CAA Conference and Exhibition, October 17-20, 2018 Balance and Hearing: What Cochlear Implants Have Taught us about the Developing Vestibular System Sharon L. Cushing
CAA Conference and Exhibition, October 17-20, 2018
Balance and Hearing: What Cochlear Implants Have Taught us
about the Developing Vestibular System
Sharon L. Cushing
CAA Conference and Exhibition, October 17-20, 2018
Disclosures
⚫ Speaker’s Bureau
⚫ Interacoustics
⚫ Royalties
⚫ Plural Publishing
⚫ Editor: Balance Disorders in the Pediatric Population
⚫ Patent Holder: ⚫ Patents #: 7041-0: Systems And Methods For Balance Stabilization
⚫ Sponsored Research Agreement⚫ Cochlear Americas
⚫ Sharon Cushing
⚫ Paolo Campisi
⚫ Mark Crawford
⚫ Maureen Dennis
⚫ Gina Sohn
⚫ Naureen Sohail
Cochlear Implant Clinical/ Research Team
DIRECTORS
⚫ Blake Papsin
⚫ Karen Gordon
⚫ Vicky
Papaioannou
RESEARCH
ASSISTANTS
⚫ Stephanie Jewell
STUDENTS
⚫ Daniel Wong
⚫ Claire Salloum
⚫ Sho Tanaka
⚫ Patrick Yu
⚫ Brad Hubbard
⚫ Lauren Schofield
⚫ Brittany Harrison
⚫ Brooke Allemang
⚫ Laurie MacDonald
⚫ Mary Lynn Feness
⚫ Pat Di Santos
⚫ Nancy Greenwald-
Hood
⚫ Susan Druker
Local - external
⚫ Sandra Trehub
⚫ Frank Russo
International
⚫ Robert Cowan
⚫ Richard van Hoesel
FELLOWS
⚫ Talar Hopyan
⚫ Neil Chadha
⚫ James Ramsden
COLLABORATORS
Local - SickKids
⚫ Bob Harrison
⚫ Tracy Stockley
⚫ Susan Blaser
⚫ Adrian James
Tien et al, 2002
distortion of the saccular
membrane
fibrosis of the vestibule
20-100% lose cVEMP
responses after CI
Vestibular Effects of Cochlear
Implantation (negative)
Vestibular Dysfunction is
Common in Children with SNHL
70% dysfunction
35-40% complete
areflexia
Otol Neurotol. 2013
Vestibular Dysfunction is
Common in Children with SNHL
70% dysfunction
35-40% complete
areflexia
vestibular impairment is the single
most common associated feature of SNHL
Otol Neurotol. 2013
Measuring Balance
Bruininks-Oseretsky (BOT2)
Balance Subtest
Balance subtest Items Max. Score
1. Standing with feet apart on a line Eyes Open 10 sec.
Eyes Closed 10 sec.
2. Walking forward on a line 6 steps
3. Standing on one leg on a line Eyes Open 10 sec.
Eyes Closed 10 sec.
4. Walking forward heel to toe on a line 6 steps
5. Standing on one leg on a balance beam Eyes Open 10 sec.
Eyes Closed 10 sec.
6. Standing heel-to-toe on a balance beam 10 sec.
N= 190 children with CI tested
*p= 0.0001
0
2
4
6
8
10
12
14
16
normal hearing hearing loss BVL
BO
T-2
Scale
Sc
ore
Bilateral Vestibular Loss
(BVL)
Vestibular Loss Impacts Balance
*p= 0.0001
0
2
4
6
8
10
12
14
16
normal hearing hearing loss BVL
BO
T-2
Scale
Sc
ore
Bilateral Vestibular Loss
(BVL)
Vestibular Loss Impacts Balance
*p= 0.0001
0
2
4
6
8
10
12
14
16
normal hearing hearing loss BVL
BO
T-2
Scale
Sc
ore
Mean 4.4 years
Bilateral Vestibular Loss
(BVL)
Vestibular Loss Impacts Balance
⚫ static and dynamic balance – BOT-2
0
2
4
6
8
10
12
14
16
standardized normals (non CI) non-reimplanted re-implanted
BO
T-2
Bal
ance
Su
bse
t Sc
ore
16
14
