Cerebral venous thrombosis

Abstract

Thrombosis of the dural sinus and encephalic veins (cerebral venous thrombosis: CVT) was until recently considered a rare, often fatal, disease. With the introduction of magnetic resonance imaging (MRI) into clinical practice, CVT became recognized with increasing frequency. The incidence of CVT is probably underestimated, because it has a rather variable clinical presentation and it is necessary to perform magnetic resonance angiography (MRA) to confirm the diagnosis.1-4 CVT is more common in neonates and in children than in adults.5,6 Adult patients with CVT are predominantly females and are usually younger than those with other types of stroke.2,7 The clinical symptoms and signs of CVT depend on the site and number of occluded sinuses and veins, on the presence of parenchymal lesions,1,2,7 on the age of the patient,5,6,8 and on the interval from onset to presentation.9 Headache is the most frequent symptom of CVT.10-14 Patients with a chronic course or delayed clinical presentation may show papilloedema on fundoscopy.9 In severe acute cases, disturbances of consciousness and mental problems (e.g. delirium, apathy, or a frontal lobe syndrome) are often present. Motor deficits and aphasia are the most frequent focal deficits. Focal or generalized seizures, including status epilepticus, are more frequent than in other stroke types.15 Symptoms and signs of CVT can be grouped in three major syndromes: isolated intracranial hypertension syndrome (headache with or without vomiting, papilloedema, and visual problems),16 focal syndrome (focal deficits, seizures, or both) and encephalopathy (multifocal signs, mental status changes, and stupor/coma).2,17 MRI, including MR venography, is necessary to confirm the diagnosis,2,18,19 by demonstrating the thrombus and the occluded sinus or vein (Figure 20.1). Alternative techniques to demonstrate the filling defect of the thrombosed sinus are digital intra-arterial venography and computed tomography (CT) venography.20,21 Confirmation of the diagnosis of cortical vein thrombosis is particularly difficult.22-24 CT and MRI can also show edema, venous infarcts, and intracerebral haemorrhages.