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6 Neurological Dysfunction > L3 Vestibular Dysfunction > Flashcards

L3 Vestibular Dysfunction Flashcards

1
Q

What are the functions of the vestibular system?

A

postural control
eye-head coordination
perception of orientation in space

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2
Q

What might vestibular dysfunction present like?

A

-unsteadiness
-dizziness
-misperceptions about where the body or head are in space
-difficulty in visually busy environments, dimly lit environments, walking on uneven surfaces

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3
Q

Semicircular canals purpose is

A

rotational movement

receptor organ is the ampulla, which is filled with endolymph fluid, that will move the hair cell dependent on the movementV

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4
Q

Vestibule purpose is

A

linear movement

receptor organ is the macula, which has otoliths that can become dislodged. has a gelatinous layer, which provides reliable info with movements

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5
Q

Pairings of Semicircular Canals

A

Left Posterior & Right Anterior
Left Anterior & Right Posterior

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6
Q

Portions of the vestibule

A

saccule and utricule

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7
Q

Action Potential of Vestibular System

A

baseline firing rate is present; always firing

turning head will increase the action potentials in the CN VIII on the same side, while decreasing the firing rate on the opposite nerve

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8
Q

medial and superior vestibular nuclei

A

MLF fibers from these nuclei synapse on oculomotor, trochlear, and abducens nuclei

assist in coordination, maintaining posture and modulating vestibular reflexes

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9
Q

Lateral vestibular nucleus

A

gives rise to the lateral vestibulospinal tract

helps with maintaining balance and extensor tone

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10
Q

Medial and inferior vestibular nuclei

A

give rise to the medial vestibulospinal tract

controls head and neck positioning

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11
Q

VOR –Vestibulo-ocular reflex

A
  1. Peripheral reflex that maintains gaze stability
  2. Generates a compensatory eye movement in response to head movement to keep visual environment stable when head is in motion
  3. The peripheral vestibular system provides info that allows the eyes to respond with equal and opposite movements when the head moves
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12
Q

Intact system and VOR

A

the vestibulocerebellum can enable visual fixation to overcome the VOR

allows eyes to move with the head

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13
Q

Gain = 1:1 meaning

A

every degree of head movement, there is an equal and opposite movement at the eyes

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14
Q

Dizziness

A

vague term used by patients to describe many different abnormal sensations

can include light-headedness, faintness, nausea, unsteadiness, orthostatic hypotension

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15
Q

Vertigo

A

spinning sensation of movement
1. typically more indicative of vestibular disease
2. can be caused by lesions anywhere in vestibular pathway
3. most cases are peripheral disorders, involving inner ear

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16
Q

Patient education with vestibular disorders

A

patient ed is INTEGRAL
1. take time to explain differences in dizziness, lightheadeness, true room spinning
2. explain that provoking is a part of the exam
3. ensure someone can drive them
4. ensure patient hasn’t taken meds that would impact exam

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17
Q

Dizziness Handicap Inventory

A

measures the patient’s perception of their handicap

Y/N Questions, deciding on perception of their disability

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18
Q

Activities-specific Balance Confidence Scale

A

measures confidence in performing 16 functional daily acitivites without LOB or fear of falling

score <67% indicates increased risk of falling

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19
Q

Medications that can lead to temporary dizziness

A

antihistamines, benzos, alpha/beta agonists, antidepressants, aspirin, calcium channel blockers, diruretics, alcohol

20
Q

Peripheral vestibular pathology

A

affecting the vestibular organs or vestibular nerves

can be unilateral or bilateral

21
Q

Benign Paroxysmal Positional Vertigo (BPPV)

A

subset of peripheral, involving displacement of otoconia from the utricle and travel into semicircular canals

22
Q

Central Vestibular Disorders

A

affecting the brainstem, areas of teh cortex that process vestibular information, or cerebellum

23
Q

Peripheral Vestibular Pathologies Names

A

meniere’s
vestibular neuritis
vestibular labyrinthitis
acoustic neuroma
ototoxicity
perilymphatic fistula
superior canal dehiscence

