7Otosclerosis, Meniere's and the Diseased Ear
When the bony labyrinth or the membranous inner ear is itself diseased, the ear can still be implanted and can hear well, but the disease leaves a signature that shapes both the surgery and the complications to expect. Far-advanced otosclerosis, end-stage Meniere's disease, chronic suppurative otitis media and the open mastoid cavity each pose distinct candidacy and counselling problems, and the recurring principle is that the underlying pathology, not the audiogram alone, predicts the difficult cases.
CFar-advanced otosclerosis: a deaf ear that still implants well
Far-advanced otosclerosis is defined by no measurable air conduction and unmeasurable or near-absent bone conduction, so the ear is functionally profoundly deaf and a candidate for implantation rather than stapes surgery. Speech outcomes after implantation are generally good and comparable to other post-lingual adults, so otosclerosis is not a contraindication and a prior failed or partial stapedectomy does not exclude the patient. The retrofenestral (cochlear) otosclerotic focus demineralises the otic capsule and creates a low-impedance shunt that lets stimulating current leak from the array toward the labyrinthine segment of the facial nerve. Imaging before surgery is essential because demineralised, pneumatised otosclerotic bone can mimic a second cochlear lumen and lead the array to mis-route into a false passage rather than the scala. Counselling should set the expectation of good hearing benefit but a realistically higher chance of programming complications than in a normal otic capsule.[2023][2009]
CFacial nerve stimulation: the price of conductive otic-capsule bone
Aberrant facial nerve stimulation is the hallmark complication of implanting an otosclerotic ear, reported in roughly one in five to one in three patients, far above the rate seen in non-otosclerotic cochleae. It arises because the abnormal, lucent bone of the otic capsule conducts current to the adjacent facial nerve, producing facial twitching, often on basal electrodes, that can appear at switch-on or emerge months to years later. First-line management is reprogramming: reducing current level, narrowing pulse width, switching to a more focused stimulation mode, or deactivating the offending electrodes. Deactivating electrodes to abolish twitching costs spectral channels and can reduce speech understanding in quiet and in noise, so the audiologist balances comfort against performance. In refractory cases revision surgery or device exchange is occasionally needed, and the risk should be disclosed during informed consent for any otosclerotic ear.[2023][2017][2014]
CMeniere's disease and the end-stage labyrinth
Patients whose Meniere's disease has burned out to severe-to-profound sensorineural loss can meet conventional candidacy criteria and achieve meaningful open-set speech, with mean monosyllabic scores near 70% reported in selected series. Fluctuating thresholds and the possibility of contralateral progression complicate ear selection and the timing of implantation in a still-active or bilateral case. Implantation does not reliably control vertigo: some patients improve, others are unchanged, so the implant is offered for hearing, not as a vestibular cure. When the implanted ear has intractable vertigo, simultaneous labyrinthectomy with cochlear implantation can abolish dizziness while rehabilitating hearing in the same operation. Counselling separates the auditory goal of the implant from the vestibular course of the disease, which the device may or may not influence.[2014][2009]
CChronic otitis media and the previously operated ear
Active infection must be eradicated before an electrode is introduced, because placing a foreign body across an infected middle ear and cochleostomy invites device infection and meningitis. An open (canal-wall-down) mastoid cavity or prior tympanomastoid surgery is a relative challenge, not a contraindication, but it removes the normal protective barrier between the array and the external environment. Strategies include staged surgery, subtotal petrosectomy with blind-sac closure of the ear canal and obliteration of the cavity with fat, and middle-ear obliteration to isolate the device from the contaminated cavity. The general principle is that otologic disease dictates a tailored surgical plan and a frank discussion of higher complication and revision rates rather than outright exclusion. A diseased ear can be implanted successfully when the disease is first controlled and the array is sealed away from infection and contamination.[2014][2009]
What is the most appropriate first step to manage the facial twitching?
Why is facial nerve stimulation so much more common after cochlear implantation in far-advanced otosclerosis than in a normal cochlea?
What is the principal reason cochlear implantation is offered in end-stage Meniere's disease?