Links for Keyword: Stroke
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Dr. Cesario V. Borlongan, neuroscientist, is trying to determine if a compound that is elevated in hibernating squirrels can one day help avoid the ravages of stroke and Parkinson's disease.] A compound that enables squirrels to hibernate may one day help minimize brain damage that results from stroke, according to a researcher at the Medical College of Georgia and Veterans Affairs Medical Center in Augusta. In an animal model for stroke, delta opioid peptide reduced by as much as 75 percent the damage to the brain’s striatum, the deeper region of the brain and a major target for strokes, according to Dr. Cesario V. Borlongan, neuroscientist. In fact, evidence suggests that the compound, which puts cells in a temporary state of suspended animation, may help protect brain cells from the ravages of Parkinson’s disease as well. Copyright 2002 Medical College of Georgia. All rights reserved.
Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 15: Language and Our Divided Brain
Link ID: 2912 - Posted: 06.24.2010
By GINA KOLATA Dr. Diana Fite, a 53-year-old emergency medicine specialist in Houston, knew her blood pressure readings had been dangerously high for five years. But she convinced herself that those measurements, about 200 over 120, did not reflect her actual blood pressure. Anyway, she was too young to take medication. She would worry about her blood pressure when she got older. Then, at 9:30 the morning of June 7, Dr. Fite was driving, steering with her right hand, holding her cellphone in her left, when, for a split second, the right side of her body felt weak. “I said: ‘This is silly, it’s my imagination. I’ve been working too hard.’ ” Suddenly, her car began to swerve. “I realized I had no strength whatsoever in my right hand that was holding the wheel,” Dr. Fite said. “And my right foot was dead. I could not get it off the gas pedal.” She dropped the cellphone, grabbed the steering wheel with her left hand, and steered the car into a parking lot. Then she used her left foot to pry her right foot off the accelerator. She pulled down the visor to look in the mirror. The right side of her face was paralyzed. With great difficulty, Dr. Fite twisted her body and grasped her cellphone. Copyright 2007 The New York Times Company
By MARIA CHENG, BARCELONA, Spain – An experimental drug reduces the stroke risk in patients with irregular heartbeats by nearly four times, compared with the popular drug warfarin — but possibly at a cost, according to new research released Sunday. Patients taking the new drug dabigatran etexilate, made by German pharmaceutical Boehringer Ingelheim, also were slightly more likely to have heart attacks or stomach pain, according to the research presented at the European Society of Cardiology meeting in Barcelona. Patients with irregular heartbeats are up to 17 times more likely to have a stroke than healthy people. About one-sixth of all strokes occur in patients with irregular heartbeats who also have other risk factors such as smoking or obesity. In the United States, there are about 2 million people with such a condition. Until now most such patients have been given warfarin, which has been around since the 1950s and has side effects including bleeding risks and requires lifestyle changes such as dietary restrictions. Doctors hope the new drug can help improve treatment for patients, who must be monitored continuously if they are put on warfarin and avoid alcohol and foods such as spinach and cranberries. © 2009 The Associated Press.
By Katherine Harmon In the months after he had surgery to fix his defective heart valve, Bruce Stutz didn't feel quite the same. It wasn't his physical fitness that was subpar, although that did require some post-op retraining, but rather his mental capacity. "I couldn't muster the concentration to deal with the problem," he wrote in a 2003 article for Scientific American. During surgery, Stutz had been hooked up to a heart–lung machine, also called a cardiopulmonary-bypass pump, for the two-hours of a procedure to keep his blood oxygenated and flowing while his heart was stopped. He found that he was not the only one who, after time on the pump, had felt their brains bogged down by simple tasks. A 2001 study in The New England Journal of Medicine found that of 261 heart disease patients who had been kept alive during surgery with the pump, 42 percent showed cognitive decline five years after the surgery, even after adjusting for age. "Interventions to prevent or reduce short- and long-term cognitive decline after cardiac surgery are warranted," the authors, led by Mark Newman of the Duke University Medical Center, concluded. And a study published earlier this year in The Annals of Thoracic Surgery, led by James Slater, a cardiothoracic surgeon at the Mid-Atlantic Surgical Associates in Morristown, N.J., supported the previous findings, showing that lowered levels of oxygen in blood flowing to the brain during surgery did correlate to increased risk of suffering from the mental impairment dubbed "pump head". © 1996-2009 Scientific American Inc.
