Components of the cerebral sinovenous system (Figure 2, page 420):
(1) cortical veins (superficial)
(2) superior sagittal sinus (superficial)
(3) lateral sinuses (superficial)
(4) straight sinus (deep)
(5) vein of Galen (deep)
(6) internal cerebral vein (deep)
(7) jugular vein (deep)
Risk factors for thrombosis:
(1) infection of the head and neck
(2) other disorder of the head and neck
(3) dehydration
(4) perinatal complication (for neonates and infants; include hypoxia, placental abruption, gestational diabetes, maternal infection)
(5) bacterial sepsis
(6) connective tissue disorder
(7) hematologic disorder (not specified but probably PNH, sickle cell disease, pediatric myelodysplasia and leukemia)
(8) cancer
(9) cardiac disease
(10) disorder requiring an indwelling vascular catheter
(11) prothrombotic disorder (hypercoagulable state; associated with antiphospholipid antibodies or lupus anticoagulant; Factor V Leiden or prothrombin G20210A; acquired deficiency of protein S, protein C or antithrombin III)
(12) procoagulant drug (asparginase, oral contraceptives)
A small percentage of patients (around 2%) will not have a risk factor identified.
