ABSTRACT NUMBER: ESOC2026A534 PROGNOSIS OF APPARENT TIAS WITH ADDITIONAL MIGRAINE AURA-LIKE SYMPTOMS: POPULATION-BASED COHORT STUDY

Abstract Background and aims Although cerebral ischaemia can mimic migraine aura, guidelines discourage diagnosis of TIA if events have some migraine-like features. Moreover, many TIA-services also advise against referral of patients with such events. We did a population-based study of the incidence and prognosis of all patients referred to TIA services with or without migraine-like features. Methods Prospective study (2002-2023) of all patients referred with acute-onset transient neurological symptoms nested within a population-based study of all vascular events in Oxfordshire, UK. Events were classified prior to investigation as guideline-consistent TIA without migraine-like symptoms versus otherwise classical TIA with additional migraine-like features (progressive or positive visual/other symptoms irrespective of headache). 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 and sex-specific rates in the underlying population. Results Among 2169 eligible patients, 1973 had guideline-consistent TIA without migraine-like features and 196 (9.0%) had an event that would otherwise be guideline-consistent but had additional migraine-like features. The 90-day stroke risk in this group was 3.06% (95%CI = 1.39-6.69) and the age/sex-adjusted 10-year stroke risk was higher than expected in the underlying population (O/E = 4.8, 2.8-7.7, P < 0.0001). The 10-year stroke risk was similar to that in the 1973 patients with guideline-consistent TIA (age/sex adjusted HR = 0.83, 0.50-1.36). Conclusions Among patients with otherwise classical TIA symptoms, the presence of additional migraine-like features should not preclude urgent investigation and treatment. Conflict of interest Maria Tuna: nothing to disclose; Peter Rothwell: nothing to disclosure; Oxford Vascular Study is supported by Welcome Trust and NIHR Oxford Biomedical Research Centre.