Praxis Review

Question 1

What does the superior vestibular branch of CNVIII innervates

Answer 1

1. Superior (anterior) and Horizontal (lateral) semi-circular canals
2. Utricle

Question 2

What does the inferior vestibular branch of CNVIII innervates

Answer 2

1. Posterior (inferior) SSCs
2. Saccule

Question 3

What is an expected condition of nystagmus for peripheral vestibular nystagmus?

Answer 3

1. Horizontal
2. Horizontal or combination of horizontal and torsional
3. Follows Alexander’s Law

Question 4

What does abnormal findings pertaining to caloric testing indicate?

Answer 4

Peripheral lesion involving the horizontal SCCs and/or superior nerve brance of the vestibular nerve on the side with the weaker response

Question 5

List common causes of peripheral vestibulopathy

Answer 5

1. Ototxicity
2. BPPV
3. Meniere’s Dx
4. Vestibular Neuritis
5. Labyrinthitis

Question 6

Define peripheral vestibulopathy

Answer 6

Disorder or dysfunction that involves the inner ear structure responsible for balance and spatial orientation; specifically the vestibular apparatus and vestibular nerve

Question 7

List of vestibular assessment testing that assess the horizontal SCCs and superior branch

Answer 7

1. Calorics
2. Rotational Chair Testing
3. vHIT

Question 8

What test assess the otolith organs?

Answer 8

VEMPs

Question 9

What does the cVEMP pathway includes?

Answer 9

1. Saccule
2. Inferior Branch of CN VIII
3. CN XI
4. Descending vestibulo-spinal pathway to Sternocleidomastoid (SCM)

Question 10

What kind of recorded response does cVEMP provide?

Answer 10

Inhibitory as the SCM nust be contracted to record the response

Question 11

What kind of recorded response does oVEMP provide?

Answer 11

Excitory contralateral reflex, right ear stimulation is recorded from the left inferior oblique

Question 12

What does the oVEMP pathway includes?

Answer 12

1. Utricle
2. Superior branch of CN VIII
3. CN III
4. Contralateral Inferior Oblique Muscle (ascending vestibulo-ocular reflex)

Question 13

Between DPOAEs & TEOAEs state what type of hearing loss woule be expected

Answer 13

1. DPOAEs: Can be recorded with up to moderate hearing loss
2. TEOAEs: Typically absent with more than a mild hearing loss (20-30 dBHL)

Question 14

For ABR testing, what is the waveform patterns for normal hearing?

Answer 14

Morphology: Good

Wave Latencies: All within normal limits

Wave Amplitude: Normal

Latency-Intensity Function: Falling within normal range

Question 15

For ABR testing, what is the waveform patterns for CHL?

Answer 15

Morphology: Good

Wave Latencies: Interwave within normative limits; Waves I-V delayed

Wave Amplitude: Normal

Latency-Intensity Function: Outsie of normative range

Question 16

For ABR testing, what is the waveform patterns for sensory HL?

Answer 16

Morphology: Poor

Wave Latencies: Interwave within normal limits; Waves I=V slightly delayed

Wave Amplitude: Waves I-III small to absent

Latency-Intensity Function: High-intensity responses within normal range; all others would be outside

Question 17

For ABR testing, what is the waveform patterns for neural HL?

Answer 17

Morphology: Poor

Wave Latencies: Interwave delayed; Waves III & V delayed

Wave Amplitude: Normal

Latency-Intensity Function: High-intensity responses within normal range; all others would be outside

Question 18

For neurodiagnositic ABR, what are the expected changes from a 21.1 to 89.1 repetition rate

Answer 18

Lower rate (e.g., 21.1):
Amplitude (Larger)
Wave V Latency (Shorter)
I-V Interpeak Latency (Normal)

Higher Rate (e.g., 89.1):
Amplitude (Shorter)
Wave V Latency (Longer)
I-V Interpeak Latency (Prolonged)

Question 19

For acute vestibular syndrome, what are the peripheral and central etiology

Answer 19

Peripheral Etiology = Vestibular Neuritis

Central Etiology = Brainstem, Cerebellar infarct

Question 20

For recurrent vertigo, what are the peripheral and central etiology

Answer 20

Peripheral Etiology = Meniere disease, superior semicircular canal dehiscence (SSCD)

Central Etiology = Vestibular migraine, transient ischemic attack (TIA)

Question 21

For positional vertigo, what are the peripheral and central etiology

Answer 21

Peripheral Etiology = BPPV

Central Etiology = Cerebellar disorder, vestibular migraine

Question 22

For chronic dizziness, unsteadiness, what are the peripheral and central etiology

Answer 22

Peripheral Etiology = Bilateral vestibulopathy, vestibular schwannoma

Central Etiology = Persistent postural-perceptual dizziness (PPPD)

Question 23

List what makes labyrinthitis different from vestibular neuritis

Answer 23

• Similar to vestibular neuritis except patient reports concurrent sudden hearing loss and tinnitus
• Hearing loss and vertigo may occur simultaneously or within a few days of sudden hearing loss and tinnitus

Question 24

What caues vestibular neuritis?

Answer 24

Infection/inflamation of the vestibular nerve, most often involving the superior branch

Question 25

What are symptoms of vestibular neuritis?

Answer 25

• Acute onset of vertigo
• Nausea/vomitting
• Generalized imbalance
• Acute phase can last for hours to days
• Imbalance may linger for weeks after
• No hearing loss or tinnitus associated

Question 26

What causes labyrinthitis?

Answer 26

Due to inflammation of the inner ear and/or CN VIII

Question 27

List all of the 3rd Window Disorders

Answer 27

1. Perilymph fistula
2. Superior Semicircular Canal Dehiscence (SSCD)
3. Enlarged Vestibular Adeduct Syndrome (EVAS)