Researchers say all patients should receive a CT scan in the 24 hours following a TIA or non-disabling stroke, as the brain images may predict their future risk of stroke.
Transient ischemic attack (TIA), often referred to as a mini-stroke, is when blood flow to part of the brain is blocked temporarily. Symptoms of TIA resemble stroke symptoms, but they often only last a few minutes.
TIA, however, can be an important indicator of a future stroke; approximately 40% of people who have a TIA will go on to have a stroke.
Most patients in the US and Canada receive a computed tomography (CT) scan in the 24 hours following a TIA or a non-disabling stroke - a stroke that has not caused long-term disability.
A CT scan provides cross-sectional images of the brain, allowing a more in-depth analysis of blood circulation and tissue damage.
But the researchers of this latest study - including Dr. Jeffrey J. Perry of the University of Ottawa in Canada - say that all patients who have a mild stroke should receive a CT scan, given how the brain images can predict when patients will be at highest risk of a subsequent stroke.
Patients with acute ischemia after TIA at higher risk of stroke
The team analyzed the brain images of 2,028 patients who underwent CT scans in the 24 hours after experiencing a TIA or non-disabling stroke. Of these patients, 814 had brain damage as a result of ischemia - restricted blood supply to the brain.
- Almost half of all strokes occur in the first few days following a TIA
- Most TIAs last less than 5 minutes, with the average being around 1 minute
- Symptoms of TIA are similar to stroke and include weakness, numbness or paralysis in the face, slurred speech and blindness or double vision.
From the images, the researchers were able to predict which patients were at highest risk of having another stroke within 90 days of the initial TIA or non-disabling stroke.
They found that patients with ischemia were 2.6 times more likely to have another stroke if the images showed they had acute ischemia - newly damaged tissue as a result of poor blood circulation - compared with patients without ischemia.
Ischemia patients were 5.35 times more likely to have a stroke if the images showed both chronic ischemia (previously damaged tissue) and acute ischemia, and they were 4.9 times more likely to have a stroke if the images showed any form of microangiopathy (small blood vessel damage) in the brain alongside acute ischemia.
What is more, the team found that ischemia patients were 8.04 times more likely to have a stroke if the images showed both acute and chronic ischemia alongside microangiopathy.
The team notes that 3.4% of study participants had a stroke in the 90 days following a TIA or non-disabling stroke, and that 25% of these displayed both chronic and acute ischemia and microangiopathy in their CT scan images.
"During the 90-day period, and also within the first 2 days after the initial attack, patients did much worse in terms of experiencing a subsequent stroke if they had additional areas of damage along with acute ischemia," Dr. Perry adds.
Commenting on what these findings mean, Dr. Perry says:
"All patients should get a CT scan of their brain after a TIA or non-disabling stroke. Images can help health care professionals identify patterns of damage associated with different levels of risk for a subsequent stroke or help predict when symptoms may get worse.
These findings should prompt physicians to be more aggressive in managing patients with TIA or non-disabling stroke who are diagnosed with acute ischemia, especially if there is additional chronic ischemia and/or microangiopathy."
Medical News Today recently reported on a study in which researchers from the UK and China claim to have identified a drug target for prevention of stroke-related brain damage.