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 3

History  Vertigo? (unsteadiness/dysequilibrium) Illusory sense of motion (internal or objects-linear/rotatory or change in orientation) Vertigo indicates a problem within the vestibular system (anywhere) 4

History  Episodic or Continuous? Most vestibulopathies cause flactuating or episodic symptom Episodic: <1min BPPV >1day Vestibular Neuritis 5

History  Semicircular canals or otolith? Movement of objects: semicircular canals Abnormal sense of tilt or sudden drop : otolith organs 6

History  Medical problem? Cause or exacerbate patient’s symptoms Disease: DM, Thyroid, Anemia, Arrhythmia, Orthostatic hypotension Drugs : AG, Cis-platin, Antiepileptic, Amiodarone, Alcohol, Barbiturates, Tricyclics, Anticoagulant 7

History  Psychogenic disorder? Anxiety Panic disorder Phobic disorder Depression / OCD agoraphobia: mimics vestibulopathy Phobic postural vertigo: fluctuating unsteadiness and subjective disturbance of balance 8

History  Triggers? Rolling over in bed/head backward and toward BPPV Foods vestibular migraine Loud noise (Tullio’s phenomenon) Meniere’s dis. 9

History  Effect of head movement? Oscillopsia Vestibular hypofunction Brief periods of vertigo induced by certain head movements Vascular compression 10

History  Associated symptoms? Aural fullness/tinnitus/HL Meniere’s dis. Dysarthria/Diplopia/Paresthesia VBI Sweating/Dyspnea/Palpitation Panic attacks Aura/Headache Migraine related vertigo 11

History Must begin in open ended fashion Complete a quastionaire 12

Evaluation of patient with dizziness  History  Physical exam  Vestibular function test 13

Vestibular System Function Balance maintained by : 1. Vestibular system 2. Eyes 3. Proprioceptors in the muscles Allows for: – gaze & postural stability – sense of orientation – detection of linear & angular accelerations

Balance Anatomy & 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 16

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

Ocular countertorsion, a 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 24

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 25

Vestibulo-spinal evaluation Static Romberg test Fukuda test Pastpointing test Dynamic Turning test External perturbation 26

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 27

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 28

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. 29

Nystagmus evaluation 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) 30

Nystagmus evaluation 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 31

Nystagmus evaluation  5-10 degree/s or less be dismissed as within normal limit  Others : if observable or recordable in patient with dizziness considered pathologic 32

Nystagmus  Jerk nystagmus Slow drift and fast jerk Due to abnormality in vestibular system Peripheral or central  Pendular nystagmus Two opposite slow phase without jerk Due to abnormality in the visual fixation system (M.S, brain stem infraction) Treatment : gabapentin 33

Vestibular Nystagmus  Spontaneous  Evoked 34

Vestibular Spontaneous Nystagmus  Peripheral nystagmus  Central nystagmus 35

Peripheral vestibular spontaneous nystagmus Horizontal-torsional or vertical-torsional Fixed direction, regardless of direction of gaze Fatigability Suppressed by visual fixation 36

Vestibular Spontaneous Nystagmus  Peripheral nystagmus  Central nystagmus 37

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 38

Central vestibular spontaneous nystagmus  Down beat SN: Disorders of cerebellum Intensified by lateral gaze, convergence or visual fixation Oscillopsia and postural instability (cerebellar degeneration & Chiari type I) 39

Central vestibular spontaneous nystagmus  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 40

Central vestibular spontaneous nystagmus  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 41

Central vestibular spontaneous nystagmus  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 42

Vestibular Nystagmus  Spontaneous  Evoked 43

Evoked Nystagmus  Gaze-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 44

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 45

Evoked Nystagmus  Valsalva-induced nystagmus : -SSSC dehiscence ( closed glottis … ICP) -Perilymphatic fistula (open glottis... MEP) (OW,RW,LSCC) -Arnold-Chiari (CCJ malformation) 46

Evoked Nystagmus  Sound/pressure evoked : (Tullio’s phenomenon : sound evoked) (Hennebert’s sign : pressure evoked) -Otic syphilis -Perilymphatic fistula -SSCC dehiscency 47

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 48

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 49

Skew deviation and ocular tilt Skew deviation : Vertical misalignment that can not be explained on the basis of an ocular muscle palsy 50

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. 53

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 54

Oscillopsia  Dynamic visual acuity  Head-shaking nystagmus  Head-thrust nystagmus 55

Oscillopsia Deficient VOR displacement or slip of the retinal image perceived as an apparent motion of target oscillopsia 56

Oscillopsia Mild 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 57

Oscillopsia  Dynamic visual acuity  Head-shaking nystagmus  Head-thrust nystagmus 58

Dynamic visual acuity 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 59

Oscillopsia  Dynamic visual acuity  Head-shaking nystagmus  Head-thrust nystagmus 60

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 61

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 nystagmus Asymmetric input no cancellation nystagmus 62

Head-shaking Bilateral vestibular hypofunction and acute[?] unilateral vestibular hypofunction, head shake is negative Central vestibular lesions : perverted nystagmus (plane other than stimulation) 63

Oscillopsia  Dynamic visual acuity  Head-shaking nystagmus  Head-thrust nystagmus 64

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 65

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 66

Position test  Positional 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 67

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 68

Positional nystagmus 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 69

Positional nystagmus 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. 70

Positional nystagmus Type 3 nystagmus: Transient, lasting less than 1 min ( =positioning nyst.) BPPV 71

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 72

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 73

Dix-Hallpike Maneuver

Positioning nystagmus CentralPeripheral Latency None2-15s Duration 30 to >120s5-30s Fatigability +/-+ Vertigo -+ Fixation Suppression -+ Direction Vertical, HorizontalRotatory, Horizontal Direction Change +- 75

Vestibulo-spinal evaluation Static Romberg test Fukuda test Pastpointing test Dynamic Turning test External perturbation 76

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 77

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 78

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 79

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 80