Surviving a Stroke: Rehabilitation

The effects of a stroke depend upon the location and extent of brain damage and availability of prompt medical attention. About 4.8 million Americans are stroke survivors. More than one-fourth of survivors have some degree of difficulty performing daily activities. Six months after an ischemic stroke, about 50 percent of survivors 65 and older report having problems with one-sided paralysis. Twenty-six percent report needing assistance with walking and 19 percent have problems speaking or understanding speech.

The goals of stroke rehabilitation are to improve quality of life and make the most use of functional ability. Many patients eventually reach a plateau in their recovery. Researchers at Arizona State University and Kinetic Muscles, Inc. are now developing and testing wearable robotic devices that may help further improve function after a stroke.

The robotic equipment, worn over the target limb, would contain sensors and parts to enable the limb to move. In physical therapy, a patient would try to move the paralyzed limb as much as possible. The robot would then complete the movement. Researchers say even older brains have some plasticity and the ability to adapt and learn new information. The goal of the wearable robotic therapy is to develop new pathways in the brain that are linked to movement of the affected limb.

Scientists have already received FDA approval for a wearable robotic hand. Investigators are also working on a wearable robot for the arm and one for the leg. The wearable robots may also be helpful for patients with spinal cord injuries and weak muscles.

SOURCES

National Stroke Association, http://www.stroke.org

What is a stroke?

A stroke is the death of an area of brain tissue due to a lack of oxygenated blood. There are two main types of stroke. An ischemic stroke is caused when an artery feeding the brain is blocked, usually by a blood clot. In a cerebral thrombosis, the clot forms directly in the clogged area of the blood vessel. A cerebral embolism occurs when a clot forms in another part of the body, breaks loose, travels through the circulatory system, and becomes caught in a narrower artery feeding the brain. Ischemic stroke is the most common form of stroke and account for 83 percent of all cases.

A hemorrhagic stroke is caused when a blood vessel ruptures, causing blood to flow out of the vessel. A rupture can occur when a weakened area in the wall of a blood vessel balloons or bulges out. This condition is called an aneurysm. Eventually, the pressure of blood as it passes over the weak area can cause the aneurysm to burst. Another condition that can cause a hemorrhagic stroke is an arteriovenous malformation, or abnormal cluster of blood vessels. These vessels tend to be weak and fragile and are at risk of rupture. Although hemorrhagic stroke is less common than ischemic stroke, they are more deadly and can quickly lead to death.

According to the American Heart Association, about 700,000 Americans experience a stroke each year. It's the third leading cause of death in this country and the leading cause of serious long-term disability.