

Inclusion Criteria

age 30-90 years
unilateral stroke experienced >6 months prior to enrollment in middle cerebral artery (MCA) territory without complete disruption of the putamen on the lesion side
walking speed <= 1.0 m/s on the 10 meter walk test
able to walk 10m over ground with assistive devices as needed and no physical assistance

Exclusion Criteria

MRI incompatibility (e.g. metallic or electronic implants, severe claustrophobia)
inability to perform mental imagery (time dependent motor imagery screening test [TDMI])
evidence of significant arrhythmia or myocardial ischemia on treadmill ECG stress test, or significant baseline ECG abnormalities that would make an exercise ECG uninterpretable
recent (<3 months) cardiopulmonary hospitalization
unable to communicate with investigators or correctly answer consent comprehension questions
significant ataxia or neglect (score of 2 on NIH stroke scale item 7 or 11)
severe lower extremity (LE) spasticity (Ashworth >2)
recent (<3 months) illicit drug or alcohol abuse or significant mental illness
major post-stroke depression (PHQ-9 ≥10) in the absence of medical management
participating in physical therapy or another interventional research study;
recent (<3 months) paretic LE botulinum toxin injection
concurrent progressive neurologic disorder or other major medical, orthopedic or peripheral vascular conditions that would limit improvement
pregnancy

Arm && Interventions

Group	Intervention	Description
Arm 1	High-intensity interval training	4-week control period with no intervention and 4-weeks of high-intensity interval training
Arm 1	No intervention	4-week control period with no intervention and 4-weeks of high-intensity interval training

Primary Outcome Measures

Name	Time	Method
Walking Speed	Change from 4-weeks to 8-weeks	10-meter walk test

Secondary Outcome Measures

Name	Time	Method
Gait Symmetry	baseline, 4 weeks, 8 weeks	Paretic step ratio
NIH Toolbox Standing Balance Test	baseline, 4 weeks, 8 weeks
Brain Locomotor Network Activation	baseline, 4 weeks, 8 weeks
Daily Walking Activity	baseline, 4 weeks, 8 weeks	activity monitor
Walking Speed	baseline, 4 weeks, 8 weeks	10-meter walk test
NIH Toolbox - Cognition Domain	baseline, 4 weeks, 8 weeks
Metabolic Cost of Gait	baseline, 4 weeks, 8 weeks	oxygen consumption rate during comfortable speed gait
Aerobic Capacity	baseline, 4 weeks, 8 weeks	oxygen consumption rate during exercise testing
Brain Locomotor Network Connectivity	baseline, 4 weeks, 8 weeks
Stroke and Aphasia Quality of Life Scale	baseline, 4 weeks, 8 weeks
Walking Capacity	baseline, 4 weeks, 8 weeks	6-minute walk test