Cerebral venous thrombosis (CVT) is a rare cerebrovascular disease that affects about 5 in 1 million people each year and accounts for 0.5% of all strokes. 1 Previously it was thought to be caused most commonly by infections (eg, mastoiditis, otitis, meningitis) affecting the superior sagittal sinus and often resulting in focal neurologic deficits, seizures, coma, and death. Although local and systemic infections are still prominent risk factors in its development, CVT is now primarily recognized as a nonseptic disease with a wide spectrum of clinical presentations.
Cerebral venous thrombosis causes reduced outflow of blood and cerebrospinal fluid, which in half of affected patients leads to significant venous infarct. As opposed to arterial infarctions, CVT mainly affects children and young adults; it is an important cause of stroke in the younger population. 2 There is significant overlap of the many risk factors for CVT and those for venous thromboembolism (VTE): cancer, obesity, genetic thrombophilia, trauma, infection, and prior neurosurgery. However, the most common acquired risk factors for CVT are oral contraceptive use and pregnancy, which explains why CVT is 3 times more likely to occur in young and middle-aged women. 3
Cerebral venous thrombosis was first recognized by a French physician in the 19th century, a time when the condition was diagnosed at autopsy, which typically showed hemorrhagic lesions at the thrombus site. 4 For many years heparin was contraindicated in the treatment of CVT, and only within the past 25 years did advances in neuroimaging allow for earlier diagnosis and change perspectives on the management of this disease.
Cerebral venous thrombosis occurs from formation of a thrombus within the cerebral venous sinuses, leading to elevated intracranial pressure and eventually ischemia or intracranial hemorrhage. Improved imaging techniques, notably magnetic resonance imaging (MRI) and computed tomography (CT) venography, allow physicians to identify thrombus formation earlier and begin anticoagulation therapy with heparin before infarction. A meta-analysis of studies found that heparin was safer and more efficacious in treating CVT compared with placebo. 5 Furthermore, several small randomized trials found treatment with unfractionated heparin (UFH) or low-molecularweight heparin (LMWH) was not associated with higher risk of hemorrhagic stroke in these patients. 6-8
Despite improvements in imaging modalities, in many cases diagnosis is delayed, as most patients with CVT have a wide spectrum of presentations with nonspecific symptoms, such as headache, seizure, focal sensorimotor deficits, and papilledema. 9 Clinical presentations of CVT depend on a variety of factors, including age, time of onset, CVT location, and presence of parenchymal lesions. Isolated headache is the most common initial symptom, and in many cases is the only presenting manifestation of CVT. 1 Encephalopathy with multifocal signs, delirium, or dysfunction in executive functions most commonly occurs in elderly populations.
Cavernous sinus thrombosis most commonly produces generalized headaches, orbital pain, proptosis, and diplopia, whereas cortical vein thrombosis often produces seizures and focal sensorimotor deficits. Aphasia may be present in patients with isolated left transverse sinus thrombosis. In the presence of deep cerebral venous occlusion, patients can present in coma or with severe cognitive deficits and widespread paresis. 10 Thrombosis of different veins and sinuses results in a wide spectrum of diverse clinical pictures, posing a diagnostic challenge and affecting clinical outcomes.