Stroke

WHAT IS IT?

A stroke occurs when the blood supply to part of your brain is interrupted or severely reduced, depriving brain tissue of oxygen and nutrients. Within minutes, brain cells begin to die.

Types

A stroke may result from a blocked artery (ischemic stroke) or the leaking or bursting of a blood vessel (hemorrhagic stroke). Some people experience a temporary disruption of blood flow to their brain without brain cell death, called a transient ischemic attack (TIA).

Ischemic stroke. About 85 percent of strokes are ischemic strokes, which occur when the arteries to your brain become narrowed or blocked, causing severely reduced blood flow (ischemia). The most common ischemic strokes include:

• Thrombotic stroke. It occurs when a blood clot forms in one of the arteries that supply blood to your brain.
• Embolic stroke. It occurs when a blood clot or other debris forms away from your brain — commonly in your heart — and travels through your bloodstream and lodges in a brain artery.

 Hemorrhagic stroke. Hemorrhagic stroke occurs when a blood vessel in your brain leaks or ruptures. Brain hemorrhages can result from many conditions, including uncontrolled high blood pressure and weak spots in your blood vessel walls (aneurysms). Types of hemorrhagic stroke include:

• Intracerebral hemorrhage. A blood vessel bursts and spills into the surrounding brain tissue, damaging brain cells. Brain cells beyond the leak are deprived of blood and also damaged.
•  Subarachnoid hemorrhage. An artery on or near the surface of your brain bursts and spills into the space between the surface of your brain and your skull. This type of stroke commonly results from the bursting of an aneurysm.

Transient ischemic attack (TIA). A TIA, also known as a ministroke, is a brief period of symptoms similar to those you’d have with a stroke. TIAs often last less than five minutes. Like an ischemic stroke, a TIA occurs when a clot or debris blocks blood flow to part of your brain. But a TIA doesn’t leave lasting symptoms because the blockage is temporary. Having a TIA puts you at greater risk of having a full-blown stroke in the future, and often indicates an underlying medical condition, so it’s important to see your doctor.

Risk factors

Many factors can increase your risk of a stroke. They include being overweight, not getting enough exercise, smoking, excessive alcohol use, and the use of illicit drugs. Medical conditions such as high blood pressure, high cholesterol, diabetes, cardiovascular disease, and obstructive sleep apnea also can increase your stroke risk. So can a family history of stroke, TIAs or heart attack.

SYMPTOM

Signs and symptoms may include:

• Trouble speaking and understanding. You may experience confusion. You may slur your words or have difficulty understanding speech.
• Paralysis or numbness of the face, arm or leg. You may develop sudden numbness, weakness or paralysis in your face, an arm or a leg, especially on one side of your body. Try to raise both your arms over your head at the same time. If one arm begins to fall, you may be having a stroke. Similarly, one side of your mouth may droop when you try to smile.
• Trouble seeing in one or both eyes. You may have blurred or blackened vision in one or both eyes, or you may see double.
• Headache. A sudden, severe headache, which may be accompanied by vomiting, dizziness or altered consciousness, may indicate you’re having a stroke.
• The trouble with walking. You may stumble or experience sudden dizziness, loss of balance, or loss of coordination.

TREATMENT

The treatment you receive will depend on whether you’re having an ischemic or hemorrhagic stroke.

1. Ischemic stroke
To treat an ischemic stroke, doctors must quickly try to restore blood flow to the brain.

Medication.

Treatment is centered around the use of clot-busting medications, which must be administered within about three to four hours of the start of symptoms — the sooner, the better. Quick treatment not only improves your chances of survival but also may reduce complications.

Other procedures.

Depending on the circumstances, certain procedures may be performed to treat a stroke. They include the following:

• Mechanical clot removal. In limited circumstances, a catheter is inserted into an artery and threaded to your brain where the device is used to physically break up or grab and remove the clot.
• Angioplasty and stents. A balloon is used to expand a narrowed artery, and a tiny mesh-like device (stent) is inserted to support the opened artery.
• Carotid endarterectomy. To decrease your risk of having another stroke or TIA, your doctor may open up an artery in your neck that’s become narrowed by fatty deposits (plaques) and remove the deposits.

2. Hemorrhagic stroke

Emergency treatment of hemorrhagic stroke focuses on controlling your bleeding and reducing the pressure in your brain.

Medication.

If you take anti-platelet drugs to prevent blood clots, you may be given drugs or transfusions of blood products to counteract the blood thinners’ effects. You may also be given drugs to lower pressure in your brain, lower your blood pressure, prevent blood vessel spasms, or prevent seizures. Once the bleeding stops, healing is similar to what happens while a bad bruise goes away. If the area of bleeding is large, your doctor may perform surgery to remove the blood and relieve pressure on your brain.

Surgery.

Surgery may be used to repair damaged blood vessels or blood vessel abnormalities in hopes of decreasing the risk of future strokes.

• Surgical clipping. A tiny clamp is placed at the base of an aneurysm to stop blood flow to it. The clamp keeps the aneurysm from bursting or it can prevent re-bleeding of the aneurysm.
• Coiling (endovascular embolization). A surgeon inserts a catheter into an artery in your groin and guides it to your brain. Tiny detachable coils are placed into the aneurysm. The coils block blood flow into the aneurysm and cause blood to clot.
• AVM removal. A surgeon may remove a type of blood vessel abnormality called an arteriovenous malformation (AVM) if it’s located in an accessible area of your brain.
• Stereotactic radiosurgery. Using multiple beams of highly focused radiation, this procedure may be used to repair some vascular malformations.

Maintain a healthy heart, keep a check on these parameters.

Excerpt From: The Mayo Clinic. “Mayo Clinic A to Z Health Guide”.