Links for Keyword: Stroke
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St. Paul, Minn. – Warning signs of an ischemic stroke may be evident as early as seven days before an attack and require urgent treatment to prevent serious damage to the brain, according to a study of stroke patients published in the March 8, 2005 issue of Neurology, the scientific journal of the American Academy of Neurology. Eighty percent of strokes are ischemic, caused by the narrowing of the large or small arteries of the brain, or by clots that block blood flow to the brain. They are often preceded by a transient ischemic attack (TIA), a “warning stroke” or “mini-stroke” that shows symptoms similar to a stroke, typically lasts less than five minutes, and does not injure the brain. The study examined 2,416 people who had experienced an ischemic stroke. In 549 patients, TIAs were experienced prior to the ischemic stroke and in most cases occurred within the preceding seven days: 17 percent occurring on the day of the stroke, 9 percent on the previous day, and 43 percent at some point during the seven days prior to the stroke.
St. Paul, Minn. – Anger and other negative emotions may be triggers for ischemic stroke, according to a study published in the December 14 issue of Neurology, the scientific journal of the American Academy of Neurology. The study found that people who had strokes were more likely to have experienced anger or negative emotions in the two hours prior to the stroke than at the same time the day before the stroke. They were also more likely to have reacted quickly to a startling event, such as getting out of bed suddenly after hearing a grandchild fall down and cry or standing up from a chair quickly after hearing an unexpected loud noise. The people were also more likely to have experienced anger, negative emotions, or sudden changes in body position in the two hours before the stroke than they were, on average, in the year before the stroke. “We know a lot about risk factors that make people more likely to have a stroke in their lifetime, such as smoking and high blood pressure, but until now we haven’t had any information on what causes a stroke to occur at a particular time,” said study author Silvia Koton, PhD, MOccH, RN, of Tel Aviv University and the Israel Center for Disease Control. “These findings may help us understand how these triggers result in stroke. We can also investigate whether people at a high risk of stroke can make behavior changes. The possibility of preventive medications to lessen the risk of stroke among specific high-risk groups might also be studied.”
Related chapters from BP6e: Chapter 15: Emotions, Aggression, and Stress; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 15: Language and Our Divided Brain
Link ID: 6610 - Posted: 06.24.2010
CHICAGO – People suffering from paralysis due to stroke or traumatic brain injury may be able to reprogram their brains to improve motor skills and to control artificial limbs, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA). Using functional magnetic resonance imaging (fMRI) and a "cyberglove" to record brain changes during motor activities, researchers demonstrated that people can learn to remap, or redirect, motor commands. This is an important step in stroke recovery and in training strategies for brain-machine interfaces--conduits between the brain and artificial limbs. "For stroke patients and others who have a brain deficit, coordinating what they see with body movement is very difficult," said the study's lead author Kristine Mosier, D.M.D., Ph.D., assistant professor of radiology at Indiana University in Indianapolis. "The brain must remap or relearn the process of matching visual input with sensory input. Our study demonstrated that individuals can learn to remap motor commands." When neurons--the primary cells of the nervous system that make all thought, feeling and movement possible--are damaged by a stroke or brain injury, other neurons take over for them. But until now, scientists weren't sure which neurons compensated for damaged neurons, or how the brain cells learned their new jobs.
SAN FRANCISCO – Researchers are conducting a groundbreaking new study that may help stroke patients regain greater use of their hands or arms through treatment with electrical stimulation. Preliminary results of the feasibility study that precedes this new study have shown that the use of electrical stimulation, called motor cortex stimulation, may be both safe and effective, according to Robert Levy, M.D., Ph.D., a neurosurgeon at Northwestern Memorial Hospital in Chicago. Dr. Levy presented this feasibility trial data at the Congress of Neurological Surgeons Wednesday in San Francisco. The trial showed that study participants – stroke survivors suffering impaired hand or arm movement – who underwent physical rehabilitation accompanied by motor cortex stimulation showed greater improvement than participants who received physical rehabilitation alone. Twenty-four subjects participated in the feasibility study, 12 in the electrical stimulation group and 12 in the control group. "Participants in the electrical stimulation group experienced meaningful motor recovery gains," Dr. Levy says. "It is our hope that by stimulating the surface of the brain we can permanently reverse paralysis and rekindle patients' function, returning them to their normal lifestyle," says Dr. Levy, who is a professor at the Feinberg School of Medicine at Northwestern University and who is leading the study at Northwestern Memorial, which is being conducted in tandem with the Rehabilitation Institute of Chicago. "Unfortunately, when patients have had a stroke, there is not much we can currently offer beyond physical rehabilitation to improve their motor functions."
