DIZZINESS Vertigo Light-headedness Dysequilibrium Imbalance Near Syncope Floating Whooziness Visual distortion Ataxia Anxiety.

DIZZINESS

• Vertigo • Light-headedness• Dysequilibrium • Imbalance • Near Syncope

• Floating• Whooziness• Visual distortion• Ataxia• Anxiety

Evaluation of patient with dizziness

History

Physical exam

Vestibular function test

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HistoryVertigo? (unsteadiness/dysequilibrium)• Illusory sense of motion

(internal or objects-linear/rotatory or change in orientation)

• Vertigo indicates a problem within the vestibular system (anywhere)

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History

Episodic or Continuous?

• Most vestibulopathies cause flactuating or episodic symptom

• Episodic: <1min BPPV >1day Vestibular Neuritis

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History

Semicircular canals or otolith?

• Movement of objects: semicircular canals• Abnormal sense of tilt or sudden drop : otolith

organs

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HistoryMedical problem?• Cause or exacerbate patient’s symptomsDisease: DM, Thyroid, Anemia, Arrhythmia, Orthostatic hypotensionDrugs : AG, Cis-platin, Antiepileptic, Amiodarone,

Alcohol, Barbiturates, Tricyclics, Anticoagulant

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HistoryPsychogenic disorder?

• Anxiety• Panic disorder• Phobic disorder• Depression / OCD

agoraphobia: mimics vestibulopathy Phobic postural vertigo: fluctuating unsteadiness

and subjective disturbance of balance

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HistoryTriggers?

• Rolling over in bed/head backward and toward BPPV• Foods vestibular migraine• Loud noise (Tullio’s phenomenon) Meniere’s

dis.

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HistoryEffect of head movement?

• Oscillopsia Vestibular hypofunction

• Brief periods of vertigo induced by certain head movements Vascular compression

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HistoryAssociated symptoms?

• Aural fullness/tinnitus/HL Meniere’s dis.• Dysarthria/Diplopia/Paresthesia VBI• Sweating/Dyspnea/Palpitation Panic attacks• Aura/Headache Migraine related vertigo

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History

• Must begin in open ended fashion

• Complete a quastionaire

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Evaluation of patient with dizziness

History

Physical exam

Vestibular function test

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Vestibular System Function

Balance maintained by :1. Vestibular system2. Eyes3. Proprioceptors in the muscles

• Allows for:– gaze & postural stability– sense of orientation– detection of linear & angular accelerations

BalanceAnatomy & Physiology

• Vestibular sense organ, consists of :

# 3 semicircular canals angular acceleration. # Utricle & saccule linear

acceleration.

Bedside examination

vestibular functions:

Vestibulo-ocular: ocular motor function

Vestibulospinal: maintain posture and muscular tone

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Vestibulo-ocular pathway

• The three planes of operation of the vestibuloocular reflex (VOR). Sagittal pitch plane (green), frontal roll plane (gray), horizontal yaw plane (green) [23].

• Nystagmus in defined disorders in the three planes of operation of the VOR. Tonus imbalance in the pitch plane leads to a vertical nystagmus (upbeat or downbeat nystagmus). Disorders in the roll plane cause a torsional nystagmus while disorders of the VOR in the yaw plane cause a horizontal nystagmus.

VOR of LSCC origin

vestibulo-ocular reflex of otolith-organ origin. When the

head is tilted to the left, the eyes rotate to the right to

assume a new angular position

about the visual axes, as shown.

Vestibulospinal pathway

Bedside examination

• Evaluation of vestibular function

-Ocular -Postural

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Vestibulo-ocular evaluation• Nystagmus -Spontaneous -Evoked • Skew deviation and ocular tilt• Oscillopsia -Dynamic visual acuity -Head-shaking nystagmus -Head-thrust nystagmus• Position test -Positional nystagmus -Positioning nystagmus

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Vestibulo-spinal evaluation

• Static Romberg test Fukuda test Pastpointing test• Dynamic Turning test External perturbation

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Nystagmus evaluation“No true vertigo without nystagmus”

• Visual acuity suffers appreciably if images that are focused upon retina slip more than 2-3 degree/s

• VOR , stabilized retinal images during head movement

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Nystagmus evaluation

• VOR , triggered by head acceleration and generated within the semicircular canals.

Nystagmus can be the result of any disorder causing a malfunction of the VOR.

