As many as 240,000 people per year in the United States experience a transient ischemic attack (TIA), (1,2) which is now defined by the American Heart Association and American Stroke Association as a "transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, without acute infarction." (3) An older definition of TIA was based on the duration of the event (ie, resolution of symptoms at 24 hours); in the updated (2009) definition, the diagnostic criterion is the extent of focal tissue damage. (3) Using the 2009 definition might mean a decrease in the number of patients who have a diagnosis of a TIA and an increase in the number who are determined to have had a stroke because an infarction is found on initial imaging.
Guided by the 2009 revised definition of a TIA, we review here the work-up and treatment of TIA, emphasizing immediacy of management to (1) prevent further tissue damage and (2) decrease the risk of a second event.
Martin L, 69 years old, retired, a nonsmoker, and with a history of peripheral arterial disease and hypercholesterolemia, presents to the emergency department (ED) of a rural hospital complaining of slurred speech and left-side facial numbness. He had an episode of facial numbness that lasted 30 minutes, then resolved, each of the 2 previous evenings; he did not seek care at those times. Now, in the ED, Mr. L is normotensive.
The patient's medication history includes a selective serotonin reuptake inhibitor and melatonin to improve sleep. He reports having discontinued a statin because he could not tolerate its adverse effects.
What immediate steps are recommended for Mr. L's care?
Common event calls for quick action
A TIA is the strongest predictor of subsequent stroke and stroke-related death; the highest period of risk of these devastating outcomes is immediately following a TLA. (1,2,4,5) It is essential, therefore, for the physician who sees a patient with a current complaint or recent history of suspected focal neurologic deficits to direct that patient to an ED for an accurate diagnosis and, as appropriate, early treatment for the best possible outcome.
Imaging--preferably, diffusion-weighted magnetic resonance imaging (DW-MRI), the gold standard for diagnosing stroke (see "Diagnosis includes ruling out mimics") (2,3)--should be performed as soon as the patient with a suspected TIA arrives in the ED. Imaging should not be held while waiting for a stroke to declare itself--ie, by allowing symptoms to persist for longer than 24 hours. (6)
Late presentation. Some patients present [greater than or equal to] 48 hours after onset of early symptoms of a TIA; for them, the work-up is the same as for prompt presentation but can be completed in the outpatient clinic--as long as the patient is stable clinically and imaging is accessible there. DW-MRI should be completed within 48 hours after late presentation. In such cases, the patient should be cautioned regarding risks and any recurrence of symptoms. (7,8)
Diagnosis includes ruling out mimics
All patients in whom a stroke is...