D-dimer testing in the diagnosis of cerebral vein thrombosis: a systematic review and a meta-analysis of the literature.

BACKGROUND: Quantitative measurement of circulating D-dimer, a product of fibrin degradation, has been shown to be a very useful diagnostic tool in the management of patients with suspected deep vein thrombosis and/or pulmonary embolism. Whether D-dimer can play a similar role in the diagnostic approach to patients with suspected cerebral vein thrombosis (CVT) remains controversial. METHODS: Studies evaluating the diagnostic accuracy of the D-dimer test in the diagnosis of CVT were systematically searched for in the MEDLINE and EMBASE databases (up to July 2011). Weighted mean sensitivity and specificity with 95% confidence intervals (CIs) were calculated with a bivariate random-effects regression approach. RESULTS: Fourteen studies, for a total of 1134 patients, were included. D-dimer accuracy was good, with a resulting weighted mean sensitivity of 93.9% (95% CI 87.5-97.1) and weighted mean specificity of 89.7% (95% CI 86.5-92.2), calculated with a bivariate approach. Potential risk factors for false-negative D-dimer results included isolated headache, longer duration of symptoms, and limited sinus involvement. CONCLUSIONS: Our findings suggest that D-dimer may be a useful diagnostic tool in the management of patients with suspected CVT. Future prospective studies are warranted to confirm our preliminary findings.