9Medical & otologic assessment

TBeyond the audiogram

A patient can meet every audiological criterion and still not be ready for surgery. The medical and otologic assessment runs in parallel with the hearing work-up, checking that the ear is safe to operate onand that the patient can tolerate surgery and engage with rehabilitation.[2009]

CThe otologic examination

The otologist looks for anything in the ear that would compromise a safe implantation. Active chronic ear disease or cholesteatoma must be treated first, because operating through infection risks a serious device infection. The mastoid and middle ear must allow the surgical approach. The state of the ear, not just the cochlea, is part of candidacy.

CAetiology as a flag, not a barrier

The cause of deafness is rarely a contraindication in itself — but it raises flags that change the plan. Meningitis and otosclerosis warn of cochlear ossification (and otosclerosis of facial-nerve stimulation); malformations alter the surgery; and a congenitally absent or deficient cochlear nerve is one of the few aetiologies that can genuinely preclude an implant and point instead to an auditory brainstem implant (Chapter 7 revisited). Knowing the cause prepares the surgeon for what they will meet.

CFitness, vaccination, readiness

Three practical checks complete the work-up. Fitness for general anaesthesia and mastoid surgery (comorbidities assessed and optimised). Meningitis vaccination — pneumococcal and others before implantation, because recipients carry a small increased risk. And readiness for the long haul: switch-on is the beginning, not the end, and the patient (or, for a child, the family) must be able to commit to programming and auditory rehabilitation, without which even a perfect operation underperforms.

TCA genetics-led work-up — and its pitfalls

The modern medical work-up is increasingly genetics-led. Rather than reflexively ordering CT, ECG, renal ultrasound and ophthalmology on every child, a comprehensive multigene panel comes first, and a positive result directs only the investigations it warrants. It also feeds candidacy: a diagnosis of Usher syndrome — roughly a fifth of the syndromic implant population, and hard to spot in a deaf infant — argues for early bilateral implantation while vision is intact, and the genotype even hints at prognosis (Module 7).

Two pitfalls deserve naming. Aetiology guides timing: post-meningitic ossification mandates implanting as early as possible before the cochlea closes, while far-advanced otosclerosis warns of facial-nerve stimulation. And non-organic (functional) hearing loss is an increasingly recognised trap — wrongly implanting a feigned or exaggerated loss can create real loss and medico-legal consequences, so objective tests (ABR/ASSR/OAE) must establish an organic floor when the picture is inconsistent. Finally, around 40% of deaf children carry additional comorbidities, prompting genetics, ophthalmology, neurology and developmental-paediatrics referral.