Predictive Value of D-Dimer to Diagnose a Patient with Cerebral Venous Sinus Thrombosis (CVST)

Open Access

Abstract

Background and Objective: Cerebral venous sinus thrombosis (CVST) is a rare but potentially life-threatening condition with diverse clinical presentations, often leading to delayed diagnosis. D-dimer, a fibrin degradation product, has shown promise as a biomarker in various thrombotic conditions. This study aimed to evaluate the predictive value of D-dimer levels in diagnosing CVST and to determine optimal cut-off values for clinical decision-making. Methods & Materials: This prospective observational study included 80 consecutive patients with clinical suspicion of CVST. All patients underwent comprehensive neuroimaging with CT/MR venography and D-dimer measurement within 24 hours of symptom onset. CVST diagnosis was confirmed by neuroimaging according to established criteria. D-dimer levels were measured using a quantitative immunoturbidimetric assay. Diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis, and optimal cut-off values were determined using the Youden index. Results: Of the 80 patients enrolled, 42 (52.5%) were diagnosed with CVST and 38 (47.5%) served as controls. The mean age was 34.2 ± 12.8 years, with a female predominance (62.5%). D-dimer levels were significantly higher in CVST patients compared to controls (median: 2,340 ng/mL [IQR: 1,450–4,280] vs. 420 ng/mL [IQR: 280–680], p < 0.001). ROC curve analysis showed an area under the curve (AUC) of 0.891 (95% CI: 0.823–0.959). The optimal cut-off value of 1,200 ng/mL provided a sensitivity of 88.1%, specificity of 86.8%, positive predictive value of 88.1%, negative predictive value of 86.8%, and overall diagnostic accuracy of 87.5%. Only 2 patients (4.8%) with confirmed CVST had normal D-dimer levels, both presenting with isolated cortical vein thrombosis. Patients with multiple sinus involvement had significantly higher D-dimer levels compared to those with single sinus thrombosis (p = 0.012). Conclusions: D-dimer demonstrates excellent diagnostic performance for CVST, with high sensitivity and specificity at the optimal cut-off of 1,200 ng/mL. It shows potential as a valuable screening tool in clinical practice, particularly for identifying patients requiring urgent neuroimaging. However, normal D-dimer levels do not exclude CVST, especially in cases of isolated cortical vein involvement. D-dimer should be interpreted within the appropriate clinical context and used as an adjunctive tool rather than as a standalone diagnostic test.