Intracranial venous thrombosis may arise from infectious or noninfectious processes. Since the introduction of antibiotics, the frequency of venous thrombosis has decreased considerably, apparently from the prevention of thrombosis related to local head infections. In recent years, most cases of intracranial venous thrombosis have been aseptic in nature, and most of these are considered idiopathic. Other causes of aseptic intracranial venous thrombosis are polycythemia vera, leukemia, dehydration, cancer, phospholipid antibody syndromes and other primary hypercoagulable states, sickle cell disease, pregnancy, Behçet’s disease and other inflammatory disorders, Crohn’s disease, ulcerative colitis, dural arteriovenous fistulae, and other hyperviscosity syndromes. Sinus thrombosis has also been reported after jugular vein catheter placement and jugular thrombosis.

The clinical presentation of cerebral venous thrombosis varies, depending on the site of the lesion, its rate of progression and extension of thrombosis, and the nature of the underlying disease. Typically, the initial symptom is severe headache, which may precede other signs and symptoms by hours or days. Vomiting and focal seizures also tend to occur early in the course along with weakness and sensory disturbances that are usually progressive and may be unilateral or bilateral. Consciousness is usually altered, and language disturbances occur in approximately one fourth of patients. There is a tendency for venous infarcts to become hemorrhagic.

The diagnosis is based on the combination of clinical findings with radiographic documentation of venous occlusion. The patient’s pelvis and legs are examined carefully to rule out coexistent peripheral thrombosis. The definitive diagnostic procedure has long been cerebral arteriography, but in recent years, computed tomography (CT) and magnetic resonance imaging have proven helpful through visualization of hemorrhagic infarcts and thrombosed veins or venous sinuses. Magnetic resonance angiography (MRA) has become the standard imaging for cerebral venous thrombosis, providing excellent visualization of the venous sinuses, and is valuable for the early diagnosis of venous thrombosis (Fig. 18-1). Computed tomography angiography (CTA) provides another noninvasive imaging option in the assessment of the cerebral veins and has a high sensitivity for thrombosis of a major venous sinus, similar to MRA. Cerebral arteriography may still be performed in patients with a high clinical suspicion but negative or equivocal MRA or CTA.

The mortality rate is approximately 20% (hemorrhagic infarction caused by cerebral venous thrombosis is associated with the worst prognosis), but functional outcome among survivors is usually favorable, with less chance of persistent focal neurologic deficit than that for patients with arterial cerebral infarction (Fig. 18-1). Clinical presentation and underlying causes for venous infarcts vary to some extent with the location of the lesion.