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The hearing implant centre at St Thomas' Hospital, in association with Kings College Hospital, offers auditory brainstem implants to children for whom cochlear implantation is not an option. There are only two specialist centres in the UK that have been commissioned by NHS England to offer this treatment to children under the age of 5.
The paediatric auditory brainstem implant team is a specialist multidisciplinary team providing highly skilled care throughout your child's assessment, inpatient stay and follow up after surgery.
The outpatient appointments both before and after surgery are carried out at the hearing implant centre at St Thomas' Hospital while the inpatient stay and operation is carried out at Kings College Hospital. The team work across both sites, so it is the same team supporting you and your child throughout their journey.
YouTube video about hearing and how it works (video by MED-EL)
What is an auditory brainstem implant (ABI)?
The auditory brainstem implant (ABI) is an electronic device that is intended to restore a degree of hearing sensation for individuals with missing or damaged cochlea and/or cochlear nerves. Historically ABI's have been used for adults who have lost their hearing following the removal of acoustic tumours, however in recent years ABI's have been offered to children when a cochlear implant is not an option.
How does the ABI work?
The ABI consists of two parts.
One part is surgically implanted under the skin on the cochlear nucleus in the brainstem. This consists of an electrode array (placed on the cochlear nucleus) and a receiver stimulator (behind the ear under the skin).
The other part is worn externally behind the ear or as a body worn configuration and is referred to as a speech processor. It is worn with a headpiece which is held in place on the head by a magnet.
The external parts of the implant can be removed at any time, for example when sleeping or swimming and bathing.
The internal device electrically stimulating the cochlear nucleus in the brainstem to produce a sensation of sound, it is powered by the external speech processor.
Sound is picked up by microphones in the external speech processor
The speech processor filters and analyses the sounds and codes it into digital signals
The coded signals are sent along the cable to the transmitting coil
The transmitting coil sends the coded signals to the implant underneath the skin
The implant delivers the signals to the electrodes on the cochlear nucleus
The electrodes stimulate the cochlear nucleus, producing stimulation that may be interpreted as sound in the auditory cortex of the brain
Med EL Synchrony ABI and Sonnet Processor
Image courtesy of Med EL
The RONDO 2 from MED-EL: watch YouTube video about the RONDO 2.
The Sonnet from MED-EL: watch YouTube video about the Sonnet.
Placement of the ABI
Surgical team
Prof Dan Jiang, Consultant skull base/ENT (GSTT)
Steve Connor, Consultant radiologist (GSTT)
Prof Shak Saeed, Consultant skull base/ENT (UCLH)
Nick Thomas, Consultant neurosurgeon (Kings)
Bassel Zebian, Consultant neurosurgeon (Kings)
Who might be suitable for an ABI?
Individuals will be assessed by a specialist multidisciplinary team who will consider options available to support hearing. If Cochlear Implants are not an option then an Auditory Brainstem Implant may be considered.
Where can my child be assessed for an ABI?
In the UK there are two hearing implant centres that are commissioned to provide paediatric ABI's for children under the age of 5 years old: St Thomas' hearing implant centre (London ABI programme) and the Richard Ramsden centre for hearing implants (Manchester).
What is involved in the surgery for ABI?
The surgery consists of placing of the electrode array onto the cochlear nucleus in the brainstem, and placement of the receiver stimulator over the skull bone behind the ear. The optimal placement of the electrode array is guided by activating electrodes during the placement and record the brain's response. The operation lasts several hours.
What are the risks of having ABI surgery?
You will meet with the surgeons who will discuss these with you.
What are the outcomes of ABI's
The degree of benefit cannot be guaranteed and varies from child to child. Published research studies relate to very small numbers of patients. Outcomes relate to a range of factors including: surgical outcome (placement of electrodes), number of electrodes active and additional needs (cognitive ability) of the child. In cochlear implantation there is strong evidence of age of implantation impacting on outcomes. Theoretically age is likely to be another factor that contributes to outcomes post ABI.
Your child's progress with the ABI may be very slow and it may take months and years before we can see how much help the ABI can give and if this translates into any functional use of hearing. It is essential that a sign based communication system is developed and used consistently within the family to support communication between parents and child. It is likely that signing will remain the dominant part of the child and families communication system in the longer term even with an ABI in use.
What is the longer term care for my child following Auditory Brainstem Implantation?
Once your child has an ABI they will be required to have regular monitoring at the Hearing Implant Centre for life.
What can I do to maximize my childs progress with their ABI?
It is vital that you establish consistent use of the speech processor as soon as possible. The speech processors should be worn by the child all waking hours.
Where does surgery take place ?
Your child will be admitted to Lion Ward at King's College Hospital.
Information for patients and visitors to King's College Hospital
Information about wards at King's College Hospital