title: Cerebral venous thrombosis and activated protein C resistance.
abstract: BACKGROUND
  Activated protein C resistance (APC-R) due to factor V Leiden has recently been established as an important risk factor for cerebral venous thrombosis (CVT). The clinical significance of abnormal or borderline functional APC-R in the absence of factor V Leiden is uncertain. Our observations suggest that APC-R due to mechanisms other than factor V Leiden may also contribute to the development of CVT.
  
  
  METHODS
  We describe three women who had superior sagittal and lateral sinus thrombosis while taking oral contraceptives and had a number of additional risk factors for CVT. Each had APC-R for different reasons.
  
  
  CONCLUSIONS
  Inherited thrombophilia, including APC-R, should be looked for in all patients with CVT. Functional APC-R is a highly prevalent coagulopathy, but the reasons for this abnormality are diverse; abnormal and borderline functional APC-R results should be supplemented by DNA analysis for the presence of factor V Leiden.
authors.affiliation: Department of Neurology, University of Wisconsin-Madison Medical School 53792, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Dulli
authors.forename: C C
authors.initials: CC
authors.lastname: Luzzio
authors.forename: E C
authors.initials: EC
authors.lastname: Williams
authors.forename: H S
authors.initials: HS
authors.lastname: Schutta
mesh_terms: D000328:Adult; D000925:Anticoagulants / Q000627:therapeutic use; D002550:Cerebral Veins; D003276:Contraceptives, Oral / Q000009:adverse effects; D004351:Drug Resistance; D005260:Female; D006801:Humans; D002542:Intracranial Embolism and Thrombosis / Q000188:drug therapy / Q000503:physiopathology*; D010314:Partial Thromboplastin Time; D011486:Protein C / Q000032:analysis / Q000502:physiology*; D017293:Protein S / Q000032:analysis; D012307:Risk Factors; D012851:Sinus Thrombosis, Intracranial / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D014859:Warfarin / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D003276:Contraceptives, Oral; D011486:Protein C; D017293:Protein S; D014859:Warfarin