Colin Barras Nine years ago, a brain-stem stroke left Erik Ramsey almost totally paralysed, but with his mental faculties otherwise intact. Today he is learning to talk again – although so far he can only manage basic vowel sounds. In 2004, Ramsey had an electrode implanted in his speech-motor cortex by Philip Kennedy's team at Neural Signals, a company based in Duluth, Georgia, US, who hoped the signal from Ramsey's cortex could be used to restore his speech. Interpreting these signals proved tricky, however. Fortunately, another team headed by Frank Guenther at Boston University, Massachusetts, US, has been working on the same problem from the opposite direction. Guenther and his colleagues have used information from brain scans of healthy patients to monitor neural activity during speech. These studies show that the brain signals don't code for words, but instead control the position of the lips, tongue, jaw and larynx to produce basic sounds. Guenther's research group then developed software that could recognise and translate the patterns of brain activity during speech. © Copyright Reed Business Information Ltd.
Amid the dazzling high-tech displays of new-generation brain-machine interfaces (including brain implants with which monkeys can operate robotic arms) was a less glamorous but elegantly simple study which promises to improve quality of life for stroke victims, or victims of traumatic brain injury, whose ability to balance has been obliterated. Monica Metea of the company Wicab in Wisconsin displayed her company’s new balancing device BrainPort which has been through a pilot study of 17 patients, allowing them to stand, walk, dance without falling over. It works on the principle of brain plasticity. It’s a slim 2 cm square grid of 100 electrodes connected to a head position-detecting sensor which sits directly above them. The patients sticks the device in their mouths, and quickly learns from the pattern of the pinprick sensations delivered by the electrodes which way is up and which way is down. The brain also learns this in a physical sense. Somehow certain circuits get reconfigured such that even after the device is removed – after 20 minutes or so – the patient maintains his or her sense of balance, for hours, sometimes for days. No need to open up the skull and implant the device directly into delicate brain tissue like the more dramatic stories which will eventually help the paralysed. But applicable to probably millions of people who can’t stand up without falling over.
It's a scenario straight out of Gray's Anatomy – a paramedic or doctor plops a mask over the face of a person struggling to breathe and begins dispensing pure oxygen. Yet growing research suggests that inhaling straight oxygen can actually harm the brain. For the first time, a new UCLA brain-imaging study reveals why. Published in the May 22 edition of Public Library of Science (PLoS) Medicine, the findings fly in the face of national guidelines for medical practice and recommend a new approach adding carbon dioxide to the gas mix to preserve brain function in patients. "For decades, the medical community has championed 100 percent oxygen as the gold standard for resuscitation. But no one has reported what happens inside our brains when we inhale pure oxygen," explained Ronald Harper, distinguished professor of neurobiology at the David Geffen School of Medicine at UCLA. "What we discovered adds to a compelling body of evidence for modifying a widely practiced standard of care in the United States." Harper's team used functional magnetic resonance imaging (fMRI) to capture detailed pictures of what occurs inside the human brain during two different breathing scenarios. The technique detects subtle increases in blood flow triggered by the activation of different parts of the brain, causing these regions to glow or "light up" on the color scan.
