Approach To Vertigo And Vestibular Function Test

Question 1

What is vertigo ?

Answer 1

Sense of spinning of oneself or their surroundings ; should be differentiated from hypoglycaemia and hypotension

Question 2

What is the most common type / cause of vertigo?

Answer 2

Positional vertigo / BPPV ( Benign Paroxysmal Positional vertigo )

Question 3

What is BPPV?

Answer 3

Paroxysmal episodes of vertigo occurring with change in position

Question 4

What is the most common semicircular involved in BPPV?

Answer 4

Posterior semicircular canal

This is because the otolith(gets dislodged mostly due to idiopathic or trauma)gets easily deposited in the ampulla of the posterior scc due to gravity and causes irritation of the endolymph causing vertigo

Least affected is superior scc

Question 5

Classical history given by patients with BPPV

Answer 5

Episodic vertigo on changing the position of head lasting for few seconds

Question 6

What is DIX-HALLPIKE manoeuvre?

Answer 6

The head is turned towards the right and posteriorly to test the posterior semicircular canal in order to check whether BPPV is related to vertical semicircular canals

Question 7

What is SUPINE ROLL?

Answer 7

To test whether the horizontal semicircular canal is affected or not

Question 8

Nystagmus in both horizontal and vertical scc involvement

Answer 8

In horizontal scc involvement - horizontal nystagmus
In vertical scc involvement - vertical nystagmus

Question 9

What is latency in peripheral nystagmus ?

Answer 9

The nystagmus will start 10-20 secs later after the stimulation of the scc . This delay in the onset of nystagmus is called LATENCY

Question 10

What is the duration of nystagmus?

Answer 10

It lasts for 1-1.5 minutes and does not last for longer period of time

Question 11

What is fatiguable in peripheral nystagmus?

Answer 11

Disappears with repetition (first time appears ; second time disappears)

Question 12

With what the peripheral nystagmus disappears ?

Answer 12

With optic fixation (focusing on an object) peripheral nystagmus disappears

Prevented by wearing FRENZEL GLASSES - high diopter glasses=+20D ; also causes magnification of the eye

Question 13

What are the components of peripheral nystagmus / jerk nystagmus ?

Answer 13

Slow component (because of disease) and fast component (corrective phase)

Direction of nystagmus is always the fast component since slow component can’t be appreciated

Question 14

In which direction does the labyrinths tries to push the eye?

Answer 14

In the opposite direction

Right side labyrinth - pushes the eye to the left
Left side labyrinth - pushes the eye to the right

Normally both functions equally and in opposite direction and maintains the position of the eye in mid line

Question 15

What happens in the case of hyperactive labyrinth ?

Answer 15

In case of hyperactive labyrinth , say the left, the eye is pushed to the right due to hyperactivity of left labyrinth(slow component)and brain senses this as abnormal and tries to correct the position back to normal (fast component)

In hyperactive labyrinth , the fast component (direction of nystagmus ) is toward the affected / diseased ear eg:BPPV

Question 16

Direction of nystagmus in hypoactive labyrinth ?

Answer 16

The direction of nystagmus / fast component is toward the normal ear eg:Ménière’s disease

Always the direction of nystagmus is towards the more active ear

Question 17

Characteristics of peripheral nystagmus

Answer 17

Latency
Fatiguable
Torsion present
Duration
Direction
Disappears with optic fixation
Direction of nystagmus is always the fast component

Question 18

What is vestibular neuritis ?

Answer 18

It is the acute infection (viral) of the vestibular nerve

Question 19

What to do if the vertigo is not suggestive of BPPV?

Answer 19

Whenever the vertigo lasts for longer period of time

Then we have to rule out whether the cause of vertigo is central or a peripheral cause

Question 20

For ruling out peripheral causes of vertigo we have to ask for ?

Answer 20

Hearing loss (in vestibular neuritis there’s only vertigo and there’s no hearing loss)
Tinnitus
And confirm there’s no cranial nerve involved

Question 21

For ruling out central causes of vertigo we have to ask for ?

Answer 21

Any cranial nerve involvement
Diplopia
Ataxia
Dysarthria
Motor weakness
Headache

Question 22

What do to if none of the history is positive for the patient except for vertigo to rule between central and peripheral nystagmus ?

Answer 22

We have to look for characteristics of nystagmus

Characteristics of peripheral nystagmus - horizontal + torsion(complete destruction of one side labyrinth leads to horizontal nystagmus) ; disappears with optic fixation ; direction - fixed,doesn’t change

Characteristics of central nystagmus - pure horizontal/pure vertical/pure torsional component will be there ; doesn’t disappear with optic fixation ; direction does not change

Question 23

Head impulse test asses what ?

Answer 23

Vestibulo - ocular - pathway

In this test , sudden movement of head is done to check if the patient is able to fix the gaze or not

Abnormality of this vestibulo - ocular pathway leads to rapid , ballistic movements of the eyes that abruptly try to come back to the point of fixation / gaze called as SACCADES

Question 24

What is the other name for caloric test ?

Answer 24

Fitzgerald - hallpike manoeuvre or bithermal caloric test

Question 25

Position of head for caloric test

Answer 25

Head is raised to 30 degrees

Question 26

What scc is tested caloric test ?

Answer 26

Lateral scc

Stimulation of inner ear with hot and cold water

Question 27

What is the temperature used as cold temp and hot temp?

Answer 27

Temperature used is +/- 7 degrees from body temperature (37 degrees)

Cold temp : 30 degrees
Hot temp : 44 degrees

Question 28

Nystagmus direction according to temperature

Answer 28

Cold temp: opposite side nystagmus since the stimulated labyrinth becomes hypoactive

Hot temp: same side nystagmus since the stimulated labyrinth becomes hyperactive

Mnemonic : COWS

Question 29

Response of labyrinth in case of it is dead or hypo functional

Answer 29

No response or decreased response

Question 30

What is the minimum gap between hot and cold water ?

Answer 30

5 - 8 mins

Question 31

Test that is done to confirm if the labyrinth is dead or not

Answer 31

Kobrak test ; here ice cold water is used and if the labyrinth is somewhat functional then it will show all the characteristics of peripheral nystagmus

Question 32

Best test to check the integrity of labyrinth in coma patient

Answer 32

Caloric test

Question 33

Fistula test uses what instrument ?

Answer 33

Siegel speculum

Question 34

Causes for vertigo when pressure changes and there’s fistula in the medial wall of tympanic cavity

Answer 34

Coughing
Sneezing
Lifting heavy weight

Question 35

Positive fistula test seen in

Answer 35

Fistula over oval window , round window , lateral sc , promontory, fenestration operation ( type 5 tympanoplasty )

Question 36

False positive test (hennebert sign) - vertigo without fistula

Answer 36

Seen in conditions where either there’s dilated utricle and saccule (Ménière’s)or when the foot plate of stapes is hypermobile (congenital syphilis)

Also seen in superior semicircular canal dehiscence

Question 37

Reasons for initially positive fistula now became negative

Answer 37

Cholestetoma covering the fistula
Dead labyrinth

Question 38

What is vertigo on loud sounds known as ?

Answer 38

Tullios phenomena

Question 39

Tullios phenomenon seen in

Answer 39

Fistula on medial wall
Ménière’s
Congenital syphilis
Superior semicircular canal dehiscence

Question 40

Tullios phenomenon mediated by

Answer 40

Inferior vestibular nerve

Question 41

Unterberger test/ fukudas stepping test is used for

Answer 41

Assessing vestibulo-spinal pathway