8:18 a.m. #42 – The right training helps emergency physicians use CT to diagnose stroke. An hour of structured teaching allowed emergency physicians to dramatically improve their ability to read a computer tomography (CT) scan and correctly diagnose different types of strokes. A CT scan, which uses X-rays to generate an image of the brain, can determine whether a stroke has occurred and identifies the type of stroke: ischemic (result of blockage) or hemorrhagic (result of bleeding). It is critical in determining what treatment patients receive. Eight emergency physicians took a 30-minute test to gauge their pre-teaching CT diagnosing capabilities and participated in a one-hour session of scripted teaching before being tested again. After 45 days, the physicians were retested. Hemorrhagic stroke was correctly identified by physicians 68 percent of the time prior to teaching, 100 percent of the time after teaching, and 100 percent of the time 45 days after the class. Physicians correctly identified the absence of hemorrhage 94 percent of the time prior to teaching, 94 percent of the time after teaching, and 92 percent of the time after 45 days. There were similar results with the ability to identify large-territory ischemic strokes. Researchers say this testing and teaching method can greatly increase an emergency physician’s ability to correctly diagnose stroke on CT and, because of improved confidence, may increase the number of patients treated.
Brian Silver, Henry Ford Hospital, Detroit, (313) 916-9107; e-mail: silver@neuro.hfh.edu.
8:30 a.m. #43 – Let’s go to the video: remote review of CT scans appears reliable. Neurologists with expertise in stroke can reliably and accurately read acute stroke computer tomography (CT) scans of the head via teleradiology to determine if a patient is a candidate for thrombolytic therapy, researchers found in the TeleRadiology Assessment of CT’s Online Reliability Study (TRACTORS). Teleradiology uses an interactive video system that allows medical information to be exchanged from one site to another. It is a reliable and valid method for reading acute head CT images to evaluate stroke patients for thrombolytic therapy. Researchers reviewed consecutive head CTs obtained during evaluation of acute stroke patients at the University of Virginia in Charlottesville. Two neurologists with specialized stroke training were allowed three minutes to analyze each of 54 acute stroke head CT scans to determine if the patients had suffered ischemic stroke and were eligible to receive thrombolysis. Half the scans were analyzed the traditional way using a light board and half by using teleradiology. The stroke neurologists’ evaluations were compared to those of the neuroradiologist who made the original evaluations when the patients came to the hospital. The stroke neurologists correctly identified all thrombolytic-eligible ischemic strokes and nonthrombolytic-eligible hemorrhagic strokes.
Bradford B. Worrall, M.D., MS.c., University of Virginia, Charlottesville, (434) 924-2784; e-mail: bbw9r@virginia.edu.
9:58 a.m. #56 – The power of friendship is strong medicine. In the future, your doctor may prescribe friendship and a housekeeper. Using data from the Northern Manhattan Stroke study researchers found that the number of friends a patient has and whether a patient receives any in-home help are the biggest indicators for predicting a second stroke. The researchers studied 655 stroke patients over four years and recorded additional strokes, heart attacks or deaths. Fifty-five percent of the participants were women, 27 percent African–American, 54 percent Hispanic and their average age was 69. After considering risk factors for coronary artery disease, atrial fibrillation, age and race-ethnicity, researchers found that stroke patients with fewer than three friends are 40 percent more likely to suffer a second event. If they have no one to help around the house, they are 80 percent more likely to suffer a second stroke. Social support remained the leading risk indicator even when compared to high blood pressure, diabetes, education, gender, insurance, occupation, marital status and the presence of a primary care doctor. Researchers suggest future secondary stroke prevention programs may need to incorporate ways to increase a stroke patient’s social support system.
Bernadette M. Boden-Albala, Columbia-Presbyterian Medical Center, New York, (212) 305-1710, bb87@columbia.edu; Ralph L. Sacco, (212) 305-1710, rls1@columbia.edu.
