A cardiac source is often implicated in strokes where the deficit includes aphasia. However, less is known about the etiology of isolated aphasia during transient ischemic attack (TIA). Our objective was to determine whether patients with isolated aphasia are likely to have a cardioembolic etiology for their TIA.

We prospectively studied a cohort of TIA patients in eight tertiary-care emergency departments. Patients with isolated aphasia were identified by the treating physician at the time of emergency department presentation. Patients with dysarthria (i.e., a phonation disturbance) were not included. Potential cardiac sources for embolism were defined as atrial fibrillation on history, electrocardiogram, Holter monitor, atrial fibrillation on echocardiography, or thrombus on echocardiography.

Of the 2,360 TIA patients identified, 1,155 had neurological deficits at the time of the emergency physician assessment and were included in this analysis, and 41 had isolated aphasia as their only neurological deficit. Patients with isolated aphasia were older (73.9±10.0 v. 67.2±14.5 years; p=0.003), more likely to have a history of heart failure (9.8% v. 2.6%; p=0.027), and were twice as likely to have any cardiac source of embolism (22.0% v. 10.6%; p=0.037).

Isolated aphasia is associated with a high rate of cardioembolic sources of embolism after TIA. Emergency patients with isolated aphasia diagnosed with a TIA warrant a rapid and thorough assessment for a cardioembolic source.