12
10
8
6
4
2
BO
T-2
Bala
nce S
ubset
Score
Standardized
normals
(non - CI)
non-
reimplantedreimplanted
p = 0.00001
p = 0.0083
0
When Balance is Poor – Implants Fail
Otol Neurotol. 2015
p = 0.0002
0
0.2
0.4
0.6
0.8
1
non-reimplanted reimplanted
Pro
po
rtio
n o
f p
ati
en
ts
abnormal
normal
re-implantednon
re-implanted
bilateral
areflexia
When Vestibular Function is Poor –
Implants Fail
Otol Neurotol. 2015
vestibular & balance
dysfunctionrisk of CI failureα
Bilateral Areflexia
Odds ratio: 8.6
Implant failure
Otol Neurotol. 2015
When Vestibular Function is Poor –
Implants Fail
CAA Conference and Exhibition, October 17-20, 2018
Screening
Vestibular & Balance Function
4 Easy Steps
1. motor milestones
2. motor function
3. horizontal canal
4. otoliths
CAA Conference and Exhibition, October 17-20, 2018
Motor Milestones – Upper Limits
⚫ head control
⚫ 4 months
⚫ sitting
⚫ 9 months
⚫ walking
⚫ 18 months
CAA Conference and Exhibition, October 17-20, 2018
Screening
Vestibular & Balance Function
4 Easy Steps
1. motor milestones
2. motor function
3. horizontal canal
4. otoliths
One Leg Standing
Age Duration (sec)
1 foot standing
30 months 1 (briefly)
36 months 2
4 years 5
5 years 10
One Leg Standing
Eyes Closed
One Leg Standing
Eyes Open
One Leg
Standing
Sensitivity Specificity
Eyes Open
< 8 seconds
100% 49%
Eyes Closed
< 4 seconds
90% 84%
Children age 5 and older
Otol Neurotol. 2016
One Leg Standing
CAA Conference and Exhibition, October 17-20, 2018
Screening
Vestibular & Balance Function
4 Easy Steps
1. motor milestones
2. motor function
3. horizontal canal
4. otoliths
CAA Conference and Exhibition, October 17-20, 2018
Screening
Vestibular & Balance Function
4 Easy Steps
1. motor milestones
2. motor function
3. horizontal canal
4. otoliths
CAA Conference and Exhibition, October 17-20, 2018
Subjective Visual Vertical (SVV)
⚫ Positive → tilt to the right
⚫ Negative → tilt to the left
⚫ Normal range: ± 2°(Brodsky 2015, 2016)
⚫ Bias →initial direction of
linear marker(Pagarkar 2008; Toupet 2015)
-2o +2o
CAA Conference and Exhibition, October 17-20, 2018
Screening
Vestibular & Balance Dysfunction
4 Easy Steps
1. motor milestones
2. motor function
3. horizontal canal
4. otoliths
CAA Conference and Exhibition, October 17-20, 2018
• Cochleovestibular
anomalies
• Phelps
• Waardenburg
• Klippel Feil
• Pendred
• Ototoxicity
• Usher Syndrome
• Meningitis
• CMV
• ANSD
• Connexin
• Mitochondrial?
• Autoimmune?
Vestibular and Balance
Dysfunction Risk by Etiology
CAA Conference and Exhibition, October 17-20, 2018
• Cochleovestibular
anomalies
• Phelps
• Waardenburg
• Klippel Feil
• Pendred
• Ototoxicity
• Usher Syndrome
• Meningitis
• CMV
• ANSD
• Connexin
• Mitochondrial?
• Autoimmune?
Vestibular and Balance
Dysfunction Risk by Etiology
CAA Conference and Exhibition, October 17-20, 2018
Ototoxicity in Cancer
cochleotoxicity ≈ vestibulotoxicity
platinum based therapy
aminoglycosides
cranial radiation
surgical therapy
25-90% ?
