Mechanisms of Walking Recovery After Stroke

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.

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