Asymmetric Superior Sagittal Sinus Thrombosis and G20210A Mutation: The Diagnostic Value of Complete Four-Vessel Angiography in Convexity Subarachnoid Hemorrhage

López-Casaperalta G.E.; Luna-Medina C.A.; Echevarría-Mendoza A.M. · SN Comprehensive Clinical Medicine (2026) · DOI: 10.1007/s42399-026-02566-7

Resumen

Backgroud: The diagnosis of cerebral venous thrombosis (CVT) presenting as spontaneous convexity subarachnoid hemorrhage (cSAH) remains a clinical challenge, particularly when associated with rare prothrombotic mutations. We present a case to highlight the critical diagnostic necessity of complete four-vessel digital subtraction angiography (DSA) and comprehensive genetic screening in accurately characterizing CVT and guiding long-term therapy. Case Presentation: A 64-year-old female with a history of glaucoma, cholecystectomy, and hysterectomy presented with a 7-day severe holocranial headache without prior trauma or focal neurological deficits. Initial non-contrast cranial CT revealed a localized right frontal cSAH. DSA was subsequently decided to further expand the diagnostic evaluation. Results: A striking hemodynamic asymmetry was observed in the superior sagittal sinus (SSS): while right internal carotid injection suggested a filling defect limited to the anterior third, the left-sided evaluation revealed an absence of flow in the anterior two-thirds of the SSS. This discrepancy underscores how unilateral angiographic assessment can significantly underestimate the total thrombotic burden. Functional compensation through recruited cortical anastomotic veins (Vein of Trolard) likely prevented venous infarction despite the extensive occlusion. Genetic screening confirmed a heterozygous prothrombin G20210A mutation. Conclusions: Performing a complete four-vessel DSA is important to characterize the true magnitude of SSS thrombosis, as significant asymmetry may exist between injections. Additionally, genetic testing contributes to a more thorough and comprehensive diagnostic workup. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2026.