title: Effect of tumor removal on tinnitus in patients with vestibular schwannoma.
abstract: OBJECTIVE
  Tinnitus is one of the most common symptoms in patients with vestibular schwannomas (VSs), but the effect of surgery on this symptom has not been fully evaluated. The aim of this study was to define the effect on tinnitus of tumor removal, cochlear nerve resection, and useful hearing preservation in patients with VSs.
  
  
  METHODS
  The authors retrospectively analyzed the status of tinnitus before and after surgery in 242 patients with unilateral VSs who underwent surgery via the retrosigmoid lateral suboccipital approach.
  
  
  RESULTS
  Of 242 patients, 171 (70.7%) complained of tinnitus before surgery; the symptom disappeared in 25.2%, improved in 33.3%, remained unchanged in 31.6%, and worsened in 9.9% of these cases after tumor removal. In the 171 patients with preoperative tinnitus, the cochlear nerve was resected in 85 (49.7%) and preserved in 86 (50.3%), but there was no significant difference in the incidence of postoperative tinnitus between these 2 groups (p = 0.293). In the 71 patients without preoperative tinnitus, the symptom developed postoperatively in 6 cases (8.5%). Among those without preoperative tinnitus, the cochlear nerve was resected in 45 cases (63.4%) and tinnitus appeared postoperatively in 3 (6.7%). The authors also analyzed the association between postoperative tinnitus and useful hearing preservation, but could not find any statistically significant association between the 2 factors (p = 0.153).
  
  
  CONCLUSIONS
  Tumor removal via the retrosigmoid lateral suboccipital approach may provide some chance for improvement of tinnitus in patients with VSs; however, neither cochlear nerve resection nor useful hearing preservation affects the postoperative development of tinnitus.
authors.affiliation: Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. kkameta@ns.med.kyushu-u.ac.jp
authors.forename: Katsuharu
authors.initials: K
authors.lastname: Kameda
authors.forename: Tadahisa
authors.initials: T
authors.lastname: Shono
authors.forename: Kimiaki
authors.initials: K
authors.lastname: Hashiguchi
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Yoshida
authors.forename: Tomio
authors.initials: T
authors.lastname: Sasaki
mesh_terms: D003056:Cochlear Nerve / Q000601:surgery; D005260:Female; D006311:Hearing Disorders / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000150:complications* / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014012:Tinnitus / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome