Stroke

What Is a Stroke ?

A stroke, or cerebrovascular accident (CVA), occurs when blood supply to part of the brain is disrupted, causing brain cells to die. When blood flow to the brain is impaired, oxygen and glucose cannot be delivered to the brain. Blood flow can be compromised by a variety of mechanisms.
Blockage of an artery
Narrowing of the small arteries within the brain can cause a so-called lacunar stroke, (lacune=empty space). Blockage of a single arteriole can affect a tiny area of brain causing that tissue to die (infarct).
Hardening of the arteries (atherosclerosis) leading to the brain. There are four major blood vessels that supply the brain with blood. The anterior circulation of the brain that controls most motor, activity, sensation, thought, speech, and emotion is supplied by the carotid arteries. The posterior circulation, which supplies the brainstem and the cerebellum, controlling the automatic parts of brain function and coordination, is supplied by the vertebrobasilar arteries.
If these arteries become narrow as a result of atherosclerosis, plaque or cholesterol, debris can break off and float downstream, clogging the blood supply to a part of the brain. As opposed to lacunar strokes, larger parts of the brain can lose blood supply, and this may produce more symptoms than a lacunar stroke.
Embolism to the brain from the heart. In situations in which blood clots form within the heart, the potential exists for small clots to break off and travel (embolize) to the arteries in the brain and cause a stroke.
Rupture of an artery (hemorrhage)
Cerebral hemorrhage (bleeding within the brain substance). The most common reason to have bleeding within the brain is uncontrolled high blood pressure. Other situations include aneurysms that leak or rupture or arteriovenous malformations (AVM) in which there is an abnormal collection of blood vessels that are fragile and can bleed.

What Is the Treatment of a Stroke ?

Tissue plasminogen activator (TPA)

There is opportunity to use alteplase (TPA) as a clot-buster drug to dissolve the blood clot that is causing the stroke. There is a narrow window of opportunity to use this drug. The earlier that it is given, the better the result and the less potential for the complication of bleeding into the brain.

Present American Heart Association guidelines recommend that if used, TPA must be given within three hours after the onset of symptoms. Normally, TPA is injected into a vein in he arm. The time frame for use can be extended to six hours if it is dripped directly into the blood vessel that is blocked. This is usually performed by an interventional radiologist, and not all hospitals have access to this technology.

For posterior circulation strokes that involve the vertebrobasilar system, the time frame for treatment with TPA may be extended even further to 18 hours.

Heparin and aspirin

Drugs to thin the blood (anticoagulation; for example, heparin) are also sometimes used in treating stroke patients in the hopes of improving the patient’s recovery. It is unclear, however, whether the use of anticoagulation improves the outcome from the current stroke or simply helps to prevent subsequent strokes (see below). In certain patients, aspirin given after the onset of a stroke does have a small, but measurable effect on recovery. The treating doctor will determine the medications to be used based upon a patient’s specific needs.

Managing other Medical Problems

Blood pressure and cholesterol control are key to prevention of future stroke events. In transient ischemic attacks, the patient may be discharged with medications even if the blood pressure and cholesterol levels are acceptable. In an acute stroke, blood pressure will be tightly controlled to prevent further damage.

In patients with diabetes, the blood sugar (glucose) level is often elevated after a stroke. Controlling the glucose level in these patients may minimize the size of a stroke. Finally, oxygen may administered to stroke patients when necessary.

Rehabilitation

When a patient is no longer acutely ill after a stroke, the healthcare staff focuses on maximizing the patient’s functional abilities. This is most often done in an inpatient rehabilitation hospital or in a special area of a general hospital. Rehabilitation can also take place at a nursing facility.

The rehabilitation process can include some or all of the following:

speech therapy to relearn talking and swallowing;occupational therapy to regain dexterity in the arms and hands;
physical therapy to improve strength and walking; and family education to orient them in caring for their loved one at home and the challenges they will face.
The goal is for the patient to resume as many, if not all, of their pre-stroke activities and functions. Since a stroke involves the permanent loss of brain cells, a total return to the patient’s pre-stroke status is unfortunately, not a realistic goal in many cases.

When a stroke patient is ready to go home, a nurse may come to the home for a period of time until the family is familiar with caring for the patient and the procedures for giving various medications. Physical therapy may continue at home. Eventually, the patient is usually left at home with one or more caregivers, who now find their lives have changed in major ways. Caring for the stroke patient at home may be easy or very nearly impossible. At times, it becomes apparent that the patient must be placed in a board and care home or a skilled nursing facility because adequate care cannot be given at home despite the good intentions of the family.