Strokes: Viprines (Ancrod) and Merci Retriever Newest Stroke Treatment Options

Stroke (brain attack) occurs every 45 seconds in the United States, when blood flow to the brain stops, blocked by a clot. The clot cuts off the supply of oxygen and nutrients to the brain, and affected area of the brain can't function. Eventually cells in that portion of the brain stop working or die. The dead brain cells cannot be revived or replaced. The devastating affect could lead to severe disabilities (Affecting the ability to control speech (Aphasia is a total or partial loss of the ability to speak and most often caused by a stroke, damages the brain's language center), movement and memory) that prohibits or stops a part of the body from working. Up to fifty percent of stroke survivors have difficulty swallowing (dysphagia), which increases the risk of choking when trying to swallow liquids or food. Three to five million people each year develop a stroke on the right side of the brain between the ear and temple, a condition called spatial neglect: Patients have trouble paying attention to one side. For example: Men may fail to shave on the left side of their face or cause a disable person to leave boxes blank on the left side of a form.

Two types of srtokes: Ischemic stroke (TIA - 80% of all strokes) - Stroke occurs because an artery is clogged with fatty deposits (atherosclerosis) or blood clot. Hemorrhagic Stroke (20 percent of all strokes) - When blood vessel in the brain bursts, and blood bleeds into the brain (cerebral haemorrhage). This is a result of an aneurysm: A weak or thin spot in an artery that balloons out and can burst or bleed. Cerebral embolism: When clot or some other particles forms in the blood vessel away from the brain (carried by the bloodstream), and usually forms in heart. The clot then travels through the bloodstream, until it lodges in an artery leading to or inside the brain, blocking the flow of blood. People with irregular type of pulse or arterial fibrillation: Blood is pumped away from the heart either faster or slower with a shorter or longer interval rate. As a result, sometimes a blood clot will develop and travel to the brain, and cause a stroke. Strokes are common in people older than 60 years of age, however can develop at any age. According to the National Institute of Neurological Disorders and Stroke (NINDS), approximately 700,000 have a stroke each year - 500,000 first stroke and 200,000 recurrent strokes. In the United States, stroke is the third leading cause of death after heart disease and cancer. In 2004, stroke killed 150,147 people and 60.9 percent were females.

Risk factors that may lead to a stroke: Family or hereditary link to high blood pressure or stroke, smoking, diabetes, and obesity. Proper diet or nutrition, exercise, living healthy and prescribed medications can prevent a stroke.

Symptoms of stroke: Vision problems in one or both eyes, numbness, weakness or paralysis (typically on one side of the body), dizziness, loss of balance or coordination, trouble walking, and severe headache. Symptoms of a stroke of may persist over minutes, hours or days. During a period of time, smaller strokes may occur. Sometimes symptoms of stroke maybe misdiagnosed for other medical conditions.

Within the first three hours of a stroke, provide the window of opportunity to be successfully treated. Preferable the person needs to be in the hospital within sixty minutes of having a stroke. The longer the blood flow to the brain is cut off the greater the brain damage. In many cases, medication can be administered to unblock a clogged artery or clot, which is most treatable for ischemic strokes. Over a period of days, weeks, months, and years rehabilitation is important to minimize the effects of a stroke, treat any depression, proper bed and wheelchair positioning. Rehabilitating is recommended to start the first day of a stroke. Some people recover better than others. The goal of rehabilitation is to reduce dependence and improve physical ability.

The Food and Drug Administration approved Activase (alteplase), a genetically engineered version of tissue plasminogen activator (t-PA) for treating the sudden onset of ischemic stroke. The drug is only effective when administered within three hours after stroke symptoms. The drug dissolves blood clot that block blood flow to the brain, improves the chance for recovery and decreasing disability. The medication is not effective beyond three hours after a stroke. Other criteria's must be met in order to use t-PA: People who have bleeding in the brain (Computer tomograpy scan of the head is used to make sure there is no bleeding inside the brain.) as result of a stroke, prior bleeding problems or high blood pressure, t-PA is not a viable treatment option. Ensuring the safety of patients taking t-PA, the medication should only be given in a hospital equipped to take care of any bleeding complications. When t-PA has been administered, medications that interfere with normal clotting (such as aspirin) should not be given for twenty-four hours. Ralph L. Sacco, M.D., associated chairman of neurology and director of the stroke division of New York Presbyterian Hospital at Columbia University said: "About 1 in 4 people who have TIA go on to have a bigger stroke within five years. Doctors may recommend drugs or surgery to reduce the risk of stroke in people who have had a TIA."