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• Nystagmus can be suppressed in voluntarily by visual fixation (Frenzel lenses : prevent visual fixation)

• Drugs : Caffeine(12h) , Alcohol(24h) , Anticonvulsant, Antidepressant, Antihistamines, BZDs, Narcotics(48h)

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• Accuracy of direct inspection: 0.1 degree/s• Accuracy of ENG : 0.5 degree/s

• Trained investigator : down to 7 degree/s• ENG : 2-3 degree/s

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Nystagmus evaluation5-10 degree/s or less be dismissed as within

normal limit

Others : if observable or recordable in patient with dizziness considered pathologic

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Nystagmus

Jerk nystagmus• Slow drift and fast jerk• Due to abnormality in vestibular system• Peripheral or centralPendular nystagmus• Two opposite slow phase without jerk• Due to abnormality in the visual fixation system (M.S ,

brain stem infraction)• Treatment : gabapentin

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Vestibular Nystagmus

Spontaneous

Evoked

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Vestibular Spontaneous Nystagmus

Peripheral nystagmus

Central nystagmus

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Peripheral vestibular spontaneous nystagmus

• Horizontal-torsional or vertical-torsional • Fixed direction , regardless of direction of gaze• Fatigability • Suppressed by visual fixation

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Vestibular Spontaneous Nystagmus

Peripheral nystagmus

Central nystagmus

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Central vestibular spontaneous nystagmus

• Prominent vertical component • Visual fixation has no effect on the nystagmus• Nystagmus often changes when gaze is

directed away from the fast phase• Significantly less vertigo

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Down beat SN:• Disorders of cerebellum • Intensified by lateral gaze , convergence or

visual fixation• Oscillopsia and postural instability (cerebellar

degeneration & Chiari type I)

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Up beat SN:• Less common• Intensified by upward gaze, convergence may

alter or reverses it• Vertical oscillopsia and postural instability• Not well defined pathology but , most commonly

associated with medullary lesion• Other : M.S, brain stem or cerebellar infraction,

neoplasms

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Periodic alternating nystagmus (PAN) :• Every 1-2 min changes direction• Visual fixation will have no effect• Chiari type I , lesions of brainstem and

cerebellum• Treatment : baclofen , gamma-aminobutyrate

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See saw nystagmus : • Elevation and intorsion of one eye while the

other depresses and extorts• Pituitary tumor, brain stroke, congenitally

with albinism

Purely torisonal :• syringobulbia , sringomyelia

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Vestibular Nystagmus

Spontaneous

Evoked

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Evoked NystagmusGaze-evoked nystagmus (GEN) :• Disorders of CNS involving cerebellum

(cerebellar flocculus ) or brainstem (MVN, nucleus prepositus in medulla, neural integrator)

• Many medications interfere with the neural integrator (anticonvulsants , hypnotics, sedatives , anxiolytics , alcohol)

-EPN : 1-3 cycle/s , Low intensity

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Evoked Nystagmus• GEN , seen in three types of patients : -Brainstem or vestibulocerebellar disorders -Peripheral vestibular dysfunction (CPA tumors) -Neuromuscular junction disease (M.G.)

• Brun’s nystagmus : GEN and SN combination in CPA tumors high amplitude , Low frequency looking toward the lesion low amplitude , high frequency looking away from the lesion

Large amplitude asymmetric GEN……Brun’s nystagmus Low amplitude symmetric GEN……… EPN

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Evoked Nystagmus

Valsalva-induced nystagmus :

-SSSC dehiscence (closed glottis … ICP)

-Perilymphatic fistula (open glottis... MEP)

(OW,RW,LSCC)

-Arnold-Chiari (CCJ malformation)

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Evoked Nystagmus

Sound/pressure evoked :• (Tullio’s phenomenon : sound evoked)• (Hennebert’s sign : pressure evoked)

-Otic syphilis -Perilymphatic fistula -SSCC dehiscency

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Evoked Nystagmus

Hyperventilation evoked:

-Anxiety -Phobic -Demyelinating lesions on vestibular nerve -Compression by small vessle -Central lesion (M.S)

Rarely noted in patients with pathologies of vestibular end organs alone

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Skew deviation and ocular tilt

• Skew deviation :

• Vertical misalignment that can not be explained on the basis of an ocular muscle palsy

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Skew deviation and ocular tilt

• Cover test , Maddox Rod test

• Hall mark of disturbance anywhere along otolith-ocular pathway: labyrinth , vestibular nerve , vestibular nucleus , medulla , MLF , midbrain , nucleus of Cajal

Skew deviation and ocular tilt• Skew deviation :

• The compensatory head tilt is in a direction opposite to the apparent head tilt

• The lower eye is on the side of lesion with peripheral or vestibular nucleus lesions and lesions above that are on the side of higher eye.

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Oscillopsia

Dynamic visual acuity

Head-shaking nystagmus

Head-thrust nystagmus

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Oscillopsia

• Deficient VOR displacement or slip of the retinal image perceived as an apparent motion of target oscillopsia

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OscillopsiaMild unilateral reduction of VOR oscillopsia

only after very rapid movement

Unilateral reduction of VOR oscillopsia primarily with movements toward the affected ear

Bilateral reduction of VOR oscillopsia during any head movement

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Oscillopsia




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• Patient’s head to and fro in horizontal plane through an 60 degree arc with frequency between 1-2cycle/s.

