CI Candidacy in Children

Who is a candidate, and why timing, aetiology and imaging shape the answer — the audiological criteria, the work-up, and the special cases of ANSD, meningitis and bilateral implantation.

The audiological threshold for candidacy

A cochlear implant is considered when a child has severe-to-profound bilateral sensorineural hearing loss and derives insufficient benefit from optimally fitted hearing aids after an adequate trial with auditory rehabilitation. “Benefit” is judged from aided thresholds and age-appropriate speech-perception measures, not from the unaided audiogram alone. Criteria have broadened over time — many programmes now implant at thresholds around 80 dB HL or worse, and guidance such as NICE defines candidacy by the audiogram combined with demonstrably limited aided benefit[22].

Earlier is better

Because the auditory system is most plastic in the first years of life, outcomes are strongly time-dependent: shorter duration of deafness and younger age at implantation predict better spoken-language outcomes[18]. Children implanted in infancy — under 12 months in experienced centres — show better long-term communication than those implanted later [21]. This is why the whole paediatric pathway is built for speed, and why a confirmed severe-profound loss is referred for implant assessment without delay.

Aetiology and imaging work-up

Candidacy is not only audiological. Every child needs an aetiological work-up — genetic testing, evaluation for congenital CMV, and assessment for associated medical and developmental conditions — and imaging of the cochlea and auditory nerve. High-resolution CT and MRI define the cochlear anatomy and, critically, confirm the presence and size of the cochlear nerve. Findings such as cochlear malformations, a common cavity, or a hypoplastic/absent cochlear nerve change the plan, the side chosen, and the expected outcome[18].

Special cases

ANSD. Children with auditory neuropathy can be excellent implant candidates when the lesion is at the synapse or distal nerve and a cochlear nerve is present; implantation can restore neural synchrony. Where the cochlear nerve is absent or deficient, benefit is limited and candidacy is questionable [13].

Meningitis. Bacterial meningitis can cause profound loss and rapid cochlear ossification (labyrinthitis ossificans). It is an emergency for implantation: assessment and surgery are expedited to implant before the cochlea ossifies and the electrode can no longer be inserted [1].

Bilateral implantation. Bilateral implants — simultaneous or sequential — are standard for suitable children, supporting binaural hearing for localisation and listening in noise [22]. Absolute contraindications are few: absence of a cochlea or cochlear nerve, and certain active middle-ear infection that must be treated first.