A study published in the March 13, 2007, issue of Neurology, researchers studied 333 people who were treated with t-PA within three hours of having a stroke. The findings of the study, revealed that three months after t-PA was administered, men are about three - times as likely as women to be able to function independently, even though fewer men than women survived. Michael S. V. Elkind, M.D., M.S, from Columbia University Medical Center in New York and author of the study reported: "There are potential biological reasons why women may not respond as well as men to t-PA, including the possibility that women have higher levels of substances in the blood that can cause blood clots, as has been seen in women with heart diseases." Also, findings of the study revealed: Three months after t-PA was administered, patients who had a stroke on the left side of the brain were more then twice as likely to have good results, compared to those strokes on the right side of the brain. Further research is essential to confirm these findings and determine why women do not respond as well as men to t-PA.

A team of researchers from the University of California Los Angeles Medical Center, studied 451 ischemic stroke patients, average age sixty-five, treated between 2003 and 2006. The patients were divided into four categories based on their body mass index (BMI). According to results of the study, the team said: "This study suggests that hospitalized obese individuals may have poorer discharge clinical outcomes than their leaner counterparts." Statistically those patients with the highest BMI (30 - 40), less likely to be discharged directly home than lean patients (26 percent vs. 45 percent). Instead, obese patients have a higher probability to be transferred to inpatient rehabilitation care, general medicine service or skilled nursing facility. Also the study found no difference in in-hospital death rates or in functional activity outcome among the different BMI categories.

In 2006 Neurobiological Technologies (NASDAQ: NTII) completed building a snake center in Germany (near Hamburg) to raise Malayan pit viper snakes for the purpose of extracting the venom from the snakes as a stroke treatment drug, Viprines (Ancrod). The facility in Germany holds 100 snakes, but has the room for 1,500. The snakes are milked once a month for venom, which has anticoagulant properties (Ability to break up blood clots associated with stroke). Maintaining natural environment were these snakes normally live, each one is housed in its own room, kept at 79 percent humidity and at 82 degrees Fahrenheit. Valley Hospital Stroke Center in Ridgewood, New Jersey was one of the fifty hospitals around the country, participated in the initial study of Ancrod, measured the effects of administering the drug within three hours to stroke victims. According to a study at the Mayo Clinic in Scottsdale Arizona, head researcher Bart M. Damaerschalk, M.D., an assistant professor of neurology at the clinic suggests, Viprines can be given up to six hours out. Dr. Kenneth A. Levin, medical director of The Valley Hospital Stroke Center, said regarding the extended time of treatment: "would allow a lot more patients to benefits." Possible side effect of Ancord like other clot busters, it carries a very small risk of causing brain hemorrhages. In 2000, Levin co-author reported in the American Medical Association, how effective Ancord anticoagulant properties compared to a placebo for treating stroke patients, assessed three months later.

New York Presbyterian Hospital in Manhattan, testing a new device that removes a blood clot in the brain. During the 1990s, Dr. Pierre Gobin, professor of radiology, professor of radiology in neurological surgery and professor of radiology in neurology at Weill Cornell Medical College and director of interventional neurobiology at New York - Presbyterian/Weill Cornell, first developed the corkscrew device ("Merci Retriever"). Merci (Mechanical Embolus Retrieval in Cerebral Ischemia) Retriever is threaded through a catheter inserted through the femoral artery in the groin, and guided using X-ray imaging to the clot in the brain. The Merci Retriever is then deployed to ensnare the clot (like a corkscrew into the cork of a wine bottle). This device is a treatment for patients that arrive in the hospital beyond the initial three hours after a stroke, when standard treatment (t-PA) would not be administered. Dr. Dana Leifer, lead investigator at New York Presbyterian Hospital/Weill Cornell Medical Center, where he is director of the stroke unit and director of the neurovascular ultrasound laboratory said: "Less then about 5 percent of ischemic stroke patients arrive at the hospital within the necessary three-hour window for treatment with medication in most studies. There is an overwhelming need for new treatments for everyone else." More than 20 hospitals in North America are participating in a randomized trial ("Merci Retriever") and a total of 120 patients expected to be enrolled. The trial is lead by the University of California, Los Angeles. In August 2004, the Food and Drug Administration approved Concentric Medical clearance and commercial release of the Merci(R) L5 Retrieval System in the United States. Presently the only company, offering devices cleared by the FDA for clot removal in ischemic stroke patients. Also, approval was granted for use in Europe and Canada. Risks associated with use of Merci Retrieval System include vessel punctures and hemorrhaging.