2026 Volume 53 Issue 1 Pages 126-131
Cerebral venous sinus thrombosis (CVST) can present with persistent headache mimicking primary headache disorders, leading to delayed diagnosis. A 28-year-old man presented with a five-month history of pulsatile left frontal headache that was refractory to migraine prophylactic therapy. He was admitted with severe headache and focal motor seizure involving the right lower extremity. D-dimer was elevated, and MRI with MR venography demonstrated thrombosis of the superior sagittal sinus and cortical veins, confirming CVST. Continuous intravenous unfractionated heparin was initiated; however, activated partial thromboplastin time was not prolonged and antithrombin activity was reduced to 52%, suggesting heparin resistance due to antithrombin deficiency. He received antithrombin concentrate supplementation and was transitioned to apixaban, resulting in rapid clinical improvement and complete resolution of headache. Genetic testing identified a heterozygous SERPINC1 missense variant (p.Cys52Tyr) , establishing the diagnosis of congenital antithrombin deficiency. No recurrence of headache or thrombosis has been observed over eight years of follow-up. This case highlights that CVST should be considered in young patients with persistent or treatment-resistant headache, particularly when atypical features such as positional worsening are present, and that early venous imaging and thrombophilia work-up, including hereditary causes, are essential for timely diagnosis and appropriate management.
