Presbycusis occurs after cochlear implantation also:  a retrospective study of pure tone thresholds over time.
OBJECTIVE
To assess aided soundfield pure tone thresholds after cochlear implantation in adults over time.


METHODS
Retrospective case review.


METHODS
Academic tertiary care center.


METHODS
Seventy-seven severe-to-profoundly deafened adults implanted with one of 5 different internal devices.


METHODS
Cochlear implantation.


METHODS
Outcome measures were cochlear implant aided soundfield pure tone thresholds at 250, 500, 1,000, 2,000, 4,000, and 6,000 Hz.


RESULTS
For the 77 adult patients in the study, pure tone aided thresholds deteriorated over time at 500, 1,000, 2,000, 4,000, and 6,000 Hz at rates ranging from 0.54 to 0.86 dB per year with the implant (p < 0.01). There was no significant change in thresholds over time at 250 Hz (p = 0.30). Overall, 55% of adults showed significantly worse thresholds at 3 or more frequencies. For adults over age 50, the rate of deterioration increased (range, 1.12-1.69 dB per year, p < 0.001), and more of these patients showed significantly worse thresholds at 3 or more frequencies (63%).


CONCLUSIONS
This long-term case review shows that a large percentage of implanted adults show a deterioration in aided pure tone thresholds over time. As in presbycusis, this deterioration is most prominent at the highest frequencies; however, the incidence and rate of deterioration is higher than that seen in presbycusis. These physiologic changes are not indicative of device failure and do not mean that performance measures will necessarily deteriorate.
University of Illinois-Chicago, Chicago, Illinois 44113, USA. Samuel.trosman@gmail.com
Samuel
S
Trosman
Deanna Kattah
DK
Matusik
Lia
L
Ferro
Weihua
W
Gao
Miriam
M
Saadia-Redleaf
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology*; D019929:Cochlear Implantation; D003054:Cochlear Implants; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009410:Nerve Degeneration / Q000473:pathology; D011304:Presbycusis / Q000175:diagnosis* / Q000209:etiology*; D011379:Prognosis; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult