VEMP testing provides a method to evaluate otolith function in the inner ear by measuring electromyographic responses from the sternocleidomastoid (cVEMP) and inferior oblique ocular muscles (oVEMP) elicited by sound stimulation. cVEMP assesses the saccule and vestibular nerve pathway while oVEMP assesses the utricle pathway. VEMP testing is useful in clinical diagnosis of various vestibular disorders including neuritis, Meniere's disease, vestibular schwannoma, and more. Standardization of stimulation and recording methods is still needed for VEMP to be effectively utilized in clinical practice.

1. VEMP
Florensia Elita Pratiwi, HR Yusa Herwanto
Refarat THT Komunitas

2. Introduction
• First sound that evoked vestibular response was explained by Von Békésy in 1935.
• He used high intensity sound (approximately 134 dB) for producing head movement
to the sound stimuli.
• This phenomenon can be explained by the fact of correlation between footplate
stapes with hair cell of macculae sacculae that activate afferent neuron.
• In the year of 1992 Colebatch., et al recorded VEMP for the first time from cervival
muscles (cVEMP)
• In 2007 Todd., et al recorded alternative type from ocular muscles (oVEMP)

3. For ensuring basic in physiology of VEMP, McCue and
Guinan identified some fibers of vestibular nerve inferior
that responding electrically to sound stimuli above 80 dB
SPL (sound presure level), that enhancing electrical activity
as stimuli that intensified, confirming hypotesis that
electrical potential for obstructing muscle from sacculus and
afferent pathway in IVN (Inferior Vestibular Nerve).

6. Inner Ear Anatomy
• Inner ear consists of cochlea with two and a half cycle of circle and vestibular that consists
of 3 semicircular canals.
• The top of cochlea is helicotrema, connecting perilymph tympanic scale with vestibuli scale.
• Semicircularis canal is connecting incompletely and forming incomplete circle.
• In cross sectional cochlea vestibuli scale in the upper side, tympani scale lower side and
media scale (cochlear duct).
• Vestibuli scale and tympani scale contains of perilymph and media scale contains of
endolymph
• Basis of vestibuli scale called of vestibuli membrane (Reissner’s membrane) and basis of
media scale is basalis membrane which organ Corti within it.
• In media scale there is tectorial membrane, and basalis membrane there is hair cell that consists of inner
hari cell, outer hair cell an Corti canal that forming organ Corti

7. Hearing Physiology
• Sound energy comes inside ear lobe (from air/ bone) to the cochlea.
• Vibration from tympanic membrane  middle ear (osiccle) amplification from osiccle stapes
(vibrate oval window perilymph in vestibuli)
• Vibration from Reissner membrane pushing endolymph  relative movement between
basilaris membrane and tectorial membrane  defflexion hair cells stereocillia  ion canal
opened  electrical ions from cell body  hair cell depolarisation  neurotransmitter to the
sinaps  action potential in auditory nerve  auditory nerve
• Nerve fibers  dorsalis and ventralis cochlear nucleus  contralateral inferior coliculus, some
fibers still in ipsilateral.
• Next crossing was in lateral lemniskus and inferior coliculus  genikulatum corpus  auditory
cortex (temporalis lobe)

8. Basic Introduction of VEMP
• In mammals, sacculi has hearing function also  high intensity of sound
stimuli, the left sacculi cells stimulated  inhibition of SCM muscle reflex
ipsilateral  relaxation  contralateral muscle contracted
• Unilateral inhibiton reflex  catch by electrode in SCM muscle = VEMP
• The remain hair cells in sacculi begin VEMP  stimulus was carried to the
center nerve system from vestibular nerve inferior (IVN)  VEMP becomes
new method for diagnosing and finding out vestibular system

9. • Otolith organ consists of sacculus and utricculus  response head linear
acceleration
• Vestibular-evoked myogenic potentials (VEMPs) was useful for evaluating otolith
function
• Two subtypes VEMP that now been using were cervical and occular
• Cervical VEMP been used for evaluating nerve pathway that consists of
sacculi, vestibular nerve, and nucleus, and vestibulospinal desendens tract
that is nerves for cervical muscle
• Cervical VEMP = biphasic waves from positive and negative that is in 13
and 23 ms, after stimulation, that can be detected in the surface of
sternocleidomastoideus muscle

