Is Magnetic Resonance Imaging Diffusion Restriction of the Optic Disc Head a New Marker for Idiopathic Intracranial Hypertension?

Background Idiopathic intracranial hypertension (IIH) is a headache syndrome due to raised intracranial pressure of unknown etiology. Before making the diagnosis of IIH, secondary causes of raised intracranial pressure must be ruled out. The radiological features associated with this condition have variable sensitivity and specificity. In this case series, we aim to describe a potential new radiological marker of IIH, that is, diffusion restriction, in the optic disc head and propose that this can be a specific finding in the appropriate clinical picture. Importance IIH causes vision loss and disabling daily headaches. The diagnosis of this condition is based on history and physical examination findings. Magnetic resonance imaging (MRI) is used to exclude other causes, but specific radiological markers for the diagnosis of IIH are lacking. Observations Five patients presented with the main complaint of headache, which was associated with blurry vision. All of our patients had a formal neuro-ophthalmological evaluation that confirmed the presence of optic disc edema in both eyes. They also underwent an MRI of the brain that showed diffusion restriction in the optic nerve head in either eye or both eyes. Patients underwent lumbar puncture in the lateral decubitus position, which revealed cerebrospinal fluid opening pressures > 25 cm H (2) O. They all responded well to standard treatments, with the resolution of symptoms in their follow-up appointments. Conclusion and Relevance The MRI diffusion restriction in the optic nerve head may be a reliable noninvasive marker for the diagnosis of IIH in the appropriate clinical picture.