Surgery


Surgery For Hyperacusis

There is no proven surgical treatment for hyperacusis in general. If the hyperacusis is caused by superior semicircular canal dehiscence (SSCD), a perilymph fistuala, or acoustic neuroma, surgical treatment is possible. The following surgery is being studied as an option for those with hyperacusis where the cause is unknown and the usual medical therapies have failed. Its effectiveness is currently being evaluated.

Round and Oval Window Reinforcement

The technique being studied is the surgical reinforcement of the round and oval windows of the inner ear. This surgery has been performed on eight hyperacusis patients to date (2/2016).
OvalvsRoundWindowSimple
The oval window is where the stapes bone displaces fluid in the cochlea toward the round window. As cochlear fluid is incompressible, the round window must be flexible so the fluid can move.

The details of the round and oval window reinforcement surgery were described by Silverstein et al. The authors originally developed the surgery in 2009 and found success with this surgery in superior semicircular canal dehiscence (SSCD) patients. This surgery has since been attempted on hyperacusis patients without evidence of SSCD. The surgery is 45 minutes and “minimally invasive.”

Hyperacusis survey results were taken before and after for both patients. This survey score can be interpreted as follows (Herraiz 2006):

Survey Score Degree of Incapacity
26-45 Very Severely Incapacitated
18-25 Severely Incapacitated
11-17 Moderately Incapacitated
1-10 Slightly Incapacitated

The survey score of the first patient went from 33 points to 12 points after surgery. The survey score of the second patient went from 29 points to 16 points. The first patient did not have pre-operative LDLs taken but the second patient showed 8 dB LDL improvement after surgery. Both patients showed 10dB-20dB hearing loss at frequencies above 4 kHz although neither patient noticed. It would be interesting to see how much of the subjective hyperacusis improvements were influenced by the high frequency hearing loss that came from surgery. Both patients reported improved quality of life. You can read the comments from one of the patients on the hyperacusis forum here.

Why does this surgery improve hyperacusis symptoms? The authors provide a hypothesis:

“It is hypothesized that round and oval window reinforcement resulted in the reduction of conductive hyperacusis secondary to compression-related volume displacement, or that changing the compliance of the round and oval windows decreases the over-responsiveness of the central auditory system through a mechanism that is not understood.”
 
-Round and Oval Window Reinforcement for the Treatment of Hyperacusis

To put it more simply, the reason why this surgery is improving hyperacusis symptoms is unknown. The authors suggest that a more compliant round window may have resulted in conductive hyperacusis because the fluid in the cochlea then moves more easily than it normally would. This will reduce the sound levels required for hair cell activation, change the resonance of the cochlea, and has potential to confuse the central auditory system. The authors believe they may have reduced conductive hyperacusis by reinforcing the round window. The study is ongoing with 5 additional patients so far “showing similar results.” Data from additional patients is expected to be published in 2016.

The full paper can be read with purchase or subscription here.

A video of a recent seminar for the surgery including a patient panel reporting their experiences has been posted here.

Surgeries are performed by the Silverstein Institute in Florida. They provide more information about the surgery on their website.

In-Depth: Hyperacusis Surgeries for Patients with Unilateral Hearing Loss

Hyperacusis Surgeries for Patients with Unilateral Hearing Loss

The following are examples of more extreme surgeries for hyperacusis patients with significant hearing loss in one ear. With these patients, the ear without hearing loss is untouched while drastic changes are made to the ear that already presented significant hearing loss. None of the surgeries listed below are common or recommended. They are listed to provide an understanding of what has been tried in the unique case of hyperacusis induced by unilateral hearing loss.

Cochlear Implant

There is a study that shows both tinnitus and hyperacusis can be alleviated by cochlear implants in those with unilateral hearing loss. Cochlear implants will only be implanted in ears with significant hearing loss. Before describing the details of the study, it is important to understand what a cochlear implant does and does not do. A cochlear implant does not restore normal hearing or swap in a fresh new cochlea. Instead, it is a string of electrodes inserted into the cochlea that electrically stimulates the nerves that would normally be stimulated by hair cells. This gives the person a useful representation of sound and helps them understand speech. General information on cochlear implants can be found on the NIH website here. A more detailed description with pictures of the surgery can be found on the Brown University website here. A simulation of what hearing with a cochlear implant might sound like is in the video below:

WARNING: START WITH VOLUME LOW. SOUNDS ARE DISTORTED. Please contact your doctor first if you have any question about your capacity to listen to unknown video files.


