Using Transcranial Direct Current Stimulation (tDCS) to Enhance the Benefit of Movement Training in Stoke Patients

This study will determine if electrical brain stimulation during movement practice can improve the ability of stroke patients to reach for objects more than movement practice alone.

People between 18 and 85 years old who have had a stroke may be eligible for this study. Participants are randomly assigned to one of two study groups: movement training with active (tDCS) or movement training with sham (tDCS).

Participants will undergo 1-hour movement training and (tDCS) sessions twice a day, 5 days a week, for 3 weeks. For these sessions, subjects will sit in front of a computer screen that shows a target (round dots) and a cursor (a line). Participants will be instructed to move the cursor to various targets on the computer screen as fast and as accurately as possible, controlling the position of the cursor by moving their arm, which will rest on a mechanical device.

Participants will receive real or sham (tDCS) during the movement training sessions. For (tDCS), electrode sponges soaked in tap water are placed on the scalp and forehead. A small electrical current is passed between the electrodes. The stimulation lasts 20 minutes.

Patients will have the following tests four times during the study - 1) before starting movement training 2) (tDCS) during the course of training and (tDCS), 3) after completing training and (tDCS), 4) and 3 months after completing training and (tDCS):

Functional magnetic resonance imaging (fMRI)

Magnetic resonance imaging (MRI) uses a magnetic field and radio waves to take pictures of the brain. Functional MRI (fMRI) shows what parts of the brain are used when a task is performed. For the test, the subject lies on a table that can slide in and out of the scanner. A computer screen can be seen from inside the scanner. During the scan, subjects may be asked to do the study task or to lie still for up to 20 minutes at a time.

Movement and function tests

• Measurement of arm stiffness
• Moving the arms actively and against resistance
• Picking up objects and moving them as quickly as possible
• Performing daily living tasks like buttoning, dressing and walking
• Performing tasks while wearing a glove that monitors the position of the arm
• Completing questionnaires on ability to perform daily activities or other movements and level of tiredness

Transcranial magnetic stimulation (TMS)

TMS uses a magnet to stimulate the brain in way that is different from (tDCS). This study us...