Acute stroke differential diagnosis: Stroke mimics.

Stroke mimics (SM) are non-vascular conditions that present with an acute neurological deficit simulating acute ischemic stroke and represent a significant percentage of all acute stroke hospital admissions. The most common clinical SM includes conversion/functional (psychiatric disorder); seizures and postictal paralysis; toxic-metabolic disturbances; brain tumours; infections, and migraine. Imaging is essential for SM recognition, being Diffusion weighted imaging (DWI), perfusion imaging and angiographic studies very useful. There are several disorders that may have imaging features that simulate acute ischemic stroke, mainly presenting with cytotoxic oedema and/or perfusion deficits. The imaging features of the most frequent clinical and imaging stroke mimics are reviewed.