Transcript PATIENT SELECTION

Hearing Problems in
People with
Spinocerebellar Ataxia
Gary Rance (PhD)
SCA Australia Meeting, Nov 8, 2009
Gary Rance
Associate
Professor
The University of Melbourne
Co-ordinator
Master of Clinical Audiology program
Wagstaff
Research Fellow in Otolaryngology
(Royal Victorian Eye & Ear Hospital)
Project: Hearing Problems in People with SCA
 Part
of a broader study of auditory function in
listeners with neurodegenerative disease
– Friedreich ataxia (FRDA)
– Charcot-Marie-Tooth syndrome (CMT)
– Combined visual/auditory neuropathies
» Lebers Hereditary Optic Neuropathy (LHON)
» Autosomal Dominant Optic Atrophy (ADOA)
Auditory Processing
 Looking
for problems in the way sound information is
transmitted from the ear to the brain
 Friedreich
ataxia findings
(2007 onwards)
– Normal sound detection
– Abnormal neural transmission
– Disrupted perception of speech
(particularly in background noise)
– 30/30 FRDA subjects showed impaired speech understanding in
“everyday” listening conditions
Why Look for Hearing Problems in SCA patients?
 Many
studies (Abele et al, 1997; Kumagi et al, 2000; Perretti et al. 1996) have
shown abnormal electrical responses in the auditory pathways of
SCA patients (50-80% affected)
 None
 This
–
–
–
–
–
of these studies looked at auditory perception
project:
sound detection (standard hearing test)
electrical responses (auditory brainstem response)
auditory processing (timing cues)
perception (speech understanding)
habilitation
Assessments
 Ethics
approval from the RVEEH ethics committee
 Non-invasive
 Based
 Run
on standard clinical tests
from a laptop computer so the testing can be carried
out at home if convenient
Assessments: Auditory Brainstem Response (ABR)
 Electrical
responses to sound from the
auditory pathway (brainstem)
 Measured
via three sensors placed on the
scalp
 Subject
response:
 Duration:
nil
 20 minutes
III
III
I
I
Subject N8 (rarefaction)
III
I
0.5 V/Div
Auditory Brainstem Response (ABR)
V
V
V
*
*
*
0
2
4
6
ms
8
10
12
14
III
III
I
I
III
III
0.5 V/Div
I
I
0
Auditory Brainstem Response (ABR)
V
V
Subject N8 (rarefaction)
V
V
FAABR (rarefaction)
(N=14)
CM
* *
FAAN (rarefaction)
(N=14)
CM
*
FAAN (compression)
(N=14)
2
4
6
ms
8
10
12
14
Assessments: Auditory Processing
 Perception
of temporal (timing) cues
 Aim:
to find the smallest change in a rapidly
fluctuating sound that a listener can perceive
 Subject
response: indicate when able to hear
a change in a constant sound
 Duration:
 20 mins
Speech Perception in Quiet &
Background Noise
Assessments: Speech Perception
CNC Word Test
recorded speech in quiet and different
levels of background noise


Subject response: imitation
Duration:

30 minutes
CNC Phoneme Score (%)
Rance et al., (2008)
100
75
50
25
FAAN
0
+20
Quiet
+10
+5
S/N Ratio (dB)
0
Project Details
 Testing
carried out by
Master of Clinical Audiology Students
 Data
collection: March-August 2010
 Typically
requires a single 1.5 hour session to test
both ears
 Subjects:
- all welcome
- particularly interested in SCA groups 1, 2 & 6