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.
You will likely have a head CT scan or brain MRI. A stroke may show changes on these tests, but TIAs will not.
CT and MRI are the recommended modality to diagnose TIA and image ischemic lesions.
Any irregularities or causes for concern show up in a CT scan approximately six to eight hours after the onset of the first signs of a stroke. During a CT scan, the patient may be intravenously injected with dyes, which will highlight any abnormal areas in the scan, giving doctors a clearer view of the head.
If you've had an ischemic stroke, it's likely that it won't show up on a CT scan of your brain for 24 to 48 hours.
Frequent causes of transient neurological symptoms that can mimic TIA include: Migraine aura. Seizure. Syncope. Functional or anxiety related.
The scans were independently interpreted by four experts, who had no other patient information. Based only on the MRI scans, experts accurately diagnosed acute strokes 83 percent of the time. Using the CT scans, however, they were right just 26 percent of the time.
CT scans are excellent at detecting the bleeding in the brain that occurs in hemorrhagic stroke. However, ischemic stroke may be difficult or impossible to see in CT images, especially during the first few hours after the stroke occurs, which is the period when treatment decisions are most important.
During a silent stroke, the interruption in blood flow occurs in part of the brain that doesn't control any vital functions. Although it doesn't cause any obvious symptoms—most people who've had a silent stroke have no idea it occurred—the damage does show up on an MRI or CT scan.
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.
Symptoms can be caused by other problems, so the specialist doctor or nurse will listen carefully to you and confirm if you've had a TIA. You may have a brain scan, but not everyone needs a scan. You'll have tests for health problems linked to stroke, such as high blood pressure, high cholesterol and diabetes.
The answer is C) 6 hours – as a rule of thumb, this is usually the earliest time frame in which you might see evidence of an ischemic stroke on CT. For most patients, presenting with the 4.5 hour tPA time window, we expect to see a normal head CT.
However, mounting evidence suggests that an MRI within 1 to 2 days of a TIA could spot evidence of a stroke that may disappear in time. MRIs can detect tissue damage even when symptoms are temporary. The sophisticated imaging technique can detect stroke lesions that may become less apparent quickly.
MRI is known to generally be more sensitive than CT in the detection of ischemia, and current experimental MRI studies with Na23 show even better sensitivity for acute stroke imaging [40]. However, the detection of hemorrhage, especially smaller hemorrhage, is not so straightforward with MRI.
Initial stroke imaging can be done using either noncontrast head CT or MRI to differentiate hemorrhagic (15%) from ischemic stroke and determine the size (whether it is more than one-third of the middle cerebral artery [MCA] territory) and location.
While partial seizures and complicated migraine are the most common and important TIA/stroke mimics, on occasion panic attacks, conversion disorder, vertigo, and syncope can also be confused with TIA. Panic attacks occasionally involve focal neurologic symptoms, but more typically the symptoms are vague and random.
Symptoms of a TIA come on suddenly. You may feel perfectly fine one minute and then suddenly develop difficulty speaking or moving one side of your body. Sometimes the symptoms will come and go several times in a short period of time.
In a previously reported study, 31% of TIA patients showed an acute infarction visualized by MRI including DWI. A strong association was found between neurological symptoms, speech dysfunction and weakness and an evidence of acute infarction by MRI including DWI (Al-Khaled and Eggers, 2013).
TIAs look like strokes in terms of signs and symptoms, but they are temporary. In other words, they leave no lasting brain damage or residual symptoms. However, they serve as a warning sign that a person is at higher risk of a major stroke and should seek immediate medical attention.
Causes of a transient ischaemic attack (TIA)
This blockage is usually caused by a blood clot that's formed elsewhere in your body and travelled to the blood vessels supplying the brain, although it can also be caused by pieces of fatty material or air bubbles.
In many cases, a stroke can be fatal. Unfortunately, misdiagnosis of a TIA is fairly common. One expert even estimated that misdiagnoses account for up to 160,000 deaths or debilitating brain injuries annually, as a prompt medical response to a TIA is critical to the prevention of a full-blown stroke.
Dipyridamole and aspirin — Dipyridamole is a medication that may be given after a TIA to reduce the risk of stroke. It is often given as an extended-release form, combined with aspirin (aspirin-extended-release dipyridamole, brand name: Aggrenox). It is taken two times per day.
TIAs are often an early warning sign that a person is at risk of stroke. About 1 in 3 people who has a TIA goes on to experience a subsequent stroke. The risk of stroke is especially high within 48 hours after a TIA .