Influence of Area of Brain Damage on Brain Reorganization After Chronic Stroke

This study will examine how the brain rewires itself to make up for the lack of movement many people with stroke experience. It will try to determine if the rewiring differs depending on the location of the stroke and the amount of time since the stroke occurred. For some stoke patients, weakness may persist, while others recover completely after time. It is not known which parts of the brain are involved in the recovery of different types of stroke and if the type of stroke affects recovery. People 18 years of age and older who have had subacute thromboembolic or hemorrhagic stroke more than 3 months before enrolling may participate in this study. Participants come to the NIH Clinical Center three times every 2 years for up to 10 years. At the first visit, patients have a neurological examination and perform tests of motor abilities such as lifting small objects, turning cards, using a spoon, stacking checkers and lifting cans during a short period of time as rapidly as possible. At the second visit, subjects have structural magnetic resonance imaging (MRI) scans of the brain. MRI uses a strong magnetic field and radio waves to obtain images of body organs and tissues. The MRI scanner is a metal cylinder surrounded by a strong magnetic field. During the scan, the subject lies on a table that can slide in and out of the cylinder, wearing earplugs to muffle loud knocking noises associated with the scanning process. Total scan time is about 30 minutes At the third visit, subjects perform some simple movement tasks during functional MRI (fMRI) scans. The procedure is the same as with structural MRI, except that subjects are asked to perform simple movement tasks in the scanner. Before the fMRI scans, electrodes are attached to the subject's arms and legs to monitor muscle activity (surface electromyography). Total scan time is about 1.5 hours. Movement tasks might include pinching a force-measuring instrument with the fingers, pressing different keys on a keyboard