Transient Ischemic Attack Differential Diagnoses

Updated: Sep 11, 2017
  • Author: Ashish Nanda, MD; Chief Editor: Andrew K Chang, MD, MS  more...
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Diagnostic Considerations

It has been suggested that transient ischemic attacks (TIAs) are a subset of a larger category termed transient neurologic attacks (TNAs). TNAs are defined as episodes of sudden onset of neurological symptoms that completely resolve within 24 hours and have no clear diagnosis. When a TNA is associated with focal symptoms attributed to an arterial territory of the brain, it is consistent with a stroke or TIA and is termed a focal TNA.

In contrast, a nonfocal TNA is a temporary event of diffuse, nonlocalizing, cerebral symptoms that set in suddenly and resolve quickly. Symptoms of nonfocal TNAs may include the following:

  • Altered consciousness
  • Nonrotatory dizziness
  • Positive visual phenomena
  • Paresthesias
  • Bilateral weakness
  • Generalized feelings of unwellness with a clinical suspicion of neurologic disease

When symptoms are both focal and nonfocal, the term “mixed TNA” would apply.

Nonfocal TNAs have long been considered benign. One study has shown, however, that patients who had suffered a prior nonfocal TNA were at higher risk of stroke and dementia, especially vascular dementia, than patients who did not have a history of prior TNA. [19]

Although more research is required, this study challenges the idea that nonfocal TNAs are benign events. Further workup should be considered in patients suffering nonfocal TNAs to elucidate the underlying cause of their transient symptoms and to achieve better risk stratification. [13, 19]

Differential Diagnoses