title: Prehospital stroke diagnostics based on neurological examination and transcranial ultrasound.
abstract: BACKGROUND
  Transcranial color-coded sonography (TCCS) has proved to be a fast and reliable tool for the detection of middle cerebral artery (MCA) occlusions in a hospital setting. In this feasibility study on prehospital sonography, our aim was to investigate the accuracy of TCCS for neurovascular emergency diagnostics when performed in a prehospital setting using mobile ultrasound equipment as part of a neurological examination.
  
  
  METHODS
  Following a '911 stroke code' call, stroke neurologists experienced in TCCS rendezvoused with the paramedic team. In patients with suspected stroke, TCCS examination including ultrasound contrast agents was performed. Results were compared with neurovascular imaging (CTA, MRA) and the final discharge diagnosis from standard patient-centered stroke care.
  
  
  RESULTS
  We enrolled '232 stroke code' patients with follow-up data available in 102 patients with complete TCCS examination. A diagnosis of ischemic stroke was made in 73 cases; 29 patients were identified as 'stroke mimics'. MCA occlusion was diagnosed in ten patients, while internal carotid artery (ICA) occlusion/high-grade stenosis leading to reversal of anterior cerebral artery flow was diagnosed in four patients. The initial working diagnosis 'any stroke' showed a sensitivity of 94% and a specificity of 48%. 'Major MCA or ICA stroke' diagnosed by mobile ultrasound showed an overall sensitivity of 78% and specificity of 98%.
  
  
  CONCLUSIONS
  The study demonstrates the feasibility and high diagnostic accuracy of emergency transcranial ultrasound assessment combined with neurological examinations for major ischemic stroke. Future combination with telemedical support, point-of-care analysis of blood serum markers, and probability algorithms of prehospital stroke diagnosis including ultrasound may help to speed up stroke treatment.
authors.forename: Moriz
authors.initials: M
authors.lastname: Herzberg
authors.affiliation: Department of Neurology, University of Regensburg, Community District Hospital, Universitätsstr,84, Regensburg 93053, Germany. sandra.boy@medbo.de.
authors.forename: Sandra
authors.initials: S
authors.lastname: Boy
authors.forename: Thilo
authors.initials: T
authors.lastname: Hölscher
authors.forename: Michael
authors.initials: M
authors.lastname: Ertl
authors.forename: Markus
authors.initials: M
authors.lastname: Zimmermann
authors.forename: Karl-Peter
authors.initials: KP
authors.lastname: Ittner
authors.forename: Josef
authors.initials: J
authors.lastname: Pemmerl
authors.forename: Hendrik
authors.initials: H
authors.lastname: Pels
authors.forename: Ulrich
authors.initials: U
authors.lastname: Bogdahn
authors.forename: Felix
authors.initials: F
authors.lastname: Schlachetzki