The procedure involves: (1) assisted hand movement by a mechanical device, (2) mechanical vibration applied to the surface of the forearm, and (3) stimulation of the brain with either transcranial magnetic stimulation (TMS) or transcortical direct current stimulation (DCS). These 3 components of the procedure are carried out simultaneously. Each subject will be evaluated pre- and post-treatment with several clinical tests of functional movement. The hypotheses of this project are that the AMES+rTMS and AMES+tDCS procedures are safe and will enable most of the stroke patients to recover finger extension.

This protocol is designed to investigate the safety and efficacy of a procedure for treating chronic (>1 year post) stroke patients who still cannot move the hand affected by the stroke. The treatment involves: (1) assisted hand movement by a mechanical device, (2) mechanical vibration applied to the surface of the forearm, and (3) stimulation of the brain with either transcranial magnetic stimulation (TMS) or transcortical direct current stimulation (DCS). Subjects receiving TMS during treatment are expected to respond more fully (i.e., increased volitional EMG) in the treated hand compared to those receiving DCS.

Inclusion Criteria:

• Stroke occurring ≥12 months before enrollment
• Hemispheric stroke (ischemic or hemorrhagic), cortical or subcortical
• Residual upper-extremity weakness without the ability to activate volitionally extensor digitorum (no volitional EMG in the long finger extensor muscle)independently
• Age 18-75 years old

Exclusion Criteria:

• Significant upper-extremity proprioceptive deficit (<70% correct detection of the direction of passive finger movement, with eyes closed)
• Cortical stroke involving the primary motor cortex
• Epilepsy not controlled by medication
• Botox injections 5 months before or during enrollment; use of intrathecal Baclofen
• Residual pain in the tested arm
• Significant neglect involving the affected limb (NIHSS 2 on the extinction and attention items)
• Exercise intolerant
• Uncontrolled hypertension or angina
• Cognitive or behavioral inability to follow instructions
• Current abuse of alcohol or drugs
• Terminal illness with anticipated survival of <12 months
• Severe apraxia; inability to understand oral directions in English; or inability to communicate adequately with study personnel
• Circumference of arm incompatible with the AMES device (checked by placing the limb in the device)
• Contractures, decreased range of motion, or skin condition preventing tolerance of the AMES muscle vibrators
• Spinal cord injury, arthritis, or fractures of affected limbs resulting in loss of range of motion
• In the tested arm, peripheral nerve injury or neuropathy resulting in significant motor or sensory loss
• Pathological neurological/physical condition other than stroke that impairs the function of the impaired arm or that produces pain in the impaired arm
• Implanted device (e.g., cardiac pacemaker, Baclofen pump) the operation of which might be adversely affected by the brain stimulation
• Previous vascular surgery on the blood vessels of the brain or heart or heart valve surgery
• Female and pregnant