Experimental sensorineural hearing loss following drill-induced ossicular chain injury.
In a guinea pig model, a standardized drill-induced injury to the body of the incus was applied, and the effects on hearing were characterized by electrocochleography. Drilling resulted in a threshold shift within seconds, and after 15 min it averaged 35.7 dB for clicks, 35 dB nHL for 4 kHz bursts, 36.7 dB nHL for 6 kHz bursts and 39 dB nHL for 8 kHz bursts. The deterioration of the threshold shift remained stable throughout the 5-week post-operative observation period. In five animals a disarticulation of the incudostapedial joint was performed prior to drilling, but this did not reduce the threshold shift. Caution is mandatory during drilling around an intact ossicular chain to avoid a permanent sensorineural hearing loss, and disarticulation of the incudostapedial joint prior to drilling has no protective value.
Gjuric
M
M
Department of Otorhinolaryngology, University of Erlangen-Nuremberg, Germany.
Schneider
W
W
Buhr
W
W
Wolf
S R
SR
Wigand
M E
ME
D000818:Animals; D001300:Audiometry, Evoked Response / Q000379:methods; D001309:Auditory Threshold; D006168:Guinea Pigs; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000209:etiology*; D007188:Incus / Q000293:injuries*; D012107:Research Design; D013997:Time Factors; D014947:Wounds and Injuries / Q000150:complications