Optimizing Transcranial Direct Current Stimulation for Motor Recovery From Severe Post-stroke Hemiparesis

Optimizing Transcranial Direct Current Stimulation for Motor Recovery From Severe Post-stroke Hemiparesis

Individuals who experienced a stroke over one year ago will be randomly assigned to receive 1 of 4 different conditions of brain stimulation. All individuals will receive therapy of the hand and arm following the stimulation. This study will try to determine which brain stimulation condition leads to the greatest improvement in hand and arm function.

This study will look at the effects of a painless, non-invasive form of brain stimulation, called transcranial direct current stimulation, or tDCS. tDCS is thought to increase the brain's ability to change. Participants will be assigned to one of four groups by chance. Three groups will receive tDCS at a level expected to increase the brain's ability to change, and will vary by the areas of the brain that are stimulated. The fourth group will receive tDCS at a level not thought to affect the brain's ability to change. All participants will receive intensive therapy of their impaired arm and hand, focusing on exercises that will improve their ability to function in daily life.

Inclusion Criteria:

• 12 or more months post-stroke
• Inability to extend the affected metacarpophalangeal joints at least 10 degrees and the wrist 20 degrees

Exclusion Criteria:

• Addition or change in dosage of drugs known to exert detrimental effects on motor recovery within 3 month of enrollment
• Untreated depression
• History of multiple strokes

Exclusion criteria for TMS evaluations:

• History of head injury with loss of consciousness
• History of severe alcohol or drug abuse, or psychiatric illness
• Positive pregnancy test or being of childbearing age and not using appropriate contraception
• Presence of ferromagnetic material in the cranium except in the mouth, including metal fragments from occupational exposure and surgical clips in or near the brain
• Cardiac or neural pacemakers