Download ADVANCES IN COCHLEAR IMPLANTATION

BME INFORMATION DAY,SCOTLAND
NDCS AND SMDCS
Presentations by:
•Dr Mary Shanks (ENT Consultant, Crosshouse)
•Dr Juan Mora (Consultant Audio Vestibular Surgeon)
ADVANCES IN COCHLEAR
IMPLANTATION
Mary Shanks
Surgical Director
Scottish Cochlear Implant Programme
NDCS 16th March 2013
Scottish Cochlear Implant
Programme
25 years old!
 700 adults and 300 children implanted
 210 bilateral cochlear implant users
 100 cochlear implant operations per year
(40 children)
What is a Cochlear Implant?
An electronic device for severe-to-profoundly deaf
people who are unable to benefit from powerful
hearing aids
The primary aim of cochlear implantation is to
promote spoken language
Normal Hearing
Organ of Corti (Hearing)
‘Critical’ Period for spoken
language development
 Neuroplasticity
 0-4 years old
 After 4 years old auditory areas in brain re-
allocated to vision and other functions
How a Cochlear Implant Works
Electrode Array in Cochlea
Surgery
 Early implantation
 Electrode Design
 Bilateral Implantation
Advances in Surgery
 Early Cochlear Implantation possible due to
Newborn Hearing Screening
 Early hearing aid fitting
 Assessment at 10 months
 Aim to implant 10-18 months
Electrode Design
 Slimmer more flexible electrodes = less
damage to cochlea
 In future - electrodes which deliver steroids
and neurotrophic factors directly to the
cochlea
Minimising Cochlear Trauma
Medel Flex electrodes
with choice of lengths 20
– 31 mm
Bilateral Implantation
Advances in Surgery
 Bilateral Cochlear Implantation
 Since 2009
 80% parents choose bilateral implantation for
their child
 Better hearing in noise
 Better sound localisation
 Back-up device (device failure rate 1-2%)
Then…Body worn processors
Now…
Waterproof Implants
Advanced Bionics Neptune
Programming
Remote Programming via Internet
What is a successful outcome?
 Children using spoken language(s) as their
main mode of communication
 Starting a mainstream school aged 5 with
children who have normal hearing
 Happy children who are able to participate
fully in family life and socialise with their
friends
 Children with special needs/disabilities may
have different but equally important
outcomes for them
Successful outcomes depend
upon……
 Child + Parental support = 90%
 Surgery + technology + programming = 10%
How to help your child develop
speech
 Ensure they wear their Cochlear Implant(s) all
day, every day
 Talk to your child and help them to learn
about everyday sounds
 Follow advice from our rehabilitation
specialists and your local team (speech
therapists & teachers of deaf)
ROLE OF GENETIC COUNSELLING
FOR HEARING IMPAIRED
CHILDREN FROM MINORITY
ETHNIC COMMUNITIES
Juan Mora
Audiological Physician
BME Information Day
16th March 2013
What is genetic counselling?
Genetic counselling provides information that
helps to understand the possibility of developing a
genetic (inherited) health condition.
Providing information to allow people to make
informed decisions
Genetic information
The organs and tissues of the body are made of
cells. The cells contain genetic information
which determines how we are, either alone or
by interacting with the environment.
The information is stored in a long molecule
called Deoxyribonucleic acid (DNA) in an
alphabet of four letters A, C, G and T. DNA is
found in chromosomes. Each cell in the body
contains 23 pairs of chromosomes.
What are genes?
Genes are sections of the DNA. Each cell
contains around 21,000 genes.
Each gene contains the instructions to make a
particular protein, in a particular cell, at a
particular time.
Proteins are complex chemicals that make up
blood, muscles and all the tissues and organs of
the body.
How are genes inherited?
One of each of the 23 pairs of chromosomes is
inherited from each parent.
Therefore there are 2 copies of each gene on
each cell, with the exception of the sex
chromosomes (X and Y).
Mutations
Mutations are changes in the sequence of DNA
in the cells. DNA is constantly being damaged
by processes like radiation, sunlight and
chemicals. The damage is usually repaired but
sometimes the repair is not perfect and this
leads to a mutation. Some mutations are neutral
and have no effect, others may improve a
protein and be beneficial and some result in a
protein that does not work, which may cause
disease.
Mutations
Mutations can be inherited from a parent or
they can occur when a sperm or egg is made,
resulting in a new mutation.
Mutations can occur in a dominant gene (only
one mutation is enough to cause a medical
condition) or in a recessive gene (the mutation
has to be present in the two copies of the gene
to cause the condition).
Patterns of inheritance
Recessive inheritance
In recessive inheritance, a child inherits a
mutation from each parent in both copies of a
particular gene and develops a health condition.
If the child inherits only one copy of the gene
with the mutation, he/she will be a carrier of the
condition but will not develop it.
When 2 parents are carriers of the same
mutation, their children have a 25% possibility of
inheriting the mutations from both parents.
Patterns of inheritance
Dominant inheritance
• In dominant inheritance, only one mutation
needs to be passed on from either the mother or
the father for the child to develop the condition.
So, if one of the parents has the condition, there is
a one in two chance it will be passed on to the
child.
Patterns of inheritance
X-linked inheritance
• Mutations in the X chromosome tend to
cause medical conditions only in males. This
is because females have two X chromosomes,
one of which is almost certainly normal.
However males only have one X
chromosome, and if there is one mutation
there is no other healthy copy of the gene like
in females.
Consanguinity
Unions contracted between persons biologically
related up to as second cousins are categorized
as consanguineous. The more common form of
consanguineous union is between first cousins,
in which the spouses share 1/8 of their genes
inherited from a common ancestor. That is, their
children are predicted to have inherited
identical gene copies from each parent at 6.25%
over the general population (1)
Consanguinity
The detrimental health effects associated with
consanguinity are caused by the expression of
rare, recessive genes inherited from a common
ancestor(s).
Every person is estimated to have around 100
mutations (4). Children of consanguineous
marriages are more likely to inherit the same
mutation in both copies of the same gene than
in the general population.
Consanguinity: morbidity and
mortality
 Empirical studies on the children of first
cousins indicate morbidity levels to be some
1% to 4% higher than in the offspring of
unrelated couples (2)
 Children of first cousin parents have higher
ratios for neonatal, postnatal, and infant
mortality (3)
Conclusions
Genetic counselling is about providing
information on the genetics of medical
conditions to help people to make informed
decisions.
Children of consanguineous parents have a
higher possibility of inheriting identical copies of
a proportion of genes from their parents. This
sometimes may lead to developing health
conditions.
Conclusions
However doctor’s views can be biased because
of the nature of their work:
Only a minority of parents with close kin
marriage have children with health conditions
attributable to the consanguinity. The majority
of consanguineous couples have healthy
children, but doctors do not see them (1).
References
1.
http://www.consang.net/index.php/Summary
2.
Bittles, A.H., and Makov, U. (1988) Inbreeding in human
populations: assessment of the costs. InMating Patterns, eds.
C.G.N. Mascie-Taylor and A.J. Boyce, pp. 153-167. Cambridge:
Cambridge University Press.
3.
Grant, J.C., and Bittles, A.H. (1997) The comparative role of
consanguinity in infant and child mortality in Pakistan.Annals of
Human Genetics61, 143-149.
4.
MacArthur D.G. et al. Science 335, 823-828 (2012).