24
Q

BPPV S/S

A

onset = sudden and correlates with movement
Intensity of vertigo = severe
Duration of vertigo = 30s - 2min

CNS findings = none
Hearing loss = none
Oculomotor = normal
Nystagmus = torsional with direction

25
Q

Peripheral Bilateral Vestibular Hypofunction

A

onset = sudden and following an illness, but can be gradual
Intensity of vertigo = absent
Duration of vertigo = absent
infrequent nausea

Hearing loss = tinnitus
Nystagmus = none

26
Q

Peripheral Unilateral Vestibular Hypofunction

A

onset = sudden, following illness, can be gradual
Intensity of vertigo = severe
Duration of vertigo = episodic
frequent nausea

Hearing loss = tinnitus
Nystagmus = horizontal with fast beat away from involved side

27
Q

Meniere’s DIsease

A

progressive problem with high pressure of inner ear fluid that most often leads to vertigo spells and hearing loss

-low frequency hearing loss
-fluctuating hearing loss, pressure in ear, innitus
-spells of vertigo that are minutes to hours, with nausea and imbalance

28
Q

Vestibular Neuritis

A

inner ear infection that is typically caused by a virus

sudden onset
duration of vertigo is hours to days
nausea
no hearing loss
usually single event

29
Q

Acoustic Neuroma

A

nerve sheath tumor found in internal auditory canal

asymmetrical hearing loss
tinnitus
vertigo

30
Q

Ototoxicity

A

bilateral peripheral pathology due to damage of hair cells, usually after antibiotics

unsteadiness, vertigo is absent, may include hearing loss, objects appear to jump

31
Q

Central Vestibular Pathologies

A

stroke
TBI
MS
Tumor
Degenerative cerebellar disorders

32
Q

Central Vestibular Dysfunction

A

can be caused by damage to any of CNS cestibular structures

onset: depends on etiology
Intensity of dizziness: longer duration or constant
Nystagmus = vertical resting, will not fatigue with testing, changes direction

33
Q

Non-vestibular causes for dizziness

A

anxiety
cardiac arrhythmias
diplopia
headache
medication
orthostatic hypotension
alcohol

34
Q

Medical Exam for Vestibular Dysfunction includes

A

rotary chair
bithermal caloric testing
MRI or CT scan
Video oculography

35
Q

Rotary Chair

A

patient is positioned in specialized chair with video goggles to monitor eye movement as chair is positioned differently

performed by audiologist

36
Q

Bithermal caloric testing

A

uses differences in temperature to diagnose damge to CNVIII

the test SHOULD produce nystagmus

37
Q

Objective Exam for Vestibular

A
  1. Screen the cervical ROM
  2. Screen vertebrobasilar insufficiency
  3. Begin objective tests
38
Q

VBI Testing

A

-artery supplies cirulation to the brain and compression of these vessels can be life threatening
-includes cervical rotation to L/R for 10 s, head and body psition that provokes S/s

39
Q

what to look for when testing VBI

A

diploplia, dizzines, dysarthria, drop attacks, dysphagia
nausea, numbness, nystagmus

40
Q

Nystagmus

A

involuntary and rhythmic rapid eye movements

includes fast phase of movement in one direction and slow phase in other

41
Q

Peripheral nystagmus

A

the fast beat is away from the side of the lesion and does not change direction

will begin to decrease over time due to central compensation and might be suppressed with gaze fixation

42
Q

IF there are central nervous system signs or suspected CNS dysfunction with no underlying diagnosis

A

this warrants and IMMEDIATE REFERRAL back to physician

43
Q

Potential findings on non-vestibular dysfunction

A

elevated HR/RR
abnormal BP to position changes

44
Q

Possible findings with Central Vestibular dysfunction

A

+ VOR cancellation
abnormal saccades (overshoot)
abnormal smooth pursuit (saccadic intrusions)

45
Q

UVH Possible findings

A

+head impulse test
+head shaking nystagmus
+DVA

46
Q

BVH Possible Findings

A

+head impulse test, bilaterally
+head shaking nystagmus
+DVA
will not see nystagmus if there is symmetric loss

6 Neurological Dysfunction (16 decks)

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