Vertigo (Clin Reasoning)

Vertigo

An illusory sensation of spinning of the body or the environment

What type of vertigo is indicative for vestibular dysfunction

Rotary / spinnign

What are the subtypes of dizziness

Vertigo

Presyncope

Disequilibrium

Lightheadedness

How does the vestibular system work

At rest, the endolymph and cupula sets still

When angular accerlation starts (spinning starts right), inertia will cause endolymph to go the opposite direction (goes left), causes the cupula to deflect in the direction of the accerleration (right) and percieves movement

With constant movement speed, the endolymph starts to moves the same direction as accerelation (right) and the cupula remains still and no movement is percieved

When decerlation or stopping happens, the endolymph continues in the direction of movement (right) and the cupula deflects to the opposite direction (left) and detects movement

Vestibular Nerve

Branch of the CN VIII that signals for balance

Scrapa’s Ganglion

The collection of cell bodies for the vestibular nerve

Superior Vestibular Nerve

Branch of the vestibular nerve that communicates with the anterior SCC, lateral SCC, and utricle

Inferior Vestibular Nerve

Branch of the vestibular nerve that communicates with the posterior SCC and saccule

Cochlear Nerve

Brach of CNVIII that deals with hearing

What structures go through the internal auditory canal

CN VIII

CN VII

Labyrinthe arter

where does CN VIII enter the brain

Pontomedullary junction

Where does CN VIII synaspe

4 vestibular nuclei in brainstem

Most vertigo is due to an issue with

Posterior circulation

What is the blood pathway for the vestibular system

Vertebral artery

Basilar artery

PICA

AICA

Anterior Vestibular Artery

Artey that supples blood for the anterior and horizontal SCC and utricle

Posterior Vestibular Arteryy

Artery that supples blood for the posteruir SCC and saccule

Vestibular Ocular Reflex (VOR)

A reflex of the ocular muscles to adjust the position of the eye to fixate on an object while moving

Contracts the opposite direction at the same velocitu

Oscillopsia

Blurring of image

When does VOR occur

High speed

Nystagmus

Involuntary, oscillatory eye movement characterized by a fast and slow phase

What can be used to dx vestibular disorderws

Nystagmus

Pathology is seen in what phase of nystagmus

Slow

What are the types of vestibular issues

Neurologic

Mechanical

Structural

Space Occuyping

Pyschological

Neurologic Vestibular Disorders

Peripheral Vestibular Dysfunction (Neuritis/ Labyrinthitis/ Vestibulopathy)

Central Vestibular Dysfunction (Migraine, TBI, Stroke, MS, PD)

What is the mechanical vestibular disorder

BPPV

What are the structural vestibular disorder

Superior Canal Dehiscence

Perilymphatic Fistula

A purely vertical nystagmus indicates that

There is a central vestibular disorder

Signs of AICA Lesion

Hearing Loss

Vertigo

Facial Paralysis

Signs of PICA lesion

Dysphagia

Dysarthria

Absent Gag Reflex

Vertigo

What central vestibular disorder can also cause a peripheral vestibular disorder

Vestibular migraines

Causes of Central Vestibular Dysfunction

• Arnold Chiari Malformation

• Stroke/TIA of vertebrobasilar circulation

• Cerebellar disease

• MS

• TBI

Red Flags for Central Vestibular Disorder

• May have cerebellar signs

• May have (+) Ocular Tilt Reaction (+) Skew Deviation

• May have mild to severe headaches

• Visual field changes or loss/ diplopia

• Ptosis

• Difficulty swallowing/ speaking

• + Babinski, increased DTR’s

• Sudden asymmetric weakness

What are signs of peripheral lesion

Hearing loss

Tinnitus

Imbalance

Episodic w/ Movement

What phase of nystagmus is the one used for naming

Fast Phase

A right beating nystagmus has pathology on what side

Left

How does nystagmus types differ with visual fixation

Peripheral → Decreases with visual fixation

Central → Unaffected

Alexander’s Law

When looking in the direction of the fast phase of peripheral nystagmus, the amplutide of the nystagmus increases