0
20
40
60
80
100
120
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000
Frequency (Hz)
Ototoxicity Related Hearing Loss
0
20
40
60
80
100
120
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000
Le
ve
l (d
B H
L)
Frequency (Hz)
Left Ear Right Ear
Conductive hearing loss
Cochlear implantn=26
0
1
2
3
4
5
6
7
8
9
10
0 5 10 15 20
seco
nd
s
participants
Eyes Open
n=26
Ototoxicity Related Balance Impairment
0
1
2
3
4
5
6
7
8
9
10
0 5 10 15 20
seco
nd
s
participants
Eyes Open
<8 sec35%
(8/23)abnormal
n=26
Ototoxicity Related Balance Impairment
0
1
2
3
4
5
6
7
8
9
10
0 5 10 15 20
seco
nd
s
participants
Eyes Open
Eyes Closed
<8 sec35%
(8/23)abnormal
n=26
Ototoxicity Related Balance Impairment
0
1
2
3
4
5
6
7
8
9
10
0 5 10 15 20
seco
nd
s
participants
Eyes Open
Eyes Closed
<8 sec35%
(8/23)abnormal
65%
15/23abnormal
<4 sec
n=26
Ototoxicity Related Balance Impairment
Horizontal Canal Dysfunction
50% Dynamic Visual Acuity
52% VOR loss vHIT
42% Utricular Dysfunction
Subjective Visual Vertical
N = 26
Vestibular Impairment from Ototoxicity
CAA Conference and Exhibition, October 17-20, 2018
Ototoxicity in Cancer
cochleotoxicity ≈ vestibulotoxicity
platinum based therapy
aminoglycosides
cranial radiation
surgical therapy
25-90% 50%
CAA Conference and Exhibition, October 17-20, 2018
Congenital Cytomegalovirus
photos courtesy of Dr. Robert Harrison
CAA Conference and Exhibition, October 17-20, 2018
Congenital Cytomegalovirus
20-50% Sensorineural Hearing Loss
CAA Conference and Exhibition, October 17-20, 2018
92% Vestibular end-organ Dysfunction
33% Complete Bilateral Loss
50% Progressive
Bernard et al. Pediatrics. 2015
50% Otolithic Dysfunction
cVempMaes, Ear & Hearing. 2016
Congenital Cytomegalovirus
20-50% Sensorineural Hearing Loss
Consequences of SSD in Children
School
Performance
Behaviour
IEP &
Speech Therapy
Unilateral Hearing
Loss
Lieu et al.. Laryngoscope. 2012
Speech & Language
Quality of Life
Grade Failure
Measuring Balance Impairment
⚫ quantitative measurement of postural
control
Force
plates
Centre of Pressure
0
5
10
15
20
25
Unilateral Normal
P=0.004
BO
T-2
Scale
d S
core
Otol Neurotol. 2016
Unilateral Hearing
LossNormal Hearing
Balance is Impaired in SSD
0
5
10
15
20
25
Unilateral Normal
P=0.004
BO
T-2
Scale
d S
core
hearing loss
Otol Neurotol. 2016
Unilateral Hearing
LossNormal Hearing
Balance is Impaired in SSD
0
5
10
15
20
25
Unilateral Normal
P=0.004
BO
T-2
Scale
d S
core
hearing loss
bilateral
vestibular
loss
Otol Neurotol. 2016
Unilateral Hearing
LossNormal Hearing
Balance is Impaired in SSD
Vestibular Dysfunction in SSD
Horizontal Canal Dysfunction
48% Caloric Reduction
50% VOR loss vHIT
Otolithic Dysfunction
62.5%
Utricular 42% oVEMP
Saccular 25% cVEMP
N = 20
Consequences of SSD in Children
School
Performance
Behaviour
IEP &
Speech Therapy
Unilateral Labyrinthine
Loss
Lieu et al.. Laryngoscope. 2012
Speech & Language
Quality of Life
Grade Failure
CAA Conference and Exhibition, October 17-20, 2018
Disclosures (cont'd)
Everything I have learned about brain development
in children I have learned from 2 people
Dr. Karen Gordon Xavier Sloan
CAA Conference and Exhibition, October 17-20, 2018
Reduced
activity
Activity no
longer reduced
Lee, et al., Nature, 2001
Auditory Deprivation
Sensory Assembly
stimulus
Processing ReassemblySenses
pattern recognition
high fidelity representation of the environment
faithful representation
Sensory Assembly
stimulus
Processing ReassemblySenses
pattern recognition
high fidelity representation of the environment
faithful representation
Sensory Assembly
stimulus
Processing ReassemblySenses
pattern recognition
high fidelity representation of the environment
faithful representation
"Ice Cream, yummy!"
Sensory Assembly - Cochlear Loss
stimulus
Processing ReassemblySenses
pattern recognition
high fidelity representation of the environment
faithful representation
Sensory Assembly - Restored
stimulus
Processing ReassemblySenses
pattern recognition
high fidelity representation of the environment
faithful representation
effort
CAA Conference and Exhibition, October 17-20, 2018
Jiwani et al., Submitted
Right Stimulation CI Experienced – Normal Hearing Dipole Differences
P1 - P1 N1 - N1 P2 - P2
How Do Humans Listen?
