Approach to a vertiginous patient.pptx

Approach to a vertiginous
patient , examination and
investigations
Dr Safika Zaman
RKMSP,VIMS
DEPT OF ENT & HNS

Vestibular
nerve
 Vestibular nerve is made
up of about 25,000
neurons.
 These neurons are
bipolar, with cell bodies
located in the vestibular
nerve near the brain
stem in Scarpa's
ganglion

PLANESOF
MOTION
 Right anterior (RA) canal
is parallel with the left
posterior (LP) canal and
both lie in a plane
denoted as the RALP
plane.
 Together with the right
posterior (RP) canal the
left anterior (LA)
constitutes the LARP
plane.
 Both horizontal canals are
also parallel with each
other in the lateral plane.

Spatial
orientation
 The vestibular system
 The visual system (retina to occipital cortex)
 The somatosensory system

FUNCTIONOF
VESTIBULAR
SYSTEM
 Gaze stabilization
 Balanced locomotion and body position
 General orientation of the body with respect to gravity .
 Readjust autonomic functions after body reorientation

MOTION
DECOMPOSITION
 Every motion in space
can be broken down
into three rotational
degrees of freedom
(yaw, pitch and roll)
and three
translational degrees
of freedom (left–right,
up–down, fore–aft).

OTOLITH
ORGANS
 Saccule and utricle are relatively
orthogonally oriented to each other.
 Horizontal plane triggers predominantly
the utricle.
 Vertical movements trigger mainly the
saccule.

 The implantation of the hair cells
is opposite for both right and left
canals as a mirror image, the
deflection on the ‘leading’ right
side induces a movement of the
stereocilia towards the
kinocilium, whereas on the
opposite ‘following’ ear the
movement of the stereocilia is
away from the kinocilium.

Cont..
 Each horizontal canal is maximally excited by a rotation toward
the side of the canal and inhibited by a rotation in the opposite
direction.
 This results in an excitatory Slow phase movement toward the
side opposite the canal and a resetting saccade toward the canal.

Cont..
 The superior canal is excited by a rotation downward and to the
side, in the plane of the canal.
 This results in a vertical-torsional nystagmus, with the slow phase
of the vertical component upward and the resetting saccade
downward.
 The posterior canal is excited by an upward rotation and to the
side, in the plane of the canal, so that the slow phase is downward
and the resetting phase upward.

Velocity
storage
 Process that maintains the sense of rotation even after the
rotation has stopped.
 In patients with peripheral vestibular dysfunction, the velocity
storage mechanism may cease to function.
 This causes rotation-induced nystagmus.

Neural
integrator
 Process that provides the signal to hold the eyes away from
"primary position" facing straight ahead. when looking away from
primary position.
 Extraocular muscles require a burst of activity to move the eyes to
their eccentric position and then a sustained level of discharge
that signals the muscles to hold the eye in an eccentric position.
 In patients with vestibular loss, this process may become
dysfunctional and the eyes may drift inappropriately toward
primary position.

Vestibulo-
ocular reflex
Resting discharge rate of 90 spikes per second. > Head
rotation is to the right.
Endolymph moves left within each SCC due to inertia
The cupula bends to the left in each canal.> In the
(leading) right SCC the stereocilia bend toward the
kinocilium.> In the (following) left SCC the stereocilia
bend away from the kinocilium.
The discharge rate increases in the leading right ear
The discharge rate decreases in the following left ear
>The vestibular nuclei interpret the difference in
discharge rates between left and right SCCs as move
and therefore trigger the oculomotor nuclei to drive
the eyes to the left to maintain gaze stabilization

History
 History is often sufficient to identify a likely cause of his or her
symptoms.
 History of a patient with a complaint related to dizziness should
begin in an open-ended fashion.

