All About Strokes: Risk Factors, Prevention and Treatment

Following the reports of Sen. Tim Johnson’s, D-S.D., recent brain surgery, we have received many questions and comments from our viewers regarding the cause and treatment of strokes.

There are two major types of stroke.

Ischemic stroke occurs when an obstructed blood vessel prevents adequate blood supply from reaching an area of the nervous system, and causes approximately 80 percent of strokes.

Hemorrhagic stroke occurs when a ruptured blood vessel bleeds into the brain, and is responsible for the remaining 20 percent of strokes.

Sen. Johnson suffered hemorrhagic stroke, as a result of a condition known as arteriovenous malformation (AVM.) An AVM is a congenital condition that Sen. Johnson was likely born with or developed shortly after birth. AVMs are tangled, dilated blood vessels in which arteries flow directly into veins. AVMs occur most often at the junction of cerebral arteries.It affects 300,000 Americans and kills about 3,000 every year. Most people with AVM do not experience symptoms.

In the senator's case, his AVM caused an intracerebral hemmorhage--the vessels bled into the brain.

The most common cause of intracerebral hemorrhage is high blood pressure (hypertension). Less common causes of intracerebral hemorrhage include trauma, infections, tumors, blood clotting deficiencies, and abnormalities in blood vessels (such as the arteriovenous malformations that triggered Sen. Johnson's stroke).

Treatment of hemorrhagic stroke depends on the underlying reason for bleeding. For example, if the hemorrhage is due to the rupture of a blood vessel aneurysm, treatment is aimed at surgically repairing the vessel to prevent further bleeding. In some situations, surgical evacuation of the hemorrhage may also be considered.

In Sen. Johnson’s case, surgical evacuation was necessary. Adm. John Eisold, attending physician of the U.S. Capitol, said that Johnson “underwent successful surgery to evacuate the blood and stabilize the malformation.”

For patients with cerebellar hemisphere hematomas that are more than 3cm in diameter and cause the brain to shift, surgical evacuation is often life-saving.

Even with abnormalities formed at birth, such as those Sen. Johnson had, we can control some of the risk factors for developing a stroke. Not smoking, managing diabetes and high blood pressure, eating a nutritious diet and getting enough exercise are all ways to minimize stroke risk.

We can also be mindful of the warning signs of possible stroke. There are tests doctors can do to detect impending stroke, and allow physicians to be pro-active in treating them with medication and surgery.

Warning signs that a stroke may be developing include loss of speech, weakness of an arm or leg, or temporary loss of vision in one eye. A prompt medical workup can sometimes lead to treatment before a stroke occurs. In addition, once a stroke develops, rapid evaluation and treatment at a stroke center--a hospitalize specializing in stroke treatment-- can minimize the brain damage associated with a stroke.

Thankfully, in Sen. Johnson’s case, his long-term prognosis may benefit from the quick action taken. Julianne Fisher, Johnson’s spokeswoman, said the senator was taken to the hospital after walking to his Capitol Hill office following the conference call in which his health problems became apparent. The Capitol physician came to his office and examined him, and it was decided he needed to go to the hospital.

“It was caught early,” Fisher said.

Catching a stroke early can mean all the difference in saving your life.

For more information on stroke, visit Stroke

Dr. Manny Alvarez is the managing editor of health news at, and is a regular medical contributor on the FOX News Channel. He is chairman of the Department of Obstetrics and Gynecology and Reproductive Science at Hackensack University Medical Center in New Jersey. Additionally, Alvarez is Adjunct Professor of Obstetrics and Gynecology at New York University School of Medicine in New York City.