Week 1 Highlights Flashcards
Oculomotor/Vestib Exam, BPPV, & other resources
peripheral vs central nystagmus
pattern of mvmt
peripheral: horizontal
* mixed plane (torsional w/ horizontal or vertical component)
central: vertical or torsional
* single plane
peripheral vs central nystagmus
consistency of pattern
peripheral - doesn’t change
central - direction and pattern may change
peripheral vs central nystagmus
effect of gaze
peripheral
* fast phase always to same side
* inc w gaze toward direction of fast phase
central
* no change or fast phase reverses direction
peripheral vs central nystagmus
fatigability
peripheral - fatigues, adaptation
central - doesn’t fatigue
peripheral vs central nystagmus
duration
peripheral - varies depending on dx but usually short duration
central - can be longer duration or >1min
peripheral vs central nystagmus
unilateral vs bilateral
peripheral - always bilateral
central - can be unilateral or bilateral
peripheral vs central nystagmus
effect of fixation
peripheral - dec amplitude
central - no impact or inc amplitude
peripheral vs central nystagmus
onset tempo
peripheral - often sudden (minutes)
central - often more gradual (more than an hour)
peripheral vs central nystagmus
severity
peripheral - mod to severe
central - mild to mod
peripheral vs central nystagmus
symptom pattern
peripheral - intermittent
* tends to be more peripheral in nature
central - persistent sx
* either peripheral or central
peripheral vs central nystagmus
headache
peripheral - usually absent
central - often present
peripheral vs central nystagmus
course throughout the day
peripheral - worse in AM, improves as day proceeds
central - no impact
peripheral vs central nystagmus
positional
peripheral - often, depends on etiology
central - minimal impact
* presence of positional impact doesn’t r/o central etiology
peripheral vs central nystagmus
concomitant ear sx
peripheral - dec hearing or tinnitis = peripheral cause more likely
central - rare, U/L sudden onset
* could be seen in TIA, interanl auditory artery or AICA stroke
peripheral vs central nystagmus
concomitant neurologic sx
peripheral - any neuro complaint = peripheral less likely
central - any neuro complaint = central more likely
* esp diplopia, dysarthria, true ataxia
peripheral vs central nystagmus
gait instability
peripheral - tendency to fall to one side
central - tendency to fall to either side
peripheral vs central nystagmus
imbalance
peripheral - mild to mod
central - severe
peripheral vs central nystagmus
n/v
peripheral - severe
central - variable, may be minimal
acute vestibular syndrome
what is it
5 differential dx
acute persistent continuous dizziness lasting days to weeks and usually associated w n/v and intolerance to head motion
- vestib neuritis
- labyrinthitis
- post circulation stroke
- demyelinating dz
- post-traumatic vertigo
triggered episodic vestib syndrome
what is it
6 differential dx
episodic dizziness triggered by specific and obligate actions, usually a change in head or body position; episodes generally last <1min
- BPPV
- postural HTN
- perilymph fistula
- superior canal dehiscence syndrome
- vertebrobasilar insufficiency
- central paroxysmal positional vertigo
spontaneous episodic vestib syndrome
what is it
5 differential dx
episodic dizziness not triggered and can last minutes to hours
- vestib migraine
- meniere’s dz
- post circulation TIA
- med side effects
- anxiety or panic disorder
peripheral vs central nystagmus
symptom pattern
peripheral - intermittent
* tends to be more peripheral in nature
central - persistent sx
* either peripheral or central
chronic vestib syndrome
what is it
5 differential dx
dizziness lasting weeks to months or longer
- anxiety or panic disorder
- med side effects
- post-traumatic vertigo
- post fossa mass lesions
- cervicogenic vertigo (variable)
what does alexander’s law mean
when gaze is shifted in direction of fast phase, nystagmus will become more pronounced
when gaze is shifted in direction of slow phase, nystagmus will diminish
what are the 3 degrees of nystagmus according to alexander’s law
1st: nystagmus on intact side only
2nd: nystagmus to intact side and in central position
3rd: nystagmus in all 3 directions
when do you usually see 3rd degree nystagmus (per alexander’s law)
acute stages w/ vestib neuritis and labyrinthitis
what is optokinetic nystagmus (OKN)
normal eye mvmt elicited by tracking of moving field
how does OKN present with distinct moving targets
OKN generally contains within it a smooth pursuit
what is the function of OKN
allows you to follow objects in motion while head remains stationary
