1. science
2. social science
3. philosophy
4. ethics

59 MEDICAL WING
Air Education and Training Command
Integrity - Service - Excellence
Wilford Hall Medical Center
Lackland AFB, Texas
Vestibular Evoked Myogenic Potential:
An Overview
Elizabeth McKenna, Capt
Audiologist
19 Feb 2008
Overview
„
„
„
„
„
„
„
Introduction and Definition
Anatomy and Physiology
VEMP Pathway
Recording Parameters and Response Components
Clinical Diagnosis
Pre and Post VEMP Procedures
Summary
Integrity - Service - Excellence
Skull Tap VEMP
Sheykholeslami K, Murofushi T, Kaga K. (1995) Tapping the head activates the
vestibular system: a new use for the clinical reflex hammer.
Neurology,
Neurology, 45(10):192745(10):1927-9.
Integrity - Service - Excellence
What is VEMP?
“Inhibitory, reflexive change in muscle activity that occurs to stabilize the
head following an unexpected translation.”
Hall, J. (2007). New handbook of auditory evoked responses. Boston, MA: Pearson
Education, Inc.
„
Related to vestibular health, not cochlear health
„
„
SNHL is not a contraindication of VEMP testing!
3 clinically-evoked vestibular reflexes:
Vestibulocollic reflex (VCR) ….. VEMP
2. Vestibulo-ocular reflex (VOR)
3. Vestibulospinal reflex
1.
Integrity - Service - Excellence
Structures
Anatomy and Physiology
„ Saccule
VEMP Pathway
„ Neural
Innervations
„ Medial Vestibulospinal Tract
Integrity - Service - Excellence
Structures
„ Saccule
„ Otolith organ, which is linear acceleration
sensitive
„ Maintenance of head & neck posture and
position
„ Located in the vestibule, proximal to staples
footplate
Integrity - Service - Excellence
Otolith Organ
Integrity - Service - Excellence
Saccule Acoustic Response
„
„
In mammals, saccule
developed along with the
hearing system
Sensitive to frequency
and vibratory stimulus
McCue MP, Guinan JJ Jr. (1994). Acoustically responsive fibers in
the vestibular nerve of the cat. J Neuroscience,
Neuroscience, 14(10):605814(10):605870.
McCue MP, Guinan JJ Jr.(1994). Influence of efferent stimulation on
acoustically responsive vestibular afferents in the cat. J
Neuroscience,14(10):6071
Neuroscience,14(10):6071--83.
Carey JP, Hirvonen TP, Hullar TE, Minor LB. (2004). Acoustic
responses of vestibular afferents in a model of superior canal
dehiscence. Otol Neurotology,
Neurotology, 25(3):34525(3):345-52.
Integrity - Service - Excellence
Neural Innervations
Superior Vestibular nerve:
Anterior canal
Horizontal canal
Utricle
Inferior Vestibular nerve:
Saccule
Posterior canal
Integrity - Service - Excellence
VEMP Pathway
Medial Vestibulospinal Tract
n Ipsilateral impulse stimulus
n Saccule movement
n Inferior vestibular nerve in IAC
n Medial Vestibular nucleus
n Vestibulospinal projections
through motor neurons of 11th
CN
n Sternocleidomastiod (SCM)
muscle
n Ipsilateral measurement of
changes tonic SCM status or
inhibition activity of muscle
Integrity - Service - Excellence
Procedure
Recording Parameters & Response Components
„
„
„
„
„
Electrode Montage
Wave Markers & Recording
EMG Monitoring
Electrophysiologic Components
„ Contralateral Response
„ Amplitude
„ Latency
„ Threshold
VEMP types
Integrity - Service - Excellence
Procedure
Electrode Montage
Non-inverting/active(+):
Ipsilateral SCM
Inverting/reference(-):
Sternoclavicular junction
Ground:
Contralateral SCM
Reversing + and - electrodes will invert VEMP peaks
Sheykholeslami K, (2001). The effect of sternocleidomastoid
electrode location on vestibular evoked
myogenic potential. Auris Nasus Larynx,
Larynx,
28(1):4128(1):41-3.
Integrity - Service - Excellence
VEMP
Biphasic response (no latency shift)
P1 at 13msec (P13)
N1 at 23msec (N23)
Integrity - Service - Excellence
Stimulus Effects
Akin FW, Murnane OD, Proffitt TM.
