Stapes hypermobility as a possible cause of hyperacusis.

Abstract

Hyperacusis is a reduction of normal tolerances for everyday sounds. Although several publications have been produced demonstrating that minimally invasive surgical procedures may improve patient symptoms, the precise etiology of hyperacusis often remains elusive. This study describes 21 patients, 7 of whom stapes hypermobility is believed to be a mechanical genesis of their hyperacusis symptoms. A prospective, repeated-measure single-arm design was used for this study. All patients were evaluated and treated at a tertiary level otologic referral center. 21 patients (Cohort A) with severe hyperacusis underwent oval and round window reinforcement. Seven patients (Cohort B) intraoperatively appeared to have subjective hypermobility of the stapes. Additional reinforcement of the stapes superstructure was performed in these patients. In Cohort A, loudness discomfort level (LDL) values improved on average from 72.7 dB to 81.9 dB. Hyperacusis questionnaire (HQ) scores improved from 30.1 to 14.7. Numeric Rating Scale scores (0-10) decreased from 8.5 to 4.0. In Cohort B, values similarly improved from an average of 72.4 dB to 88.2 dB. HQ scores improved from 35.8 to 18.9. Numeric Rating Scale scores fell from 10.0 to 3.7. Postoperatively there were no complaints of hearing loss. Sixteen out of 21(76%) reported improved quality of life and diminished symptoms of hyperacusis. It is possible that patients suffering from hyperacusis may have a mechanical cause for their symptoms. Further research is necessary to clarify stapes mobility in patients with these symptoms. Excess temporalis tissue reinforcement of the stapes along with round window reinforcement shows promise as a minimally invasive surgical option for patients suffering from hyperacusis.