1. VESTIBULAR DISORDERS
Joannalyn B. Juego

2. ANATOMY: Peripheral Vestibular System
Stabilizing the visual images on the fovea of the retina during head movements to allow clear vision
Maintaining postural stability
Providing information used for spatial orientation

3. ANATOMY: Peripheral Vestibular System
Semicircular canals
Otolith organs
Central vestibular system

4. Vestibular System Dysfunction
Peripheral Pathology
Central Nervous System Pathology

5. Peripheral Pathology: Mechanical
BPPV
Most common cause of vertigo
A biomechanical disorder
Nystagmus & vertigo without change in head position; nausea with or without vomiting; & dysequilibrium
Latency to onset of the vertigo & nystagmus occurs within 15 seconds once the head is in the provoking position; the duration is less than 60 seconds

6. Cupulolithiasis
Fragments of the otoconia break away & adhere to the cupula of one of the SCCs
When the head is moved into certain positions, the weighted cupula is deflected by the pull of gravity
The abnormal signal results in vertigo & nystagmus, which persists as long as the patient is in the provoking position

7. Canalithiasis Otoconia are freely floating in one of the SCCs
When a patient changes head position, the pull of gravity causes the freely floating otoconia to move inside the SCC resulting in endolymph movement & deflection of the cupula

8. Peripheral Pathology: Decreased Receptor Input
UVH
Viral insults, trauma, & vascular events
Vertigo, spontaneous nystagmus, oscillopsia during head movements, postural instability, & dysequilibrium
Resolves within 3-7 days assuming the patient is exposed to common daylight conditions

9. Peripheral Pathology: Decreased Receptor Input
BVH
Ototoxicity
Meningitis, autoimmune DO, head trauma, tumors on the 8th CN, transient ischemic episodes of vessels supplying the vestibular system, & sequential unilateral vestibular neuronitis
Dysequilibrium, oscillopsia, & gait ataxia

10. Central Nervous System Pathology
Cerebrovascular insults involving the AICA, PICA, & vertebral artery
Vertebrobasilar insufficiency (VBI)
TBI due to labyrinthine or skull fractures
Demyelinating diseases such as MS affecting CN VIII

11. CENTRAL VESTIBULAR PATHOLOGY PERIPHERAL VESTIBULAR PATHOLOGY
Ataxia often severe
Ataxia mild
Abnormal smooth pursuit & abnormal saccadic eye movement tests
Smooth pursuit & saccades usually normal; positional testing may reproduce nystagmus
Sx usually do not include hearing loss; if so, it is often sudden & permanent
Sx may include hearing loss (insidious – may recover), fullness in ears, tinnitus
Sx might include diplopia, altered conscious, lateropulsion
Sx of acute vertigo not usually suppressed by visual fixation
Sx of acute vertigo usually suppressed by visual fixation
Sx of acute vertigo usually intense (more than central vestibular pathology)
Pendular nystagmus (eyes oscillate at equal speeds)
Nystagmus will incorporate slow & fast phases (jerk nystagmus)
Pure persistent vertical nystagmus persists regardless of positional testing
Spontaneous horizontal nystagmus usually resolves within 7 days in a patient with UVH

12. PHYSICAL THERAPY EXAMINATION
History & Systems Review
Identification of symptoms
Duration & circumstances of symptoms

13. Identification of Symptoms
Dizziness
Vaguely defined as the sensation of whirling or feeling a tendency to fall
Patients should be directed away from using the word & to use more precise terms
Vertigo, lightheadedness, dysequilibrium, oscillopsia

14. Vertigo Illusion of movement Episodic
Indicates pathology at one or more locations along the vestibular pathways
Acute stage of UVH
Displaced otoconia (BPPV)
Acute unilateral brainstem lesion

15. Lightheadedness Feeling that fainting is about to occur Causes
Orthostatic hypotension
Hypoglycemia
Anxiety
Panic disorder

16. Dysequilibrium Sensation of being off balance Causes BVH
Chronic unilateral vestibular hypofunction
Lower extremity somatosensation loss
Upper brainstem/vestibular cortex lesion
Cerebellar & motor pathway lesions

17. Oscillopsia
Subjective experience of motion of objects in the visual environment that are known to be stationary
Occur with head movements in patients with vestibular hypofunction since the vestibular system is not generating an adequate compensatory eye velocity during the head motion

18. Duration & Circumstances of Symptoms
How recent the attacks happened
Whether the symptom is constant or episodic
Episodic: average duration of the episodes
Seconds to minutes – BPPV
Minutes to hours – Meniere’s disease
Days – vestibular neuronitis or migraine-associated dizziness

19. Duration & Circumstances of Symptoms
Whether the patient experiences symptoms with particular movements, positions, or at rest
Is the patient sensitive to motion as the passenger in a moving car?
Does the patient experience a vigorous vertigo when the head is moved into certain positions?

