What is a stroke?


A stroke occurs when a blood clot blocks an artery or blood vessel in the brain or when a blood vessel breaks thereby interrupting the blood flow to an area of the brain.

When a stroke occurs, it kills brain cells in the immediate area. Death of these brain cells causes the release of chemicals that can kill brain cells in a larger surrounding area of brain tissue. This can happen at a fast pace. In fact, the "window" for interventional treatment of a stroke is about six hours.

There are two types of strokes: hemorrhagic strokes and ischemic strokes. Ischemic strokes occur when a blood clot blocks or plugs a blood vessel in the brain. A hemorrhagic stroke occurs when a blood vessel ruptures or breaks in the brain. Ischemic strokes occur in two ways: Embolic stroke and Thrombotic Stroke. In embolic strokes, a blood clot forms in another part of the body (usually the heart), and travels through the bloodstream to the brain. When it arrives in the brain, the clot lodges in a blood vessel causing a stroke. In thrombotic strokes, blood flow is impaired because of a blockage to one or more of the arteries supplying blood to the brain.

Stroke & Brain Injury

58% of stroke patients do not present until 24 hours or more after its onset. 17% of adults over the age of 50 cannot name a single symptom of stroke. These statistics prove the need for public education on strokes. The five most common symptoms of stroke are (i) sudden weakness or numbness in the face or an extremity(especially on one side of the body) (ii) sudden vision trouble in one or both eyes; (iii) trouble speaking or understanding (sudden confusion); (iv) sudden severe headache of unknown origin; and (v) sudden dizziness or loss of balance or coordination.

Treatment of strokes/ brain injury may depend on the type of stroke. For instance, ischemic strokes are often treated with drugs called thrombolytics. This class of drugs help reestablish cerebral circulation by dissolving the clots that obstruct blood flow. Another class of drugs used to treat strokes are called neuroprotectives. These drugs work to minimize the effects caused by the release of chemicals following the death of brain cells. Another potential treatment for an acute stroke is called Oxygenated Fluorocarbon Nutrient Emulsion Therapy (OFNE). OFNE delivers oxygens and nutrients to the brain through the cerebral spinal fluid. Neuroperfusion is an experimental treatment for strokes that involves rerouting oxygen-rich blood through the brain to prevent damage from an ischemic stroke.

Use of diagnostic imaging devices such as an MRI or CT scan can help the physician determine whether the stroke is ischemic or hemorrhagic. This is an important determination to be made before therapy is instituted. Thrombolytic drugs used on a hemorrhagic stroke will greatly exacerbate the stroke and perhaps cause immediate death.