Gaia Vince Methamphetamine may protect the brain after a stroke, according to new research in rats and gerbils. The illicit street drug – also known as speed – helped reduce brain damage when used up to 16 hours after stroke, potentially widening the window of opportunity for drug intervention. Researchers induced strokes in gerbils, causing them to become twice as active and agitated as normal gerbils. But when the animals were given a low dose of methamphetamine up to 16 hours after the event, the animals became calmer. Dissection later showed that the neurons of the gerbils given methamphetamine were as intact as in animals that had not suffered stroke. “Methamphetamine is a drug that has been shown to exacerbate stroke damage when administered before a stroke, but we have seen roughly 80% to 90% protection of neurons when administered after a stroke,” says Dave Poulsen, who led the research at the University of Montana in the US. The team also looked at slices of rat brain taken from the hippocampus – a region involved in memory and learning – which they kept in a nutritious culture for nine days. The slices were then deprived of glucose and oxygen for 90 minutes to mimic the conditions of a stroke. © Copyright Reed Business Information Ltd
Related chapters from BP7e: Chapter 19: Language and Hemispheric Asymmetry; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 15: Language and Our Divided Brain; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 9466 - Posted: 06.24.2010
NEW BRUNSWICK/PISCATAWAY, N.J. – Engineers at Rutgers, The State University of New Jersey, have modified a popular home video game system to assist stroke patients with hand exercises, producing a technology costing less than $600 that may one day rival systems 10 times as expensive. The Rutgers hand rehabilitation system is an example of virtual rehabilitation, which combines virtual reality – computer-generated interactive visual environments in which users control actions in a lifelike way – with traditional therapy techniques. Virtual rehabilitation gives therapists new tools to do their jobs more effectively and engages patients who may otherwise lack interest or motivation to complete normal exercise regimens. The Rutgers engineers are describing their work at the fifth International Workshop on Virtual Rehabilitation taking place Aug. 29 and Aug. 30 in New York City. “Virtual reality is showing significant promise for promoting faster and more complete rehabilitation, but the cost of many systems is still prohibitive for widespread deployment in outpatient clinics or patients’ homes,” said Grigore Burdea, professor of electrical and computer engineering and a noted inventor of virtual rehabilitation technology. “While it’s essential to keep pursuing breakthrough technologies that will initially be costly, it’s just as important that we find ways to make innovative treatments accessible to the many patients who need them.” © 2006 Rutgers, The State University of New Jersey
Alison Motluk Aspirin prevents cardiovascular events in both women and men – but in different ways, a new meta-study suggests. In women, aspirin reduces strokes, and in men it cuts down on heart attacks. But there are no statistically significant benefits the other way round, according to the analysis. “It appears that women respond differently to a given dose of aspirin than men,” says David Brown, a cardiologist at the Stony Brook School of Medicine in New York, US, and one of the authors. “Everything about the study is telling us that there’s a gender difference and we don’t understand it.” In people who already have cardiovascular disease, the benefits of low-dose aspirin are well-established – in both sexes. Aspirin’s cardiovascular effects are exerted by blocking the synthesis of thromboxane A2, a substance that causes the blood to clot. Even a single 100 milligram dose can be effective. But in people with moderate risk, the picture is less clear. Studies seem to indicate a reduction in coronary events, but most studies included few, if any, women. Brown and colleagues were interested in knowing if moderate-risk women would benefit to the same degree as men. © Copyright Reed Business Information Ltd
Related chapters from BP7e: Chapter 19: Language and Hemispheric Asymmetry; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 15: Language and Our Divided Brain; Chapter 8: Hormones and Sex
Link ID: 8405 - Posted: 06.24.2010
Toni Baker A bi-polar hormone that can contribute to strokes and minimize their damage is emerging as a therapeutic target in the battle against these brain attacks, researchers say. “It costs about $56 billion a year to look after stroke patients, never mind the quality-of-life issues for these patients,” says Dr. Anne M. Dorrance, Medical College of Georgia physiologist and senior author of a review article on the cover of the November issue of Trends in Endocrinology and Metabolism. Despite better management of blood pressure – the number-one risk factor for strokes – stroke incidence is not declining and aging baby boomers likely will cause rates to spike, says Dr. Dorrance. She is among an increasing number of scientists who think the hormone, aldosterone, is part of the problem and blocking it may be part of the solution. Scientific momentum surrounding the hormone secreted by the adrenal gland prompted the journal to ask Dr. Dorrance to write the article, “Aldosterone: Good Guy or Bad Guy in Cerebrovascular Disease.” Copyright 2005 Medical College of Georgia
Related chapters from BP7e: Chapter 19: Language and Hemispheric Asymmetry; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 15: Language and Our Divided Brain; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 8238 - Posted: 06.24.2010
St. Paul, Minn. – Looking into our eyes may help doctors predict who is at risk for stroke. A new study found that people with changes in the small blood vessels in their eyes are more likely to later suffer a stroke than people without these signs. The results held true even after researchers took into account traditional risk factors for stroke such as smoking and high blood pressure, according to the study published in the October 11, 2005 issue of Neurology, the scientific journal of the American Academy of Neurology. The study involved 3,654 Australians age 49 and older. Researchers took special photographs of the retina of the eyes of the participants and examined them for changes suggestive of small blood vessel damage, or retinopathy. These small vessel changes can be seen in the early stages of the condition, well before eyesight is affected. “The blood vessels in the eyes share similar anatomical characteristics and other characteristics with the blood vessels in the brain,” said Paul Mitchell, MD, PhD, of the University of Sydney in Australia. “More research needs to be done to confirm these results, but it’s exciting to think that this fairly simple procedure could help us predict whether someone will be more likely to have a stroke several years later.”
