Papilledema With Facial and Vestibulocochlear Nerve Involvement in Idiopathic Intracranial Hypertension: An Unusual...

Idiopathic intracranial hypertension (IIH) is defined by elevated intracranial pressure in the absence of an intracranial mass or cerebrospinal fluid abnormality and is commonly associated with papilledema. Although cranial nerve involvement may occur, simultaneous facial and vestibulocochlear nerve dysfunction is rare and may lead to diagnostic confusion.

A 42-year-old obese woman with metabolic comorbidities developed acute right-sided peripheral facial palsy preceded by facial pain and accompanied by severe headache, pulsatile tinnitus, and blurred vision. A 5-day course of oral prednisolone for presumed Bell's palsy yielded no improvement. Ophthalmologic referral on Day 7 revealed bilateral Frisén Grade I papilledema with normal automated perimetry and absence of visual field defects. Neurological examination confirmed House-Brackmann Grade III facial palsy, and audiometry demonstrated bilateral high-frequency sensorineural hearing loss (right worse than left). After systematic exclusion of cerebellopontine angle lesions, demyelinating disorders, infectious neuritis, and venous sinus thrombosis, brain MRI showed a Grade IV sellar arachnoidocele and a neurovascular contact of the right facial nerve (Chavda Grade I). Lumbar puncture on Day 12 documented an opening pressure of 36 cm H₂O with normal cerebrospinal fluid, confirming IIH. Acetazolamide was started on Day 13 together with a structured weight-management program. At the 2-month follow-up, audiometry demonstrated complete recovery. By 3 months, papilledema persisted (Frisén Grade I), best corrected visual acuity improved to 20/100 in both eyes, visual fields remained without enlargement of the physiological blind spot, and facial nerve function returned to House-Brackmann Grade I. However, at the 6-month follow-up, a new localized inferior scotoma was detected on Humphrey perimetry, representing a progression from previously normal visual fields, whereas spectral-domain OCT demonstrated bilateral optic atrophy with ganglion cell-inner plexiform layer thinning, indicating irreversible axonal damage despite persistent papilledema.

This case broadens the phenotypic spectrum of IIH, showing that facial and vestibulocochlear neuropathies are reversible with pressure reduction. Yet, progressive visual field loss may ensue despite stable papilledema, revealing the optic disc as an unreliable proxy for neuronal integrity. Only spectral-domain OCT-by quantifying inner retinal layer loss-can expose silent axonal degeneration and must therefore become the cornerstone of long-term monitoring, independent of clinical appearance.