Assessments of vestibular system

2. ASSESSMENTS OF
VESTIBULAR SYSTEM
DR ABDUL QAWI
ENT RESIDENT
NISHTAR MEDICAL UNIVERSITY
MULTAN

3. VESTIBULAR SYSYTEM
PERIPHERAL :
 MEMBRANOUS LABYRINTH (SEMICIRCULAR DUCTS, UTRICLE &
SACCULE) AND VESTIBULAR NERVE
CENTRAL:
 Nuclei and fibre tracts in the central nervous system to
integrate vestibular impulses with other systems to
maintain body balance

5. VESTIBULAR SYSYTEM FUNCTION
 Provides information concerning gravity, rotation
and acceleration
 Serves as a reference for the somato-sensory &
visual systems
 Contributes to integration of arousal, conscious
awareness of the body via connections with
vestibular cortex, thalamus and reticular
formation
 Allows for:
 gaze & postural stability
 sense of orientation
 detection of linear and angular acceleration

7. DISORDERS OF VESTIBULAR
SYSTEM
Cause vertigo and are divided into:
 Peripheral (85% of all cases of vertigo) :
involve vestibular end organs and vestibular
nerve.
Ex: Meniere's disease, benign paroxysmal
positional vertigo, labyrinthitis, acoustic neuroma
etc.
 Central: CNS after the entrance of vestibular
nerve and vestibulo-ocular, vestibulo-spinal and
other CNS pathways
Ex: vertebro-basilar insufficiency, basilar migraine,
cerebellar disease, multiple sclerosis, tumours of
brain stem etc.

8. Investigations of vestibular system involves two categories:
They are:
Clinical methods
• Spontaneous Nystagmus
• Fistula test
• Romberg test
• Gait
• Past-pointing and falling
• Hallpike-manoeuvre (positional test)
• Test of cerebellar dysfunction
Laboratory
methods
1. Caloric Test
2. Electronystagmography
3. Optokinetic Test
4. Rotation Test
5. Posturography

9. SPONTANEOUS NYSTAGMUS
NYSTAGMUS – defined as involuntary, rhythmical, oscillatory movement
of eyes
it isan important sign in evaluation of vestibular system
It can be either horizontal /vertical/rotatory
It has 2components
SLOW FAST
The direction of this
component indicates the
direction of the
nystagmus

11. Intensity of nystagmus is indicated by its degree.
AS PER ALEXANDER’S LAW,
This law may not hold true in case of nystagmus of central region
1st DEGREE
2nd DEGREE
3rd DEGREE
It is weak nystagmus and is
present when patient looks in
the direction of fast component
It is stronger than 1st degree and
is present when patient looks
straight ahead
It is stronger than the 2nd degree
and is present when the patient
looks in the direction of the slow
component

12. PROCEDURE:
Patient is seated in front of the examiner/lie in supine position on
bed
Examiner keeps his finger 30cm away from patient’s eye in central
position
Examiner moves his finger to the right, left, up or down
( but not moving anytime more than 30˚ from the central position
to avoid gaze nystagmus)
INDICATION:
PRESENCE of spontaneous nystagmus is indicative of ORGANIC
LESIONS
Tone of imbalance of vestibulo-ocular reflux

13. VESTIBULAR NYSTAGMUS consists of two types of lesions:
central
Vestibular nuclei,
Brainstem,
cerebellum
Due to lesion in
central neural
pathway
peripheral
Due to lesion of
labyrinth/viii
nerve
Irritative lesions(Sensory
labyrinth)
Nystagmus is on
the side of lesion
Paretic lesions
Nystagmus is on
the opposite side
Includes:
Purulent labyrinthitis
Trauma to labyrinth
Section of viii nerve

14. Peripheral nystagmus – is suppressed by optic fixation
Enhanced by darkness and use of FRENZEL GLASS
Central nystagmus is not supressed by optic fixation
TORSIONAL NYSTAGMUS – Indicates lesion of brainstem/vestibular nuclei
E.g.. SYRINGOMYELIA
VERTICAL DOWNBEAT NYSTAGMUS – Lesion is at cranio-cervical region
Arnold-chiari malformation/degenerative lesion o
f
cerebellum
VERTICAL UPBEAT NYSTAGMUS – Lesion at the junction of
pons and medulla/pons and midbrain
PENDULAR NYSTAGMUS – congenital/acquired
E.g.. Multiple sclerosis
May also be disconjugate
Via., vertical in one eye
and horizontal in other.

