Abstract Number: Esoc2026a1876 Posterior Circulation Stroke: Delayed Recognition in Fast-Negative Patients

Abstract Background and aims Posterior circulation strokes (PCS) frequently present with non-classical symptoms and may be missed by the FAST (Face, Arm, Speech, Time) screening tool recommended for early stroke recognition, potentially delaying diagnosis and time-critical management. This study evaluated the effectiveness of FAST in identifying PCS, and whether FAST-negative presentations were associated with delayed stroke team referral. Methods We conducted a retrospective observational study of all patients diagnosed with PCS at Queen’s Hospital, Romford UK, between April and June 2025. Cases were identified using hospital discharge coding and confirmed through review of neuroimaging and clinical documentation. Data collected included FAST status at presentation, and time from hospital arrival to stroke team referral. Patients were stratified as FAST-positive or FAST-negative, with referral times compared between groups. Results Of the 81 patients identified with PCS, 49 (60.5%) were FAST-positive and 32 (39.5%) FAST-negative. One FAST-negative patient was excluded from timing analysis due to unavailable records. Among the remaining FAST-negative patients, the median time to stroke team referral was 8 hours (range 0–216 hours). The mean referral time was approximately 31 hours, skewed by several prolonged outliers. Notably, 7 (23%) FAST-negative patients experienced referral delays exceeding 48 hours, while 3 (10%) were referred immediately despite being FAST-negative. Conclusions Nearly 40% of posterior circulation strokes were FAST-negative, with a substantial proportion experiencing significant delays in specialist referral. These findings highlight the limitations of FAST in identifying PCS and support consideration of expanded screening approaches incorporating visual and cerebellar symptoms, such as acute ataxia, to improve timely recognition and management. Conflict of interest Miss Zaynah Islam: Nothing to disclose. Dr Tariq Suleiman: Nothing to disclose. Dr Farhad Huwez: Nothing to disclose.