Vestibular Exam Flashcards
what is the cardinal sign of vestibular dysfunction?
abnormal eye movements
central vestib damage: impaired ____ and ____
smooth pursuits, saccades
what type of abnormal eye movement do you see with peripheral vestib damage?
nystagmus
caloric testing is the gold standard for diagnosing what?
unilateral peripheral vestibular hypofunction
what does “COWS” mean when talking about caloric testing?
Cold irrigations generate nystagmus in the Opposite direction, Warm irrigations in the Same direction
what is considered to be “significant asymmetry” with caloric testing?
> 25% difference in peak slow component eye movement velocities obtained bilaterally
Vestibular Evoked Myogenic Potential (VEMP) testing measures ____ function
otholith
what is the most common type of VEMP testing?
cVEMP
describe the cVEMP
-measures saccule function via VST
-healthy response: reflexive contraction of ipsi SCM in response to sound
describe the oVEMP
-measures utricle function via MLF
-healthy response: reflexive contraction of contra inferior oblique in response to air or bone conducted sound (eye elevation)
what would be considered abnormal results during VEMP testing?
no muscular response to sound OR asymmetrical response L v R
rotary chair test = gold standard for diagnosing what?
bilateral vestibular hypofunction (BVH)
what is a healthy response during the rotary chair test?
nystagmus
if someone has BVH, what will happen during the rotary chair test?
no VOR gain will be observed
what is the TRUE major indicator of vestibular dysfunction?
vertigo
T/F: vertigo can be experienced with eyes open or closed
true
T/F: oscillopsia can be experienced with eyes open or closed
False! Oscillopsia is only experienced when the eyes are open
what red flags should you look out for during a vestibular exam? (hint: RAIDS DUDAD)
Rapid hearing decline
Acute weakness
Incoordination
Dysarthria
Severe HA
Diplopia
Urinary incontinence
Dec mentation
Additional cranial nerve dysfunction
Dec consciousness
Motion Sensitivity Quotient mild/mod/severe scores
Mild: 0-10
Moderate: 11-30
Severe: 31-100
Dizziness Handicap Inventory mild/mod/severe scores
Mild: 0-30
Moderate: 31-60
Severe: 61-100
Dizziness Handicap Inventory MCID
18
what is the difference btw spontaneous and evoked nystagmus?
-spontaneous: occurs when pt is relaxing, typically seen w central injury or in the acute stages of peripheral injury
-evoked: specific trigger, central OR peripheral injury
what are some common causes of up-beating nystagmus (hint: FCCWS)
Focal brainstem lesion (usually midline pontine)
Cerebellar lesions
Cancer
Wernicke’s Syndrome
Side effect of nicotine, alcohol intoxication
what is the biggest single cause of down-beating nystagmus?
Chiari malformation (1/3 of cases)
what are some other causes of down-beating nystagmus (hint: MC DID)?
MS
Cerebellar degenerations/injury
Demyelinating disease
Idiopathic
Drug toxicity (e.g. amiodarone)
Down-beating nystagmus (esp on lateral gaze) is the cardinal sign of what?
paraneoplastic cerebellar degeneration syndrome
what are some causes of pure torsional nystagmus?
-most common: lesions to medulla or cerebellar peduncles (i.e. Lateral Medullary Syndrome)
-also seen with midbrain lesions that impact oculomotor nuclei
-rare occasions: seen with SCDS