how is OKN different from smooth pursuit
smooth pursuit - eye mvmt elicited by tracking a single distinct target
OKN - tracking a moving field
chronic vestib syndrome
what is it
5 differential dx
dizziness lasting weeks to months or longer
- anxiety or panic disorder
- med side effects
- post-traumatic vertigo
- post fossa mass lesions
- cervicogenic vertigo (variable)
peripheral vs central nystagmus
symptom pattern
peripheral - intermittent
* tends to be more peripheral in nature
central - persistent sx
* either peripheral or central
what is the ocular tilt reaction (OTR)
triad comprising head tilt, conjugate ocular torsion, and hypotropia d/t skew deviation
how will a (+) OTR present
head tilt toward side of lower eye and ocular torsion in same direction w upper poles of eye rotating to lower eye
how will (+) OTR present in cerebellar lesions
ipsi or contra depending on structures involved
describe the course of the pathway responsible for OTR and how the location of the lesion will impact the (+) OTR presentation
crosses the midline above the abducens nucleus level and ascend into contralateral MLF
- below lower pons = ipsi
- more rostral = contra
how do you determine the side of the lesion in contraversive vs ipsiversive abnormal OTR
the lesion is ipsi or contralateral to the lowermost eye
what is the pathological ocular tilt reaction (OTR)
triad comprising head tilt, conjugate ocular torsion, and hypotropia d/t skew deviation
how will peripheral lesions impact all parts of the OTR
peripheral - utricle, vestib n., medial and superior vestib nuclei
all tilt effects (perceptual, ocular motor, postural) are all ipsiversive
ipsiversive = lesion is ipsilateral to the lowermost eye
what are examples of potential etiologies of eye mvmt abnormalities on pressure change
- abnormalities at craniocervical junction (ie arnold-chiari malformation)
- disorders of inner ear - ie perilymphatic fistula, superior canal dehiscence (SCD)
- middle ear problems with ossicular chain
what are 3 examples of pressure tests to use to sus out any eye mvmt abnormalities on a pressure change
- tragal compression
- valsalva
- hyperventilation (1 breath/sec x40-60)
what is the key to dx a SCD etiology for an eye mvmt abnormality w pressure changes
thorough hx
subjective c/o
* sensitive to noise
* can hear heartbeat
* can hear eyeballs move
what is the most commonly involved SCC in BPPV
posterior
BPPV
post SCC nystagmus presentation
upbeating and torsional
BPPV
ant SCC nystagmus presentation
- downbeating and torsional
- or just downbeating
BPPV
lat SCC nystagmus presentation
horizontal nystagmus (geo vs apogeo)
BPPV lateral SCC nystagmus
geotropic vs apogeotropic
geotropic -> ground loving
* side of inc intensity = side of affected LC = canalithiasis
- apogeotropic -> away from ground, to ceiling
- side of lesser intensity = side of affected LC = cupulolithiasis
in lateral SCC, will present with nystagmus sx during head rotation to both sides during roll test
peripheral vs central nystagmus
symptom pattern
peripheral - intermittent
* tends to be more peripheral in nature
central - persistent sx
* either peripheral or central
how do you differentiate nystagmus in HC from nystagmus of cervicogenic origin
HC = BPPV, gravity dependent
cervico = dependent on position of neck
a triggering mvmt like reaching for the top shelf would be indicative of BPPV in what canal
post SCC
a triggering mvmt reading would be indicative of BPPV in what canal
ant SCC
what pt pop is 3x more likely to develop BPPV
migrainers
having vertigo with what functional activity makes it 4.3xs more likely to have BPPV
vertigo w rolling in bed
describe excitation vs inhibition in vertical canals
flow of endolymph away from ampulla = excites nerve
flow of endolymph toward ampulla = inhibits
d/t position of kinocilium w/i ampulla
what is the primary treatment for BPPV
CRP
when is Meclizine prescribed and why? what is a consideration for PT with this?
prescribed during peripheral event to manage sx of vertigo and motion sickness
* sedative effect on vestib system
sedative effect –> beneficial to not take long term
* if testing a pt, have them hold the med bc can suppress nystagmus
no strong evidence to support use of meds in treatment of BPPV
peripheral vs central nystagmus
symptom pattern
peripheral - intermittent
* tends to be more peripheral in nature
central - persistent sx
* either peripheral or central
what does research say about the efficacy of daily exercise like Brandt Daroffs or Self CRP
doesn’t prevent recurrence of BPPV