[Aseptic cerebral sinus thrombosis. 5 cases and a review]

From 1988 to 1990, we observed five cases of aseptic dural sinus and cerebral venous thrombosis, all in non-smoking women (age 18 to 47 years) receiving low dose oral contraceptives. Treatment consisted of full anticoagulation over 2 to 6 months, over which time the neurologic symptoms disappeared almost completely. Extensive tests of the blood clotting system in 4 patients after 6 to 19 months revealed a reduction of free protein S in 2 patients with a history of contraceptive use over several years, and normal results in 2 patients in which the sinus thrombosis occurred within the first 6 weeks of use of the oral contraceptive. Whether the protein S deficiency was congenital or caused by the oral contraceptive cannot be decided retrospectively. Even modern oral contraceptives seem to lead to an increased incidence of sinus thrombosis. Initial symptoms of sinus thrombosis include headache and somnolence, followed either by focal neurologic deficits (often associated with focal seizures) or by signs of increased intracranial pressure. CT scans show venous infarcts or general brain edema and may specifically show the "empty triangle sign" and "delta sign". The CT scan may also be normal if focal neurologic deficits are absent. MRI is favoured as it can directly show the thrombosed sinus or veins. Differential diagnosis includes arterial stroke, brain tumor, encephalitis or "benign intracranial hypertension", which should only be diagnosed after sinus venous thrombosis has been appropriately ruled out. Recently, full anticoagulation has been recommended as therapy.