Cochlear implant surgery and perioperative dizziness is associated with utricular hyperfunction

Area of Science:

• Otolaryngology
• Neuroscience
• Vestibular System

Background:

• Dizziness is a frequent complication following cochlear implantation (CI).
• The precise etiology of post-CI dizziness remains elusive.
• Emerging evidence suggests potential alterations in otolith function, specifically the utricle, after CI surgery.

Purpose of the Study:

• To investigate the association between cochlear implantation surgery, perioperative dizziness, and changes in utricular function.

Main Methods:

• An observational study involving adult patients undergoing routine CI.
• Assessment of utricular function using the Subjective Visual Vertical (SVV).
• Perioperative dizziness evaluated via questionnaire, with follow-ups at 1-day, 1-week, and 6-weeks post-implantation.

Main Results:

• A statistically significant deviation in SVV away from the operated ear was observed post-CI (2.17° at 1 day, 0.889° at 1 week, -0.25° at 6 weeks).
• Dizziness correlated with a 0.5° tilt away from the implanted ear.
• Forty-one adult CI recipients were included in the analysis.

Conclusions:

• Cochlear implantation induces transient utricular hyperfunction in the operated ear, which normalizes within six weeks.
• The observed SVV deviations in dizzy participants suggest that utricular hyperfunction may be a contributing factor to post-CI dizziness.