Optic nerve sheath enhancement in patients with a new diagnosis of idiopathic intracranial hypertension

ONSE is a radiologic sign that may occur in approximately 7% of patients with newly diagnosed IIH. However, the distinction between mild ONSE and blood vessels surrounding or within the optic nerve sheath is challenging. A location at the distal infraorbital portion of the optic nerve sheath and a corkscrew appearance are suggestive of a vascular etiology. Awareness of this radiologic sign in patients with IIH is important to avoid optic perineuritis diagnosis in excess.