(below 1cycle/s pursuit system)

• Unilateral loss : lose 2 to 4 lines• Bilateral loss : lose 5 to 6 lines

• Excellent test for ototoxicity

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Oscillopsia




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Head-shaking• Abrupt stop after shaking the head rapidly for 10-20s Slow phases initially directed toward the affected side A reverse phase with slow phase toward unaffected side

• Head shake test does not elicit oscillopsia but instead exploits changes in central vestibular processing produced by asymmetric inputs from vestibullar labyrinths

Not sensitive or specific enough to be used as a routine

screening test for peripheral vestibular lesions

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Head-shaking• Head shaking vestibular labyrinths activity charge up central vestibular system (velocity

storage) discharge over 5-20s (constant of VOR)

Symmetric inputs cancellation no nystagmusAsymmetric input no cancellation nystagmus

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Head-shaking

• Bilateral vestibular hypofunction and acute[?] unilateral vestibular hypofunction, head shake is negative

• Central vestibular lesions : perverted nystagmus (plane other than stimulation)

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Oscillopsia




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Head thrust

Based on doll’s eye reflex Loss of doll’s eye implies bilateral and extensive

involvement of the brainstem

• Refixation saccades will occur during head movement toward the affected side

Highly sensitive in detecting asymmetry of VOR +Head thrust 68% weakness in caloric test - Head thrust 90% normal caloric test

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Position testPositional nystagmus (sustained) Presents in static head posture and induced by

new head position

Positioning nystagmus (transient) Presents in head motion and caused by head

movement

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Positional nystagmus

• Eyes in center gaze (with or without fixation) for 30s

• Up right/supine/right ear-down/left ear-down

• Position as slowly as possible

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Type 1 nystagmus : persistent, lasting longer than 1 min, change

direction in the same or different head position

• Central pathology/barbiturates/salicylates/ alcohol/ horizontal BPPV

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Type 2 nystagmus: Longer than 1 min, direction is the same

whenever present (consistently rotatory, horizontal or vertical in one or more head positions)

• Either central or unilateral peripheral lesion pathology.

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Type 3 nystagmus: Transient, lasting less than 1 min ( =positioning nyst.)

• BPPV

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Positional nystagmus(SUSTAINED)

• Positional nystagmus almost always indicates a vestibular disorder, but it is often non-localizing due to overlap among finding in peripheral and central disorders

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Positioning nystagmus(TRANSIENT)

• Dix-Hallpike maneuver

• Peripheral : BPPV, Meniere’s disease, vestibular neuritis,perilymphatic fistula, SSCC dehiscence syndrome

• Central : M.S, vascular insufficiency, mass lesion,Chiari malformation, alcohol intoxication

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Dix-Hallpike Maneuver

Positioning nystagmus

Central Peripheral

Latency None 2-15s

Duration 30 to >120s 5-30s

Fatigability +/- +

Vertigo - +

Fixation Suppression - +

Direction Vertical, Horizontal Rotatory, Horizontal

Direction Change + -

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Vestibulo-spinal evaluation

• Static Romberg test Fukuda test Pastpointing test• Dynamic Turning test External perturbation

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Romberg test

• Examine proprioception and vestibulospinal

• Acute peripheral vestibular lesion will usually veer toward the side of problem

• Chronic vestibular injury may not produce abnormality

Sharpened Romberg (tandem Romberg) is more sensitive for vestibular impairment

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Fukuda test

• With and without vision, marches in place March forward up to 50cm or turn within

30degree is normal

• Unilateral vestibular weakness leads to slowly marches toward the side of weakness

• Non specific but quite remarkable(+) 71% in A.Neuroma

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Pastpointing test

Should not be used in place of the term “dysmetria”

• Although it may be a result of cerebellar abnormality, often considered a vestibulospinal test and shows vestibular abnormality (peripheral or central) without cerebellar dysfunction

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Turning test

• Patient walk with closed eye and then turn quickly 180degree to right or left, stopping at the point of attention

• Sway or staggering represent a positive test Patient’s tend to fall toward the side of vestibular

weakness

• Perilymphatic fistula

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DIZZINESS Vertigo Light-headedness Dysequilibrium Imbalance Near Syncope Floating Whooziness Visual distortion Ataxia Anxiety.

Documents

nystagmus head

vestibular system2

horizontal nystagmus

torsional nystagmus

downbeat nystagmus

vestibuloocular pathwaythe

day vestibular neuritis

vertical nystagmus upbeat