Stroke mimics transported by emergency medical services to a comprehensive stroke center : the magnitude of the problem

Background: Despite the use of validated prehospital stroke screens, stroke mimics are frequent among patients transported by Emergency Medical Services to the Emergency Department. We aimed to describe the frequency and characteristics of neurological and non-neurological mimics transported to a comprehensive stroke center for acute stroke evaluation. Methods: This was a retrospective analysis of a database consisting of all consecutive patients with suspected stroke transported to the Emergency Department of a comprehensive stroke center during an 18-month period. Hospital charts and neuroimaging were utilized to adjudicate the final diagnosis (acute stroke, stroke mimic, and specific underlying diagnoses). Results: 950 patients were transported with suspected stroke, among whom 405 (42.6%) were stroke mimics (age 66.9±17.1 years; 54% male). Neurological mimics were diagnosed in 223 (55.1%) patients and mimics were non-neurological in 182. The most common neurological diagnoses were seizures (19.7%), migraines (18.8%) and peripheral neuropathies (11.2%). Cardiovascular (14.6%) and psychiatric (11.9%) diagnoses were common non-neurological mimics. Patients with neurological mimic were younger (64.1±17.3 years vs. 70.5±16.1 years, p<0.001) and had less vascular risk factors than non-neurological mimics. The proportion of non-neurological mimics remained high (38%) despite the use of a prehospital identification scale. Conclusion: Stroke mimics are common among patients transported by Emergency Medical Services to a comprehensive stroke center for suspected stroke, with a considerable proportion being non-neurological in origin. Studies refining triage and transport of suspected acute stroke may be warranted to minimize the number of mimics transported by to a comprehensive stroke center for acute stroke evaluation