FACTOR-V LEIDEN MUTATION IN CEREBRAL VENOUS THROMBOSIS

Background and Purpose Resistance to activated protein C is a common i nherited risk factor for venous thrombosis, which is due to a mutation in coagulation factor V (factor V Leiden mutation). It is present in approximately 20% of unselected consecutive patients with deep vein th rombosis. The rate of resistance to activated protein C in patients wi th cerebral venous thrombosis (CVT) is unknown. Methods We investigate d the association of factor V mutation with CVT using a case-control s tudy. Nineteen unselected patients with CVT and 57 healthy control sub jects were tested for the point mutation. Results The mutation was fou nd in a heterozygous form in 4 of the 19 patients with CVT (21%) and i n only 1 of the 57 control subjects (2%) (P=.02, Fisher's exact test): The prevalence of the coagulation defect found in our patients with C VT was consistent with that observed in previous studies in patients w ith deep vein thrombosis. In 3 of the 4 patients positive for the muta tion, CVT developed in the presence of an acquired prothrombotic state , including oral contraceptive use in 2 patients and puerperium in the third. Conclusions Factor V Leiden mutation is a risk factor for CVT and may be the most common inherited coagulation defect associated wit h this condition.