Electrocochleographic findings in recurrent idiopathic sudden sensorineural hearing loss.
CONCLUSIONS
The main differences in electrocochleography (ECochG) between recurrent and nonrecurrent idiopathic sudden sensorineural hearing loss (iSSNHL) were the high prevalence of an abnormally increased action potential (AP) recovery (iR) in nonrecurrent iSSNHL and the very low prevalence of iR in recurrent iSSNHL. An enhanced SP/AP ratio, low AP threshold, low initial hearing level, and up-sloping type of audiogram appear to be favorable prognostic factors in recurrent iSSNHL.


OBJECTIVE
This study aimed to characterize differences in ECochG findings and other confounding prognostic factors between recurrent and nonrecurrent iSSNHL and to estimate how these findings are related to hearing outcome in recurrent iSSNHL.


METHODS
ECochG was performed transtympanically in 23 and 42 ears with recurrent and nonrecurrent iSSNHL, respectively. AP recovery was measured using a paired-click stimulation paradigm. Differences in ECochG findings associated with confounding prognostic factors between recurrent and nonrecurrent iSSNHL, and between three outcome groups were assessed.


RESULTS
iR was significantly more common in nonrecurrent iSSNHL (16 ears) than in recurrent iSSNHL (1 ear). In the outcome of recurrent iSSNHL, the prevalence rates of an enhanced summating potential (SP)/AP ratio, lower AP threshold, lower initial hearing level, and up-sloping type of audiogram were significantly higher in the cure group than in the improvement and no-recovery outcome groups.
Department of Otorhinolaryngology, Hadano Red Cross Hospital, Hadano-Si, Kanagawa-Ken, Japan. tohashi@vc-net.ne.jp
Toru
T
Ohashi
Hirohito
H
Nishino
Yoko
Y
Arai
Yositane
Y
Nishimoto
Tomoyasu
T
Kakutani
Izumi
I
Koizuka
D000200:Action Potentials / Q000502:physiology; D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D001300:Audiometry, Evoked Response / Q000379:methods*; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis*; D003639:Hearing Loss, Sudden / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors; D055815:Young Adult