TM. (2003). The effects of click and tonetone-burst stimulus
parameters on the vestibular evoked myogenic potential (VEMP).
Journal of the American Academy of Audiology,
Audiology, 14(9):50014(9):500-9.
Integrity - Service - Excellence
VEMP Parameters
Transducer:
Type:
Duration:
Rate:
Intensity:
Polarity:
Window:
Filters:
Gain:
Sweeps:
Insert earphones (and other ways…)
500 Hz TB
2-0-2 cycle TB
3-6 per second (5.1)
95+ dBnHL
Rarefaction
100ms (prestim 25ms + stim 75ms)
1-10Hz HP, 250-1500 LP, no notch
500
50 to 200 (2 runs)
No Need for Impedance Checks!
Integrity - Service - Excellence
Recording Considerations
„
„
Amount of muscle tension
will affect amplitude &
threshold of response
Consistent muscle tension
required during all
recordings for reliability
*Muscle monitor
*Blood pressure cuff
*Biologic rectifying
software vs. Eclipse
ratio measurement
Integrity - Service - Excellence
Muscle Monitoring
„ EMG
Monitor
Akin FW, Murnane OD. (2001) Vestibular evoked
myogenic potentials: preliminary report. Journal of
the American Academy of Audiology,
Audiology, 12(9):44512(9):445-52.
The Clinical Application of the Vestibular Evoked
Myogenic Potential 2005 ASHA Annual Convention
Integrity - Service - Excellence
Muscle Monitoring
„ Blood
pressure cuff
Vanspauwen R, Wuyts FL, Van De Heyning PH. (2006).
Validity of a new feedback method for the VEMP
test. Acta Otolaryngology,
Otolaryngology, 126(8):796126(8):796-800.
Integrity - Service - Excellence
VEMP Response
Studies report VEMP response
present when the SCM muscle is
activated ipsilateral to the ear
acoustically stimulated
Welgampola MS, Colebatch JG. (2005). Characteristics and clinical applications of vestibular
vestibular--evoked
myogenic potentials. Neurology,
Neurology, 24;64(10):168224;64(10):1682-8.
Integrity - Service - Excellence
VEMP Amplitude
Measured in µV
„ Amplitude is affected by…
„ Sound Level
„ Sound Frequency (500-750 Hz provides largest response)
„ Tonic EMG Level
„ VEMP amplitude decreases as age increases
„ Possibly caused by the decrease of:
„ Vestibular hair cells (Merchant, et al., 2000)
„ Scarpa’s ganglion cells (Velazquez-Villasenor, et al.,
2000)
„ Cells of the vestibular brain-stem (Tang, et al., 2001)
Integrity - Service - Excellence
VEMP Amplitude & Age
Tampas J, Clinard C, Akin F, Murnane O. (2006).
(2006). The effects of
aging on tonic EMG and VEMP. American
Academy of Audiology 2006 Convention (Poster).
Integrity - Service - Excellence
VEMP Latency
„
VEMP latency varies approximately 1-2 msec and
should remain constant for that individual, despite
intensity level
„
PI at 13msec (P13)
„ NI at 23msec (N23)
„
Neurological impairment can affect latency
„
No statistical differences found for latency and
gender
Integrity - Service - Excellence
Does Latency Increase with
Age?
YES
Zapala DA, Brey RH. (2004). Clinical
experience with the vestibular evoked
myogenic potential. Journal of the
American Academy Audiology,
15(3):198-215.
Su HC, Huang TW, Young YH, Cheng PW.
(2004). Aging effect on vestibular
evoked myogenic potential. Otology &
Neurotology, 25(6):977-80.
NO
Basta D, Todt I, Ernst A. (2005).
Normative data for P1/N1latencies of vestibular evoked
myogenic potentials induced by
air- or bone-conducted tone
bursts. Clinical Neurophysiology,
116(9):2216-9.
Tampas J, Clinard C, Akin F,
Murnane O. (2006). The effects of
aging on tonic EMG and VEMP.
The American Academy of
Audiology, 2006 Convention
(Poster).
