Cerebral venous sinus thrombosis associated with hyperhomocysteinemia due to methylenetetrahydrofolate reductase homozygous gene mutation: A case report

Abstract

Cerebral venous sinus thrombosis (CVST) is a rare but potentially life-threatening condition requiring a high 
index of suspicion for diagnosis. We report a case of a 20-year-old vegetarian male presenting with acute severe 
headache, vomiting, and papilledema, diagnosed with left transverse and sigmoid sinus thrombosis secondary to 
hyperhomocysteinemia caused by a homozygous methylenetetrahydrofolate reductase gene mutation. Treatment 
with anticoagulants, mannitol, therapeutic lumbar puncture, and vitamin supplementation led to significant clinical 
improvement and partial thrombus recanalization at 6 months. This case underscores the importance of considering genetic causes of hyperhomocysteinemia in young patients with CVST, even in populations with dietary risk factors such as vegetarianism.