Stroke
Warning Signs Often Occur Hours Or Days Before Attack
American
Academy Of Neurology
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.
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."
"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).