Stroke is the #3 cause of death and the #1 cause of disability in the United States. A stroke occurs when there is an interruption of the blood supply to the brain. All of the cells in the brain need a constant supply of blood to provide oxygen and nutrients and carry away waste products generated by the cells. Cells in the brain will only survive for a few minutes from the time they lose their blood supply. Brain cells surrounding this area may be supplied by other blood vessels and survive for longer periods of time. Patients can have a variety of symptoms depending on which part of the brain loses its blood supply. Different areas of the brain are involved in movement, sensation, vision, speech and coordination. Depending on which areas are supplied by the affected blood vessel, the patient may have weakness, numbness, vision loss, difficulty speaking, or clumsiness, separately or in combination.

A stroke can take two forms
The first is an ischemic stroke where there is a blockage of an artery carrying blood to the brain. The blockage may be due to a blood clot coming from the heart or from the large arteries carrying blood from the heart to the brain. Blood clots are more likely to form in people with an irregular heartbeat due to atrial fibrillation, problems with the valves of the heart, or a variety of conditions where the body’s blood clotting mechanism is disturbed and the blood clots too easily. Individual blood vessels within the brain can become narrowed or completely blocked because of the effects of aging, high blood pressure, high cholesterol or other lipid problems, diabetes, and smoking. In some patients no clear cause for the stroke is identified.

The second kind of stroke is a hemorrhagic stroke. This occurs when a blood vessel in the brain leaks or ruptures spilling blood over the surface of the brain or within the substance of the brain. If there is enough bleeding, the collection of blood can cause pressure on the surrounding brain. Hemorrhages can occur in patients with untreated high blood pressure, because of abnormal bulges in blood vessels known as aneurysms, with disturbances of the blood clotting mechanism where blood is too slow to clot, and with trauma. As was the case with ischemic stroke, not all patients have a clear explanation for this hemorrhage.

The treatment of the stroke depends on whether the stroke is a hemorrhagic or ischemic stroke. Computerized axial tomography (CAT scan) is an advanced type of x-ray that produces a picture of the brain. A CAT scan will show whether the stroke is ischemic or hemorrhagic. An ischemic stroke can be treated with a new medication that dissolves the clot blocking a blood vessel, restoring the flow of blood. This drug can be given through a vein in the patient’s arm or in select patients through a catheter inserted in an artery in the leg and advanced into the brain right to the site of the blockage. This clot-dissolving medication must be given soon after the onset of symptoms. For most patients, the medicine must be started within three hours from the time the stroke occurred. Because it is a clot-dissolving medication, a potential side effect is bleeding. In a small number of patients, this bleeding may be severe. Because time is critical with this medicine, we must learn to recognize a stroke when it occurs and treat it as an emergency.

Patients with hemorrhage need careful treatment of their blood pressure and management of the effects of increased pressure and swelling. If the blood clot is large or in a critical location, the patient may need an operation to remove the clot, performed by a neurosurgeon. Most patients with a hemorrhage cannot be treated with the new clot-dissolving medication because it will worsen the bleeding in the brain.

All patients with a stroke of either type, hemorrhagic or ischemic, will need an evaluation to try to determine why the stroke occurred. Some patients will need further testing to look for abnormalities of their blood vessels, the presence of heart problems, blood clotting problems, or other medical conditions that can cause stroke. The treatment will depend on the size and location of the stroke and how it affects the patient. Patients with large strokes can be critically ill, requiring care in an intensive care unit. Many stroke patients will need speech therapy, physical therapy, and occupational therapy, often under the supervision of a rehabilitation specialist.

Many strokes can be prevented. Recognizing and treating high blood pressure, diabetes, heart disease, high cholesterol and lipids, and stopping smoking are all very effective ways to reduce the chance of a stroke