Diagnostic Accuracy of MRI in The Evaluation of Patients with Idiopathic Intracranial Hypertension

Abstract

Background: Idiopathic intracranial hypertension (IIH), previously known as pseudotumor cerebri, is a disease characterized by elevation of intracranial tension with no apparent cause e.g. space occupying lesion or ventricular pathway obstruction. Patients usually complain of headache and sometimes burring of vision. It is believed that impaired drainage of the cerebrospinal fluid (CSF) from the dural venous sinuses and decrease spinal fluid absorption or increased secretion contribute to the development of IIH. As the optic nerve is covered by meninges and surrounded by CSF, the elevated pressure is inevitably transmitted to the nerve and can cause damage. Objective: To assess the accuracy of different MRI findings in the early diagnosis of idiopathic intracranial hypertension to achieve better prognosis. Patients and methods: twenty patients and ten controls were enrolled in the study and underwent ophthalmological tests, lumbar punctures analysis for pressure, MRI study of the brain and orbit with IV contrast administration and MR venography. Results: Six signs were analyzed from which intraocular optic nerve protrusion was the most specific (90%) and empty sella sign was the most sensitive (90%). There was statistically significant correlation between empty sella sign (r= 0.784; p = 0.01) and posterior globe flattening (r= 0.65; p = 0.04) with the idiopathic intracranial hypertension. Conclusion: MRI findings can be used to suggest idiopathic intracranial hypertension and increasing accuracy can be made by combining several signs.