A stroke results in an injury to the brain, either from loss of blood flow to a portion of the brain or from bleeding into the brain itself destroying tissue as a result. So our brains control the body through nerve pathways that pass usually from the opposite side of the brain to the opposite side of the body. So the left side of my brain controls the right side of my body. The right side of my brain controls the left side of my body. So when a patient has a stroke, an artery gets blocked, we lose blood flow to a portion of the brain. There’s an area of brain that dies. If that area of brain includes the motor pathways, that control movement in the body, the opposite side of the body will lose significant function. Sometimes strokes can be a small area where there’s just a little bit of increased tone and dysfunction of the movements of the hand or causing walking to be a little less smooth. And sometimes stress can be a very large area of brain resulting in complete loss of function in the opposite side of the body. Where the hand and arm are entirely useless and the patient is limited to living in a wheelchair and not able to walk.