Idiopathic Intracranial Hypertension Presenting as Auditory Neuropathy Hearing Disorder in a Child

Sensorineural Hearing Loss and Tinnitus Characteristics in Patients With Idiopathic Intracranial Hypertension

OBJECTIVES

To characterize patterns of sensorineural hearing loss (SNHL) and tinnitus in patients with idiopathic intracranial hypertension (IIH).

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

PATIENTS

Adult patients diagnosed with IIH via lumbar puncture (LP) between 2010 and 2020 who had available audiograms. The study included a total of 40 patients; 33 women, and 7 men with a median age of 43.

INTERVENTIONS

Diagnostic LP and audiogram.

MAIN OUTCOME MEASURES

Otologic symptoms, ophthalmologic signs, hearing thresholds, cerebrospinal fluid opening pressures.

RESULTS

The most commonly reported symptoms were tinnitus in 28 (70%, 23 pulsatile and 5 tonal), aural fullness in 11 (28%), and vertigo in 10 (25%). Twenty-nine patients had ophthalmologic examinations and 18 had evidence of papilledema. Twenty-five (63%) patients had hearing loss in at least one ear at one frequency range. Patients presented with both unilateral and bilateral hearing loss across low, middle, and high frequency ranges. No significant association was observed between hearing loss threshold and LP opening pressure except for 250 Hz in the left ear. After stratification by tinnitus group (pulsatile, tonal, and no tinnitus), no significant difference was found between mean hearing loss threshold at different frequencies. In addition, no significant mean age difference was identified in patients within each tinnitus group.

CONCLUSIONS

There was no classic pattern or presentation for hearing loss in our IIH patients. They developed sudden, unilateral, or bilateral SNHL in low, middle, or high frequency range. The degree of hearing loss did not correlate with CSF opening pressure.

Atypical presentations of idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is a disorder of unknown etiology that results in isolated raised intracranial pressure. Classic symptoms and signs of IIH include headache, papilledema, diplopia from sixth nerve palsy and divergence insufficiency, and pulsatile tinnitus. Atypical presentations include: (1) highly asymmetric or even unilateral papilledema, and IIH without papilledema; (2) ocular motor disturbances from third nerve palsy, fourth nerve palsy, internuclear ophthalmoplegia, diffuse ophthalmoplegia, and skew deviation; (3) olfactory dysfunction; (4) trigeminal nerve dysfunction; (5) facial nerve dysfunction; (6) hearing loss and vestibular dysfunction; (7) lower cranial nerve dysfunction including deviated uvula, torticollis, and tongue weakness; (8) spontaneous skull base cerebrospinal fluid leak; and (9) seizures. Although atypical findings should raise a red flag and prompt further investigation for an alternative etiology, clinicians should be familiar with these unusual presentations.