Auditory Brainstem Implantation in Chinese Patients With Neurofibromatosis Type II: The Hong Kong Experience.
To describe our experience and outcomes of auditory brainstem implantation (ABI) in Chinese patients with Neurofibromatosis Type II (NF2).



Retrospective case review.



Tertiary referral center.



Patients with NF2 who received ABIs.



Between 1997 and 2014, eight patients with NF2 received 9 ABIs after translabyrinthine removal of their vestibular schwannomas. One patient did not have auditory response using the ABI after activation. Environmental sounds could be differentiated by six (75%) patients after 6 months of ABI use (mean score 46% [range 28-60%]), and by five (63%) patients after 1 year (mean score 57% [range 36-76%]) and 2 years of ABI use (mean score 48% [range 24-76%]). Closed-set word identification was possible in four (50%) patients after 6 months (mean score 39% [range 12-72%]), 1 year (mean score 68% [range 48-92%]), and 2 years of ABI use (mean score 62% [range 28-100%]). No patient demonstrated open-set sentence recognition in quiet in the ABI-only condition. However, the use of ABI together with lip-reading conferred an improvement over lip-reading alone in open-set sentence recognition scores in two (25%) patients after 6 months of ABI use (mean improvement 46%), and five (63%) patients after 1 year (mean improvement 25%) and 2 years of ABI use (mean improvement 28%). At 2 years postoperatively, three (38%) patients remained ABI users.



This is the only published study to date examining ABI outcomes in Cantonese-speaking Chinese NF2 patients and the data seems to show poorer outcomes compared with English-speaking and other nontonal language-speaking NF2 patients. Environmental sound awareness and lip-reading enhancement are the main benefits observed in our patients. More work is needed to improve auditory implant speech-processing strategies for tonal languages and these advancements may yield better speech perception outcomes in the future.
The Chinese University of Hong Kong, Shatin, Hong Kong, China.
Jiun Fong
JF
Thong
John K K
JK
Sung
Terence K C
TK
Wong
Michael C F
MC
Tong
D000328:Adult; D038263:Auditory Brain Stem Implantation / Q000379:methods*; D038262:Auditory Brain Stem Implants; D005260:Female; D006723:Hong Kong; D006801:Humans; D008085:Lipreading; D008297:Male; D008875:Middle Aged; D016518:Neurofibromatosis 2 / Q000150:complications / Q000601:surgery; D009464:Neuroma, Acoustic / Q000209:etiology / Q000601:surgery*; D012189:Retrospective Studies; D013067:Speech Perception / Q000502:physiology*; D016896:Treatment Outcome