Cerebral venous thrombosis is caused by clots in the dural sinuses and/or cortical veins, and it accounts for 0.5% to 1.0% of all strokes. It disproportionally affects women who are pregnant or taking oral contraceptives and in people aged 45 and younger. The incidence of cerebral venous thrombosis during pregnancy and postpartum ranges from 1 in 2,500 deliveries to 1 in 10,000 deliveries in Western countries. The greatest risk periods are during the third trimester and in the first 4 postpartum weeks. Up to 73% of cerebral venous thrombosis in women occurs during the time immediately after childbirth. The risk for complications during future pregnancies, however, is low.
In 2011, the American Heart Association/American Stroke Association (AHA/ASA) unveiled its first scientific statement on cerebral venous thrombosis to help clinicians identify and manage this cause of stroke. Published in the February 3, 2011 online issue of Stroke, the AHA/ASA guidelines are intended to improve awareness and recognition of the condition and to standardize approaches to treatment.
Summarizing Key Recommendations
The AHA/ASA guidelines recommend that patients with suspected cerebral venous thrombosis undergo blood studies to determine if they have a prothrombotic factor, including protein C or S, antithrombin deficiency, antiphospholipid syndrome, prothrombin G20210A mutation, and factor V Leiden. A predisposing condition to form clots or a direct cause is identified in about two-thirds of patients with cerebral venous thrombosis. About 30% to 40% of patients with cerebral venous thrombosis may develop an intracranial hemorrhage. The AHA/ASA guidelines note that it’s important to distinguish hemorrhages caused by rupturing of brain arteries from those associated with cerebral venous thrombosis because the mechanisms and treatment of the bleeding are different. Patients with brain hemorrhages who do not have a clearly identified cause are advised to undergo imaging of their cerebral veins.
Headache has been identified as the most common symptom and is noted in about 90% of patients. The usual appropriate acute treatment of cerebral venous thrombosis includes prevention of complications and use of anticoagulation therapy. The AHA/ASA guidelines report that MRI and magnetic resonance venography are the most sensitive screening tools and are recommended diagnostics. In the emergency department, cerebral venous thrombosis should be strongly suspected. CT and CT venography may be useful when MRI is not readily available. For patients who develop a stroke, receipt of care in an appropriate setting (eg, a stroke unit) is paramount for the prevention and management of complications.
Limitations & Future Research
The guidelines indicate that testing for prothrombotic conditions in the acute phase of cerebral venous thrombosis has limited value, and it’s advised that thorough blood work be completed later. Additionally, the duration of anticoagulation therapy should ultimately depend on the underlying etiology. There is also limited evidence regarding endovascular treatment or thrombolysis in patients with cerebral venous thrombosis. The AHA/ASA guidelines recommend that this treatment strategy be used only in patients with progressive neurological deterioration despite the best medical treatment.
Although much has been learned about cerebral venous thrombosis, more research is needed. These guidelines only provide general approaches based on the available evidence. Ultimately, more information is needed on the most appropriate methods for tailoring treatment strategies based on individual patient characteristics.
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