Change in Hearing and Tinnitus in Conservatively Managed Vestibular Schwannomas

ABSTRACT

Objectives: The aim of this study was to evaluate the change of hearing and tinnitus in a group of conservatively managed unilateral vestibular schwannomas (VS). Design: Retrospective case series review. Setting: Tertiary referral otoneurological and skull base surgery department. Participants: Seventy patients affected by unilateral VS with at least two audiograms available were retrospectively evaluated. Main outcome measures: Changes in pure tone average (PTA), speech discrimination score (SDS), and tinnitus were analyzed. Results: At diagnosis 16 patients (22.9%) had a PTA of 0 to 30 dB and 38 (54.4%) a PTA of 0 to 50 dB. At the end of the follow-up period, 9 patients (12.9%) had a PTA of 0 to 30 dB and 27 (38.7%) had a PTA of 0 to 50 dB, representing a hearing preservation rate of 56% and 70%, respectively. Of patients with both tonal and speech audiometry, 71.4% with class A hearing (PTA < 30 dB/SDS > 70%) maintained their initial hearing and 60% with class A or B hearing (PTA < 50 dB/SDS > 50%) maintained this useful hearing. Forty-two patients (60%) did not show a significant growth in their tumor over the period of observation. In this group of patients the mean PTA after a mean follow-up time of 40 months decreased from 44 dB HL to 50.8 dB HL, with a yearly rate of 2.47 dB HL. The chance of maintaining a PTA of 0 to 30 dB in this group of patients was 57.1% and a PTA of 0 to 50 dB was 81.4%. Conclusions: In this group of patients affected by VS and managed conservatively with a mean follow-up of 33.3 months, the risk of losing eligibility for hearing preservation surgery was lower than 30%.

KEYWORDS

Vestibular schwannoma - conservative management - hearing preservation

REFERENCES

• 1 Tschudi D C, Linder T E, Fisch U. Conservative management of unilateral acoustic neuromas.  Am J Otol. 2000;  21 722-728
• 2 Hoistad D L, Melnik G, Mamikoglu B, Battista R, O'Connor C A, Wiet R J. Update on conservative management of acoustic neuroma.  Otol Neurotol. 2001;  22 682-685
• 3 Fucci M J, Buchman C A, Brackmann D E, Berkliner K I. Acoustic tumor growth:implications for treatment choices.  Am J Otol. 1999;  20 495-499
• 4 Charabi S, Tos M, Thomsen J, Charabi B, Mantoni M. Vestibular schwannoma growth: the continuing controversy.  Laryngoscope. 2000;  110 1720-1725
• 5 Warrick P, Bance M, Rutka J. The risk of hearing loss in nongrowing, conservatively managed acoustic neuromas.  Am J Otol. 1999;  20 758-762
• 6 Walsh R M, Bath A P, Bance M L, Keller A, Tator C H, Rutka J A. The role of conservative management of vestibular schwannomas.  Clin Otolaryngol. 2000;  25 28-39
• 7 Massick D D, Welling D B, Dodson E E et al.. Tumor growth and audiometric change in vestibular schwannoma managed conservatively.  Laryngoscope. 2000;  110 1843-1849
• 8 Graamans K, van Dijk J E, Janssen L. Hearing deterioration in patients with non-growing vestibular schwannoma.  Acta Otolaryngol. 2003;  123 51-54
• 9 Moffat D A, Baguley D M, Beynon G J, Da Cruz M. Clinical acumen and vestibular schwannoma.  Am J Otol. 1998;  19 82-87
• 10 [No authors listed.] Committee on Hearing and Equilibrium guidelines for the evaluation of hearing preservation in acoustic neuroma (vestibular schwannoma). American Academy of Otolaryngology-Head Neck Surgery Foundation Inc.  Otolaryngol Head Neck Surg. 1995;  113 179-180
• 11 Boothroyd A. Developments in speech audiometry.  Sound. 1968;  2 3-10
• 12 Rosenberg S I. Natural history of acoustic neuromas.  Laryngoscope. 2000;  110 497-508
• 13 Stipkovits E M, Graamans K, van Dijk J E. Vestibular schwannoma: negative growth and audiovestibular features.  Eur Arch Otorhinolaryngol. 2001;  258 467-471
• 14 Tos M, Charabi B, Thomsen J. Incidence of vestibular schwannomas.  Laryngoscope. 1999;  109 736-740
• 15 Kobayashi T, Aslan A, Chiba T, Takasaka T, Sanna M. Measurement of endocochlear DC potentials in ears with acoustic neuromas: a preliminary report.  Acta Otolaryngol. 1996;  116 791-795
• 16 Kveton J F. Delayed spontaneous return of hearing after acoustic tumor surgery: evidence for cochlear nerve conduction block.  Laryngoscope. 1990;  100 473-476
• 17 Prasher D, Tun T, Brookes G, Luxon L. Mechanisms of hearing loss in acoustic neuroma: an otoacoustic emission study.  Acta Otolaryngol. 1995;  115 375-381
• 18 Moffat D A, da Cruz M J, Baguley D M, Beynon G J, Hardy D G. Hearing preservation in solitary vestibular schwannoma surgery using the retrosigmoid approach.  Otolaryngol Head Neck Surg. 1999;  121 781-788
• 19 Satar B, Jackler R K, Oghalai J, Pitts L H, Yates P D. Risk-benefit analysis of using the middle fossa approach for acoustic neuromas with > 10 mm cerebellopontine angle component.  Laryngoscope. 2002;  112 1500-1506
• 20 Friedman R A, Kesser B W, Slattery III W H, Brackmann D E, Hitselberger W E. Hearing preservation in patients with vestibular schwannomas with sudden sensorineural hearing loss.  Otolaryngol Head Neck Surg. 2001;  125 544-551
• 21 Magnan J, Barbieri M, Mora R et al.. Retrosigmoid approach for small and medium-sized acoustic neuromas.  Otol Neurotol. 2002;  23 141-145