neuro-ophtho / otology Flashcards
asymmetry or loss of OKN is what?
parietal lobe lesion
OKN uses same side of brain to pursue and to correct the saccade to catch the next stripe
pursuit vs saccade brain regions
saccades: catch it with contralateral frontal lobe
pursuit: ipsilateral parietal temporal lobe
lesion of fasicle and superior cerebellar peduncle causes what and name of lesion
nothnagel: ipsilat CN 3 palsy and cerebellar ataxia
what will a third nerve nucleus lesion give you?
right nuclear cn3: loss of CN3 on third side AND gets levator palpebrae nucleus which is single, so both eyes get ptosis, and superior rectus on opposite side will also be affected.
6th and 7th nerve palsy with contralat hemiparesis
millard gubler
ipsilat gaze palsy, 5, 7, and horner’s
foville’s
where is the vertical gaze center locted
near midbrain / CN III nucleus
where is the horizontal gaze center in brain
in pons, near CN VI nucleus
area of brain responsible for saccades vs pursuit
saccades: contralat frontal lobe (jerk correction / fast phase)
pursuit: ipsilat parieto/occipital lobe (slow phase)
lesion is where when you get an isolated CN 6 and a horner’s
small cavernous sinus lesion near the CN 6/ICA w/ sympathetics sparing the wall of the sinus where the other CNs are
how do you differentiate a supranuclear vs brainstem gaze palsy
if doll’s eye can move eyes, the lesion is supranuclear
2 main possible causes of a vertical gaze palsy
- dorsal midbrain / parinaud syndrome
2. PSP (PD + syndrome)
4 components of a dorsal midbrain lesion syndrome?
- vertical gaze palsy
- OKN downgoing, get a convergence/retraction nystagmus
- Pupil: convergence response but no light response: light/near dissoc and pupils are BIG
- lid retraction
If you get a vertical gaze palsy and convergence retraction nystagmus, but positive doll’s eye movement, what is diagnosis?
PSP
bilateral failure of adduction with horizontal gaze with fully abducted other eye beating?
INO
complete failure to look right, and when looking left, the right eye doesn’t adduct
1.5 syndrome gets the pPRF and CN6 nuclear complex and the MLF
what are the three components of the SNS pathway for pupil dilation
1st order: in brainstem
2nd order: C8-T2 at ciliospinal center of Budge to apex of lung and around subclavian artery to superior cervical ganglion
3rd order: along the ICA (in part with CNVI in the cavernous sinusO)
what is Hutchinson sign with zoster lesions?
lesion of tip of nose: may indicate involvement of nasociliary branch and means eye is at risk
involvement of mild ptosis with upper and lower lid involved
mullers / SNS
what does aproclonidine drop do
Horners tests that would dilate the pupil in a Horners even when cocaine would not.
what does hydroxyamphetamine / paradrine drop do
horners: will distinguish between 1/2 or 3rd order; dilates only in 1/2nd not benign third
only type of horners usually benign unless what
3rd order, unless with pain, in which case worry about carotid dissection
what do you get if you have a Horners and heterochromia
congenital issues b/c SNS is also responsible for giving color or iris
vermiform eye movements with light
this pupil is very sensitive to what drop
tonic pupil
very sensitive to pilocarbine
what is Adie’s
tonic pupil plus loss of DTRs
argyll robertson pupil vs parinaud pupils and adie’s pupils
argyll robertson has small pupils.
parinauds and adies have large pupils
all accomodate but don’t really react to light well
think of what with bilateral central visual field defects (3 examples)
toxic or genetic
- ethambutol
- Lebers
- NMO/Devics
micro vs macroadenoma
10mm
when someone is complaining on intermittent diplopia or blindness without any CN palsy, think what?
could be a loss of vision convergence due to bitemporal blind fields overlapping OR loss of intermittent phoria/drift
Think pituitary tumor
bow tie atrophy of fundi seen in what?
bitemporal visual field lesions w/ pituitary tumors
where is lesion if you get a large central visual field defect in one eye and a upper temporal field cut (pie in sky) in other eye?
large optic nerve lesion that catches the looping fibers: junctional scotoma
lesion that creates visual field defects with wedges / wisps of spared areas?
