Cerebral venous thrombosis is considered as a rare type of stroke with an annual incidence of 3 to 4 per million people. It occurs generally in young patients (mean age of occurrence = 40 years) and principally in young females (75%) generally in pregnancy or oral contraceptive use situations.

The onset may be acute (less than 2 days), subacute (between 2 and 30 days) or chronic (more than 30 days). The clinical presentation is highly variable and includes patients with only a mild headache, others with focal neurological deficits and a few with a dramatic syndrome and a coma. Moreover the evolution can be very different with unpredictable outcome: more often it is favorable with a low mortality rate, but in some cases it can be a worse course. The aim of this study is to evaluate the correlation of some biological markers: thrombin generation test and D-Dimers (marker of fibrin generation and degradation) with the type of onset or the wide spectrum of clinical presentations or the different modes of evolution.

All patients over 16 years ago may be included in the program when CVT diagnosis is proved by magnetic resonance angiography (MRA). For each included patient, there are four blood assays: the first just at the time of diagnosis and before the beginning of treatment, the second before the beginning of the oral anticoagulant treatment. The third assay is done in the third month at the time of a MRA. The last assay is made one month after the end of the anticoagulant treatment or in 12th month after the beginning of the disease if the treatment goes on.

For each sample, the investigators perform a thrombin generation test and a D-Dimers measurement.

Inclusion Criteria:

• Patients over 16 years old hospitalized with an acute cerebral venous thrombosis, confirmed by by cerebral imaging