The researchers found that nearly one in three ischemic stroke survivors had a “mini-stroke,” known as a transient ischemic attack (TIA), before the actual event, most of which occurred in the previous week.
Ischemic strokes account for 80% of all strokes and are caused by blockages in the blood vessels that supply the brain. The remaining 20% of strokes are caused by ruptured blood vessels.
The researchers said TIAs, which have stroke-like symptoms, were known to often precede major strokes. These services usually last less than five minutes and do not cause permanent brain damage.
Peter M. Radcliffe, a researcher in the Department of Clinical Neurology. In Oxford Hospital News, England. “This study shows that the timing of a TIA is critical, and the most effective treatment should be initiated within hours of a TIA to prevent a major attack.”
Early warning signs of a stroke
In a study published in the current issue of Neurology, researchers evaluated 2,416 people with ischemic stroke.
They found that 23% of stroke patients had had a stroke before their stroke. 17% of those who experienced a TIA occurred on the day of the stroke, 9% on the day before, and 43% at some point in the week before the stroke.
Given the short time window between a TIA and a stroke, researchers say, all people with a TIA should be treated promptly to prevent permanent brain damage from a stroke.
In many countries, people with a TIA are discharged on an outpatient basis, usually for up to two weeks. But to be most effective, prophylactic treatment needs to be started within hours of a stroke and clinical guidelines need to be revised accordingly, the researchers say.
According to the National Institute of Neurological Disorders and Stroke, about one-third of people who experience a TIA will have a full-blown stroke in the future.