Megan Brooks
January 20, 2023
A new scientific statement from the American Heart Association (AHA) offers a standardized approach to rapidly evaluate patients with suspected transient ischemic attack (TIA), keeping in mind the challenges faced by rural centers with limited resources.
TIAs are “warning shots” of a future stroke and require emergency evaluation, Hardik Amin, MD, chair of the writing committee and medical stroke director, Yale New Haven Hospital, New Haven, Connecticut, said in an AHA podcast.
A key aim of the scientific statement is to help clinicians properly risk-stratify patients with suspected TIA and determine which patients need to be admitted to the hospital and which patients might be safely discharged as long as proper and prompt follow-up has been arranged, Amin explained.
The statement, published online January 19 in the journal Stroke, addresses “how we can identify and be confident in diagnosing a TIA patient and what might suggest an alternative diagnosis,” he added.
Diagnostic Challenge
It’s estimated that nearly 1 in 5 people who suffer a TIA will have a full-blown stroke within 3 months; close to half of these strokes will happen within 2 days.
The challenge with TIAs is that they can be tough to diagnose because many patients no longer have symptoms when they arrive at the emergency department. There is also no confirmatory test. Limited resources and access to stroke specialists in rural centers may exacerbate these challenges, the authors note.
The statement points out that the F.A.S.T. acronym for stroke symptoms (Face drooping, Arm weakness, Speech difficulty, Time to call 911) can also be used to identify a TIA — even if the symptoms resolve.
The statement also provides guidance on how to tell the difference between a TIA and a TIA mimic.
Table. Factors Distinguishing TIA from TIA Mimics
| Factors | TIA | TIA Mimics |
|---|---|---|
| Demographics | Older age | Younger patient; no vascular risk factors |
| Medical History | Vascular risk factors | Epilepsy, migraines, brain tumor |
| Symptoms | – abrupt onset- maximal symptoms at onset- duration <60 min- preserved mentation- focal neurological symptoms- dizziness with cranial neuropathies, vision loss, trouble with coordination/gait, truncal ataxia, severe nausea- hypertensive at presentation- headache with ptosis/miosis | – symptoms that spread from site of onset might indicate seizure- altered mentation- migraine- signs of alternative diagnosis (ie, positive visual phenomena, seizure-like activity, positional vertigo with focal symptoms) |
If available, a non-contrast head computed tomography (NCCT) scan should be done initially in the emergency department to evaluate for subacute ischemia, hemorrhage, or mass lesion. Although the sensitivity of NCCT to detect an acute infarct is low, NCCT is useful for ruling out TIA mimics, the writing group says.
Multimodal brain MRI is the “preferred” method to evaluate for acute ischemic infarct and ideally should be obtained within 24 hours of symptom onset, and in most centers will follow an NCCT.
“When MRI cannot be obtained acutely to definitively distinguish TIA from stroke, it remains reasonable to make a clinical diagnosis of TIA in the ED on the basis of a negative NCCT and symptom resolution within 24 hours,” the authors say.
“A potential next step would be hospital admission for MRI, comprehensive workup, and neurology consultation. Other options might include transferring patients to a facility with advanced imaging and vascular neurology expertise or arranging a timely (ideally <24 hours) outpatient MRI,” they advise.
The statement also provides guidance on the advantages, limitations, and considerations of doppler ultrasonography, computed tomography angiography, and magnetic resonance angiography for TIA assessment.
Once TIA is diagnosed, a cardiac work-up is advised because of the potential for heart-related factors to cause a TIA.
An individual’s risk of future stroke after TIA can be rapidly assessed using the ABCD2 score, which stratifies patients into low, medium, and high risk based on age, blood pressure, clinical features, duration of symptoms and diabetes.
“It is up to each center to use the resources available and create a pathway to ensure successful management and disposition of patients with TIA, with the ultimate goal of reducing the risk of future stroke,” the authors conclude.
This scientific statement was prepared by the volunteer writing group on behalf of the American Heart Association’s Emergency Neurovascular Care Committee of the Stroke Council and the Council on Peripheral Vascular Disease. The American Academy of Neurology affirms the value of this statement as an educational tool for neurologists, and it is endorsed by the American Association of Neurological Surgeons/Congress of Neurological Surgeons (AANS/CNS).
Stroke. Published online January 19, 2023.
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