Yoshihiro Noguchi1, Masatoki Takahashi2, Taku Ito2, Taro Fujikawa2, Yoshiyuki Kawashima2, Ken Kitamura2. 1. Department of Otolaryngology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan; Department of Hearing Implant Sciences, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan. Electronic address: noguchi.oto@gmail.com. 2. Department of Otolaryngology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
Abstract
OBJECTIVE: To assess possible delayed recovery of the maximum speech discrimination score (SDS) when the audiometric threshold ceases to change. METHODS: We retrospectively examined 20 patients with idiopathic sudden sensorineural hearing loss (ISSNHL) (gender: 9 males and 11 females, age: 24-71 years). The findings of pure-tone average (PTA), maximum SDS, auditory brainstem responses (ABRs), and tinnitus handicap inventory (THI) were compared among the three periods of 1-3 months, 6-8 months, and 11-13 months after ISSNHL onset. RESULTS: No significant differences were noted in PTA, whereas an increase of greater than or equal to 10% in maximum SDS was recognized in 9 patients (45%) from the period of 1-3 months to the period of 11-13 months. Four of the 9 patients showed 20% or more recovery of maximum SDS. No significant differences were observed in the interpeak latency difference between waves I and V and the interaural latency difference of wave V in ABRs, whereas an improvement in the THI grade was recognized in 11 patients (55%) from the period of 1-3 months to the period of 11-13 months. CONCLUSION: The present study suggested the incidence of maximum SDS restoration over 1 year after ISSNHL onset. These findings may be because of the effects of auditory plasticity via the central auditory pathway.
OBJECTIVE: To assess possible delayed recovery of the maximum speech discrimination score (SDS) when the audiometric threshold ceases to change. METHODS: We retrospectively examined 20 patients with idiopathic sudden sensorineural hearing loss (ISSNHL) (gender: 9 males and 11 females, age: 24-71 years). The findings of pure-tone average (PTA), maximum SDS, auditory brainstem responses (ABRs), and tinnitus handicap inventory (THI) were compared among the three periods of 1-3 months, 6-8 months, and 11-13 months after ISSNHL onset. RESULTS: No significant differences were noted in PTA, whereas an increase of greater than or equal to 10% in maximum SDS was recognized in 9 patients (45%) from the period of 1-3 months to the period of 11-13 months. Four of the 9 patients showed 20% or more recovery of maximum SDS. No significant differences were observed in the interpeak latency difference between waves I and V and the interaural latency difference of wave V in ABRs, whereas an improvement in the THI grade was recognized in 11 patients (55%) from the period of 1-3 months to the period of 11-13 months. CONCLUSION: The present study suggested the incidence of maximum SDS restoration over 1 year after ISSNHL onset. These findings may be because of the effects of auditory plasticity via the central auditory pathway.