Association of Diagonal Earlobe Crease (Frank’s Sign) with Intracranial Aneurysm Rupture at Small Sizes

Background: The diagonal earlobe crease (DELC), or Frank’s sign, has been associated with systemic vascular degeneration. Whether this cutaneous marker correlates with intracranial aneurysm (IA) instability remains unclear. Methods: We conducted a hospital-based observational registry study including 186 consecutive patients with IA. DELC was dichotomized into absent/low-grade versus high-grade creases. Associations between DELC and aneurysm rupture, rupture at small sizes (<7 mm), and clinical outcome were analyzed using multivariate logistic regression models adjusted for demographic and vascular risk factors. Results: High-grade DELC was significantly associated with overall aneurysm rupture (adjusted OR 3.42, 95% CI 1.39–8.41, p = 0.007). Patients with high-grade DELC harbored ruptured aneurysms at significantly smaller mean sizes than those without the sign (6.11 mm vs. 7.94 mm, p = 0.015). High-grade DELC was also associated with a distinct anatomical shift toward the anterior communicating artery complex (p = 0.021) and was independently associated with rupture at <7 mm (adjusted OR 2.08, 95% CI 1.03–4.21, p = 0.041), even after adjustment for aspect ratio and clinical covariates. DELC was not independently associated with post-hemorrhagic clinical outcome. Conclusions: Frank’s sign may represent a readily observable clinical marker associated with IA instability and rupture at conventionally low-risk sizes (<7 mm). These findings support further investigation into DELC as a potential adjunct for individualized risk stratification in patients with small incidental intracranial aneurysms to prevent catastrophic subarachnoid hemorrhage.