Hyperhomocysteinemia and Cerebral Venous Sinus Thrombosis in a Young Patient: A Case Report

Abstract Homocysteine is a sulfhydryl-containing amino acid formed during the metabolism of methionine. Hyperhomocysteinemia is currently considered a weak prothrombotic factor, and it is still unclear whether administration of folate and B12, that reduce homocysteine levels acting as cofactors of the enzymes involved in the methionine metabolism, may decrease the risk of arterial and/or venous thromboembolic events. In this case report, we describe a young patient admitted at Tan Tock Seng Hospital in Singapore, with cerebral venous thrombosis associated with intermediate hyperhomocysteinemia treated with direct oral anticoagulation and vitamin supplementation. Hyperhomocysteinemia is generally a modest prothrombotic risk factor. Persistent intermediate elevations may be observed in young patients with recurrent arterial and venous thrombosis, but causality cannot be inferred from a single case. In this patient, long-term anticoagulation was guided by recurrent unprovoked events, and vitamin supplementation addressed a correctable deficiency. The case highlights the importance of comprehensive evaluation and individualized management in young patients presenting with unexplained thrombotic events.