Integrity - Service - Excellence
VEMP Threshold
Typical thresholds can range from 70-100dBnHL
„ VEMP response does not have to be symmetrical
with the opposite ear
For example:
„
„
90dBnHL, left ear
„ 100dBnHL, right ear… OR
„
75dBnHL left ear
„ 95dBnHL right ear
Integrity - Service - Excellence
VEMP Threshold
Akin FW, Murnane OD, Proffitt TM.
TM. (2003). The effects of click and tonetone-burst
stimulus parameters on the vestibular evoked myogenic potential
(VEMP). Journal of the American Academy Audiolody,
Audiolody, 14(9):50014(9):5009.
Integrity - Service - Excellence
Capt McKenna’s Right VEMP
Integrity - Service - Excellence
Capt McKenna’s Left VEMP
Integrity - Service - Excellence
Clinical Considerations
„
Clinical Diagnosis
„
Neurologic & Otologic Conditions
„ VEMPs in Children & Infants
„
Pre and Post VEMP Procedures
„
„
Case History
References & Questions
Integrity - Service - Excellence
VEMP Response Assessment
VEMP Norms:
„
Amplitude 25µV - 200µV (peak to trough)
„
„
200µV+ amplitude abnormal, but consider symmetry
Left to right ratio comparison with tonic muscle monitoring:
„
100*I(AL – AR)/(AL + AR)I
„
< 0.35 normal
„ > 0.35 abnormal, consistent with saccular dysfunction
„
Latency P13: 11-15ms, N23: 21-25ms
„
„
Latency will remain consistent for the individual, regardless of stimulus
intensity level
Threshold
„
70dBnHL-limits of equipment, normal
„ Absent response, abnormal
„ Below 70dBnHL, abnormal, consistent with superior canal dehiscence (SCD)
Integrity - Service - Excellence
Clinical Diagnosis
Diagnosis
Absent
VEMP
Vestibular Schwannoma
Increased
Amplitude
Delayed
Latency
Decreased
Threshold
X
Normal
VEMP
X
BPPV
X
Cerebellar disease
X
Hydrops
X
Vestibulopathy
X
Ramsay-Hunt
X
Meniere’s
X
X
NF2
X
SCDS
X
X
MS
X
X
Basilar Migraine
X
X
Integrity - Service - Excellence
Otologic & Neurologic
Conditions
VEMP Recording
Pathology
Absent
Reduced
Enhanced
Delayed
Otologic
Meniere’s Disease
X
X
Superior Canal Dehicsence
X
X
Neurolabyrinthitis
X
X
Vestibular Neuritis
X
X
Migrane
X
X
Spinocerebellar Degeneration
X
X
Multiple Sclerosis
X
X
Brainstem Stroke
X
X
Neurologic
Integrity - Service - Excellence
X
VEMPs in Children
Kelsch TA, Schaefer LA, Esquivel CR. (2006). Vestibular evoked myogenic
potentials in young children: test parameters and normative data.
Laryngoscope, 116(6):895-900.
„
30 subjects, divided into 4 age groups:
„
„
„
3-5, 6-7, 7-9, and 10-11 years
SCM kept contracted by head elevation from reclining
position
N1 latencies prolong with aging
Integrity - Service - Excellence
Types of VEMPs
„
„
„
„
Air Conduction
Bone Conduction
Skull tap
Galvanic (through mastoid)
Integrity - Service - Excellence
Bone Conduction VEMP
„
Conductive hearing loss
„
BC stimulation generates
compressional waves that
simulate head
accelerations
Basta D, Todt I, Ernst A. (2005) Normative data for P1/N1latencies of vestibular evoked myogenic potentials
induced by air- or bone-conducted tone bursts.
Clinical Neurophysiology, 116(9):2216-9.
Recordings acquired with IHS Smart-EP
Integrity - Service - Excellence
Case History
„
„
„
„
„
„
Do you get dizzy with loud sounds? (SCDS)
Do you have any cervical neck issues? Have you ever
been diagnosed with any pathologies of the neck?
Is there a significant conductive hearing loss?
Is there a family history of otosclerosis, MS, etc.?
Were the vestibular symptoms sudden onset?
(labyrinthitis, vestibular neuritis: Superior VN)
Are there any working diagnosis from the ENT?