How does central and peripheral nystagmus differ on onset

Peripheral → sudden and severe

Central → Poor and vagu

How does central and peripheral nystagmus differ on fatgiue

Peripheral → Will fatigu

Central → Won’t

How does central and peripheral nystagmus differ on signs

Peripheral → Frequent nausea but no CNS

Central → Rarely nauseuous but present CNS signs

What viruses can cause UVL

HSV

EBV

Mumps

Rubella

Vestibulopathy

Refers to vestibular disease either neuritis or labyrinthitis

How does neuronitis differ from labyrinthitis

Labyrinthitis → Issue with Vestibulocochlear Nerve (Hearing issues)

Neuritis → Issue with Superior Vestibular Nerve (No hearing issues)

Unilateral vestibular lesion (UVL)

A unilteral peripheral vestibular neuritis caused by a viral infection

UVL Presentation

URI/ Gastritis usually precedes symptoms by 2 weeks

Sudden onset

vertigo,

spontaneous horizontal nystagmus,

nausea / vomiting

dizziness lasting seconds with quick head movemnt

Resolves in 2 weeks

Treatment of UVL

Vestibular Rehabiliation Therapy (VRT)

What is considered acute vertigo

3 days or less

What is considered chronic vertigo

More than 3 days

Vertigo that lasts < 5 seconds is typically due to

Hypoactive Labyrinth

Vertigo that lasts 5-90 seconds is typically due to

BPPV

Cervicogenicc

Vertigo that lasts 90 seconds - 20min is typically due to

TIA

Migraine

Vertigo that lasts 20min -24 hours is typically due to

Meniere’s

TIA

Perilymph Fistula

Vertigo that lasts >24 hours is typically due to

Vestibular Neuritis

CNS Disease

Head Impulse Test

Tilt pt’s head down 30 degrees to align H-canal. Instruct pt to look at your nose.

Slowly move head back and forth making sure pt is relaxed. Suddenly move pt’s head quickly in one direction (< 30 degrees!).

Observe maintenance of visual fixation. Repeat to other side.

What should be done before doing a head impulse test

Clear the C-spine

What are the results of Head Impulse Test

Able to fixate on nose → Normal

Inability to fixate on nose → Positive (UVL or BVL)

What directions can head impulse test be don

Vertical Plane

Mixed Plane

What is important to get good result for head impulse testing

30 degree pitch down

Unpredictable timing / direction

HiNTS examination

A assessment of peripheral vs central cause of acute vestibular syndrome (AVS) by combing head impulse, nystagmus, and test of skew

What is more sensitive for early CVA then an MRI

HiNTS

How will peripheral vestibular issues appear on HiNTs

(+) Head Impulse and Non-Direction Chaning Nystagmus

(-) Skew

How will central vestibular issues appear on HiNTS

(+) Direction changing nystagmus and skew deviation

(-) Head Impulse

skew deviation

(one eye lower than the other and vertical movement seen w/ cover/ uncover)

Sign of central vestibular issues

What type of CVA is screened for using HiNTS

Posterior circulation

A positive HiNTS for central criteria indicates what testing should be done

Audiological testing

What are the assessments for acute vertigo / stroke rule out

HiNTS

TITRATe Test

ABCD2

TRiAGe+

CATCH2

Componenets of TITRATE test

Timing, Triggers And Targeted Exams

Componenets of ABCD2

Age

BP

Clinical Features

Duration of symptoms

Diabetes

Components of TRiAGe+

Triggers

A-fib

Gender

BP

Clinical Features

Dizziness

History

Components of CATCH2

Central Featurees

Age

Triggers

Cover Test w/ Skew

Head Impulse Test

Hx of Dizziness / Vertigo

Head Shake Nystagmus Test

Tilt head forward 30 degrees to align H-canal. Have pt close eyes. Shake head side to side 20 times. Have pt open eyes. Look for nystagmus.

Repeat head shaking vertically

What is the preferred speed for Head Shake Impulse Test

2Hz / 240 bpm

A positive head shake nystagmus test indicates

UVL

Dix-Hallpike

Atest for BPPV only (A-SCC and P-SCC)

Turn head 45 degrees to either side. Quickly have patient lie down with head extended 30

degrees off bed. Observe for nystagmus. Hold position at least 30 seconds. Sit up and hold for at least 30 seconds.

Test both sides.

Usually indicative of BPPV.

Which ear is tested during a Dix-Hallpike

Down ear

Roll Test

A test for H-canal BPPV

Patient lies supine. Head flexed 20 degrees. Quickly turn head to one side. Hold at least

30 seconds. Slowly return to midline and quickly roll head to other side.

Positive test will cause nystagmus and vertigo