Hyperhomocysteinemia in cerebral vein thrombosis.

High plasma levels of total homocysteine (tHcy) are a risk factor for deep vein thrombosis. Because no information on the relationship between cerebral vein thrombosis and hyperhomocysteinemia is available, a case-control study of 121 patients with a first episode of cerebral vein thrombosis and 242 healthy control subjects was carried out. Fasting plasma levels of tHcy and their postmethionine load (PML) increments, together with other laboratory markers of thrombophilia, were measured in plasma or DNA. Hyperhomocysteinemia (high fasting tHcy and/or PML increments) was diagnosed in 33 patients (27%) and 20 control subjects (8%) (odds ratio, 4.2; 95% confidence interval [CI], 2.3-7.6). Low levels of serum folate and the 677TT methylene tetrahydrofolate reductase were associated with hyperhomocysteinemia, but in a multivariate model hyperhomocysteinemia only was associated with an increased risk of cerebral vein thrombosis. Oral contraceptive intake was associated with the disease with an odds ratio of 6.1 (95% CI, 3.3-11.0). The combined presence of the latter and hyperhomocysteinemia increased the risk of the disease with an odds ratio of 19.5 (95% CI, 5.7-67.3). In conclusion, hyperhomocysteinemia is associated with a 4-fold increased risk of cerebral vein thrombosis; whether or not its correction with vitamins reduces the risk of the disease remains to be demonstrated.