Integrity - Service - Excellence
Summary
„
„
„
„
„
„
„
Anatomy and Physiology
VEMP Pathway
Recording Parameters
Response Components
Clinical Diagnosis
Pre and Post VEMP Procedures
References & Questions
Integrity - Service - Excellence
References
Akin, F., et al. (2004). The influence of voluntary tonic EMG level on the vestibular-evoked myogenic
potential. Journal of Rehabilitation Research and Development, 41 (3B), 473-480.
Akin FW, Murnane OD. (2001) Vestibular evoked myogenic potentials: preliminary report. Journal of the
American Academy of Audiology, 12(9):445-52.
Backous, D. (1999). Relationship of the utriculus and sacculus to the stapes footplate: anatomic
implications for sound and/or pressure-induced otolith activation. Ann Otol Rhinol Laryngol, 108, 548553.
Basta D, Todt I, Ernst A. (2005) Normative data for P1/N1-latencies of vestibular evoked myogenic
potentials induced by air- or bone-conducted tone bursts. Clinical Neurophysiology, 116(9):2216-9.
Carey JP, Hirvonen TP, Hullar TE, Minor LB. (2004). Acoustic responses of vestibular afferents in a model
of superior canal dehiscence. Otol Neurotology, 25(3):345-52.
Chen, C. (2002). Preoperative versus postoperative role of vestibular-evoked myogenic potentials in
cerebellopontine angle tumor. The Laryngoscope, 112, 267-271.
Halmagyi GM, McGarvie LA, Aw ST, Yavor RA, Todd MJ. (2000) The click-evoked vestibulo-ocular reflex
in superior semicircular canal dehiscence. Neurology, 60(7):1172-5.
Hall, J. (2007). New handbook of auditory evoked responses. Boston, MA: Pearson Education, Inc.
Kelsch, T., et al. (2006). Vestibular evoked myogenic potentials in young children: test parameters and
normative data. The Laryngoscope, 116, 895-900.
McCue MP, Guinan JJ Jr. (1994). Acoustically responsive fibers in the vestibular nerve of the cat. J
Neuroscience, 14(10):6058-70.
McCue MP, Guinan JJ Jr.(1994). Influence of efferent stimulation on acoustically responsive vestibular
afferents in the cat. J Neuroscience,14(10):6071-83.
Integrity - Service - Excellence
References
Mikulec, A., et al. (2004). Superior semicircular canal dehiscence presenting as conductive hearing loss
without vertigo. Otology and Neurology, 25, 121-129.
Minor, L. (2005). Clinical manifestations of superior semicircular canal dehiscence. The Laryngoscope, 115,
1717-1727.
Murofushi, T. (2001). Diagnostic value of prolonged latencies in the vestibular evoked myogenic potential.
Archives of Otolaryngology: Head and Neck Surgery, 127 (9), 1069-1072.
Sheykholeslami K, (2001). The effect of sternocleidomastoid electrode location on vestibular evoked
myogenic potential. Auris Nasus Larynx, 28(1):41-3.
Sheykholeslami K, Murofushi T, Kaga K. (1995) Tapping the head activates the vestibular system: a new
use for the clinical reflex hammer. Neurology, 45(10):1927-9.
Tsutsumi, T. (2001). Postoperative vestibular-evoked myogenic potentials in cases with vestibular
schwannomas. Acta Otolaryngol, 121, 490-493.
Wang, C. (2006). Comparison of the head elevation versus rotation methods in eliciting vestibular evoked
myogenic potentials. Ear and Hearing, 27 (4), 376-381.
Welgampola MS, Colebatch JG. (2005). Characteristics and clinical applications of vestibular-evoked
myogenic potentials. Neurology, 24;64(10):1682-8.
Welgampola MS, Colebatch JG. (2001) Vestibulocollic reflexes: normal values and the effect of age.
Clinical Neurophysiology, 112(11):1971-9
Zapala, D. (2007). The VEMP: ready for the clinic. The Hearing Journal, 60 (3), 10-20.
Integrity - Service - Excellence
Questions?
Integrity - Service - Excellence
Electrophysiologic
Components
„ Contralateral
Response
„ Amplitude
„ Latency
„ Threshold
Integrity - Service - Excellence
Superior Canal Dehiscence
Halmagyi GM, McGarvie LA, Aw ST, Yavor RA, Todd MJ. (2000) The clickclick-evoked vestibulovestibulo-ocular reflex in superior
semicircular canal dehiscence. Neurology,
Neurology, 60(7):117260(7):1172-5.
