A new research has found that half of mini-strokes lead to a major stroke within 24 hours of the first attack.
The research has been published in the June 2, 2009, print issue of Neurology, the medical journal of the American Academy of Neurology.
"Our study highlights the need for someone who is experiencing the symptoms of a mini-stroke or transient ischemic attack to get to an emergency room fast," said Peter Rothwell, MD, PhD, FRCP, FMedSci, with the University of Oxford in the United Kingdom.
"That's because even after a very minor initial stroke, the immediate risk of a major stroke is very high," the expert added.
For the study, researchers analyzed the medical records of 1,247 people who experienced a TIA, or minor stroke. Of those, 35 had recurrent strokes within 24 hours during the first month after experiencing the TIA.
Scientists looked at whether patients had another stroke within six, 12 and 24 hours after the first stroke. The timeline started when the person either experienced symptoms of a stroke or first called for medical help.
The study found that after six hours, the risk of a second stroke went up by 1.2 percent. After 12 hours, the risk climbed another percent and by 24 hours the risk increased to 5 percent.
"This is the first rigorous population based study of the risk of a second stroke within 24 hours of a minor stroke," said Rothwell.
"We found a second stroke rate of about 5 percent, with half of all second strokes within seven days occurring in the first 24 hours, and half of these early recurrent strokes being disabling or fatal," he added.