Electronic supplementary material
The online version of this article (doi:10.1186/2036-7902-6-3) contains supplementary material, which is available to authorized users.
Moriz Herzberg, Sandra Boy contributed equally to this work.
The authors declare that they have no competing interests.
MH performed data analysis and drafted the manuscript; SB acquired clinical data, participated in the study design and drafted and corrected the manuscript; TH participated in the study design and corrected the manuscript; ME acquired clinical data; MZ participated in the study design; KPI participated in the study design; JP contributed clinical data and was involved in logistics; HP contributed clinical data as clinical collaborator; UB corrected the manuscript and was involved in the study design; FS acquired clinical data, participated in the study design and drafted and corrected the manuscript. All authors read and approved the final manuscript.
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.
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.
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%.
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.