16. PERIPHERAL CENTRAL
LATENCY 2-20 s No latency
DURATION Less than 1 min More than 1 min
DIRECTION OF NYSTAGMUS Direction fixed towards the
under most ear
Direction changing
FATIGUABILITY fatiguable nonfatiguable
ACCOMPANYING SYMPTOMS Severe vertigo none or slight
DIFFERENCES IN NYSTAGMUS OF PERIPHERAL N CENTRAL LESIONS

17. FISTULA TEST
PRINCIPLE:
Induce NYSTAGMUS
Pressure changes in external auditory canal are produced
These changes are transmitted to the labyrinth
Stimulation of the labyrinth
Production of NYSTAGMUS and VERTIGO

18. PROCEDURE:
Apply intermittent pressure on tragus
OR
By using Siegel's speculum
INDICATIONS:
IN NORMAL PERSON: NEGATIVE
because pressure changes in external auditory canal can’t be
transmitted to labyrinth
ABNORMALITY: POSITIVE
Erosion of horizontal semi-circular canal- cholesteatoma
Surgically created window in horizontal canal- fenestration
operation
Abnormal opening in oval window- poststapedectomy fistula
Abnormal opening in round window- rupture of round
window membrane
ALSO INDICATES THAT LABYRINTH IS STILLFUNCTIONAL

19. RUPTURE OF ROUND WINDOW MEMBRANE

20. FALSE NEGATIVE FISTULA TEST :
 IN CHOLESTEATOMA: it covers the site of
fistula and it doesn’t allow pressure
changes to be transmitted to the labyrinth
 IN LABYRINTH DEAD
FALSE POSITIVE FISTULA TEST :
 Means +ve test without presence of fistula
It is seen in two conditions : 1.congenital syphilis
2.Meniere’s disease.
 Congenital syphilis: stapes footplate is
hypermobile
 Meniere’s disease: due to fibrous bands connecting
utricular macula to the stapes
footplate.

21. ROMBERG TEST
PROCEDURE :
Patient is asked to stand with feet together and arms by side with eyes first
open and then closed.
Witheyes open : patient can still compensates the balance
With eyes closed : patient cant compensate –Here VESTIBULAR SYSTEM is at
MORE DISADVANTAGE
If patient perform this test without sway then SHARPENED ROMBERG TEST is
performed.
Peripheral:
Patient sways to
side of lesion
Central:
instability
PROCEDURE:
Patient is asked to stand
with one heel in front of
toes and arms folded across
the chest.
Inability to perform this test
Indicates vestibular impairment

23. SHARPENED ROMBERG TEST

24. GAIT
PROCEDURE:
Patient walks along a straight line to a fixed point first with
eyes opened and then closed.
In the case of uncompensated lesion of peripheral vestibular system,
with eyes closed
Patient deviates to affected side

25. PAST-POINTING AND FALLING
PAST-POINTING
FALLING
SLOW COMPONENT OF NYSTAGMUS
E.g. In ACUTE VESTIBULAR FAILURE on RIGHT side
All fall in the same
direction
NYSTAGMUS – on left side
Past pointing
Falling
On right
side
i.e. towards the
side of the slow
component

26. PROCEDURE:
First, the patient is asked to touch his/her index finger to the
examiner’s index finger with the eyes open
Next, the same is repeated with the eyes closed
If abnormality is present then the patient cannot elicit the
procedure with his/her eyes closed.

27. PAST-POINTING AND FALLING TEST- WITH
EYES OPENED

28. PAST-POINTING AND FALLING TEST-
WITH EYES CLOSED

29. HALLPIKE MANOEUVRE
(POSITIONAL TEST)
USES: 1. when patient complains of vertigo in head position
2. helps to differentiate a peripheral from a central lesion.
METHOD:
Patient sits in the couch
Examiner holds the patient’s head, turns it 45˚ to the right and then places the
patient in a supine position so that his head hangs 30˚ below the horizontal.
Patient’s eyes are observed for nystagmus
The test is repeated with head turned to left and then again in straight head-
hanging position .
Four parameters are observed: 1. Latency
2. duration
3. direction
4. fatiguability

33. In benign paroxysmal positional vertigo
Nystagmus appears after latency : 2-20s
duration : less than 1 min
direction : one i.e. towards the ear that is
under most
On repetition – nystagmus may be elicited but lasts for a shorter period.
On
subsequent
repetition
Nystagmus
disappears
altogether
NYSTAGMUS IS
FATIGUABLE

34. IN CENTRAL LESIONS Tumours of 4th ventricle
Cerebellum
Temporal lobe
Multiple sclerosis
Vertibrobasilar insufficiency
or
Raised intracranial tension
 Nystagmus is produced immediately
as soon as the head is in critical
position
 No latency
 Duration: lasts as long as head is in
that critical position
 Direction: changes
 Fatiguability: nonfatiguable

35. TEST OF CEREBELLAR DYSFUNCTION
Cerebellar
diseases
MIDLINE DISEASE OF CEREBELLUM
CAUSES:
1. Wide base gait
2. Falling in any direction
3. Inability to make sudden turns
while walking
4. Truncal ataxia
For cerebellar diseases – all cases of giddiness should be tested.
CEREBELLAR HEMISPHERE CAUSES:
1. Asynergia(abn finger-nose
test)
2. Dysmetria(inability to control
range of motion)
3. Adiadochokinesia (inability to
perform rapid alternating
movements)
4. Rebound phenomenon
(inability to control
movement of extremity when
opposing forceful restraint is
suddenly released)

36. Nystagmus observed in cerebellar diseases either in
hemisphere or midline diseases include
GAZE
EVOKED NYSTAGMUS
REBOUND NYSTAGMUS
ABNORMAL OPTOKINETIC NYSTAGMUS

