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Highlights from the International Stroke Conference

Clotting risk after pregnancy, driving after a stroke and more from the San Diego meeting

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Special ambulance for stroke patients

An ambulance crew that includes a neurologist and a portable CT scanner can limit the damage wrought by a stroke while en route to the hospital, researchers reported February 13.

The specially equipped team can distinguish those stroke patients who would benefit from a clot-dissolving injection of tissue plasminogen activator, or tPA – the first-choice drug for strokes caused by blood clots in the brain. The CT scanner distinguishes whether a blood clot is the cause. Some strokes result from bleeding in the brain, and giving tPA to such patients risks catastrophe.

Stroke treatment is time-sensitive. Giving tPA within 4.5 hours of a clot-based stroke can provide dramatic benefits by dissolving the clot and restoring blood flow.

Physician Martin Ebinger of Charité University Medicine Berlin reported such a vehicle team had better results than conventional ambulances. Of 614 patients with clot-caused strokes that were diagnosed and treated in the special ambulance, 33 percent received clot-dissolving treatment within the 4.5-hour window, compared with only 22 percent of 1,497 similar patients getting a standard ambulance ride. The special vehicle team also dissolved more clots within the first hour, resulting in those patients’ earlier release from the hospital.

Clotting risk lingers after pregnancy

Women spend the 12 weeks after giving birth at a higher-than-average risk of blood clots, a study finds.

Hooman Kamel, a neurologist at Weill Cornell Medical College in New York City, and his colleagues analyzed medical records of nearly 1.7 million women admitted to California hospitals for labor and delivery from 2005 to 2010. He reported February 13 at the conference and in the New England Journal of Medicine that while the risk of clotting in these women afterward was low overall, it increased by a factor of nearly 11 in the first six weeks postpartum and remained at least doubled during weeks seven through 12. In the first six weeks, the clot rate was 24.4 per 100,000 women compared with 2.3 per 100,000 in these women a year later. Risk in the 7-12 week period was 5.6 per 100,000.

Lee Schwamm, a neurologist at Harvard Medical School, said the low incidence of clotting makes it impractical to preventively treat the huge population of postpartum women. But he said women with pregnancy complications putting them at risk of clots do merit monitoring beyond childbirth. Obstetricians should be aware of the longer risk period, he said, “because they are, for many women, the primary care providers.”

Driving after a stroke

At least half of people who survive a stroke resume driving afterward, some within a few weeks, a study finds. But only about 6 percent received any kind of formal driving evaluation, neurologist Shelly Ozark of the Medical University of South Carolina in Charleston reported February 13.

Ozark and her colleagues interviewed 162 people with an average age of 67 who had suffered a stroke about 10 months earlier. The scientists asked about their ability to handle daily activities.

The researchers found that 83 of the 162 were back behind the wheel, and 49 had resumed driving within a month of their stroke. While most of the 83 drivers reported no effects from their stroke, 26 admitted to “some effect” on their ability to engage in life activities, and nine acknowledged a “great effect.”

Such self-assessment may not capture a stroke survivor’s true deficits. Apart from vision and physical issues, Ozark said, “stroke can affect subtle things like the ability to adequately process multiple simultaneous stimuli and the ability to recognize when there is something wrong. And reaction time could very well be impaired.”

Doctors should warn stroke patients that their driving abilities might be compromised, Ozark said.

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