10. • Occular VEMP was used for evaluating nerve pathway that consists of
utricculus, vestibular nerve, and nucleus, and medial longitudinal fasiculus,
that end in inferior oblique muscle.
• Occular VEMP also a biphasic wave that formed from negative and positive
potential that observed each in 10 and 15 ms, after stimulation, and can be
measured precisely below middle line inferior orbital

11. • Stimuli and neural substrate from
VEMP. AC: air conducted; BC: bone
conducted (suara); IO: inferior oblique
muscle; III; oculomotor nucleus, IV:
trochlear nucleus; MLF: medial longitudinal
fasciculus; VI: abducens nucleus; VNs:
vestibular nucleus; U: utricle; VST:
vestibulospinal tract; S: saccule; SCM:
sternocleidomastoid muscle

12. Testing type of VEMP
• Two kind of VEMP types: Cervical VEMP (cVEMP) and occular VEMP
(oVEMP).
• cVEMP  sound stimuli to 1 ear concomitanly with recording of EMG
surface of sternocleidomastoideus ipsilateral.
• Vestibular cells that responsive for sound, particularly sacculi inner ear for
inhibiting ipsilateral muscle tonus via cervical vestibulocholic pathway
• EMG response in the surface of ipsilateral sternocleidomastoid muscle that
contracts tonic, for resulting response in biphasic wave shape.

14. • Electrode placing for cVEMP right
ear.
• Elektrode that record in the surface
placed in right sternocleidomastoid
kanan that contracted (get from
patients moving their head
circularly active to the left and
moving upward) during recording

15. A. VEMP test in left side
with earbud and
elektrode placing in
SCM, B. VEMP wave
typical in normal patient.
Showing first positive
(P1) approximately 13
ms and 2nd negative wave
(N1) approximately 23
ms, C. Typical VEMP
curve in normal patient,
showing response
threshold in main
frequency that measured

16. Main wave in cVEMP in normal patient.
Recording from right sternocleidomastoid
muscle in responding toneburst (2 ms duration, 2
ms up/down), with intensity 130 dB pSPL. Wave
shows positive-negative cVEMP cVEMP (p13-
n23) in the side where sound stimuli is given.
Measurement such as latency, amplitude, and
threshold (sound with lowest intensity that still
give respons). Response happened in sound
stimuli from the only sound source side. Some
laboratorium shows inversion wave with wave to
the top positive.

18. • oVEMP test  measures vestibular function
from utricculus via superior vestibular nerve
 crossing midline to contralateral medial
longitudinal fasiculus and oculomotor
nucleus
• oVEMP is using sound stimuli that using
sound stimuli that sent by air or bone and
mean of EMG respond oblique muscle in
surface from contralateral for producing
biphasic wave form.
• Measurement made from beginning of peak
of latency (n10 or n1 and p16 or p2 for
oVEMP) and amplitude peak from peak.

19. Recording from EMG electrode surface
above surface of left inferior oblique as
sound stimuli respond in right ear. Wave
form shows negative-positive oVEMP
(n10-p16, sometimes simply as n1 and p1).
Measurement such as latency, amplitude
and threshold (the lowest intense sound
stimuli that still can give respond).
Response held in only different side on
that accept sound stimuli.

21. VEMP test in clinical appearence
1. Neuritis (VN)

22. 2. Acute vestibular neuropathy
3. Meniere’s disease
4. Vestibular Schwannoma
5. Perilymp fissure
6. Vestibular migrain
7. BPPV
8. Superior semicircular canal dehiscense
9. Central Lesion
10. Intratympanic gentamycin treatment monitoring

23. Reccomendation for upcoming research
• More standarization needed for stimulation and recording method, and normal
range and pathology from amplitude and latency, with report measurement
specification, if cVEMP and oVEMP will use effectively in clinical practice.
• The laboratorium determines normal range and pathology for every test for
younger and older patients
• Quality studies with low bias risk needed for informing berkualitas dengan risiko
bias rendah diperlukan untuk lebih menginformasikan VEMP role in clinical
evaluation several otology and neurology disturbance.

24. Conclusion
• VEMP test is new supplement, that contributed, with other neurological test,
for diagnosing several vestibular disturbance
• Standarization for monitoring SCM muscle contraction, because VEMP
respons widely depends on the muscle activity level.
• VEMP test becomes supplemental test that promising, especially that giving
information about sacculus function and inferior part vestibular nerve.

26. TERIMA KASIH