paediatric cochlear implants: challenges and future directions...early cochlear implantation...
TRANSCRIPT
Prof. Gerard M. O’Donoghue University of Nottingham, UK
Paediatric cochlear implants: challenges and future directions
Current Developments and New Directions In
Pediatric Audiology, Istambul 2011
The best of times ...
Late identification
Delayed diagnosis
Poor amplification
Education : low expectation
No cochlear implants
Public Health Policy
Prostheses
Prostheses - implantable
Overview
Neurobiology of deafness Plasticity into Practice Early cochlear implantation Bilateral CI Medical and surgical aspects Electro-acoustic hearing / ABI etc Turkish Temple
Human Auditory System
Lost around time of birth Normal morphogenesis Critical gene product (Steel 2009)
50-90% loss of CN neurones
Quality and number of synapses Hyperexcitability (Eggermont 2008)
Ryugo et al 1997
a
a
No sensory system exists in isolation
Non-auditory effects of deprivation – attention, working memory, executive functioning etc
Conel, 1939-1967
-1 Mo. Birth 1 Mo. 3 Mo. 6 Mo.
15 Mo. 2 Years 4 Years 6 Years
Development Human Cortex
Huttenlocher, Dabholkar 1997, J Comp Neurol 387:167-178.
Auditory cortex Visual cortex Prefrontal cortex
1 y. 2 y. 4 y. 6 y. 15 y. Adult Birth -3. M.
Age
Syn
ap
ses /
100 µ
m³
Synaptic Pruning
Synaptic Maturation
Kral and O’Donoghue, New Eng J Med 2010
Cochlear Implants and Brain Plasticity
Cochlear Implants and Plasticity
1.0
0.8
0.6
0.4
0.2
0.0
0.2
Coch
lea-t
o-c
ort
ex c
orr
ela
tion (
r)
Normal Deaf Stim.
Cochleotopic Organisation of Cortex - CI
1.0
0.8
0.6
0.4
0.2
0.0
0.2
Coch
lea-t
o-c
ort
ex c
orr
ela
tion (
r)
Normal Deaf Stim.
(Fallon et al., 2009)
Cochleotopic Organisation of Cortex - CI
Dorman et al 2009
Cross modal reorganisation after CI
Overview
Neurobiology of deafness Plasticity into Practice Early cochlear implantation Bilateral CI Medical and surgical aspects Electro-acoustic hearing / ABI etc Turkish Temple
Plasticity into Practice [ Carol Flexer]
Not about ears: its all about the brain
Prostheses: brain access tools
‘Its not what we hear, its what we do with what we hear’
Plasticity in Practice
46 million words heard by age 4 (Hart and Risley)
20,000 hours listening for reading (Dehaene)
Hearing loss: 3 times exposure to learn new words / concepts (Pittman)
Acoustically favourable conditions
Huttenlocher, Dabholkar 1997, J Comp Neurol 387:167-178.
Auditory cortex Visual cortex Prefrontal cortex
1 y. 2 y. 4 y. 6 y. 15 y. Adult Birth -3. M.
Age
Syn
ap
ses /
100 µ
m³
Synaptic Pruning
46 Million Words
Huttenlocher, Dabholkar 1997, J Comp Neurol 387:167-178.
Auditory cortex Visual cortex Prefrontal cortex
1 y. 2 y. 4 y. 6 y. 15 y. Adult Birth -3. M.
Age
Syn
ap
ses /
100 µ
m³
Synaptic Pruning
46 Million Words
X3
Huttenlocher, Dabholkar 1997, J Comp Neurol 387:167-178.
Auditory cortex Visual cortex Prefrontal cortex
1 y. 2 y. 4 y. 6 y. 15 y. Adult Birth -3. M.
