Brain cells start to die when the blood flow to one's brain is disrupted, depriving the brain vital nutrients and oxygen. This interruption may be caused by a clot (ischemic stroke) or a blood vessel that has burst (hemorrhagic stroke).
In the United States, stroke is the leading cause of serious long-term disability, and the fourth most common cause of death, reports the American Heart Association.
Ninety percent of strokes are ischemic. When the arteries leading to the brain are blocked or narrowed, blood flow is halted or reduced, causing an immediate and dire loss of brain cells. Thrombotic and embolic stroke are two common types of ischemic strokes.
Thrombotic strokes occur when a blood clot (typically from fatty deposits) develops in one of the two carotid arteries, which bring blood to your brain. An embolic stroke happens when a blood clot develops away from your brain and travels through the bloodstream, eventually getting stuck in the brain arteries. The clot typically develops in the heart.
A hemorrhage stroke occurs when a blood vessel in the brain leaks or bursts. High blood pressure or weak blood vessel walls (intracerebral hemorrhage) or aneurysms (subarachnoid hemorrhage) can spur this kind of stroke.
The Stroke Awareness Foundation reports that stroke symptoms include confusion, difficulty understanding speech, vision troubles, loss of coordination or balance and severe headaches.
J Mocco, associate professor of neurological surgery at Vanderbilt University, said that "sudden onset of weakness of half the body or face (inability to move one's face, arm or leg)" is another common warning sign.
Shalini Bansil, stroke neurologist at Overlook Medical Center, said that every moment a stroke goes untreated can have devastating neurological effects, potentially leading to disability or fatality.
Although most people have never heard of it, aphasia (the sudden inability to speak, read, write and/or understand language) affects 25 to 40 percent of all stroke survivors. "The lack of awareness is almost as devastating as the disorder since people do not know where to access resources and services," explains Ellayne Ganzfried, executive director of the National Aphasia Association.
Doctors will screen for a stroke if a patient demonstrates symptoms or suffers a transient ischemic attack (TIA), which is also called a mini-stroke. TIAs occur when one suffers through stroke symptoms for less than five minutes due to a temporary decrease of blood to the brain.
Along with reviewing the patient's medical history and administering physical and neurological exams, the doctor can conduct brain-centric diagnostic tests: Imaging tests (MRI, CT scan), electrical tests to understand electrical impulses (EEG, Evoked Response) and blood flow tests (B-mode imaging, Doppler testing,duplex scanning).
Specific types of ultrasounds may help as well. Murray Flaster, a neurologist and stroke specialist at Loyola University Medical Center, explained, "B-mode imaging is one mode of ultrasound. Doppler testing is a second mode of ultrasound. Duplex scanning is a combination of B-mode and doppler mode."
The Mayo Clinic reports that treatments vary depending on the type of stroke. For ischemic strokes, the goal is to return blood flow to the head. Aspirin helps thin the blood and tissue plasminogen activator, injected intravenously, can break up blood clots. Sometimes, a doctor must remove the clot manually through a catheter.
With a carotid endarterectomy, a surgeon opens the blocked artery to remove the plaque buildup.
Angioplasty entails moving a balloon-tipped catheter into the clogged artery. By inflating the balloon, the plaque is pushed against the artery walls, opening the passage for blood flow. A stent is left behind to keep the passage wide.
Hemorrhagic strokes are treated differently because the goal is to decrease bleeding rather than increase blood flow. Therefore, drugs like aspirin do not help. Doctors provide blood pressure-lowering drugs. To prevent clots, warfarin or clopidogrel may be provided. Surgical procedures for hemorrhagic strokes include aneurysm clipping, coiling and surgical AVM removal. Bed rest is prolonged medical attention are necessary for recovery.
For more information visit the National Stoke Association.