Clinical case · clinician

Compensated vestibular schwannoma

Vignette

A 49-year-old man with a 12 mm right-sided vestibular schwannoma diagnosed on surveillance MRI is referred for baseline vestibular function testing before considering microsurgery vs stereotactic radiosurgery. He reports occasional mild unsteadiness in busy environments but no episodes of vertigo. He has unilateral right SNHL (50 dB pure-tone average) with reduced word recognition (60%). HIT shows a positive corrective saccade to the right; caloric testing shows a 64% right canal paresis. CDP is performed.

CDP findings

SOT pattern vs normal

MCT — medium-amplitude backward translation

ADT — sway energy across five trials per direction

Audiometric findings

Vestibular schwannoma — asymmetric high-frequency sensorineural loss on the affected (right) ear.

Asymmetric high-frequency sensorineural hearing loss on the side of the schwannoma is the most common audiometric finding, present in roughly 95% of patients at diagnosis. The pattern is downsloping, with the high frequencies most affected. Paired with mild C5/C6 reduction on CDP and asymmetric speech discrimination, the audiometric signature is part of the case for MRI.

Single-best-answer

Which CDP pattern is most expected, and what is CDP most useful for in this clinical context?

Teaching point. Vestibular schwannomas grow slowly enough that central compensation usually keeps patients functional on quiet stance. CDP scores for C5/C6 are typically modestly reduced. The main utility of CDP in this population is to establish a baseline before intervention and to track postoperative recovery — not diagnosis.