Point to remember: Note the Vestibular nerve innervations of Sup and Inf. Vest N.
Dizzy battery at a glance
Dizzy battery at a Glance
MOHAMMAD S. ASGHAR
AU.D (USA) , AUD (C), REG.CASLPO.
M.SC AUDIOLOGICAL MEDICINE (UK),
M.B,B.S (PB) M.C.P.S (ENT)
CERTIFIED BY THE AMERICAN BOARD OF AUDIOLOGY (ABA)
DIRECTOR HEARING & BALANCE SERVICES
Common Cochlear Artery
Main Cochlear Artery
Vestibulo Cochlear artery
Post Vest A
Post SCC Ampulla
Majority of Scaula
Ant Vestibular A
Anterior SCC Ampulla
Horizontal SCC Ampulla
Minority of Sacula
Anatomic and Basic Medical considerations:
Vestibular system consists of two groups of specialized
1: Three semicircular canals Lateral or
horizontal, Posterior or inferior, Superior or
vertical SSC, which originate from utricle and
also end at utricle at a dilated end called
2: Two otolith organs: Utricular macula and
Vestibular testing, (Introduction)
In vestibular testing we are always testing output of
We do not have any direct clinical measurement for
1) For ENG, vHIT and Rotary Chair tests we use VOR
2) For Posturography we use VSR.
3) For VEMP we use vestibulocolic response (VCR)
4) For Meniere's Disease and endolymphatic
Hydrops we use Ecoch.G and VEMP.
The Vestibulo-ocular reflex;
The VOR normally acts to maintain stable vision
during head motion. This reflex has two
The angular VOR, mediated by the SCCs,
compensates for rotation.
The linear VOR mediated by the otoliths,
compensates for translation.
-- Tests based on VOR: ENG, rotary chair test, VAT,
Active head rotation test, Dynamic visual acuity test,
oVEMP & vHIT
The Vestibulospinal Reflex
The purpose of the VSR is to stabilize the body. The
activity is induced on the side to which the head is
inclined, and flexor activity s induced on the
-- Tests Based on VSR: Computerized dynamic
posturography (CDP, Sensory integration test).
The Vestibulocollic Reflex.
The VCR acts on the neck musculature to stabilize
-- Tests Based on VCR: cVEMP
Tests involving Sup. and inf. divisions of
Sup. Vestibular N: ENG, caloric test, High frequency
head shake test, Rotary chair test, VAT, oVEMP &
Inf. Vestibular N: VEMP , This is the only test
available to test the integrity of the Inf. Vestibular N
of Vestibular nerve & Now vHIT can also test part of
Inf Vest N.
What are we testing?
Five motion sensors –
VOR (i.e. Input/output, ENG /R chair) lateral canal
only & now vHIT and oVEMP (Utricle and All SSC).
VCR (VEMP test) saccule only
Abnormal gravity sensitivity (positional nystagmus)
Tracking (pursuit, saccade test, OKN test) ,
Sensorimotor integration (posturography)
only VSR, documents functional aspects of the
Believe in yourself (your own exam)
Quality control on vestibular testing is nonexistent
Computer software is crude
No method exists of recording torsion (which you
need for BPPV)
There are many places where corners can be cut or
things can go wrong
Experienced eyes (with Frenzel's) are sometimes are
more reliable than most ENG’s
So no substitute for experience and your clinical
VEMP may add
Inf. Vest. N
Assessment of vestibular function has advances from
ENG being the only test to a test battery approach
where we can actually diagnose the site of lesion to
the exact receptor site in the ear.
Although we are still struggling to manage the dizzy
patients after diagnoses but armed with the
diagnoses we can better prepare the patient to deal
with the problem and become a part of rehab team.