Cochlear implant and vestibular function.
OBJECTIVE
To document incidences of vestibular dysfunction after cochlear implantation and investigate why it occurs. This work was also motivated by a desire to provide the basis for better preoperative counseling and postoperative vestibular therapy to cochlear implant patients.


METHODS
Melbourne Cochlear Implant Clinic at a tertiary referral hospital.


METHODS
Prospective observational study.


METHODS
One hundred forty-six adult implant recipients, mean age, 60 years (range, 20-90 yr).


METHODS
Postoperative vestibular disturbance was defined as symptoms lasting for 1 week or longer after surgery. The differences in preoperative and postoperative vestibular function were measured from subjective assessments (Dizziness Handicap Inventory and Activity Balance Confidence questionnaires) and objective assessments (bithermal caloric tests). The position of the postoperative electrode was classified as "loose", "regular", or "tight" fitting.


RESULTS
Thirty-two percent of patients reported vestibular disturbance and had poorer Dizziness Handicap Inventory, Activity Balance Confidence, and caloric results in the implanted ear after surgery. Patient age, cause, and preoperative caloric result did not predict postoperative vestibular symptoms. Recipients aged 70 years or older had significantly poorer caloric results on the implanted side after surgery that was not related to the intracochlear electrode position or surgical team.


CONCLUSIONS
One-third of recipients can expect to experience a significant vestibular disturbance after surgery, regardless of age, cause, or preoperative caloric result. "Older" ears seem more prone to permanent injury after cochlear implantation.
Enticott
Joanne C
JC
Department of Otolaryngology, The University of Melbourne, Melbourne, Australia. enticott@unimelb.edu.au
Tari
Sylvia
S
Koh
Su May
SM
Dowell
Richard C
RC
O'Leary
Stephen J
SJ
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002150:Caloric Tests; D019929:Cochlear Implantation / Q000009:adverse effects*; D003054:Cochlear Implants; D004244:Dizziness; D005260:Female; D034381:Hearing Loss / Q000628:therapy*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D011446:Prospective Studies; D012027:Reflex, Vestibulo-Ocular; D015837:Vestibular Diseases / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D014724:Vestibular Function Tests