Children with MOG-IgG positive bilateral optic neuritis misdiagnosed as fulminant idiopathic intracranial hypertension.

Background: Fulminant idiopathic intracranial hypertension (IIH) is characterized by headache, rapid decrease of vision and elevated CSF-opening pressure. Objective: To delineate a subgroup of MOGAD mimicking fulminant IIH. Methods: In this case series children with MOGAD with vision loss, optic disc swelling and elevated CSF opening pressure, initially diagnosed with fulminant IIH, were included. Results: 8 MOGAD patients (median age 12.5y, f:m = 7:1) with an initial diagnosis of fulminant IIH were included. Rapid bilateral visual loss and headache was present in all patients in addition to bilateral optic disc swelling and decreased visual acuity. In 2 patients cMRI showed prominent optic discs or an empty sella sign. In 7 patients the CSF opening pressure was markedly elevated. Patients were treated with Acetazolamide (n = 6), CSF external drainage (n = 2) or implantation of VP shunt (n = 1). Intravenous Methylprednisolone was administered in all patients because of worsening of sym...