Neurological assessment with FAST to better detect posterior circulation stroke

Posterior circulation stroke (PCS) represents up to 25% of ischaemic strokes and affects more than 20 000 people annually within the UK. Prehospital clinical practice guidelines recommend the use of a validated stroke screening tool, such as the ‘Face, Arms, Speech, Time’ [FAST] tool for the assessment of all patients presenting with stroke symptoms. However, with PCS, patients may present with vestibular symptoms, which cannot be detected with ‘FAST’. Furthermore, over one-third of patients with PCS are delayed or misdiagnosed due to a lack of apparent ‘typical’ acute stroke symptoms. The ‘FAST’ tool is deemed to have high sensitivity and moderate specificity in the recognition of ischaemic stroke; yet there is evidence within the literature determining that the ‘FAST’ tool is not adequate for prehospital screening of PCS, leading to misdiagnosis, treatment delay, and severe life-limiting deficits or death. The aim of this literature search is to evaluate how the use of additional neurological assessment, alongside the validated ‘FAST’ tool, could be used within the prehospital setting for the improved paramedic detection of PCS.