Praxis Review Flashcards
What does the superior vestibular branch of CNVIII innervates
- Superior (anterior) and Horizontal (lateral) semi-circular canals
- Utricle
What does the inferior vestibular branch of CNVIII innervates
- Posterior (inferior) SSCs
- Saccule
What is an expected condition of nystagmus for peripheral vestibular nystagmus?
- Horizontal
- Horizontal or combination of horizontal and torsional
- Follows Alexander’s Law
What does abnormal findings pertaining to caloric testing indicate?
Peripheral lesion involving the horizontal SCCs and/or superior nerve brance of the vestibular nerve on the side with the weaker response
List common causes of peripheral vestibulopathy
- Ototxicity
- BPPV
- Meniere’s Dx
- Vestibular Neuritis
- Labyrinthitis
Define peripheral vestibulopathy
Disorder or dysfunction that involves the inner ear structure responsible for balance and spatial orientation; specifically the vestibular apparatus and vestibular nerve
List of vestibular assessment testing that assess the horizontal SCCs and superior branch
- Calorics
- Rotational Chair Testing
- vHIT
What test assess the otolith organs?
VEMPs
What does the cVEMP pathway includes?
- Saccule
- Inferior Branch of CN VIII
- CN XI
- Descending vestibulo-spinal pathway to Sternocleidomastoid (SCM)
What kind of recorded response does cVEMP provide?
Inhibitory as the SCM nust be contracted to record the response
What kind of recorded response does oVEMP provide?
Excitory contralateral reflex, right ear stimulation is recorded from the left inferior oblique
What does the oVEMP pathway includes?
- Utricle
- Superior branch of CN VIII
- CN III
- Contralateral Inferior Oblique Muscle (ascending vestibulo-ocular reflex)
Between DPOAEs & TEOAEs state what type of hearing loss woule be expected
- DPOAEs: Can be recorded with up to moderate hearing loss
- TEOAEs: Typically absent with more than a mild hearing loss (20-30 dBHL)
For ABR testing, what is the waveform patterns for normal hearing?
Morphology: Good
Wave Latencies: All within normal limits
Wave Amplitude: Normal
Latency-Intensity Function: Falling within normal range
For ABR testing, what is the waveform patterns for CHL?
Morphology: Good
Wave Latencies: Interwave within normative limits; Waves I-V delayed
Wave Amplitude: Normal
Latency-Intensity Function: Outsie of normative range
For ABR testing, what is the waveform patterns for sensory HL?
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
For ABR testing, what is the waveform patterns for neural HL?
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
For neurodiagnositic ABR, what are the expected changes from a 21.1 to 89.1 repetition rate
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)
For acute vestibular syndrome, what are the peripheral and central etiology
Peripheral Etiology = Vestibular Neuritis
Central Etiology = Brainstem, Cerebellar infarct
For recurrent vertigo, what are the peripheral and central etiology
Peripheral Etiology = Meniere disease, superior semicircular canal dehiscence (SSCD)
Central Etiology = Vestibular migraine, transient ischemic attack (TIA)
For positional vertigo, what are the peripheral and central etiology
Peripheral Etiology = BPPV
Central Etiology = Cerebellar disorder, vestibular migraine
For chronic dizziness, unsteadiness, what are the peripheral and central etiology
Peripheral Etiology = Bilateral vestibulopathy, vestibular schwannoma
Central Etiology = Persistent postural-perceptual dizziness (PPPD)
List what makes labyrinthitis different from vestibular neuritis
- 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
What caues vestibular neuritis?
Infection/inflamation of the vestibular nerve, most often involving the superior branch