20. Tests & Measures Visual Analogue Scale Dizziness Handicap Inventory
Functional Disability Scale
Vestibular Rehabilitation Benefit Questionnaire
Motion Sensitivity Quotient
Examination of Eye Movements

21. Observation for Nystagmus
Nystagmus is the primary indicator used in identifying most peripheral & central vestibular lesions
The direction of the nystagmus is named by the direction of the fast component
Left beating nsytagmus: eyes move slowly to the right & the resetting eye movement is to the left

23. Head Impulse Test (Examination of the VOR at High Acceleration)
Widely accepted clinical tool used to examine semicircular canal function
Patient first fixates on a near target
When testing the horizontal SCC, the head is flexed to 30 deg

24. Head Impulse Test (Examination of the VOR at High Acceleration)
Patient is asked to keep their eyes focused on a target while his head is manually rotated in an unpredictable direction using a
Small amplitude (5 – 15 deg),
Moderate velocity (~200 deg/sec), and
High-acceleration (3,000 – 4,000/sec) angular impulse

25. Head Impulse Test (Examination of the VOR at High Acceleration)
Normal
Eyes will move in the direction opposite to the head movement & gaze will remain on the target
With a loss of vestibular function
The VOR will not move the eyes as quickly as the head rotation & the eyes will move off the target
The patient will then make a corrective saccade to reposition the eyes on the target
Corrective saccade: rapid eye movement used to reposition the eyes to the target of interest

26. Head Impulse Test (Examination of the VOR at High Acceleration)
Unilateral peripheral lesion or pathology of the central vestibular neurons
Patient will not be able to maintain gaze when the head is rotated quickly toward the side of the lesion
Bilateral loss of vestibular function
Patient will make corrective saccades after a head impulse to either side

28. Head-Shaking Induced Nystagmus Test (HSN)
Useful aid in the diagnosis of a unilateral peripheral vestibular defect
Patient is instructed to close his eyes
Clinician flexes the head 30 deg before oscillating horizontally for 20 cycles at a frequency of 2 repetitions per second
On stopping the oscillation, the patient opens the eyes & the clinician checks for nystagmus

29. Head-Shaking Induced Nystagmus Test (HSN)
Normal
Nystagmus will not be present
Presence of asymmetry between the peripheral vestibular inputs to central vestibular nuclei
May result in HSN
UVH
Horizontal HSN
Quick phases of the nystagmus directed toward the healthy ear & the slow phases directed toward the lesioned ear

30. Positional Testing
Commonly used to identify whether otoconia have been displaced into the SCC, causing a condition referred to as Benign Paroxysmal Positional Vertigo (BPPV)
Dix-Hallpike Test
Patient is moved from a long-sitting position with the head rotated 45 deg to one side, to a supine position with the head extended to 30 deg beyond horizontal, head still rotated to 45 deg
Observe the eyes for nystagmus

32. Positional Testing Dix-Hallpike Test Side-lying
Patient sits on the edge of the examination table
Clinician turns the head horizontally 45 deg
Patient is quickly brought down to the side opposite the head rotation
Examiner checks for nystagmus & vertigo, & then slowly brings the patient to the starting position
The other side is then tested

34. Positional Testing Roll test If horizontal SCC BPPV is suspected
Patient is positioned supine with the head flexed 20 deg
Rapid rotations to the sides are done separately & the clinician observes for nystagmus & vertigo

36. Dynamic Visual Acuity (DVA) Test
Measurement of visual acuity during horizontal motion of the head
Static visual acuity is first determined
Patient is asked to “Read the lowest line you can see” on a wall-mounted acuity chart
Lighthouse ETDRS (Early Treatment Diabetic Retinopathy Study) wall charts are recommended
Patient then attempts to read the chart while the clinician horizontally oscillates the patient’s head at a frequency of 2Hz

38. Dynamic Visual Acuity (DVA) Test
Normal
Head movement results in little or no change of visual acuity compared with the head still (less than 1 line difference)
Loss of vestibular function
Eyes will not be stable in space during head movements
Decrement in DVA compared with visual acuity when the head is still
A 3-line or more decrement in visual acuity during head movement is suggestive of vestibular hypofunction

39. Examination of Gait & Balance
TEST
BPPV
UVH
BVH
CENTRAL LESION
Romberg
(-)
Acute: (+)
Chronic: (-)
Often (-)
Tandem Romberg
(+), eyes closed
(+)
Single-legged stance
May be (+)
May be unable to perform

40. TEST BPPV UVH BVH CENTRAL LESION
Gait
Normal
Acute: wide-based, decreased arm swing, & rotation
Compensated: (N)
Compensated: mild gait deviation
May have pronounced ataxia
Turn head while walking
May produce slight unsteadiness
Acute: may not keep balance
May not keep balance or slows cadence
May not keep balance, increased ataxia