Related chapters from BP6e: Chapter 19: Language and Hemispheric Asymmetry; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 15: Language and Our Divided Brain; Chapter 5: The Sensorimotor System
Link ID: 6285 - Posted: 06.24.2010
St. Paul, Minn. – A recent analysis of tamoxifen studies completed since 1980 revealed an increased risk of stroke in women who were randomized to tamoxifen versus placebo or other therapies. Details of the analysis and the researchers’ conclusions are reported in the October 12 issue of Neurology, the scientific journal of the American Academy of Neurology. More than 250,000 U.S. women are diagnosed with breast cancer each year. Breast cancer accounts for nearly one in three cancers diagnosed in the U.S. and is the second leading cause of death for women. Fortunately, 90 percent of breast cancers are now diagnosed at localized and regional stages, for which five-year survival rates are 97 percent and 79 percent, respectively. Tamoxifen, a medication in pill form that interferes with the activity of estrogen, has been used for more than 20 years to treat patients with advanced breast cancer. It is used as adjuvant, or additional, therapy following primary treatment for early stage breast cancer. In women at high risk of developing breast cancer, tamoxifen reduces the chance of developing the disease. In addition to its effects on breast cancer, the benefits of tamoxifen include increased bone mineral density, reduced risk of hip fractures, and lower levels of cholesterol. While tamoxifen is known to increase the risk of blood clotting in women with cancer, its relationship to stroke risk has been unclear.
Related chapters from BP6e: Chapter 19: Language and Hemispheric Asymmetry; Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 15: Language and Our Divided Brain; Chapter 8: Hormones and Sex
Link ID: 6231 - Posted: 06.24.2010
ST. LOUIS -- Testosterone -– the hormone responsible for a man's sex drive -– may help him recover from a stroke, according to preliminary animal research at Saint Louis University. Researchers will present their findings at the annual meeting of the American Neurological Association in October. "It looks like testosterone speeds up the recovery from a stroke," said Yi Pan, M.D., Ph.D., assistant professor of neurology at Saint Louis University School of Medicine and principal investigator on the study. "While the results are encouraging, this is still very preliminary and we need to do more research." The scientists compared two groups of castrated rats that had suffered strokes. Half received testosterone and half a placebo. The rats that received testosterone showed significant improvement in neurological deficits while those in the control group did not. Based on the promising findings, plans are on the drawing board to test whether testosterone helps people recover from strokes, said Aninda B. Acharya, M.D., assistant professor of neurology at Saint Louis University School of Medicine and a researcher on the project.
Related chapters from BP6e: Chapter 5: Hormones and the Brain; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 15: Language and Our Divided Brain
Link ID: 6200 - Posted: 06.24.2010
St. Paul, Minn. – As many as 65 percent of stroke patients are likely to be treated with antihypertensive medications during the first four days of hospitalization, despite current guidelines of the American Stoke Association that recommend against treating all but the most severe cases of hypertension during the first few days following a stroke. A recent retrospective study found that nearly all stroke patients who were being treated for hypertension prior to admission had their medication regimens continued or intensified, and a third who were not taking medications for hypertension had antihypertension treatment initiated during the hospitalization. Study details are published in the July 27 issue of Neurology. Hypertension (high blood pressure) is common at the time of an ischemic stroke and is believed to be the body’s response that maintains adequate blood flow to the area immediately around the stroke site. Lowering elevated blood pressure through medication, while an appropriate measure in stroke prevention, can result in the extension and worsening of acute stroke symptoms, and has even been shown to result in worse short- and long-term outcomes. The dangers of antihypertensive therapy in the setting of acute ischemic stroke have been recognized for some time. Despite active efforts to promote clinical guidelines, first established in 1994, little is known about how often, and under what circumstances, antihypertensive agents are used in the treatment of patients with acute ischemic stroke. “We sought to determine whether the use of antihypertensive agents was consistent with guidelines, and if such use placed patients at further risk of negative outcomes,” noted study author Peter Lindenauer, MD, MSc, of Baystate Medical Center and Tufts University School of Medicine, Springfield.
