Transient Ischemic Attack: Know What It Is and Take Immediate Action

A transient ischemic attack(TIA) is now defined as a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, without acute infarction.

The symptoms of a TIA are the same as those of a stroke. The difference is that stroke occurs when there is death of brain tissue (permanent damage). TIA occurs when there is dysfunction of brain tissue due to temporary ischemia (meaning not enough blood flow for brain tissue to function normally). But in a TIA there is no death of brain tissue so complete recovery occurs when the blood flow returns to normal.

But if you have symptoms that could be a TIA you should get to the ER or your doctor’s office right away even if the symptoms have completely gone away. The reason to get diagnosis and treatment right away is that patients who have a TIA are at markedly increased risk of having a stroke. It is estimated that a person with a TIA has a 10% chance of having a stroke over the next 90 days. And as many as one quarter to one half of that increased risk occurs in the two days immediately after the TIA symptoms.

By going to the doctor right away you can get treatment that will markedly reduce your risk of having a stroke. So again even if the TIA symptoms have completely gone away you need to go to the ER or to your doctor right away.

The symptoms of transient ischemic attack are the same as the symptoms of stroke. They are:

–Sudden weakness or numbness of the face, arm, or leg, especially on one side of the body
–Sudden confusion
–Trouble speaking or understanding
–Sudden trouble seeing in one or both eyes
–Sudden trouble walking
–Dizziness or loss of balance or coordination
–Sudden severe headache with no known cause

You should call 911 right away if have these symptoms as it could be a stroke rather than a TIA because unless the symptoms get better very quickly, within several minutes but no more, you need emergency department evaluation and treatment.

If your symptoms have gotten completely better within several minutes, then you should see your doctor right away within the next two hours (I think). If for some can’t get in to see your doctor within the next two hours you should go to the emergency immediately even if your symtoms are completely gone within several minutes.

And if they aren’t completely gone in several minutes or you are not sure they are gone, you need to call 911 right away and go by life squad.

Regardless of whether your doctor or the emergency doctor evaluates you for TIA, the evaluation needs to go quickly.

The ABCD2 score attempts to stratify stroke risk in patients with TIAs. Patients with TIA score points (indicated in parentheses) for each of thefollowing factors: age 60 years (1); blood pressure 140/90 mm Hg on first evaluation (1); clinical symptoms of focal weakness with the spell (2) or speech impairment without weakness (1); duration 60 minutes (2) or 10 to 59 minutes (1); and diabetes (1).
The ABCD2 score can then be used, along with other data (imaging studies), to decide if a patient with TIA should be hospitalized for observation.

In the past 41 to 68% of patients with TIA are admitted to the hospital for close observation since they are known to be at increased risk of stroke. And if in the hospital the patients develop acute stroke, then  effective stroke treatment can be more quickly started.

The 2009 AHA guideline Definition and Evaluation of Transient Ischemic Attack makes the following recommendations:

Class I Recommendations

1. Patients with TIA should preferably undergo neuroimaging evaluation within 24 hours of symptom onset. MRI, including DWI, is the preferred brain diagnostic imaging modality. If MRI is not available, head CT should be performed (Class I, Level of Evidence B).
2. Noninvasive imaging of the cervicocephalic vessels should be performed routinely as part of the evaluation of patients with suspected TIAs (Class I, Level of Evidence A).
3. Noninvasive testing of the intracranial vasculature reliably excludes the presence of intracranial stenosis (Class I, Level of Evidence A) and is reasonable to obtain when knowledge of intracranial steno-occlusive disease will alter management. Reliable diagnosis of the presence and degree of intracranial stenosis requires the performance of catheter angiography to confirm abnormalities detected with noninvasive testing.
4. Patients with suspected TIA should be evaluated as soon
as possible after an event (Class I, Level of Evidence B).

Class II Recommendations

1. Initial assessment of the extracranial vasculature may involve any of the following: CUS/TCD, MRA, or CTA, depending on local availability and expertise, and characteristics of the patient (Class IIa, Level of Evidence B).
2. If only noninvasive testing is performed before endarterectomy, it is reasonable to pursue 2 concordant noninvasive findings; otherwise, catheter angiography should be considered (Class IIa, Level of Evidence B).
3. The role of plaque characteristics and detection of MESs* is not yet defined (Class IIb, Level of Evidence B).
4. ECG should occur as soon as possible after TIA (Class I, Level of Evidence B). Prolonged cardiac monitoring (inpatient telemetry or Holter monitor) is useful in patients with an unclear origin after initial brain imaging and electrocardiography (Class IIa, Level of Evidence B).
5. Echocardiography (at least TTE) is reasonable in the evaluation of patients with suspected TIAs, especially in patients in whom no cause has been identified by
other elements of the workup (Class IIa, Level of Evidence B). TEE is useful in identifying PFO, aortic arch atherosclerosis, and valvular disease and is reasonable when identification of these conditions will alter management (Class IIa, Level of Evidence B).
6. Routine blood tests (complete blood count, chemistry
panel, prothrombin time and partial thromboplastin time,
and fasting lipid panel) are reasonable in the evaluation of
patients with suspected TIAs (Class IIa, Level of Evidence B).
7. It is reasonable to hospitalize patients with TIA if they present within 72 hours of the event and any of the following criteria are present: a. ABCD2 score of 3 (Class IIa, Level of Evidence C).
b. ABCD2 score of 0 to 2 and uncertainty that diagnostic workup can be completed within 2 days as an
outpatient (Class IIa, Level of Evidence C). c. ABCD2 score of 0 to 2 and other evidence that indicates the patient’s event was caused by focal ischemia (Class IIa, Level of Evidence C).

*MESs means microembolic signals detected on transcranial doppler ultrasound (of the intracranial blood vessels) seen with embolism from the heart or from the internal carotid in the neck.

I’d like to make one further point about TIAs. Risk of heart disease is increased after a TIA. Over the next five or more years, persons who have had a TIA will have about the same number of myocardial infarctions or sudden cardiac death as they will strokes. Therefore people who have had a TIA will need to be evaluated for heart disease which if found requires preventive treatments.

The 2009 AHA guideline Definition and Evaluation of Transient Ischemic Attack is available at http://stroke.ahajournals.org/content/40/6/2276.full.pdf

 

This entry was posted in Advanced Cardiac Life Support, Emergency Medicine, Internal Medicine, Neurology and tagged , , . Bookmark the permalink.