A negative D-dimer assay does not rule out cerebral venous thrombosis: a series of seventy-three patients.

BACKGROUND AND PURPOSE Cerebral venous thrombosis (CVT) is an infrequent variety of cerebrovascular disease with a wide spectrum of clinical presentations and a notoriously difficult diagnosis. Previous reports have emphasized the potential clinical utility of D-dimer assay in CVT diagnosis. METHODS A rapid sensitive D-dimer assay was performed at entry in 73 patients with CVT <30 days duration, examined in our institution between 1999 and 2003. RESULTS The mean value of D-dimer levels was 1521 ng/mL; 7 patients (10% of all patients and 26% of those presenting with isolated headache) had values <500 ng/mL. In a multivariate analysis, isolated headache was the only variable associated with a negative D-dimer assay. CONCLUSIONS A negative D-Dimer assay does not confidently rule out CVT, particularly in the setting of recent isolated headache.