Susceptibility‐weighted venous features in DWI ‐negative migraine with aura and transient ischemic attack presentations: A retrospective study with preliminary score derivation

OBJECTIVE: This study aimed to evaluate the discriminative performance of venous asymmetry and index vein sign on susceptibility-weighted images (SWI) and to construct a preliminary, derivation-stage score for distinguishing migraine with aura (MA) from transient ischemic attack (TIA) in diffusion weighted imaging (DWI)-negative patients exhibiting lateralizable hemispheric deficits, defined by symptom-concordant clinico-radiologic features. BACKGROUND: Distinguishing migraine with aura from transient ischemic attack in patients with acute neurological deficits remains diagnostically challenging. Imaging biomarkers may aid this differentiation. METHODS: This study was designed as a retrospective, single-center, single-gate hypothesis-generating study with embedded preliminary score derivation and prospective blinded imaging assessment. Patients presenting with acute stroke-like symptoms between January 2023 and December 2024 to Hacettepe University Faculty of Medicine Hospitals were enrolled. Reference diagnoses had been assigned during routine clinical care using American Heart Association/American Stroke Association (AHA/ASA) criteria for transient ischemic attack (TIA) and the final International Classification of Headache Disorders, 3rd edition (ICHD-3) (2018) criteria for MA, without independent adjudication; retrospective per-patient tabulation of criterion C followed the ICHD-3 (2018) formulation. Clinical and demographic data were extracted retrospectively, and SWI images were evaluated prospectively. Clinico-radiologic characteristics of venous asymmetry and index vein sign (IVS) were examined in primary analyses along with their associations. From these analyses, a preliminary score named SVI (the symptom-concordant venous imaging) was derived. RESULTS: Of 290 DWI-negative patients, only 21 had MA (TIA = 269). Marked or mild venous asymmetry was observed in 19/21 (90.5%) of MA and in 44/269 (16.4%) of patients with TIA (predominantly mild). The IVS was observed in 18/21 (85.7%) of MA versus 28/269 (10.4%) of patients with TIA. In a small follow-up subset, venous signs tended to resolve interictally in MA, representing a hypothesis-generating observation. Symptom-concordant venous asymmetry and the IVS, together with younger age, hypoesthesia, and speech impairment, were independently associated with MA. As derivation-cohort estimates, the SVI score yielded an area under the receiver operating characteristic curve (AUC) = 0.97 (95% confidence interval [CI] 0.94-0.99); at a data-derived cutoff of eight or more points, selected to prioritize specificity, sensitivity was 15/21 (71.4%, 95% CI 47.8-88.7%), and specificity 258/269 (95.9%, 95% CI 92.8-97.9%). CONCLUSION: In this single derivation cohort, venous imaging findings were associated with MA and are potentially informative but merit further study. The preliminary SVI score requires independent prospective validation and should not presently guide diagnosis or treatment.