St. Paul, MN – Boys are 28 percent more likely than girls to have a stroke, and black children are more than twice as likely to have a stroke as other ethnic groups, according to a study in the July 22 issue of Neurology, the scientific journal of the American Academy of Neurology. Researchers identified 2,278 first admissions for childhood stroke in a 10-year period in California by examining a statewide hospital discharge database. Children were one month through 19 years of age and were classified by their parent or guardian as white, black, Hispanic, Asian or other. Boys made up 51 percent of the population, and girls made up 49 percent. Ischemic stroke (the most common type of stroke, resulting from blocked arteries) accounted for 51 percent of the cases. Hemorrhagic stroke accounted for the rest, and was broken down into intracerebral hemorrhage (vessels bleed into the brain) and subarachnoid hemorrhage (abnormal vessels rupture near the membrane surrounding the brain). The annual stroke incidence rate was found to be 2.3 strokes per 100,000 children.
WEST LAFAYETTE, Ind. – Stroke victims may retain more motor coordination than previously thought, according to research led by Purdue University. The findings challenge current understanding of brain function and open new possibilities for aiding the physically challenged. The research team, which included faculty from Purdue and University of California-Berkeley, was led by Purdue professor Howard Zelaznik. The team found that the cerebellum may not be as fully responsible for the timing of "continuous" motions, such as drawing circles repeatedly on paper, as it is for "discontinuous" motions that have a more start-stop nature, such as tapping your finger rhythmically on a table. Patients with cerebellum damage who participated in the study had difficulty tapping a steady beat, but no such trouble with drawing circles in rhythm. The study indicates that stroke victims may retain some motor skills thought to have been lost to cerebellar damage.
ST. PAUL, MN - – Many of the 1.1 million heart attacks and 731,000 strokes that occur each year in the United States might be prevented by controlling risk factors. Among those with a history of heart disease or stroke, African Americans could possibly benefit most from a greater degree of awareness and control of risk factors, as they are significantly more likely to have a higher risk factor profile than many other groups. According to a study published in the January 14 issue of Neurology, the scientific journal of the American Academy of Neurology, inadequate rates of awareness and control of risk factors remain prevalent among African American stroke patients. Risk factors studied include hypertension, diabetes, cigarette smoking, excessive alcohol use, and high cholesterol. “We sought to determine rates of awareness, treatment and control of major risk factors among patients at the time of enrollment into the African American Antiplatelet Stroke Prevention Study (AAASPS),” said study author Sean Ruland, DO, of Rush University in Chicago. The AAASPS is a clinical trial comparing the effectiveness of ticlopidine hydrochloride (an anti-clotting agent) with aspirin in preventing recurrent stroke, heart attack and other vascular-related death.
Related chapters from BP6e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 15: Language and Our Divided Brain
Link ID: 3290 - Posted: 06.24.2010
St. Paul, MN – Using transplants of bone marrow cells improved the recovery from stroke in rat experiments, according to a study published in the August 27 issue of Neurology, the scientific journal of the American Academy of Neurology. The rats treated with an intravenous transplant of adult human stromal cells (mature cells from bone marrow) had significant improvements in their ability to function 14 days after the stroke, compared to rats that did not receive transplants after a stroke. "These are smart cells that selectively migrate to the site of injury and become little factories producing an array of helpful molecules to repair the tissue," said study author Michael Chopp, PhD, of Henry Ford Hospital in Detroit, Mich., and Oakland University in Rochester, Mich. "We believe this therapy shows promise in treating stroke, Parkinson's disease, spinal cord injury and traumatic brain injury."
Related chapters from BP6e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 15: Language and Our Divided Brain
Link ID: 2545 - Posted: 06.24.2010
DALLAS, – Giving patients aspirin within 48 hours of the onset of an acute ischemic stroke can reduce death and severity of stroke, according to a joint scientific statement from the American Stroke Association and the American Academy of Neurology. An ischemic stroke is caused by a blood clot and is the most common type of stroke. The statement, published in the July issues of Stroke: Journal of the American Heart Association, and Neurology, the scientific journal of the American Academy of Neurology, aims to define the roles of the drugs such as aspirin – which is in a class of drugs called antiplatelet agents that prevent blood clot formation – and drugs such as heparin, a type of anticoagulant that slows blood clotting.
