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Feature

A blood clot retrieved from an artery

One way the University's interventional neurologists treat stroke is to physically remove blood clots from arteries in the brain.

A strike against stroke

The University's Minnesota Stroke Initiative takes aim at a swift, silent killer

By Deane Morrison

June 12, 2007

For Sue Bardill, the morning of April 30 started like any other. After getting ready for work, the Minneapolis resident started to tell her husband it was time to go. Then the first warning sign hit. "I heard my voice change," says Bardill. "I heard myself saying 'Something's wrong.' I saw the right side of my face sliding. I knew it was a stroke." Bardill's husband called 911. In minutes, an ambulance crew was inserting an IV tube in Bardill--who now could neither speak coherently nor move anything on her right side--and radioing ahead to Fairview-University Hospital. Twenty minutes after the first symptom appeared, Bardill was in the emergency room, and within an hour University stroke neurologist Robert Taylor had administered a drug to dissolve the blood clot that was blocking an artery in her brain. Another 30 minutes, and it may have been too late for the drug to work. But it did, and Bardill was walking and talking in a matter of days. As Bardill's experience shows, strokes strike suddenly, but prompt and expert treatment can minimize the damage. That's the goal of the University's new Minnesota Stroke Initiative, an ambitious effort begun in August 2006 to counter this stealthy killer through top-quality research, clinical services and education. "We want to excel in all three components," says Adnan Qureshi, executive director of the initiative. Qureshi, along with Taylor and Vallabh Janardhan, forms the inner core of the initiative. All three are interventional neurologists trained to interrupt a stroke in progress. A neurosurgeon specializing in blood vessel repair and a neurocritical care specialist will join the University later this summer. A formidable foe Stroke is the leading cause of longterm disability in the United States and the third leading cause of death, after heart disease and cancer. According to Stroke Center statistics, stroke claims about 2,300 victims in Minnesota every year, and state hospitals report 10,000 admissions for stroke. The American Heart Association reports that adults over 55 have more than a one-in-six lifetime risk for stroke. "In the United States, there are about 700,000 new cases a year," says Janardhan. "But we've identified only about half the risk factors."

"We start worrying immediately," says Taylor. "Damage can be done very quickly."

Stroke comes in two varieties. About 85 percent are ischemic strokes, which are similar to heart attacks in that a blood clot blocks an artery--but in the brain, not the heart muscle. The remaining 15 percent are called hemorrhagic strokes. One type of hemorrhagic stroke occurs when an artery balloons out-an aneurysm-and ruptures. Another cause of hemorrhagic stroke is uncontrolled high blood pressure. The buildup of blood puts pressure on the brain and can cause widespread damage. Risk factors for stroke include smoking, high blood pressure, diabetes, high cholesterol, and lack of exercise. Among the symptoms are numbness or weakness in the face, arm, or leg, especially on one side; difficulty speaking or moving; dizziness or balance problems; and trouble seeing in one or both eyes. Often, hemorrhagic stroke is preceded by a severe headache. In every case, time is of the essence in treating stroke. "We start worrying immediately," says Taylor. "Damage can be done very quickly." Interventional neurologists can, if a patient's situation warrants, perform treatments to stop a stroke in its tracks. The clotbuster drug called TPA (tissue plasminogen activator) is used to dissolve the clots that form in ischemic strokes. The physicians may also insert a catheter into the blocked vessel in the skull; there, they use a tiny device to secure a clot, which they then pull out of the body. They can also administer drugs right to the site of the clot. Stents, too, can be placed in arteries to keep them open. To treat aneurysms, the weakened, expanded section of artery is plugged with a coiled platinum wire that aids in clotting and, therefore, helps disconnect the aneurysm from the blood vessel. Other blood vessel problems that cause hemorrhagic stroke include abnormal connections between arteries and veins that can be treated with injections of special substances that act like glue and seal the injury. Cutting the wait, expanding the options As Bardill's experience shows, the University is already well equipped to deal with strokes. But through the initiative, Qureshi and his colleagues aim to shorten the time between stroke onset and treatment and to improve existing therapies. The effects of all this work will be felt from the very beginning, with a dedicated emergency medical service for stroke patients. "This could reduce the time to treatment by half," says Qureshi. With strong support from neurology department head David C. Anderson, the Zeenat Qureshi Stroke Research Center at the University is opening new vistas for treatment. Taylor, for example, is studying gene function in the cells that line blood vessels to see if they hold clues to future "events" such as the deposition of plaque, which is as dangerous in arteries of the brain as in those of the heart. Also, Qureshi is conducting a multicenter clinical trial funded by the National Institutes of Health to test the safety and benefit of blood pressure medications in the treatment of hemorrhagic stroke. He is also studying new ways to inhibit future clot formation following an ischemic stroke. Working with colleagues at the U's Stem Cell Institute, Center for Magnetic Resonance Research, and the Stroke Center, Janardhan is investigating the use of stem cells from the same patient to repair stroke damage. Often, ischemic stroke patients arrive at a hospital with a core of dead brain cells surrounded by dying cells that can be saved if treated in time. "To salvage the dying cells, we use drugs to dissolve the clot, or tiny devices to pull out the clot," says Janardhan. "The next step would be to inject bone marrow stem cells from the patient through a catheter to replace the dead cells." The work is in the preliminary stages, but the University team is the first to try this approach. "The science of [stroke] is expanding rapidly," says Qureshi. Thanks to the initiative, the University has "the largest interventional neurology training program in the world." As for Bardill, her speech now sounds perfectly normal. But, she says, "I read and understand about two-thirds as fast as before. However, if I were to get no better than today, I'd have a full life."