LAB 2: PVH exam Flashcards
If your patient has any positive 5Ds and 3Ns with cervical screen, is this a good SNOUT or SPIN test?
SPIN 63-97%
SNOUT: 0% (poor accuracy)
If +, may have VBI, but if -, cannot rule out VBI
oculomotor tests
*Spontaneous Nystagmus
*Gaze Evoked Nystagmus
*Ocular ROM
*Vergence
*Skew-Eye Deviation, OTR
*Smooth Pursuit
*Saccades
VOR tests
*Head Shake Nystagmus Test
*Head Impulse Test
*Dynamic Visual Acuity
*VORx1
*VOR x 2
*VORc
spontaneous nystagmus:
how can you tell if its peripheral or central?
If fixation decreases nystagmus: peripheral
If fixation does not change nystagmus: central
Is nystagmus rotary, vertical, or change directions?
no change in intensity of nystagmus, is direction changing, pure horizonal/vertical, or pendular, & is not fatigable
central vestibular
nystagmus
intensity increases, is unidirectional/direction fixed,
has rotary component & is fatigable when observed
w Frenzels or IR goggles
peripheral vestibular
What is Alexander’s law and nystagmus?
- Nystagmus is named for the fast phase directed towards the
healthy ear - intensity of nystagmus increases when eye moves in direction of the fast phase (healthy ear)
- Nystagmus is enhanced/increased during center gaze when there is no
visual fixation (wearing Frenzels or Video IR Googles)
nystagmus present with gaze center, gaze toward &
gaze away from side of lesion; most intense when gaze directed towards healthy ear.
3rd Degree (1st day; acute lesion):
nystagmus present with gaze center & away from
side of lesion (healthy ear)
2nd degree (subacute)
nystagmus present only with gaze away from
side of lesion (healthy ear)
1st degree (within 1 week, chronic)
If GEN is positive for central, what does it nystagmus look like?
- seen with fixation (in room light) due to an acute or chronic (>3 mo) lesion of CNS
- direction changing/bi-directional
- vertical or pure torsional or rebound
no change/slight decrease without fixation
not fatigueable
If GEN is positive for peripheral, what does it nystagmus look like?
more intense without fixaton, fatiguable
increased intensity in direction of the intact ear
direction fixed
What is abnormal Ocular ROM exam?
visual field deficits, ocular asymmetry, diplopia
*also age decreases ocular ROM
Abnormal vergence test
disconjugate eye
movement or diplopia (central)
before target is 6 cm from nose
Also: aversion reaction
(sympathetic)
skew deviation: what test can you use?
alternate cover test:
skewed eye will jump back to target with uncover
Non-skewed eye will cause skewed eye to jump
back to the target with cov
smooth pursuits: what would be an abnormal sign?
Saccadic intrusions,
central sign
test: head still, follow target 12-18 inch away, move target slowly 30 deg in each direction
saccades:
what is a central sign?
overshooting, undershooting
slow scan instead of quick jump
VOR is ___ driven at __ Hz
velocity driven at 2 Hz
240 bpm
VOR: HSN test: is this passive or active for the patient?
passive
close eyes, shake head passively 20 sec at 240 bpm
open eyes, look R center and L WITH FRENZELS
Does ewald’s 2nd law apply to horizontal canal BPPV and horizontal VOR?
YES
applies to HIT: will see corrective saccade to side of head thrust, indicating vestib hypofunction to that same side
positive/abnormal DVA test
Unilateral Vestibular Hypofunction: >3-line difference or (+) dizziness
Bilateral Vestibular Hypofunction: >3-line difference, no dizziness, (+) oscillopsia, (+) postural instability
VORx1 abnormal/positive test:
target becomes blurry or is jumping and/or (+) dizziness or unable to move their head at 2Hz
Document speed at which target becomes blurry (their baseline).
Mechanism for suppressing VOR during combined eye-head tracking when eyes and head move together in same direction; assesses visual-vestibular integration in CNS
when is this impaired? lesions in cerebellum flocculus or paraflocculus
