Brain Stimulation for Gait Rehabilitation After Stroke

Inclusion Criteria: * Age greater than 18 years * First ever monohemispheric stroke \> 3 months since onset * Residual hemiparetic gait deficits (e.g. abnormal gait pattern) * Able to walk for 5 minutes at self-paced speed. Handheld assistive device is acceptable. * Walking speed lesser than 1.2 m/s * Lower limb Fugl-Meyer Motor score between 15-30 * At least 5 deg of ankle dorsiflexion necessary to perform the ankle-tracking task Exclusion Criteria: * General exclusion criteria * Severe osteoporosis * Contracture-limiting range of motion of lower limb * Score of more than 2 on the Modified Ashworth Scale (indicating increased muscle tone through ankle range of motion) * Uncontrolled anti-spasticity medications during the study period * Score less than 6 on the Fugl-Meyer Sensory Assessment Scale for the Lower Limb * Cardiorespiratory or metabolic diseases (e.g. cardiac arrhythmia, uncontrolled hypertension or diabetes, chronic emphysema) * Unhealed decubiti, persistent infection * Significant cognitive or communication impairment (Mini-Mental State Examination (MMSE)\<21), which could impede the understanding of the purpose of procedures of the study or prevent the patient from performing the ankle-tracking task. * Lesions involving the brainstem and cerebellum * Failure to pass the graded exercise stress test TMS exclusion criteria * Implanted cardiac pacemaker * Metal implants in the head or face * Unexplained, recurring headaches * History of seizures or epilepsy * Currently under medication that could increase motor excitability and lower seizure threshold * Skull abnormalities or fractures * Concussion within the last 6 months * Currently pregnant tDCS exclusion criteria * Skin hypersensitivity * History of contact dermatitits * History of allodynia and/or hyperalgesia * Any other skin or scalp condition that could be aggravated by tDCS