Validated Pre-Hospital Stroke Scales to Predict Large Vessel Occlusion: A Systematic Review

Background Occlusions of large cerebral vessels, including the internal carotid artery and middle cerebral artery, result in significant burden of morbidity. Treatment was previously limited to intravenous thrombolysis, however multiple studies have shown significant improvements when patients undergo endovascular clot retrieval. Early identification and triage to centres capable of delivering this is likely to contribute to improved outcomes. This systematic review aims to compare clinical assessment tools and their performance ‘in-field’ to identify usability and reliability to assist pre-hospital providers with identification of this sub-group of stroke patients. Methods Several databases were reviewed to identify studies that have validated large vessel occlusion clinical assessment tools within the pre-hospital environment. Sensitivity, specificity and predictive value were compared along with any biases. Six studies met the study criteria and were included. A total of 1384 patients were involved in the studies with sensitivities ranging from 51.9% to 100% and specificities ranging from 68% to 90%. Conclusion There is significant variation among studies and the emergency medical systems they have been performed within. It is likely that no single tool will suit every system and further research is required to determine the best tool for the Australian pre-hospital environment.