Abstract Number: Esoc2026a539 Stroke Risk in Patients With Apparent Migraine Aura-Like Tia Mimics: Population-Based Cohort Study

Abstract Background and aims New-onset or changed migraine aura is a common mimic diagnosis in TIA/stroke services. Although patients with such events are often reassured on the basis of clinical history alone that investigation/treatment are not required, the evidence-base on prognosis is limited. We did a population-based-study of the prognosis of all patients referred to TIA/stroke services with symptoms potentially consistent with a migraine aura. Methods Prospective study (2002-2023) of all patients referred with acute-onset transient neurological symptoms within a population-based-study of all vascular events in Oxfordshire, UK. Patients with symptoms that prior to investigation were potentially consistent with a new-onset migraine aura or a change from any previous auras were stratified according to the presence of ‘red flags’ for stroke risk based on the Essen-score (age≥65; vascular risk factors). Risks of stroke (90-days/10-years) were determined by face-to-face follow-up to 2026 and compared with the stroke incidence rate expected based on age/sex-specific rates in the underlying population. Results Among 400 patients with an aura-like event, 204 had ≥1 ‘red flag’ for stroke risk. All five 90-day strokes occurred in this group (risk=2.44%, 95%CI=1.02-5.76; Observed/expected=27.9, 9.0-65.0, p0.0001). The age/sex-adjusted 10-year stroke-risk was also high in this group (O/E=5.6, 3.6-8.3, p0.0001) but not in the 196 patients without ‘red flags’ (O/E=1.1, 0-6.0, p=0.99). Conclusions In TIA-referrals with migraine aura-like events, the short and long-term stroke risks in patients aged≥65 years or with vascular risk factors are similar to those in patients with more typical TIAs. Conflict of interest Maria Tuna: nothing to disclose. Peter Rothwell: nothing to disclose; Oxford vascular study is supported by the Welcome Trust and the NIHR Oxford Medical Research Centre