Age
Syn
ap
ses /
100 µ
m³
Synaptic Pruning
Reading 20,000 hours listening
(normally hearing)
Receptive and Expressive standardised language scores
as a function of age of identification for children with
'normal cognition' (Yoshinago-Itano, 1999)
Receptive
<6m
>6m
Expressive
<6m
>6m
Age of identification
40 60 80 100 120
Language quotient
Early intervention
Receptive and Expressive standardised language scores
as a function of age of identification for children with
'low cognition' (Yoshinago-Itano, 1999)
Receptive
<6m
>6m
Expressive
<6m
>6m
Age of identification
40 60 80 100 120
Language quotient
Early intervention
Overview
Neurobiology of deafness Plasticity into Practice Early cochlear implantation Bilateral CI Medical and surgical aspects Electro-acoustic hearing / ABI etc Turkish Temple
Early Cochlear Implantation
Age of implant 0-4 years 2000 to 2010
0%
20%
40%
60%
80%
100%
Benelux France Germany Italy Poland United
Kingdom
Benelux France Germany Italy Poland United
Kingdom
2000 2010
2 to 4 Years
1 to 2 Years
0 to 1 Years
Source: Cochlear Ltd database
Implanted < 1y
40%
60%
80%
100%
2000
Bex Fr Ger It Pol UK
20%
2000
0%
Age at implant 0-4 years 2000 to 2010
0%
20%
40%
60%
80%
100%
Benelux France Germany Italy Poland United
Kingdom
Benelux France Germany Italy Poland United
Kingdom
2000 2010
2 to 4 Years
1 to 2 Years
0 to 1 Years
Source: Cochlear Ltd database
2010 Belx Fr Ger It Pol UK Belx Fr Ger It Pol UK
2000
40%
60%
80%
100%
20%
0%
Age at implant 0-4 years 2000 to 2010
Audiological Certainty
What age?
What measures?
What validity?
Who decides?
Parameters of hearing aid trial
Overview
Neurobiology of deafness Plasticity into Practice Early cochlear implantation Bilateral CI Medical and surgical aspects Electro-acoustic hearing / ABI etc Turkish Temple
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
19
92
19
93
19
94
19
95
19
96
19
97
19
98
19
99
20
00
20
01
20
02
20
03
20
04
20
05
20
06
20
07
20
08
Nu
mb
er
of
bila
tera
l
Nu
cle
us
rec
ipie
nts
European Data - Bilaterals
Source: Cochlear Ltd database
Bilateral implants children 2005:2010
Source: Cochlear Ltd database
0%
20%
40%
60%
80%
100%
Benelux France Germany Italy Poland United Kingdom Benelux France Germany Italy Poland United Kingdom
2005 2010
Bilateral Unilateral
40%
60%
80%
100%
20%
0% Bex Fr Ger It Pol UK Bex Fr Ger It Pol UK
2005
Source: Cochlear Ltd database
0%
20%
40%
60%
80%
100%
Benelux France Germany Italy Poland United Kingdom Benelux France Germany Italy Poland United Kingdom
2005 2010
Bilateral Unilateral
40%
60%
80%
100%
20%
0% Belx Fr Ger It Pol UK Belx Fr Ger It Pol UK
NICE 2009
2010 2005
Bilateral implants children 2005:2010
Bilateral implantation recommended for children & some adults
Simultaneous
Additional contralateral
Bilaterals – UK Provision
National Audit Bilaterals:UK
Localisation
Speech recognition in background noise
Speech
Language
Listening
Parental perception
Quality of life
Surgical data including complications
Overview
Neurobiology of deafness Plasticity into Practice Early cochlear implantation Bilateral CI Medical and surgical aspects Electro-acoustic hearing / ABI etc Turkish Temple
Surgical challenges - BICI
Minimal Access Surgery
Operating time
Anesthesia
Facial nerve injury
Co-morbidity – known or unknown
Electrocautery
Loss vestibular function / residual hearing
Meningitis risk
Overview
Neurobiology of deafness Plasticity into Practice Early cochlear implantation Bilateral CI Medical and surgical aspects Electro-acoustic hearing / ABI etc Turkish Temple
&
Electrical Stimulation Acoustical Stimulation
Hearing aids + Implants
Frequency (kHz)
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
0,125 0,25 0,5 1
Heari
ng L
oss
(dB
HL
)
Lower Limit Upper Limit
1 1,5 2 3 4 6 8 10
Electro-acoustic hearing
Single Side Deafness and CI
CI CROS Aid
Drug and Stem Cell delivery systems
Advances in Implant Technology
Auditory Brainstem Implant
(Lenarz et al , Colletti et al 2006)
Overview
Neurobiology of deafness Plasticity into Practice Early cochlear implantation Bilateral CI Medical and surgical aspects Electro-acoustic hearing / ABI etc Turkish Temple
Temple of Artemis
J. Gravel 2007
J. Gravel 2007
Information and systems give meaning to everything we do; there is no point in going through the motions of providing a service if there are no systems on which to support, record or monitor the process and outcomes Sir Muir Gray 2007
Deafness - not just about hearing loss
Prostheses as brain access tools
Earlier is best - but not a cure!
Bilateral CI - timely, safe, efficient
Combined acoustical and electrical hearing
Audiological certainty - central
Paediatric audiology ‘Temple’
Summary