Isolated aphasia in the emergency department: The likelihood of ischemia is low

•Aphasia is a common presentation of ischemic stroke but can also be due to mimics.•Aphasia due to stroke is often accompanied by weakness, numbness, or vision changes.•In 788 patients with new neurologic symptoms due to suspected acute stroke, only 21 (3%) had isolated aphasia.•Isolated aphasia was almost always due to a stroke mimic rather than ischemia. Aphasia is a common presentation of ischemic stroke, often diagnosed in the acute setting using tools such as the NIH Stroke Scale (NIHSS). Due to the vascular distribution of the middle cerebral artery, it is often accompanied by other symptoms such as weakness, sensory loss, or visual changes. Isolated aphasia due to ischemia is possible, but language problems mimicking aphasia syndromes can also be seen with other diagnoses such as metabolic abnormalities or dementia. In this study, we determine the incidence of aphasia-only strokes using the NIHSS, and factors associated with a higher likelihood of ischemia. Over a 2year period, 788 patients presented to our Emergency Department with symptoms of acute stroke. Data were collected regarding patient demographics, medical history, presenting symptoms (based on NIHSS), work-up results, and final diagnosis. The incidence of aphasia-only stroke was calculated. Student’s t-tests and chi square analysis were used to determine factors associated with ischemia. Of 788 patients, 21 (3%) presented with isolated “aphasia”. None of the 21 had infarcts on neuroimaging. Three (14%) were diagnosed with possible transient ischemic attacks and the rest with stroke mimics. Toxic/metabolic disturbances were the most common mimics (39%). Prior history of stroke or transient ischemic attack was associated with ischemia over mimic (p=0.023). Strokes affecting language without motor or sensory deficits are uncommon. In the acute setting, isolated “aphasia” is most often due to a stroke mimic; however can occur rarely, particularly in those with prior history of ischemia.