EMBARGOED FOR RELEASE UNTIL 4 PM ET, March 07, 2005
Stroke Warning Signs Often Occur Hours or Days before Attack
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. “We have known for some time that TIAs are often a precursor to a major stroke,” said study author Peter M. Rothwell, MD, PhD, FRCP, of the Department of Clinical Neurology at Radcliffe Infirmary in Oxford, England. “What we haven’t been able to determine is how urgently patients must be assessed following a TIA in order to receive the most effective preventive treatment. This study indicates that the timing of a TIA is critical, and the most effective treatments should be initiated within hours of a TIA in order to prevent a major attack.” Rothwell also noted that clinical guidelines should be amended accordingly. The study included two population-based studies (Oxford Vascular Study and Oxfordshire Community Stroke Project) as well as two randomized trials (UK-TIA Aspirin Trial and European Carotid Surgery Trial).
The American Academy of Neurology is the world's largest association of neurologists and neuroscience professionals, with 32,000 members. The AAN is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer's disease, stroke, migraine, multiple sclerosis, concussion, Parkinson's disease and epilepsy.
Editor's Notes:Common symptoms of a TIA, which are similar to those of a stroke yet temporary, include:
Sudden numbness or weakness of the face, arm or leg, especially on one side of the body
Sudden confusion or problems understanding
Sudden difficulty speaking
Sudden vision difficulty in one or both eyes
Sudden dizziness, loss of balance or coordination, or difficulty walking
Sudden, severe headache with no apparent cause