Isolated intracranial hypertension as the only sign of cerebral venous thrombosis

Background: Cerebral venous thrombosis (CVT) is often overlooked when intra cranial hypertension (ICH) is isolated, hence mimicking idiopathic intracra nial hypertension (IIH). Objective: To describe the characteristics of pati ents with CVT and ICH. Methods: We examined 160 consecutive patients with C VT between 1975 and 1998. They were separated into two groups according to their clinical presentation-isolated ICH and other neurologic symptoms and signs. Results: Fifty-nine patients with CVT (37%) presented with isolated ICH. Neuroimaging showed involvement of more than one sinus in 35 patients (59%). Brain CT was normal in 27 of 50 patients (54%). Lumbar puncture was performed in 44 patients and showed elevated opening pressure in 25 of 32 ( 78%) and abnormal CSF content in 11 (25%). Etiologies and risk factors incl uded local causes in 7 of 59 (12%), surgery in 1, inflammatory diseases in 18 (30.5%), infection in 2, cancer in 1, postpartum state in 1, coagulopath ies in 11 (1.9%), oral contraception in 7 (12%), and remained unknown in 11 (19%). Anticoagulants were used in 41 of 59 patients (69.5%), steroids or acetazolamide in 26 (44%), therapeutic lumbar puncture in 44 (75%), and sur gical shunt in 1. Three patients had optic atrophy with severe visual loss, 1 died from carcinomatous meningitis, and 55 (93%) had complete recovery. Conclusions: Central venous thrombosis (CVT) can present with all the class ical criteria for idiopathic intracranial hypertension (IIH), including nor mal brain CT with normal CSF content. Because the recognition of CVT has cr ucial prognostic and therapeutic implications, MRI, with magnetic resonance venography when necessary, should be performed in patients with isolated i ntracranial hypertension. The outcome of CVT is unpredictable, and manageme nt of patients with CVT should not differ whether they present with isolate d raised intracranial pressure or with other neurologic symptoms and signs. Therefore, isolated raised intracranial pressure from CVT differs in manag ement from IIH and should be classified neither as "IIH" nor "pseudotumor c erebri."