Integrity - Service - Excellence
Superior Canal Dehiscence
„
„
„
„
„
Originally discovered by Lloyd Minor, MD in the 1990s
Dehiscence of the bony labyrinth of the superior
semicircular canal
Thinning of the bone over time creates a third window, in
which the membranous labyrinth can dissipate energy
Impedance in system is reduced
Surgically, resurfacing or plugging of superior canal
Integrity - Service - Excellence
Superior Canal Dehiscence
„
Symptoms & Signs:
1. Tullio’s phenomenon
2. Conductive hypersensitivity at 250-1000 Hz
3. Normal tymps & acoustic reflex pattern
4. VEMP threshold below 70dBnHL
5. Increased VEMP amplitudes (250+µV)
*Test bone conduction below 0dBHL with ipsilateral insert
removed
*Audiometric results can mimic otosclerosis
Integrity - Service - Excellence
VEMPs in Infants
Sheykholeslami K, Megerian CA, Arnold JE, Kaga K. (2005).
Vestibular-evoked myogenic potentials in infancy and early childhood.
Laryngoscope, 115(8):1440-4.
„
„
„
„
24 subjects, mean age 2.3 months
SCM kept contracted by baby being placed in supine
position on a parent’s lap with head rotated as far as
possible to the contralateral side
VEMPs could be recorded to both air-conducted and
bone-conducted stimuli
Variable latency, shorter N1 latencies
Integrity - Service - Excellence
History
„
1964:
„
Bickford, Jacobson and Cody recorded evoked responses to clicks at the inion and
concluded the responses were vestibular in origin and were affected by the tension of
the neck muscles and were therefore “myogenic” responses.
(as opposed to cortical responses suggested by Geisler et al. (1958))
„ Bickford RG, Jacobson JL, Cody DT. (1964). Nature of average evoked
evoked potentials to sound and other
stimuIi in man. Ann N Y Acad Sci.,
Sci., 112:204112:204-23.
„ Geisler CD, Frishkopf,
Frishkopf, LS, Rosenblith WA. (1958). Extracranial responses to acoustic clicks in man.
Science,
Science, 128(3333):1210128(3333):1210-1
„
1969:
„
Cody and Bickford provided further evidence that these responses originated from the
saccule.
„ Cody DT, Bickford RG. (1969). Averaged evoked myogenic responses in normal man. Laryngoscope,
Laryngoscope,
79(3):40079(3):400-16.
„
1994:
„
Colebatch, Halmagyi and Skuse reported recording more reliable responses using the
sternocleidostoid muscle (SCM) electrode placement.
„ Colebatch JG, Halmagyi GM, Skuse NF. (1994). Myogenic potentials generated by a clickclick-evoked
vestibulocollic reflex. J Neurol Neurosurg Psychiatry,
Psychiatry, 57(2):19057(2):190-7.
Integrity - Service - Excellence
Coding
„
„
„
There is no specific code for VEMP testing
92585 or 92586
Auditory evoked potentials for evoked response
audiometry and/or testing of the central nervous
system
„
92585 is for limited testing; suggests unilateral testing
„ 92586 is for comprehensive; suggests bilateral testing
„
Don’t do ABR and VEMP in the same session, as
you can only bill for one.
Integrity - Service - Excellence
VEMP Reports
“Responses were recorded down to 80dBnHL in the left ear and 60dBnHL
in the right ear. Amplitude values of 110µV in the left ear and 312µV in
the right ear were consistently recorded. Results in the right ear only
indicate superior canal dehiscence syndrome.”
“Responses were recorded at 85dBnHL in the right ear and 90dBnHL in
the left ear. Consistent amplitude values of 120µV in the right ear and
100µV in the left ear were obtained. Results indicate normal saccular
function in both ears.”
“No responses were obtained in the right ear at the limits of the equipment.
Threshold responses were obtained in the left ear at 85dBnHL and a
consistent amplitude value of 80µV was obtained at 100dBnHL. Results
in the right ear are consistent with patient’s diagnosis of Meneire’s
disease. Results in the left ear are normal.
Integrity - Service - Excellence