Overview

Achieving functional ambulation post stroke continues to be a challenge for stroke survivors, clinicians, and researchers. In the effort to enhance outcomes of motor training, cortical priming using brain stimulation has emerged as a promising adjuvant to conventional rehabilitation. This project focuses on the development of a long term gait rehabilitation protocol using brain stimulation to improve walking outcomes in people with stroke. The project will also aim to understand the neural mechanisms that are associated with response to the intervention.

Eligibility

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