NEURON BY NEURON, PENN RESEARCHERS STUDY BRAIN CELLS' ATTEMPTS TO HEAL THEMSELVES AFTER SEVERE INJURIES
PHILADELPHIA – Researchers at the University of Pennsylvania have won a $3.1 million bioengineering research grant to study brain injuries at a level of detail never before attained. The team, lead by Penn bioengineer David F. Meaney, will detect the genes and proteins altered in single neurons in the brain to better understand the cells' responses to contusions and other forms of brain trauma. The Penn team will focus initially on contusions, bruises to the brain surface that often occur with skull fractures. These injuries are often localized in regions along the surface of the brain and can result in problems with the brain's ability to process data and sensory input. Penn investigators will examine the response of individual neurons both within and alongside areas of contusion in the brain, searching for patterns of genes and associated proteins that are activated or suppressed following an injury. For each neuron studied, researchers will compare the activated genes and protein levels to the mechanical stress experienced by the neuron at the moment of injury.
By RONI CARYN RABIN Surgery on blocked neck arteries has long been considered the best procedure for preventing a stroke. Now a large North American study has found that a less invasive approach may be just as safe and effective, but other researchers are not so sure. The findings, released Friday at a medical meeting in San Antonio, have the potential to make the less invasive procedure — inserting a small tube called a stent in the carotid artery — a more appealing option for many patients. Yet just a day earlier, European investigators reported dismal results from another international trial involving carotid stents, published online Thursday by the British medical journal The Lancet. In that study, patients treated with stents suffered almost double the rate of complications as those treated surgically, leading the British researchers to conclude that surgical treatment of carotid blockages, called endarterectomy, remains the treatment of choice. The disparate findings — which could help determine whether Medicare expands coverage to cover the stent procedure — left scientists trying to explain why two fairly similar clinical trials came to such starkly different conclusions. Copyright 2010 The New York Times Company
By Nathan Seppa SAN ANTONIO — As many as four in 10 people referred to a clinic with signs of a “ministroke” may have subtle cognitive damage that standard tests miss, a new study shows. The findings, reported by Canadian researchers February 24 at the International Stroke Conference in San Antonio, Texas, suggest that after suffering the ministrokes many patients lose some ability to process abstract thoughts, reason things out and make quick calculations — what doctors call “executive function.” While full-blown strokes cause a clear loss of cognitive function, most often due to a blood vessel blockage in the brain that shows up on an MRI or CT scan, ministrokes are caused by smaller obstructions. They result in more subtle deficits that are less likely to be detected by brain scans or even by patients themselves. Some scientists consider the term ministroke a misnomer, preferring the technical term transient ischemic attack, while others use the terms interchangeably. The symptoms of a ministroke or a full-blown one might start out the same, with numbness in the face or extremities, confusion, vision problems, dizziness or headache. But in a ministroke, these symptoms wane after minutes or hours. In the new study, researchers tested 140 such patients in whom symptoms subsided within 24 hours, indicating they had ministrokes instead of full-blown ones. They gave the subjects a test of cognitive acuity that is routinely given to patients who show up at a clinic or hospital with signs of a stroke. Known as the Mini-Mental Status Exam, the test quickly gauges 30 cognitive functions including short-term recall, attention span, spatial recognition and executive function. © Society for Science & the Public 2000 - 2010
By Katie Moisse The same technology that has people swinging imaginary rackets and bowling virtual balls for entertainment at home might help people recovering from strokes, according to research presented February 25 at the American Stroke Association's International Stroke Conference. The pilot study, carried out at the Toronto Rehabilitation Institute at the University of Toronto, suggests that video games for the Nintendo Wii could help stroke victims regain lost motor function. "This is the first randomized clinical study showing that virtual reality using Wii gaming technology is feasible and safe and is potentially effective in enhancing motor function following a stroke,” said the study’s lead investigator, Gustavo Saposnik, in a prepared statement. “But our study results need to be confirmed in a major clinical trial.” The study examined the Wii’s potential for helping patients recover fine motor function (such as finger dexterity) and gross motor function (such as arm movements) two months after a stroke. Twenty patients were randomly assigned to two groups: one played recreational games (such as cards or the block-stacking game Jenga); the other played virtual games such as Wii tennis and Wii Cooking Mama—a simulation game that has players cutting potatoes, peeling onions and shredding cheese. Both groups played for about six hours over the course of the two-week study. © 2010 Scientific American, a division of Nature America
by Greg Miller SAN DIEGO—The hormone progesterone is best known for its work in the female reproductive system, where it plays various roles in supporting pregnancy. But starting next month, it will be the focus of a phase III clinical trial for traumatic brain injury (TBI). Researchers hope an infusion of progesterone given within a few hours of a car accident or other trauma will help prevent brain damage, said the trial’s principal investigator, David Wright of Emory University in Atlanta. He described the upcoming trial here today at the annual meeting of the American Association for the Advancement of Science (which publishes ScienceNOW). The rationale for the trial springs from a chance finding made more than a quarter of century ago. While studying the effects of head injuries in rats, Emory researcher Donald Stein noticed that females had fewer ill effects than did males. Females who were at the progesterone peak of their menstrual cycle did even better. Follow-up studies with other animals also pointed to neuroprotective effects of progesterone, which is present in both the male and the female brain. In recent years, two small clinical trials suggested that progesterone can reduce mortality and disability after TBI in people. The new trial will provide a sterner test. It aims to enroll 1140 patients at 17 centers across the United States. Each patient will receive an infusion of progesterone starting within 4 hours of his or her injury and lasting 4 days. © 2010 American Association for the Advancement of Science.