5:30 p.m. #P148 – Exercise can thin the blood. Although a strong association exists between higher levels of physical activity and a reduced risk of heart disease and stroke, it is still unclear what biological mechanisms are involved in this protective effect. Platelet aggregation, (a measure of how the blood clots) and blood cholesterol levels can be used to assess an individual’s risk of ischemic cardiovascular disease, because they are components of blood clots. Blood clots can cause heart attack and ischemic stroke, the most common form of stroke. Sixteen young people (50 percent women), average age 26, participated in a six-week, low-impact, moderate-intensity aerobic exercise program. Platelet aggregation and cholesterol levels were measured at baseline, after a session of exercise, after six weeks of training and after two weeks of deconditioning. Regardless of exercise status, cholesterol concentrations did not change from the baseline measurements at any point in the study. However, platelet aggregation was inhibited after six weeks of exercise, which meant the blood was less likely to form clots. The changes brought about by exercise persisted even after two weeks of deconditioning. Researchers conclude that regular exercise can inhibit the formation of blood clots without altering cholesterol levels.
Robert N. Gan, St. Luke’s Medical Center, Quezon City, Philippines, (61) 8-9224-2598; rgan@info.com.ph.
5:30 p.m. #P150 – General public needs stroke awareness education. A statewide sample of 2,512 adults in Michigan indicates a continued need for public education on stroke. One in five respondents could not identify any stroke risk factors and almost one in three were not aware of at least one stroke warning sign. Eighty percent of the respondents could identify at least one risk factor for stroke, and 28 percent were able to identify three risk factors. The most frequently mentioned risk factors named were high blood pressure (32 percent), smoking (29 percent), and physical inactivity (26 percent). When asked about warning signs for stroke, 69 percent were able to identify at least one, and 14 percent could identify three. The most frequently mentioned warning signs were sudden weakness or numbness (46 percent), sudden confusion or trouble speaking (30 percent) and sudden trouble walking or dizziness (24 percent). Most participants (79 percent) reported that once stroke signs were recognized their first action would be to call 9-1-1. A 2001 nationally representative survey conducted by the American Stroke Association found that 41 percent of respondents could not correctly recall any stroke warning sign.
Mathew J. Reeves, Ph.D., Michigan State University, (517) 353-8623; e-mail: reevesm@msu.edu.
5:30 p.m. #P164 – Chiropractic manipulation may be underestimated as cause of stroke Stroke as a result of chiropractic manipulation may be underreported, especially in young women, according to the largest known prospective study of arterial trauma and stroke. In this ongoing study, Canadian researchers examined 98 cases in which external trauma ranging from “trivial” to “severe” was identified as the trigger of ischemic strokes, the type of strokes caused by the formation of blood clots in arteries supplying the brain with blood. Chiropractic-style neck manipulation was the apparent cause in 39 percent of cases (38 cases). Of the 98 cases, there were 30 vertebral and 8 carotid dissections. More occurred in women (36) than in men (12). Sixteen percent of individuals studied had a congenital disorder such as Marfan’s Syndrome, fibro-muscular dysplasia (FMD) or Ehles-Danlos Type IV Syndrome. These conditions may make individuals more vulnerable to trauma-related injuries to their fragile arteries. Epidemiological data from Canadian statistics indicate the incidence of ischemic strokes in people under age 45 is about 750 a year. The researchers say that their data indicates that 20 percent are due to neck manipulation, so there may be a “gross underreporting” of chiropractic manipulation as a cause of stroke.
Dr. Beletsky can be reached at (416) 480-4287 and by e-mail at vados@istar.ca.
