Intracranial hypertension associated with unruptured cerebral arteriovenous malformations.

Only 6 patients with intracranial hypertension associated with unruptured cerebral arteriovenous malformations have been reported. We report 6 additional patients seen at the Cleveland Clinic during the past 10 years. The average age was 28 years (range, 19-44 years); 4 were women. Symptoms and signs included papilledema (6 patients), headache (6), transient nonepileptic focal symptoms (4), visual obscurations (3), ipsilateral carotid or ocular bruits (3), abnormal visual fields (3), focal seizures (2), and progressive visual loss (1). Enhanced computed tomography (CT) or magnetic resonance imaging (MRI) demonstrated the malformations in all 6 patients. The malformations were large, supplied by the branches of the middle and anterior cerebral arteries, with the posterior cerebral artery contributing in 3 patients, and all drained into the superior sagittal sinus. Associated venous obstruction was seen in 2 patients. Four patients underwent excision of the arteriovenous malformation, with resolution of papilledema in all 4. Measurements of cortical arterial and venous pressures during surgery in 3 patients showed decreased feeding artery pressures and elevated draining vein pressures, which normalized after removal of the malformation. Treatment in the 2 remaining patients consisted of medical therapy (acetazolamide, furosemide, steroids) alone in 1 patient, and in conjunction with proton beam radiation in the other. Papilledema resolved in the former patient, but the patient receiving proton beam radiation still had papilledema 2 years later. Intracranial hypertension associated with unruptured cerebral arteriovenous malformations occurs in young patients with high flow malformations that drain into the superior sagittal sinus, and is likely the result of increased cortical venous and superior sagittal sinus pressure. Excision of the malformation effectively reduces the intracranial pressure.