Acute stroke is the leading cause of morbidity and mortality. The emergency medical technicians (EMTs) must confirm acute stroke rapidly at the scene and transport these patients to the applicable medical facilities for treatment. Acute stroke presents with neurologic deficits, and many conditions may present with stroke-like symptoms, known as stroke mimics. This study aims to analyze the characteristics of stroke mimics affecting prehospital identification transported to Wakayama Medical University by helicopter emergency medical service during 7.5 years. Totally 349 patients were identified as potential strokes by EMTs, of which 284 (81.4%) had a definitive diagnosis of acute stroke, and 65 (18.6%) were stroke mimics. Epileptic Seizure was the most likely to be misdiagnosed as acute stroke. While all cases of acute stroke required admission to hospital, 10 patients of stroke mimics needed no hospitalization due to dramatic symptomatic recovery. The major symptoms of stroke mimics judged as acute stroke by EMTs were consciousness disturbance, hemiparesis, eye deviation. In these cases, there were 5 cases of the ipsilateral hemiparesis with eye deviation following seizure. Overtriage for potential strokes by EMTs should be acceptable. However, follow-up medical inspection is educationally important for EMTs to improve the quality of prehospital emergency care.