38. • The basis of the test is to induce nystagmus by thermal
stimulation of the vestibular system. It includes,
MODIFIED KOBARK TEST:
•The patient is seated with the head tilted 60˚ backwards
to place horizontal canal in vertical position.
•The ear is irrigated with ice water for 60s, first with 5ml
and if there is no response 10, 20 and 40mL
•Normally, nystagmus beating towards the opposite ear
will be seen with 5 mL of ice water •If response is seen
with increased quantities of water between 5 and 40mL,
labyrinth is considered hypoactive

39. FITZGERALD-HALLPIKE TEST
(BIOTHERMAL CALORIC TEST)
The patient lies supine with head tilted 30˚ forward so
that horizontal canal is vertical
Ears are irrigated for 40 s alternatively with water at
30˚C and at 44˚C and eyes are observed for appearance of
nystagmus till its end point
Time taken from the start of irrigation to the end point of
nystagmus is recorded and charted on calorigram
If no nystagmus is elicited from any ear, test is repeated
with water at 20˚C for 4 min before labelling the labyrinth
dead
A gap of 5 min should be allowed between 2 ears
Cold water induces nystagmus to opposite side

40. COLD-AIR CALORIC TEST:
This test is done when there is tympanic
membrane perforation because irrigation with
water is contraindicated in such case. the test
employs dundas grant tube, which is a coiled
copper tube wrapped in cloth. the air In the tube
is cooled by pouring ethyl chloride and then blown
into the ear. It is a rough qualitative test.

41. CANAL PARESIS :
It indicates the response elicited from a particular
canal (labyrinth) right or left after stimulation
with cold and warm water is less than that from
the opposite side
DIRECTIONAL PREPONDERANCE
It considers the duration of nystagmus to right or
left irrespective of whether it is elicited from right
or left labyrinth. if the nystagmus is 25-30% or
more on one side than the other , it is called
preponderance to that side

42. ELECTRONYSTAGMOGRAPHY
It is a method of detecting and recording
nystagmus, which is spontaneous or induced by
caloric, positional, rotational or optokinetic
stimulus
The test depends on the presence of corneo-
retinal potentials which are recorded by placing
electrodes at suitable places round the eyes .
o Useful to detect nystagmus which is not seen
with naked eyes.
o Permits to keep a permanent record of
nystagmus.

43. OPTOKINETIC TEST
Optokinetic nystagmus, is the eye movement elicited by the tracking
of a moving field.
Patient is asked to follow a series of vertical stripes on a screen
moving first from right to left and then from left to right
Normally it produces nystagmus with slow component in the direction
of moving stripes and fast component in the opposite direction
Optokinetic abnormalities are seen in brainstem and cerebral
hemisphere lesions.
ROTATION TEST
Patient is seated in barany’s revolving chair with his head tilted
30˚forword and then rotated 10 turns in 20s, the chair is stopped
abruptly and nystagmus observed.
Normally there is nystagmus for 25 to 40s . It is useful in cases of
congenital abnormalities

44. GALVANIC TEST
The patient stands with his feet together, eyes closed and arms
outstretched and then a current of 1mA is passed to one ear
It is the only vestibular test which helps in differentiating an end
organ lesion from that of vestibular lesion
Normally, person sways towards the side of anodal current.
POSTUROGRAPHY
The vestibular function is evaluated by measuring postural stability
It is based on the fact that maintenance of posture depends o three
sensory inputs ie. Visual, vestibular and somatosensory.
It uses either a fixed or moving platform, visual cues can also be
varied

45. BENIGN PAROXYSMAL POSITIONL
VERTIGO ( BPPV)
Characterized by vertigo when head is placed in certain
critical position
Caused by disorder of posterior semicircular canal
PATHOPHYSIOLOGY
Otoconial debris ( consisting of crystals of calcium
carbonate ) is released from the degenerating macula of
utericle and floats freely in the endolymph . When it
settles on the capula of posterior semicicular canal in a
critical head position , it causes displacement of capula
and vertigo . The vertigo is fatigable on assuming the same
position repeatedly due to dispersal of otoconia but can be
induced again after a period of rest

46. MANAGEMENT OF BPPV
BPPV can be treated by performing EPLEY`S MANOEUVRE
PRINCIPLE OF EPLEY MANOEUVRE:
Reposition the otoconial debris from posterior semicircular
canal back into utricle

47. EPLEY`S MANOEURVE
MANOEURVE consists of 5 positions
 Position 1: with the head turned 45 degree , the patient
is made to lie down in head hanging position . It will
cause vertigo and nystagmus. Wait till vertigo and
nystagmus subsides
 Position 2: Head is now turned so that affected ear is
facing up to 90 degree rotation
 Position 3: the whole body and head are now rotated
away from affected ear to a lateral recumbent postion in
a 90 degree rotation face down position .
 Position 4 : patient is now brought to a sitting position
with head still turned to the unaffected side by 45
degree
 Position 5 : the head is now turned forward and chin
brought down 20 degree