5:30 p.m. #P172 – Hyperglycemia linked to poor stroke prognosis. Animal and human studies indicate that high blood sugar (hyperglycemia) during stroke is associated with larger areas of brain-damaged tissue and a poor prognosis. In this study, researchers analyzed the outcomes of patients who had hyperglycemia before receiving thrombolysis (clot-busting). Of 119 patients treated with thrombolytics between December 1998 and July 2001, 37 had blood glucose (sugar) levels greater than 8 millimoles per liter (mmol/L) at admission (group A) and 76 had glucose levels lower than 8mmol/L (group B). Researchers measured improvement on the National Institutes of Health Stroke Scale (NIHSS) at 24 hours and three months, and three-month mortality. Eighteen patients in group A and 42 patients in group B improved their NIHSS scores by more than four points at 24 hours. At three months, the rate of greater-than-four-point improvement was higher in group B (79 percent compared to 54 percent). At three months, 36 percent of group A patients and 8 percent of group B patients had died. Researchers conclude that individuals who have hyperglycemia before receiving tPA have a greater risk of death, and those who survive recover less compared to patients with normal glucose.
Arturo Tamayo, M.D., London Health Science Centre University, London, Ontario, Canada, (519) 663-3113; tamayoarturo@hotmail.com.
5:30 p.m. #P197 – Viagra has potent effect on stroke recovery in rats. Researchers induced ischemic stroke in rats, then investigated the effects of sildenafil citrate – commonly known as Viagra – on the production of new brain cells and on functional recovery. Viagra was administered orally to rats for six days after stroke. At 28 days, the number of new brain cells was significantly higher in rats treated with Viagra. Rats that received two milligrams (mg) of Viagra showed 237.27 millimeters squared (mm2 ) of new cells; those treated with five mg of Viagra had 541.02 mm2 of new cells, while untreated rats had only 177.94 mm2. To measure the severity of brain impairment, the rats’ performance on sensory, motor and agility tests were measured at two and 28 days after stroke. The animals’ speed at removing adhesive from their feet was tested as well as their adeptness at walking on a grated pathway. Viagra-treated rats showed significantly improved recovery of neurological function. Subsequent research has found that Viagra given one day after stroke substantially reduced function deficits. Researchers conclude that Viagra promotes changes in the brain that contribute to the restoration of function.
Michael Chopp, M.D. Henry Ford Health Science Center, Detroit (313) 916-3936, chopp@neuro.hfh.edu.
5:30 p.m. #P269 – Inverse link found between homocysteine and exercise in stroke survivors. An excess of homocysteine, an amino acid found in blood, has been identified as a marker for an increased risk of both stroke and heart attack. Previous studies have linked lower levels of physical activity with higher levels of homocysteine. To determine if regular exercise influences levels of this amino acid, researchers identified stroke survivors one month after their stroke, measured their homocysteine levels and assessed their level of physical activity prior to stroke with a questionnaire. Of the 81 individuals enrolled, 51 percent were men, their average age was 63, and 65 percent were African–American. Thirty percent of the enrollees were categorized as regular exercisers, which meant that they exercised longer than 20 minutes up to seven times a week. The regular exercisers had lower homocysteine levels (8.4 microcentimeters per liter) than non-exercisers (10.4 mcm/L) and the number of exercise sessions per week was inversely associated with lower homocysteine levels, independent of age, alcohol use and smoking history. The researchers note that additional study is needed to determine the role nutrition may have played in these results. Previous studies have linked a reduced level of B vitamins, such as folate, in the diet, with an increased level of homocysteine. The American Heart Association does not consider an excess of homocysteine a major risk factor for cardiovascular disease.
Souvik Sen, Seton Hall University School of Graduate Medical Education, Edison, N.J., (732)321-7000, ssen@solarishs.org.
5:30 p.m. #P292 – Do post-stroke depression patients respond well to Zoloft? The antidepressant sertraline (Zoloft) appears to be safe, well tolerated and effective in treating the depression that follows stroke in 20 percent to 30 percent of survivors. In four Swedish stroke centers, 123 stroke patients were included in a randomized, placebo-controlled, 26-week treatment study of the selective serotonin re-uptake inhibitor sertraline. Depression improved in stroke survivors treated with sertraline and placebo. Researchers will report detailed results of sertraline’s effects on neurological recovery, quality of life, healthcare costs and other variables.
Veronica Murray, M.D. Ph.D., Karolinska Institute at Danderyd Hospital, Stockholm; 46-8-655-50-00, e-mail: veronica.murray@ki.ds.sll.se.