Concurrent Presentation of Idiopathic Intracranial Hypertension and Bilateral Optic Perineuritis in a Young Boy: A Rare Clinical Entity

Idiopathic intracranial hypertension (IIH) is a rare neurological syndrome characterized by increased intracranial pressure (>28 cm H₂O in children), in the absence of intracranial space-occupying lesions, and with normal cerebrospinal fluid (CSF) composition. Optic perineuritis (OPN) is an orbital inflammatory disease confined to the optic nerve sheath. We report a case of concurrent IIH and bilateral OPN in a previously healthy child. A 13-year-old male, with normal body mass index, presented with diplopia, visual blurriness without ocular pain, and occipital headache. Neurological examination was notable only for right sixth nerve palsy. Ophthalmological assessment revealed bilateral papilledema. Brain and spinal cord magnetic resonance imaging (MRI) and computed tomography (CT) scans demonstrated bilateral optic nerve perineuritis. Lumbar puncture showed an opening pressure of 98 cm H₂O, with normal CSF composition. The patient was treated with acetazolamide and corticosteroids, resulting in marked clinical improvement and complete restoration of vision at two-month follow-up. The concurrent occurrence of IIH and bilateral OPN is extremely rare, particularly in pediatric patients. To our knowledge, this is the first reported case in a child. Recognition of this dual pathology is essential for timely diagnosis and effective treatment.