Related chapters from BP7e: Chapter 19: Language and Hemispheric Asymmetry; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 15: Language and Our Divided Brain; Chapter 7: Vision: From Eye to Brain
Link ID: 8017 - Posted: 06.24.2010
La Jolla, Calif. – A research team lead by the Burnham Institute has synthesized and tested a new series of inhibitors that can prevent the type of nerve cell injury and death associated with many neurodegenerative diseases and stroke. The study, led by Stuart Lipton, MD, PhD, professor and director of Burnham's Del E. Webb Center for Neuroscience and Aging Research, is published in the July issue of the Journal of Neuroscience. There is but one medical treatment approved for stroke, the third leading cause of death in the United States: tissue plasminogen activator ("tPA"). tPA must be administered within 3 hours of stroke onset to restore the flow of blood to the brain. Unfortunately, treatment with tPA can also contribute to nerve cell damage. In recent years, medical scientists have begun to understand that tPA activates an entire family of enzymes, called matrix metalloproteinases, that normally regulate how cell structures are held together. Dr. Lipton, together with first author Dr. Zezong Gu, and other colleagues at Burnham, University of Notre Dame, and Wayne State University in Detroit, have found that a molecule called SB-3CT blocks the activity of one member of the metalloproteinase family, called MMP-9. Previous work at Burnham and elsewhere has shown that damage to the brain triggers excessive activity among MMPs, especially MMP-9. The enzymes degrade cell structures, inducing cell death and escalating brain damage in mice. In the current study, the researchers determined the particular mechanism of action for MMP-9. In doing so, they identified a new drug target and, armed with this knowledge, generated a lead therapeutic compound, SB-3CT.
St. Paul, Minn. – A new therapy that uses magnetic pulses to stimulate the brain may improve recovery after a stroke, according to a study published in the May 24 issue of Neurology, the scientific journal of the American Academy of Neurology. The treatment, called repetitive transcranial magnetic stimulation, improved motor function in a small group of people. For the stimulation, an insulated wire coil is placed on the scalp, and a brief electrical current is passed through the coil, creating a magnetic pulse that stimulates the outer part of the brain, called the cortex. The study involved eight people, ages 35 to 63, who had a stroke within the last year and were relearning to use their affected hands. They were compared to six people who had never had a stroke. The stroke patients received three sessions of magnetic stimulation to the side of the brain that had not been affected by the stroke using different parameters, including sham (mock) stimulation. A sham is the application of the procedure excluding the actual treatment being studied and is intended to address the question of a placebo effect. The six healthy participants were tested with the same battery of tests to evaluate the learning effect associated with repeated testing. All of the participants performed tests before and after the stimulations. The tests evaluated the motor function of the hand that was affected by the stroke. For example, reaction time was tested, along with how many finger taps could be performed over a period of time.
In 2001, a massive stroke left Pete Cornelis all but paralyzed – robbing him of his passion for painting, as well as everyday things like walking and eating. "The only thing I could move on my entire body was my two fingers," he recalls. But thanks to his treatment at The Neurological Institute of New York, part of Columbia University Medical Center, followed by years of hard work, perseverance and extensive physical therapy, Cornelis managed to regain almost all of his lost movement. "I was surprised by how much I had to relearn," he ays. But, "it is absolutely possible to retrain you brain, to re-wire it, and have it learn what the old [damaged brain] parts used to do." His brain had to slowly work to compensate for the areas of his brain that were basically dead and could not be revived. When a stroke occurs, blood flow to part of the brain is interrupted when a blood vessel becomes damaged or blocked. The blood normally brings oxygen and nutrients that the brain cells in the immediate area need to survive. Without the blood the brain cells begin to die and stroke victims lose the functions that were controlled by those brain cells. About 80% of all strokes are ischemic, caused by a blood clot that blocks a blood vessel or artery in the brain. The other 20% are caused by a weakened blood vessel that breaks and bleeds into the brain. This is known as hemorrhagic stroke, and is often fatal. Around 600,000 new strokes, or "brain attacks" are reported each year. (C) ScienCentral, 2000-2005.
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 BP7e: 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 BP7e: 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 BP7e: 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