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Neuro E&I 2 > Vestibular Dysfunction > Flashcards

Vestibular Dysfunction Flashcards

1
Q

Function of the Vestibular System

A

Gaze stability (VOR)

Postural stability

Orientation in space

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2
Q

How does the Vestibular System play a role in Balance

A
  1. Processes multimodal sensory information
  2. Drives appropriate motor output
  3. Provides sense of position in space
  4. Feedback in relation to gravity
  5. Slowest but “final decision maker” (side: fastest is somatosensory)
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3
Q

Components of Vestibular System

A
  1. Peripheral Sensory apparatus (PVS)
  2. Central Processor (CVS): brainstem/cerebellum
  3. Mechanism for motor output
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4
Q

Motor output of the Vestibular system includes

A

VOR

VSR

COR

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5
Q

VOR

A

vestibular ocular reflex: generates eye movements consist with head movements

If you turn your head, the eye will go the opposite way to stay in the middle. When you look toward where your head is turning you are overwriting the VOR

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6
Q

VSR

A

Vestibular spinal reflex: generates compensatory body movements to keep head upright

Train with high level balance

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7
Q

COR

A

Cervical occular reflex:generates eye movements opposite to head movements (similar to VOR but not as active)

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8
Q

Anatomy of Peripheral Vestibular System (PVS)

A
  1. Housed int he inner ear
  2. Size of a dime
  3. petrous portion of temporal bone
  4. labyrinths & oroliths
  5. CN 8
  6. Labyrinthine artery
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9
Q

Anatomy of the Labyrinths

A

Semicircular canals taht consist of Anterior, posterior, horizontal canals

has a bony outer portion (perilymph) & membranous portion (endolymph)

Both peri/endolympth should not communicate with each other

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10
Q

Perilymph and Endolymph has high _____ : _____ ratio

A

Perilymph: high Na:K ratio

Endolymph: high K:Na ratio

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11
Q

Function of perilymph vs. endolymph

A

perilymph: protection
endolymph: fluid movement allow for the body to sense which way the head is moving secondary to movement of hair cells

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12
Q

Anatomy of the Bony labyrinths

A

5 sensory organs:

  • 3 membranous labyrinths
  • 2 otolith organ (utricle/saccule)
  • ampullae
  • hair cells
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13
Q

Role of Labyrinth

A
  1. Register head velocity
  2. VOR
  3. Rate sensors
  4. 3 coplanar pairs (aligned with plane of extraocular mm)
  5. push-pull relationship
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14
Q

Vestibular system is most effect at _____ degree/sec

A

~30 degrees/sec

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15
Q

Explain the push pull relationship of the vestibular system

A

As the head rotates to one side, the ipsilateral side is being excited while the contralateral side becomes inhibited.

sensory redundancy

ignore changes that affect both sides

assists in compensation for sensor overload

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16
Q

Role of the otoliths

A

Consist of utricle and saccule

respond to linear movement

accelereation in relation to gravity

register tilt (plane assent/descent, take off/landing)… eventually you get to constant speed and can’t feel accel/decel.

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17
Q

How long of a blockage is needed to lead to hearing lost?

A

15seconds

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18
Q

Central vestibular system (CVS)

A

Vestibular Nerve

Vestibular Nuclei

Cerebellum

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19
Q

vestibular nuclei location

A

4 primary on each side in the pons and medulla

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20
Q

input to Vestibular Nuclei

A
  • CN8
  • visual system
  • auditory system
  • somatosensory system
  • Inhibition from the cerebellum
  • ocular motor nuclei
  • brainstem
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21
Q

Output from Vestibular nuclei

A

VOR/VSR control

Extraocular/neck mm (MVST)

postural ms (LVST)

Cerebellum (“repair shop” for PVS)

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22
Q

Symptoms of vestibular dysfunction

(what they feel)

A

Vertigo

dizziness

oscillopsia

dysequilibrium

tinnitus

23
Q

Oscillopsia

A

they are not able to keep their eye fix, so the world is moving.

it occurs in standing/moving

if feel when sitting “red flag” not a true sign

24
Q

Tinnitus

A

Ringing of the ear.

ear damage due to loud noise.

PT cannot treat

25
Q

Signs of Vestibular Dysfunction

(what we observe)

A

Decrease gaze stability (VOR)

ataxia gait (central sign)

imbalance

motion sensitivity (fear of movement, slowness in movement, rigid movement)

Nystagmus

26
Q

Nystagmus

A

Nonvoluntary rhythmic oscillation of the eyes

Defined by fast/slow component

named by the fast

Direction of slow component indicates side of unilateral hypofunction with horizontal nystagmus

27
Q

Explain: Right beat nystagmus…. which way is fast? which way is side of deficit?

A

Right beat: Right is fast

left hypofunction

28
Q

Peripheral causes of Vestibular system dysfunction

A

Labyrinthitis

neuronitis

BPPV

Acoustic Neuroma Resection

Meniere’s Disease

Chronic Subjective Dizziness

29
Q

Central cause of Vestibular System Dysfunction

A

Mild TBI/PCS

TBI

CVA of brainstem, MO, cerebellum

Brainstem CVA

Cerebellar Dysfunction

Vertebral artery insufficiency

MS

30
Q

If you suspect of vestibular dysfunction what should you rule out?

