Understanding Stroke: Causes, Symptoms, and Treatment

Every two seconds, someone in the world experiences a stroke, highlighting the urgency of understanding this critical health issue. Strokes are a leading cause of death and preventable disability, impacting one in six people during their lifetime. But what exactly happens during a stroke, and what can be done to mitigate its effects?

The Brain's Vulnerability

The brain, despite making up only 2% of the body's mass, demands over 20% of the body's oxygen supply. This oxygen is delivered via a network of arteries, including the carotid arteries (supplying the front of the brain) and vertebral arteries (supplying the back). These arteries branch into smaller vessels, ensuring that billions of neurons receive the oxygen they need to function. When this blood flow is interrupted, the consequences can be devastating.

Two Types of Strokes

There are primarily two ways a stroke can occur:

Hemorrhagic Stroke: This happens when a blood vessel ruptures, causing blood to leak into the brain.
Ischemic Stroke: This is the more common type, occurring when a blood clot blocks a vessel, halting blood flow.

The Danger of Embolism

Ischemic strokes often result from an embolism. In some instances, an irregular heart rhythm can cause blood to pool in the heart's upper chambers. This slowed blood flow allows platelets, clotting factors, and fibrin to clump together, forming a clot. This clot can then travel through the bloodstream towards the brain, lodging in an artery too small to pass through. This blockage cuts off oxygen to the downstream brain cells.

While the brain itself lacks pain receptors, the effects of oxygen deprivation are rapidly noticeable. Depending on the affected area, symptoms can include:

Slurred speech
Muscle weakness, often on one side of the body

The body attempts to compensate by diverting blood flow, but this is not a long-term solution. Without prompt intervention, oxygen-deprived cells begin to die, leading to potentially severe and permanent brain damage.

Time is Brain: The Importance of Rapid Treatment

Seeking immediate medical attention is crucial. The primary treatment for ischemic stroke is an intravenous medication called Tissue Plasminogen Activator (tPA). This medication works to dissolve the blood clot and restore blood flow. When administered within a few hours of the stroke's onset, tPA significantly improves the chances of survival and reduces the risk of lasting disabilities.

In cases where tPA is not suitable (due to medication conflicts, bleeding risks, or large clot size), doctors may perform an endovascular thrombectomy. This procedure involves inserting a catheter into an artery (usually in the leg) and guiding it to the blockage using X-ray imaging. A retriever is then passed through the catheter to grab and remove the clot, restoring blood flow.

Recognizing a Stroke: The FAST Test

Because rapid treatment is essential, knowing how to identify a stroke is vital. Use the FAST test to quickly assess someone:

Face: Ask the person to smile. Does one side of their face droop?
Arms: Ask the person to raise both arms. Does one arm drift downward?
Speech: Ask the person to repeat a simple phrase. Is their speech slurred or strange?
Time: If you observe any of these signs, call emergency services immediately.

Acting quickly can save lives and minimize the long-term impact of a stroke. Knowing the signs and seeking immediate medical attention are the best defenses against this potentially devastating condition.