title: Change in tinnitus after treatment of vestibular schwannoma: microsurgery vs. gamma knife radiosurgery.
abstract: OBJECTIVE
  Tinnitus is a very common symptom of vestibular schwannoma, present in 45 to 80% of patients. We evaluated changes in tinnitus after translabyrinthine microsurgery (TLM) or gamma knife radiosurgery (GKS).
  
  
  METHODS
  Among 78 patients with vestibular schwannoma who underwent TLM or GKS at Severance Hospital from 2009-2012, 46 patients with pre- or postoperative tinnitus who agreed to participate were enrolled. Pure tone audiometry, tinnitus handicap inventory (THI), visual analogue scale (VAS) scores for loudness, awareness, and annoyance were measured before and after treatment. Changes of THI and VAS were analysed and compared according to treatment modality, tumour volume, and preoperative residual hearing.
  
  
  RESULTS
  In the TLM group (n=27), vestibulocochlear nerves were definitely cut. There was a higher rate of tinnitus improvement in TLM group (52%) than GKS group (16%, p=0.016). The GKS group had a significantly higher rate of tinnitus worsening (74%) than TLM group (11%, p<0.001). Mean scores of THI and VAS scores significantly decreased in the TLM group in contrast to significant increases in the GKS group. Tumor volume and preoperative hearing did not affect the changes in THI or VAS.
  
  
  CONCLUSIONS
  GKS can save vestibulocochlear nerve continuity but may damage the cochlea, cochlear nerve and can cause worsening tinnitus. In cases where hearing preservation is not intended, microsurgery with vestibulocochlear neurectomy during tumor removal can sometimes relieve or prevent tinnitus.
authors: Department of Otorhinolaryngology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea. ismoonmd@yuhs.ac.
authors: Soon Hyung
authors: SH
authors: Park
authors: Hee So
authors: HS
authors: Oh
authors: Ju Hyun
authors: JH
authors: Jeon
authors: Yong Ju
authors: YJ
authors: Lee
authors: In Seok
authors: IS
authors: Moon
authors: Won-Sang
authors: WS
authors: Lee
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000601:surgery*; D016634:Radiosurgery / Q000379:methods*; D014012:Tinnitus / Q000601:surgery*; D016896:Treatment Outcome
keywords: Vestibular schwannoma; cochlear nerve; gamma knife radiosurgery; microsurgery; tinnitus