Spatial
Knowledge
Vision
Kinesthetic
InputVestibular
Hearing
Proprioception
Efference
Copy
Balance and Navigation
Cognitive Load
Spatial
Knowledge
Vision
Kinesthetic
InputVestibular
Hearing
Proprioception
Efference
Copy
Balance and Navigation
Cognitive Load
*p= 0.0001
0
2
4
6
8
10
12
14
16
normal hearing hearing loss BVL
BO
T-2
Scale
Sc
ore
Bilateral Vestibular Loss
(BVL)
Vestibular Loss Impacts Balance
Spatial
Knowledge
Vision
Kinesthetic
InputVestibular
Hearing
Proprioception
Efference
Copy
Balance and Navigation
Cognitive Load
Control Strabismus Amblyopia
BO
T2
Ba
lan
ce
Sco
re
0
5
10
15
20
25
30
P = <0.001
P = <0.001
Balance is Impaired in
Developmental Visual Anomalies
Bachar et al in preparation
Control Strabismus Amblyopia
BO
T2
Ba
lan
ce
Sco
re
0
5
10
15
20
25
30
P = <0.001
P = <0.001
Balance is Impaired in
Developmental Visual Anomalies
hearing loss
bilateral
vestibular
loss
Bachar et al in preparation
Spatial
Knowledge
Vision
Kinesthetic
InputVestibular
Hearing
Proprioception
Efference
Copy
Balance and Navigation
Cognitive Load
Sensory Assembly - Vestibular Loss
stimulus
Processing ReassemblySenses
pattern recognition
high fidelity representation of the environment
faithful representation
Sensory Assembly – Vestibular Loss
stimulus
Processing ReassemblySenses
pattern recognition
high fidelity representation of the environment
faithful representation
effort
Sensory Assembly – Vestibular Loss
stimulus
Processing ReassemblySenses
pattern recognition
high fidelity representation of the environment
faithful representation
effort
Spatial
Knowledge
Vision
Kinesthetic
InputVestibular
Hearing
Proprioception
Efference
Copy
Balance and Navigation
Cognitive Load
CAA Conference and Exhibition, October 17-20, 2018
3
3.5
4
4.5
5
5.5
6
1 2
6
0
1
5
CI off CI on
Bala
nce s
co
re
(BO
T-2
)
*p= 0.029
Vestibular Effects of Cochlear
Implantation (positive)
Sensory Assembly – Restored?
stimulus
Processing ReassemblySenses
pattern recognition
high fidelity representation of the environment
faithful representation
effort
Spatial
Knowledge
Vision
Kinesthetic
InputVestibular
Hearing
Proprioception
Efference
Copy
Balance and Navigation
Cognitive Load
CAA Conference and Exhibition, October 17-20, 2018
VEMP Waveforms (same ear)
acoustic electric
P
1
P
1
N1N1
Laryngoscope. 2016
Electrically-Evoked VEMPs are Faster
P1 and N1 peak latencies of cervical VEMPs
N1 and P1 peak latencies of ocular VEMPs
p<0.01, paired t-test
CAA Conference and Exhibition, October 17-20, 2018
Vestibular Abnormalities
Cause Functional Deficits
by Stephanie Jewell
Electrical Stimulation Shifts the Perception
of Vertical Back to CenterLeaning left
Leaning right
Shifted right
Shifted left
p<0.001
Sensory Assembly – Restored?
stimulus
Processing ReassemblySenses
pattern recognition
high fidelity representation of the environment
faithful representation
effort
TransCochlear Stabilization of Balance
⚫ accelerometer and
gyroscopic sensor
⚫ conversion to CI
stimulation
⚫ head referenced
⚫ deviation signalled
⚫ transferred electrically
to implant
⚫ 16 patients
P = 0.041
Mean S
cale
d B
OT
Score
0
1
2
3
4
5
6
7
8
9
CI off Head referenced CIstimulation
Hearing and Implants Help Balance
CAA Conference and Exhibition, October 17-20, 2018
0
2
4
6
8
10
12
Tandem Eyesopen
One Foot EyesOpen
BB - One FootEyes Open
BB - TandemEyes Open
Tandem Eyesclosed
One Foot EyesClosed
BB - One FootEyes Closed
Max time
Tim
e t
o F
all (
s)
NORMAL
HEARING
Time to Fall Approaches Normal
CAA Conference and Exhibition, October 17-20, 2018
0
2
4
6
8
10
12
Tandem Eyesopen
One Foot EyesOpen
BB - One FootEyes Open
BB - TandemEyes Open
Tandem Eyesclosed
One Foot EyesClosed
BB - One FootEyes Closed
Max time
Tim
e t
o F
all (
s)
Time to Fall Approaches Normal
NORMAL
HEARING
CI
CAA Conference and Exhibition, October 17-20, 2018
0
2
4
6
8
10
12
Tandem Eyesopen
One Foot EyesOpen
BB - One FootEyes Open
BB - TandemEyes Open
Tandem Eyesclosed
One Foot EyesClosed
BB - One FootEyes Closed
Max time
Tim
e t
o F
all (
s)
Time to Fall Approaches Normal
NORMAL
HEARING
CI
HEAD
REFERENCED
CI STIMULATION
Summary
⚫ vestibular & balance dysfunction
⚫ common
⚫ matters
⚫ screening is feasible
⚫ performance impaired by labyrinthine
⚫ implants can stimulate an impaired
vestibular system