41. Vestibular Function Tests: Semicircular Canal Tests
Electronystamography (ENG) & Videonystamography (VNG)
Oculomotor & inner ear function
Rotational chair test
Rotating subjects in the dark
Standard test for bilateral vestibular dysfunction

42. Vestibular Function Tests: Otolith Tests
Vestibular-evoked myogenic potential (VEMP)
Cervical VEMP
Ocular VEMP

43. INTERVENTIONS

44. Benign Paroxysmal Positional Vertigo
The otoconia will be returned into the vestibule
The patient will demonstrate reduced vertigo associated with head motion
The patient will demonstrate improved balance
The patient will demonstrate independence in ADLs

45. Benign Paroxysmal Positional Vertigo
Canalith repositioning maneuver (CRM)
BPPV due to canalithiasis, posterior SCC canalithiasis is the most common
Liberatory (Semont) maneuver
BPPV due to cupulolithiasis, posterior SCC cupulolithiasis is the most common
Brandt-Daroff exercises
Persistent/residual or mild vertigo (even after CRM); for the patient who may not tolerate CRM

46. Unilateral Vestibular Hypofunction
The patient will demonstrate improved stability of gaze during head movement
The patient will demonstrate diminished sensitivity to motion
The patient will demonstrate improved static & dynamic postural stability
The patient will be independent in proper performance of a HEP that includes walking

47. Unilateral Vestibular Hypofunction
Gaze Stability Exercises
Improve the VOR & other systems that are used to assist gaze stability with head motion
Designed to expose patients to retinal slip

48. Retinal Slip
Occurs when the image of an object moves off the fovea of the retina, resulting in visual blurring
Necessary as this is the signal used to drive vestibular adaptation within the brain
Because the brain can tolerate small amounts of retinal slip yet see a target clearly, the patient must try to keep the target in focus
Otherwise, head motion that is too rapid will result in excessive retinal slip

49. Primary Paradigms of Vestibular Adaptation
x1 exercises
Patient is asked to move the head horizontally as quickly as possible while maintaining focus on a stable target
Patient must learn how to slow the head movement if the target becomes blurred
Starting target distance should be an arm’s length away

50. Primary Paradigms of Vestibular Adaptation
x2 exercises
Requires the patient to move the head & the target in opposite directions

51. Postural Stability Exercises
Stand with feet shoulder-width apart, arms across the chest
Progress to: Bring feet closer together. Close eyes. Stand on a sofa cushion or foam.
Practice ankle sways: medial-lateral & anterior-posterior
Progress to: Doing circle sways. Close eyes.
Attempt to walk with heel touching toe on firm surface
Progress to: Do the same exercise on carpet.

52. Postural Stability Exercises
Practice walking 5 steps & turning 180 deg (left & right)
Progress to: Making smaller turns. Close eyes.
Walk & move the head side to side, up & down
Progress to: Counting backward from 100 by threes

53. Habituation Exercises
Warranted when a patient with UVH has continual complaints of dizziness
Habituation: reduction in response to a repeatedly performed movement

54. Habituation Exercises
PT must determine the provoking positions first
When a position elicits a mild to moderate dizziness, the patient remains in the provoking position for 30 seconds or until the symptoms abate, whichever comes first
The patient is provided with a HEP based on the results of the positional test
The provoking exercises are performed 3-5 times each, 2-3 times a day

55. Habituation Exercises
Patient keeps an activity diary to monitor response to training
The exercises are designed to reproduce the dizziness & the patient should be encouraged that the sxs normally decrease within 2 weeks
If other 2 weeks the sxs are no better, the habituation exercises should be first changed

56. Bilateral Vestibular Hypofunction
The patient will demonstrate improved stability of gaze during movement
The patient will demonstrate reduced subjective complaints of gaze instability
The patient will demonstrate improved static & dynamic balance
The patient will be independent in proper performance of HEP that includes walking
The patient will demonstrate enhanced decision-making skills regarding performance of ADLs

57. Bilateral Vestibular Hypofunction
Gaze stability exercises similar to the x1 paradigm
Balance exercises
Walking program
Patient education is high priority
2 years may be necessary to ensure as complete a recovery as possible
Pool therapy
Tai Chi

58. Abnormal Central Vestibular Function
The patient will demonstrate enhanced decision making skill regarding fall prevention strategies & necessary safety precautions to allow safe functioning within the home & the community
The patient will demonstrate enhanced decision making skills regarding use of compensatory strategies to assist in gaze stability
The patient will be independent in performance of an HEP that includes walking

59. Abnormal Central Vestibular Function
Patient education
Time to recover will be 6 months or more, & may be incomplete
Habituation exercises
Gait & balance exercises designed to incorporate somatosensory, visual, & vestibular contributions

60. Diagnoses Involving the Vestibular System
Meniere’s Disease
Perilymphatic Fistula
Vestibular Schwannoma
Motion Sickness
Migraine-Related Dizziness
Multiple Sclerosis
Multiple System Atrophy
Cervicogenic Dizziness