Vertigo – a clinical approachMan Mohan Mehndiratta,Rohit Kumar, New Delhi

Causes of
vertigo
Vertigo among elderly people: Current opinion
Santosh Kumar Swain1, Nishtha Anand1, Satyajit Mishra2

Drugs
Vertigo: Helping Patients Identify and Manage It
March 17, 2015
Yvette C. Terrie, BSPharm, RPh

Examination  Much of the examination of peripheral labyrinthine function is
dedicated to evaluating semicircular canal function,

Post
headshaking
nystagmus
 Post head shaking nystagmus occurs in patients with imbalance in
dynamic vestibular function.
 Unilateral loss of labyrinthine function, however, there is usually a
vigorous nystagmus with slow-phase components initially
directed toward the lesioned side.

Kerber KA, Baloh RH. Dizziness, vertigo, and hearing loss. In: Bradley
WG, Daroff RB, Fenichel GM, Jankovic J. eds. Neurology in clinical practice

Nystagmus
 It is a rhythmic, involuntary, rapid, oscillatory movement of the
eyes. It may have a slow, fast, or a combination of both. It can be
continuous, paroxysmal, with positional or gaze or head
positioning triggers.

Inspection for
Spontaneous
Nystagmus
 Vestibular evoked nystagmus is termed "jerk nystagmus" and
comprises a drifting slow phase followed by a rapid resetting
motion.
 The direction of this type of nystagmus is typically named
according to its fast phase.
 The amplitude of nystagmus is often reduced if a patient is able to
fixate on a target.
 Examination for nystagmus should therefore take place with the
patient wearing Frenzel goggles.

Clinical tests
Examination Method Interpretation
Spontaneous Nystagmus Patient sitting in upright
position and looking in the
Primary gaze position
(looking straight ahead 0
degree and horizontal) to a
fixed target, first with the
eyes best corrected vision
(glasses if needed)
Normal: fixed gaze
Vestibular pathology:
Horizontal—torsional, jerk
nystagmus
Central pathology:
changing in direction,
horizontal, vertical,
torsional, or pendular
nystagmus,

Clinical tests
Gaze-evoked Nystagmus Patient’s head fixed
ahead, eyes looking in
eccentric gaze (off the
Primary gaze position) to
a point within 0 to 30
degrees right and left
Normal: fixed gaze
Direction fixed
nystagmus, increases
while gazing in the
direction of the fast phase
(better vestibule)
Central pathology:
Direction changing
nystagmus, fast-phase
movement in the direction
of gaze, or rebound
nystagmus in neutral gaze

ClinicalTests
Eyes Saccades Alternate patient’s eyes
fixation (head fixed
straight ahead), on the
nose of the examiner in
the Primary gaze
position and his finger
in 15 degrees right ,
left, up, and down
normal fixed
Central pathology:
Abnormalities in eyes
movement (Accuracy,
conjugate movement,
velocity ,and initiation

ClinicalTests
Smooth pursuit Examiner positions his
index finger directly in
front of the patient and
moves the target
smoothly 20 to 30
degrees per second
fast, first in the
horizontal plane and
then in the vertical
plane.The testing area
is restricted to 30
degrees to the left,
right, up, and down
from Primary gaze
position
Normal patients,
Normal smooth
movement.
Central pathology:
catch-up saccades

ClinicalTests
Head ShakingTest Patient’s head tilted 30
degrees forward to
make the LSCC
horizontal, head is
rotated 30 degrees
alternating to both
sides, in a 2HZ
frequency for 20
seconds, then sudden
stop the head and
observe the eyes
fixation.Test can be
repeated in vertical
plane
Normal patient or equal
vestibular loss on both
sides: fixed gaze.
Asymmetric vestibular
pathology (> 50%
unilateral damage):
nystagmus (in plane of
damaged canal with
fast phase toward
stronger ear). Central
pathology: cross
coupling of nystagmus

Clinical tests
Head impulse test (HIT) To test the SCCsThe
patient is asked to
fixate his eyes on the
examiner's nose, while
the head is impulsively
(suddenly) and
unpredictably moved
20 to 30 degrees in one
direction.The velocity
of the head movement
must exceed 200
degrees/second,
examiner should start
at low speed and
gradually increase to
the test speed
Normal: fixed gaze
Vestibular pathology (>
50% unilateral
damage): Re-fixation
saccade generated
when doing rotational
head thrusts in a
direction supposed to
stimulate the
pathologically inhibited
SCC Central Pathology:
Test negative (most of
the time)

