A female patient in her early 30s was presented to the otolaryngology and communicative sciences department at a large medical center. The patient presented with symptoms of pressure localized to both ears, however greater in right ear, occasional tinnitus in right ear (described as high pitch buzzing), and mild vertigo/dizziness (provoked by movement), lasting minutes in duration.
The symptoms started several months ago and reportedly worsened over time. The patient denied childhood hearing loss, family history of hearing loss, or use of ototoxic drugs. The patient’s reported medical history was significant for sinusitis, migraines, and occasional noise exposure, including concerts and hunting without hearing protection use. The remaining reported medical history was otherwise unremarkable. ENT referred the patient for a comprehensive audiometric evaluation and tympanometry.
Otoscopy: Clear canals and intact eardrums, no signs of infection, fluid, or retraction
Tympanometry: Normal ear canal volume, middle ear air pressure, and admittance in both ears; normal gradient in both ears (Type A)
Audiogram: See FIGURE 1
Based on these results, further testing was suggested:
DPOAEs: Present and robust in both ears 1500–10000 Hz
Reflexes: Elevated or absent both ipsi and contra for both ears
You be the detective! What is your interpretation and recommendation?
What Would You Do?
At first, the complaints reported during history intake appeared consistent with possible Eustachian tube dysfunction or other conductive pathology, or something mimicking a conductive pathology with balance disturbance, maybe superior semicircular canal dehiscence (SSCD), fistula of the round or oval window. However, normal tympanometry, sensorineural hearing loss, and absence of air-bone gaps were not very supportive of a conductive pathology, SSCD, or fistula.
Perhaps noise exposure, maybe a left-handed shooter? However, DPOAEs were robust and present in both ears, which likely rules out cochlear pathology; unless there was a primary neural loss due to noise, which would not likely explain the threshold shift.
Reflexes elevated and/or absent, but in both ipsi and contra conditions? Bilateral tumors?
Based on these findings, the patient was referred for imaging.
Well, “it’s not a tumor!” (in your best Schwarzenegger voice). What is it?
Chiari malformation (CM). CM are structural deficits in the cerebellum, where part of the cerebellum is located below the foramen magnum; the resulting pressure may affect functions controlled by these areas (like hearing and balance) and block cerebrospinal flow. CM type I is the most common form of CM and is usually first noticed in adolescence or adulthood and often by accident during examination for another condition. The most common presentation is occipital and neck pain exacerbated by physical activity and Valsalva maneuver. Recently, a case series of nine patients demonstrated the most common audio-vestibular signs were hearing loss and tinnitus followed by vertigo (Guerra et al, 2015).
Course of Care
The patient was referred to neurology and pursuing surgery. Hearing and balance will be evaluated post-surgical intervention. Improvement with surgical intervention is not well studied, but reversible hearing loss following surgery has been reported (Sivakanthan et al, 2014).