Related chapters from BP6e: Chapter 19: Language and Hemispheric Asymmetry; Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 15: Language and Our Divided Brain; Chapter 8: Hormones and Sex
Link ID: 13785 - Posted: 06.24.2010
Millions of people carry two common genetic variants that significantly increase the risk of stroke, researchers have found. A stroke is a brain injury caused by a lack of blood. It is the third-leading cause of death in the U.S., and 50,000 Canadians have strokes each year. In Wednesday's online issue of the New England Journal of Medicine, researchers in the U.S. said they found two genetic variants on chromosome 12 that are linked to ischemic strokes — the most common type of stroke, caused by blocked blood vessels in the brain. "Even though this variant is common, it has a modest effect on stroke risk," said study author Eric Boerwinkle, chair in human genetics at University of Texas Health Science Center at Houston. "Therefore, everyone, whether they carry this variant or not, should be aware of the risk factors for stroke, such as high blood pressure and smoking, and do everything they can to avoid those risk factors," he added in a release. To find the variants, researchers compared the genomes of 1,544 individuals who developed stroke with the genomes of 18,058 individuals who did not. © CBC 2009
By ERIC NAGOURNEY Stroke patients who practice tai chi may improve their balance — reducing the risk of falls, researchers say. Writing in the journal Neurorehabilitation and Neural Repair, the researchers reported improvement in volunteers after as little as six weeks of training. The lead author was Stephanie S. Y. Au-Yeung of Hong Kong Polytechnic University. In earlier research, one of the article’s co-authors, Christina W. Y. Hui-Chan, found that tai chi improved balance among healthy elderly people. For this study, the researchers wanted to see if the same effect would occur among stroke patients. They took 136 people who had a stroke six months or more earlier and divided them into two groups. Over 12 weeks, one group did general exercise, the other a modified version of tai chi. The tai chi group met once a week for an hour, and were asked to practice at home about three hours a week. While the exercise group showed little improvement in balance, the tai chi group made significant gains when they were tested on weight-shifting, reaching and how well they could maintain their stability on a platform that moved like a bus. The benefit of tai chi, the researchers said, is that once the forms are mastered, they can be done without supervision. Copyright 2009 The New York Times Company
By DONALD G. McNEIL Jr. After her stroke, Francine V. Corso, a software engineer who worked on NASA’s lunar lander, was housebound from 1992 to 2001. Her left arm was twisted up near her neck, making it difficult to pull on a blouse, and her fingers curled so rigidly that her nails buried themselves in her palm. When she finally learned to rise from her wheelchair, her contorted left leg had the so-called horse gait of many brain-injury victims — she stepped toe-downward, and then fought to keep her foot from rolling over. Now, with injections of botulinum toxin every three months, she says, “I’m completely transformed — I drive, I volunteer, I take art classes.” Her fingers are so relaxed that a manicurist can lacquer her nails red. Botulinum toxin, the wrinkle smoother best known by the brand name Botox, has many medical uses, some official and some off label. It helps dystonia victims regain control of spasming muscles, actors who struggle with flop sweat slow down the flow, and children with clubfoot avoid surgery. Its use in stroke victims is still off label — that is, it is not approved for that purpose by the Food and Drug Administration. But it is so widely accepted that Medicare and other insurers will usually reimburse for its use. Copyright 2009 The New York Times Company