A

acute or progressive CNS pathology

cardiac or vascular pathology

Medication AR

Migraines

Cervical spine

thryoid disease/lyme disease (via blood test)

Consider sinus or inner ear infection/pathology

refer to ENT or neurologist

31
Q

Diagnostic tests

A

MRI/CT scan

ENG: electronystagmography: emg measures of spontaneous and induced eye movement

caloric testing (PVH vs CVH and % loss): stimulus of endolymph movement by water in IAC

rotary chair: recorded eye movements with sinusoidal chair movement: this can ID % lost better than caloric testing

32
Q

Labyrinthitis/Neuronitis

A

inflammation/infection to canals or CN8

  • Acute symptoms very intense / sick (not appropriate for PT)
    • spontaneous nystagmus for few days
  • use of medication to reduce vertigo/nausea

PT indicated ipt does not appear to be independently compensating, but usually ppl go straight to the ED

33
Q

Meniere’s Disease (aka endolymphatic hydrops)

A

disorder of inner ear function (malabsorption of endolymph)

age 30-60

chronic hearing loss/imbalance

residual imbalance

TIME LIMITED: few years and it will completely go away by itself

34
Q

signs and symptoms of Meniere’s Disease

A

aural fullness, hearing loss, tinnitus, rotational vertigo, n/v

lasting 30 min-24 hour

35
Q

PT for Meniere’s Disease

A

after an attack:

VOR, standing exercises, habituation exercises

36
Q

Benign Paroxysmal Postional Vertigo (BPPV)

A

Short episodes of vertigo (<60 sec)

Quick head movements (head up/rotated toward affected side)

Associated with nausea and rotary nystagmus

Due to displaced otoconia in canal

37
Q

Questions to ask if suspecting BPPV or to r/o?

A

When the sx comes on, how long does it last and what do you feel? If it last for hours (not BPPV)

typically: roll out of bed causes sx. Sit and focus goes away, head up and down causes onset of sx

38
Q

Hallmark assessment of BPPV

A

Dix-Hallpike Test

39
Q

What is a positive Dix-Hallpike?

A

Torsional nystagmus

upbeat/downbeat

duration (<1min, crescendo, decresendo)

once nystagmus goes away, sx goes away

40
Q

Most common site for crystal to be located in

A

posterior canal

41
Q

Canalithiasis vs. cupulolithiasis

A

canalithiasis: crystal in the canal
cupulolithiasis: crystal in ampula (harder to remove)

42
Q

How to treat BPPV?

A

Use of Dix Hallpike followed by Canalithiasis Repositioning maneuver (Epley)

43
Q

Chronic Subjective Dizziness (CSD)

Signs and symptoms

A

Perisistent dizziness or subjective imbalance

  • Ligh-headness, head “swimming/heavy”
  • Ground moving
  • hypersensitive motion (self and world)
  • Sx aggravated with demanding visual tasks (like computer), and lost of horizon (crowd, bridges)
  • Clinical impression of anxiety

Testing does not pick up PVS hypofunction or gross balance dysfunction

44
Q

CSD with anxiety

A

3 types

Neuro-otologic illness => anxiety

anxiety => dizziness

Hx of anxiety and transient episode of true vertigo or other dx resulting in dizziness

45
Q

Anxiety questionnaires

A

Hospital Anxiety and Depression scale

Patient health questionnaire

Dizziness handicap inventory: F scale = anxiety, E subscale = depression

46
Q

Management of CSD

A
  1. Focus on desensitization and reduction of “Threat System” with:
    • Habituation vs. retraining VOR
    • Pts vestibular system is working => they’re just not using it
    • Dec. “perception” of imbalance
  2. Go Slowly
  3. PT Education
  4. cognitive Therapy with Vestibular rehabilitation & balance therapy (VBRT)
47
Q

Compare peripheral vs Central injuries in term of:

  1. Duration of symptoms
  2. intensity
  3. time to adapt
  4. others
A

Peripheral injuries

  1. shorter duration of sx
  2. inc. intensity
  3. less time to adapt

Central injuries

  1. longer duration of sx
  2. greater imbalance with basic task
  3. cognitive deficits
  4. greater time to adapt
  5. more motion sensitive
  6. Vertical and/or spontaneous nystagmus beyond acute
48
Q

Vestibular Systems Evaluation should include

A

General Systems screening

Strong hx

vertibular ocular assessment (head thrust)

visual screening

postural and balance assessment

impairment based assessment/screen

motion sensitivity (MSQ)

Assessment of BBPV

49
Q

History for vestibular evaluation should include:

A

How long do sx last?

What provokes them?

When did it start?

Meds? (side effects)

sinus/allergies

new glasses

what makes u better?

Fall d/t this?

did you drive here?

50
Q

Motion Sensitivity Quotient (MSQ)

A

16 different positional changes

sx in response to change in position

uses ordinal scale to capture intensity and duration of sx

NORMAL: 0%

51
Q

Vestibular dysfunction Interventions should focus on

A

Symptom mmgt

patient education/early HEP

Endurance/conditioning program

improve VOR gain/gaze stability

Dec. sensitivity to position change

balance retraining

Address functional impairments

52
Q

Examples of Vestibular Exercises

A

VOR x2, 2-3 times/day

habituation exercises

balance exercises (near couch, counter, corner for safety)

walking program (avoid TM b/c of mismatch between somatosensory [walking] vs visual [not walking] senses)

53
Q

Frequency/Duration of care for

  • Central injuries
  • Peripheral
  • BPPV
A

Central: 1-2x week/10-12 weeks OP

Peripheral: 1x week/6-8 weeks OP

BPPV: a few visits then HEP

Neuro E&I 2 (8 decks)

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