Cochlear implants have already been found to alleviate tinnitus symptoms in bilaterally deaf patients. A recent study led by Angel Macias analyzed the impact of cochlear implant surgery on 16 patients who had unilateral hearing loss and severe tinnitus. All patients presented hyperacusis symptoms before the surgery. 7 patients have had their 12 month follow up visit that included filling out a hyperacusis questionnaire to assess post-operation hyperacusis. Comparing Pre and post op results show all patients with a fully inserted cochlear implant reported a reduction in hyperacusis symptoms. For hyperacusis and crippling tinnitus caused by sudden unilateral deafness,  cochlear implants might provide a last resort solution.

The full paper can be found here.

Cochlear destruction

A musician who had sudden hearing loss due to an acoustic trauma from a gunshot presented hyperacusis and diplacusis symptoms 40 years later. Work was becoming intolerable as symbol sounds were “distressingly unpleasant and distorted.” As there was significant hearing loss in the effected side already, a labyrinthectomy was suggested to abolish the residual hearing and consequently abolish the hyperacusis and diplacusis. A labyrinthectomy is a surgical procedure to destroy the cochlea that was more commonly done in very severe cases of unilateral Meniere’s disease with intractable vertigo. After the operation, the hyperacusis patient was relieved of his hyperacusis and diplacusis symptoms. However, since this procedure destroys the vestibular function of the inner ear, the patient was left with a persistent feeling of unsteadiness.

The paper can be read with purchase or subscription here.

Disconnection of Middle Ear Bones

A 1991 report by Peter Prinsely and Nicholas Frootko describes a woman who experienced progressive deafness in one ear over a two year span. This deafness resulted in hyperacusis and distortion from sounds. The patient pleaded for anything to be done so the doctors suggested the disarticulation of the ossicular chain. This would effectively disconnect the middle ear bones and worsen the deafness in the effected ear. Before surgery hearing thresholds were 50dB-60dB in the bad ear. After surgery, the hearing thresholds changed to 100dB-120dB. The patient reported complete relief from hyperacusis and distortion symptoms.

This surgery is the functional equivalent of adding a super ear plug into the ear (with 50+dB attenuation) and appears to work in cases where hearing loss is already significant in one ear. Any thought to have this surgery performed in two normal hearing ears should be disregarded for many reasons. First, hyperacusis would likely not be completely relieved with only 50 dB attenuation and could very well be exacerbated over time (the patients in each of the surgeries above developed hyperacusis as a result of sudden hearing loss). Second, tinnitus would develop or worsen as a result of the hearing loss. Third, losing the sense of hearing without the option of a hearing aid would have a negative impact on the quality of life.

Next: Other


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References

Cherry J, Brown M. Relief of severe hyperacusis and diplacusis in a deafened ear by cochlear labyrinthectomy. Journal of Laryngology and Otology 1996:110:57-58.

Herraiz C, Santos G, Diges I, Diez R, Aparicio J.M.. Assessment of Hyperacusis: The Self-Rating Questionnaire of Hypersensitivity to Sound. Acta Otorrinolaringol Esp 2006:57(7):303-306.

Macias A, Gonzalez J, Manrique M, Morera C, Gacia-Ibanez L, Cenjor C, Coudert-Koall C, Killian M. Cochlear Implants as a Treatment Option for Unilateral Hearing Loss, Severe Tinnitus and Hyperacusis. Audiol Neurotol 2015:20:60-66.

Nikkar-Esfahani A, Whelan D, Banerjee A. Occlusion of the round window: a novel way to treat hyperacusis symptoms in superior semicircular canal dehiscence syndrome. Journal of Laryngology and Otology 2013:127(7):705-707.

Prinsley P.R., Frootko N. Disarticulation of the Ossicular Chain for Severe Recruitment. Ear Nose & Throat Journal 1991:70:115-117.

Silverstein H, Wu Y, Hagan S. Round and Oval Window Reinforcement for the Treatment of Hyperacusis. American Journal of Otolaryngology 2015:36:158-162.