Guidelines to raise awareness of a rare stroke

The American Heart Association for the first time released guidelines for clinicians to help detect and treat cerebral venous thrombosis, a rare stroke that disproportionately affects young people, especially women who are pregnant or on oral contraceptives, or who just gave birth.

The guidelines include an algorithm for diagnosing and managing cerebral venous thromboembolism (CVT), which is caused by a clot in the dural venous sinuses, veins that drain blood from the brain toward the heart. The guidelines were released online.

CVT is difficult to recognize because of its diverse risk factors and presentations. The diagnosis and management of CVT requires a high level of suspicion, said the co-director of the stroke program at the university of Toronto who chaired the guidelines writing committee of nine experts from five countries, which reviewed the literature of CVT and rated the evidence behind the recommendations.

The guidelines have been endorsed by the American Academy of Neurology, the American Association of Neurological Surgeons, the Congress of Neurological Surgeons, the Society of Neurointerventional Surgery, and the Ibero-American Stroke Society.

Many kinds of physicians may be the first to encounter a patient with CVT because of its many causes and symptoms. The guidelines should be helpful not only to neurologists but also to emergency physicians, internists, family physicians, obstetricians, oncologists, pediatricians, hematologists, and more.

Approximately five people per million develop CVT each year, accounting for 0.5%-1% of all strokes. In the largest cohort study of patients diagnosed with CVT, 54% were on oral contraceptives, 345 had an inherited or acquired prothrombotic condition, and 21% were pregnant or in the immediate postpartum period. Other predisposing conditions included infection in 12%, the presence of certain drugs in 8%, cancer in 7%, and other hematologic disorders in 12%. (Some patients had more than one predisposing condition.)

Patients may present with slowly progressive symptoms, and delays in diagnosis are common. Studies have reported a mean lapse of 4 days from onset of symptoms to hospital admission, and 7 days from onset of symptoms to diagnosis. Headache, the most common symptom, occurs in about 905 of cases. Seizures also are common.

Approximately 30%-40% of patients with CVT present with intracranial hemorrhage. For the appropriate treatment, it is important to identify CVT as the cause of hemorrhage, instead of a ruptured brain artery or other causes.

Women outnumber men with CVT at ages younger than 61 years. The largest cohort study of CVT reported that patients younger than 50 years accounted for 78% of cases. The incidence of CVT during pregnancy and postpartum in Western countries ranges from one to four cases per 10,000 deliveries, with the greatest risk during the third trimester and in the first 4 weeks after delivery.

CVT is not a contraindication for future pregnancy.

If a clinician suspects CVT, either MRI or magnetic resonance venography (MRV) is recommended to make the diagnosis by showing a thrombus obstructing the venous sinuses or cerebral veins.

Anticoagulation is the usual first-line therapy, with IV heparin or subcutaneous low-molecular-weight heparin in patients without contraindications.

There are several things that we still don’t know. For example, the anticoagulation regimen and duration of IV anticoagulation therapy is not clear.