ClinicalTests
Posture
Romberg tests
patient is asked to
stand with his feet
together and arms
down
Normal: Normal
postureVestibular
Pathology: Fall to the
weak side with eyes
closed, balance
improves when eyes
open Central
Pathology: Falls with
eyes open
ISSN 2515-8260 Volume 08, Issue 03, 2021 319
Vestibular Physiology andTesting
ApproachedAuthor:Dr. Basel Samman

ClinicalTests
GaitTandem gait,
Unterberger (Fukuda)
stepping test
Tandem gait: Patient
walks in line with his
heals touching toes,
eyes open and closed
Unterberger (Fukuda):
Patient marches in
place with his arms
extended in front for 2
minutes eyes open and
closed stepping test:
Patient walks 2 steps
forward and backward
repeatedly eyes open
and closed
Normal: Normal gate
Vestibular Pathology:
Abnormal tandem gait
with eyes closed,
rotation to side of
lesion.Gate improves
with eyes open Central
Pathology: Gait
abnormalities (e.g.,
ataxia, shuffling, etc.)
with eyes open and
closed
ISSN 2515-8260 Volume 08, Issue 03, 2021 319
Vestibular Physiology andTesting
ApproachedAuthor:Dr. Basel Samman

Positional
Testing
 The Dix-Hallpike maneuver- BPPV: Posterior canal BPPV results in
a vertical-torsional nystagmus with the slow phase components of
the nystagmus directed downward and toward the uppermost ear.

Dynamic visual
acuity
 The patient reads a Snellen chart with the head stationary and
visual acuity is recorded.
 Letters can be read from an optotype chart or a computer screen.
 Passive or active head movements can be used, or the individuals
can walk on a treadmill
 Normal vestibular function typically show no more than a one-line
decline during head movement but thoseWith vestibular
hypofunction (particularly bilateral hypofunction) may show up to
a five-line decline in acuity.

CochlearVIII
nerve function
 Rinne test
 Weber test

Electrocochleo
graphy
(ECochG)
 Cochlea – transducer of sound energy to electrical energy .
 The electrical energy generated at the cochlear end of auditory
nerve , documented and measured in a system called
electrocochleography.

 Invasive – intra –
tympanic electrode
placement.
 Non – invasive –
intracanalicular
electrode placement

Electronystag
mography
(ENG)
 Besically evaluates the functioning ofVOR.
 Parameters – slow phage velocity , amplitude , frequency ,
duration , fast phase velocity , total number of beats , latency etc .
 By convention , a movement of the eyes to the right is recorded as
upward deflection.
 A movement to the left is downward deflection.

The caloric test
 It allows independent assessment of reponce from right and left
labyrinths.
 Does not require head movement to be conducted, rendering
better patient compliance in those patients whose symptoms
worsen with movement.
 Brain stem testing in comatose patients. lack of nystagmus could
indicate a brainstem lesion.

Caloric test
 Bilateral weakness – total responses from the right and left is less
than 12 / sec
 Abnormal spontaneous nystagmus - more than 6 / sec.
 Unilateral weakness- difference between the right and left ear is
25%.

VEMP
 Ears are stimulated with air-conducted sound or bone-conducted
vibration and muscle reflexes are recorded from electrodes on the
sternocleidomastoid (SCM) neck muscles or near the inferior
extraocular muscles.

Clinical
Application
 Diagnosis of SCD and other third window disorders, in which
VEMPs provide evidence of vestibular hypersensitivity to sound.
 Air-conducted cVEMP and oVEMP thresholds are lowered and air-
conducted oVEMP amplitudes are enlarged.
 Return to normal following surgery

Videonystagm
ography (VNG)
 Technique – to see the subjects eye even in complete darkness
 The person wears a goggle.
 The eyes are illuminated with infrared goggle
 Infrared camera captures a video of the eye
 A tracing of pupil centre movement is obtained.

 Clinical Audiovestibulometry – DrAniran Biswas

Approach to a vertiginous patient.pptx

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