LGN lesion: onion / laminar sparing of layers
pie in the sky field defect is lesion where?
inferior temporal optic tract/radiations lesion
increased congruity in visual field defects r/l eyes with lesions where
more posterior leads to more congruity
where is the lesion if you get a large homonymous hemianopsia but with an area of far temporal field spared?
occipital lobe
far temporal and macular sparing hemianopsia- where is lesion?
occipital lobe
where is lesion if you get monocular loss in one eye and half loss in other
hemichiasmal: chiasm gives temporal loss, but also get the optic nerve so lose other whole eye
central bitemporal hemianopsia where is lesion
very back of chiasm only in pre-fixed chiasm variant
radial vessels shooting straight out
morning glory disk
double ring sign on fundo exam
seen when
optic nerve hypoplasia
seen in maternal DM, drug/alcohol
calcified nodules and very branched vessels on ophtho exam but good vision
Drusen
see saw nystagmus
chiasmal lesion, craniopharyngioma
downbeat nystagmus in what conditions (3)
lithium, cerebellar ataxia, chiari
what part of retina is responsible for central vision
macula and fovea in very center of that
Rods vs cones in location and function
rods: periphery of retina for night vision
cones: near fovea for color
what causes a bi-nasal hemianopsia
calcified internal carotid arteries w/ b/l lateral compression
muscle for eyelid closing and nerve
orbicularis oculi by facial nerve
muscle for depression and intorsion
superior oblique
elevation and intorsion
superior rectus
depression and extorsion
inferior rectus
(inferiors extort)
AND IRS makes us depressed (inferior rectus depresses)
elevation and extorsion
inferior oblique
inferiors extort
pathway of pupillary light reflex
optic nerve, chiasm, tract
pretectal nuclei
Edinger Westphal nuclei
ciliary ganglion –> short ciliary nerves
(extrageniculate)
what colliculus is responsible for generating saccades
superior colliculus
w/ CN 3 less diplopia looking far or near?
less looking far due to impaired convergence (PNS of CN 3)
the only cranial nerve that decussates
trochlear
which eye is bad in a head tilt / trochlear palsy
the eye that is elevated in primary gaze and has trouble looking down
short vs long ciliary nerves and PNS/SNS
short ciliary: PNS: to iris sphincter for pupil constriction and ciliary muscle for accomodation (short makes pupil small)
long ciliary: SNS for pupil dilators (long makes pupil large)
where is MLF/ connects what
connects abducens nucleus to oculomotor nucleus on opposite side
where is lesion in an INO (ie left eye impaired adduction)
left MLF
lesion causing 1.5 syndrome
pontine lesion causing PPRF OR CN6 nucleus AND MLF to be involved
PPRF projects where
ipsilat CN6 nucleus AND contralat CN3 nucleus thru MLF
LGN lesion that gives the homonymous defect w/ spared horizontal sector is often caused by stroke where
anterior choroidal artery / lateral geniculate body
homonymous hemianopia with macular sparing
occipital cortex lesion (cortex looks like C)
how can monocular lesion occur with cortical lesion
anterior calcarine cortex can cause a moon shaped temporal defect only in one eye
posterior commissure important for what eye movement
upgaze
rostral interstitial nucleus of MLF is important for what
downgaze
what causes painless vision loss of sudden onset
anterior ischemic optic neuropathy
poor pupil response to direct light, but responds consenually
APD / usually from optic nerve damage anterior to chiasm
unilateral ptosis and synkinesis of CNV and III causing eyelid movement with jaw movement
marcus gunn jaw winking
marcus gunn pupil
relative afferent pupillary defect: pupil appears to dilate when light is pointed at it but constricts consensually
pinpoint reactive pupils seen with what?
pontine lesions
riddoch phenomenon
person only sees person’s fingers when they are ridonculously wiggling them but not when still
triad of spasmus nutans
- titubation
- nystagmus
- torticollis
decreased visual acuity with increased temp seen in what
optic nerve disease: Uhthoff’s phenom
lag of upper lid during down gaze
von graefe sign in thyrotoxicosis
optic nerve coloboma and chorioretinal lacunae
aicardi
susac’s syndrome
branch retinal artery occlusions
oculomasticatory myokymia is seen in what disease
whipple’s disease
ptosis and impaired extraocular movement without diplopia and swallowing issues
dz and what genetics and what pathology
oculopharyngeal muscular dystrophy
GCG repeat expansion in gene encoding PABP2 on chr 14
Rimmed vacuoles
most common presentation of NARP (Neuropathy, ataxia, retinitis pigmentosa)
night blindness
pendular convergent-divergent oscillations of eyes w/ movement of jaws and bursts of myoclonus
Whipple disease
sunflower cataracts
Wilson’s disease
in labyrinthitis nystagmus is toward which side?
unaffected ear
how to distinguish between vestibular neuritis and viral labyrinthitis?
hearing loss ALWAYS present in viral labyrinthitis
main precipitant for bacterial suppurative labyrinthitis?
cholesteatoma
type of hearing loss with menieres
low frequency
dx with hearing loss, vertigo, tinnitus, nystagmus away from bad ear
labrynthitis
what CNs are involved potentially in cerebellopontine angle lesions
V1, 7, 8, 9, 10
BAERS wave 1 and 2
cochlear nerve then cochlear nucleus
BAERs wave III and V?
III: superior olive
V: Inferior colliculus
what will a CN 6 nuclear lesion cause?
it causes limited abduction ipsilateral and also adduction of contralat eye through contralat MLF connections
