title: Do normal D-dimer levels reliably exclude cerebral sinus thrombosis?
abstract: OBJECTIVE
  Cerebral sinus thrombosis (CST) needs to be considered in the differential diagnosis of all patients with acute headache. Early diagnosis is essential because early treatment may prevent morbidity and may even be life-saving. Definite exclusion, however, needs advanced neuroradiologic diagnostics, which are not readily available in many hospitals. Because measurement of D-dimers has been demonstrated to be helpful in excluding thromboembolic disease, our aim was to investigate whether D-dimers would be also sensitive enough to exclude CST.
  
  
  METHODS
  We undertook a prospective multicenter study over a 2.5-year period including all patients who came to the emergency departments with symptoms suggestive of CST. All patients were diagnosed either by magnetic resonance venography, spiral computed tomography scan venography, or intra-arterial digital subtraction angiography. D-dimer levels were measured at admission and analyzed by the same method in all patients.
  
  
  RESULTS
  A total of 343 patients were included. CST was diagnosed in 35 patients, of whom 34 had D-dimers above the cutoff value (>500 microg/L). From the 308 patients not having CST, D-dimers were elevated in 27. Sensitivity of D-dimers was 97.1%, with a negative predictive value of 99.6%. Specificity was 91.2%, with a positive predictive value of 55.7%. D-dimers were positively correlated with the extent of the thrombosis and negatively correlated with the duration of symptoms (Spearman rank correlation coefficients 0.76, -0.58, respectively).
  
  
  CONCLUSIONS
  D-dimer measurement is useful in patients with suspected CST. Normal D-dimers make the presence of CST very unlikely.
authors.affiliation: Department of Neurology, Universitätsklinikum Aachen, Pauwelsstrasse 30, D-52074 Aachen, Germany. CKosinski@ukaachen.de
authors.forename: Christoph M
authors.initials: CM
authors.lastname: Kosinski
authors.forename: Michael
authors.initials: M
authors.lastname: Mull
authors.forename: Michael
authors.initials: M
authors.lastname: Schwarz
authors.forename: Benno
authors.initials: B
authors.lastname: Koch
authors.forename: Rolf
authors.initials: R
authors.lastname: Biniek
authors.forename: Joachim
authors.initials: J
authors.lastname: Schläfer
authors.forename: Eva
authors.initials: E
authors.lastname: Milkereit
authors.forename: Klaus
authors.initials: K
authors.lastname: Willmes
authors.forename: Johannes
authors.initials: J
authors.lastname: Schiefer
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D020767:Intracranial Thrombosis / Q000097:blood* / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D