Neuro-Ophthalmology Flashcards
Sixth Nerve Syndromes
1- Raymond’s syndrome:
Sixth nerve paresis
Contralateral hemiparesis (pyramidal tract)
2- Millard-Gubler syndrome:
6th & 7th
Contralateral hemiparesis (pyramidal tract)
3- Foville’s syndrome:
CN 5, 6, 7, 8 palsies
Horizontal conjugate gaze palsy
Ipsilateral Horner’s syndrome
4 - Gradenigo:
6th with mastoiditis
5 - Pseudogradenigo:
6th with nasal cancer
6 - Mobius:
not a fascicular but a nuclear 6th & 7th (no contralateral hemiparesis)
Light near dissociation ddx
Divide it by location.
Edinger Westphall nucleus:
- syphillis
- dorsal midbrain syndrome
Ciliary ganglion:
- DM
- Adie’s tonic pupil
- Aberrant regeneration (CN3)
Long posterior ciliary nerves:
- PRP
Other:
- severe loss of bilateral afferent input (e.g. dense VH)
- Myotonic dystrophy
Miosis ddx
- drugs (pilo, other cholinergics)
- Horner’s
- Argyll Robertson
- Posterior synechiae
- spasm of near reflex
Mydriasis ddx
- CN3
- drugs (atropine, scopolamine, sympathetic agonists, anti-cholinergics, anti-histamines)
- trauma
- iris sphincter damage after surgery
Ptosis ddx
Neurogenic:
- horner’s
- CN 3
Myogenic:
- CPEO (Kearns sayer, OPMD)
- myotonic dystrophy
NMJ:
- MG
Mechanical (tumors)
Involutional
Pseudo-ptosis ( enophthalmos, contralateral retraction)
Optociliary shunt vessels
Optic nerve meningioma, glioma
CRVO
GC axons project to (4)
- LGB
- hypothalamus
- superior colliculus
- EW nucleus
Macular sparing occipital infarct. Where is the lesion & what vessel
Anterior tip of occiput, which is supplied by middle and posterior cerebral artery. Posterior = more posterior, so if its infarcted all that’s left is the macula (supplied by middle cerebral artery)
Where is the temporal crescent on the occipital lobe
Posterior tip (?)
Which CN go through what parts of brainstem
Midbrain: 3,4
Pons: 5-8
Medulla: 9-12
Constricted visual fields
Malingering RP or its variants Vitamin A deficiency CSNB Advanced glaucoma ONH drusen PRP
Arcuate VF ddx
Glaucoma ONH drusen Hemiretinal artery occlusion Myelinated NFL Optic nerve coloboma AION, NAION Optic neuritis
Bitemporal vf defect ddx
Pituitary/sellar lesion
Tilted discs
ONH drusen
Enlarged blind spots
Junctional scotoma - ddx of lesions
Pituitary adenoma Craniopharyngioma Glioma Meningioma AVM, anneurysm Rathke's pouch cyst
Optic disc edema ddx
ONH drusen NAION, AION Optic neuritis Papilledema (IIH or tumor) Infiltration (sarcoid, syphillis, TB) Compressive optic neuropathy Neuro-retinitis Diabetic papillitis HTN papillopathy Impending CRVO
Bilateral central scotoma ddx
Toxic, nutritional
Bilateral optic neuritis
Macular (dystrophy, AMD, bilateral CSR)
Hereditary (LHON, other hereditary optic atrophies)
Painful ophthalmoplegia
Thyroid Myositis/IOI/other orbital inflammations (Wegener, sarcoid, etc) Orbital apex mass Tolosa Hunt Pituitary apoplexy Optic neuritis CCF Cavernous sinus thrombosis Orbital infections (bacterial, mucor)
Vertical diplopia ddx
CN 4 palsy Brown's Skew DVD Inferior oblique palsy (rare) Thyroid, MG Mass Myositis, IOI
Pituitary hormones to check for if you suspect a pituitary adenoma
FLAT PIG (for anterior), OA for posterior
FSH LH ACTH TSH (and free T3, T4) Prolactin i Growth Hormone
Oxytocin
ADH (check FBS too)
Painful sudden loss of vision with ophthalmoplegia. What are you worried about.
Pituitary apoplexy
Abduction deficit
Duane's type I CN 6 Thyroid, mass, myositis, IOI Decompensated strab Slipped muscle after surgery
Tram track on CT
Optic nerve meningioma
Enlarged blind spot
Papilledema Papillitis ONH drusen Megalopapillae MEWDS/IEBSS
Blood supply of LGB
anterior & lateral choroidal arteries
Blood supply of optic tract
Middle and posterior cerebral arteries
Blood supply to chiasm
ICA
Which layers of LGB are crossed vs not
CI, IC IC
Crossed: 1, 4, 6
Ipislateral: 2, 3, 5
Layers of LGB that are magno vs parvocellular
Magno = 1,2 (M=motion, stereo, contrast) Parvo = 3-6 (parvo=fine detail)
Anneurysms - which are most common
85% ICA. Of these, PCOM most common
ACOM can compress ON and chiasm
ONTT - what are the 3 groups
- nothing
- oral pred (1 mg/kg x 14 days)
- IV pred (250 mg IV QID x 3d, then 1 mg/kg oral x 11 d)
ONTT - 1 year rates of MS
7.5% in IV group
15% in oral group
17% in placebo group
ONTT - what is IV steroid better for?
Shortens duration of current optic neuritis attack
No change in overall Va recovery
Decreased attacks of optic neuritis
Less MS at 2 years, but same as other groups by 3 years
ONTT - why is oral steroid bad
More recurrences of optic neuritis at 1 and 5 years. More MS at 1 year, but no difference in rates of MS overall
ONTT - rates of MS based on MRI findings
5 years:
-
ONTT - bad prognostic factors for development of MS
previous attacks of optic neuritis
history of episodes of neurologic symptoms
and MRI findings
ONTT - protective factors for MS
atypical optic neuritis (no pain, + disc edema, only mild Va loss)
no MRI findings
Where is the lesion - spasmus nutans
Rule out chiasmal glioma
Where is the lesion - gaze evoked nystagmus
If assymetric, rule out cerebellar lesion (stroke, MS, tumor)
Where is the lesion - rebound nystagmus
Cerebellar lesion
Where is the lesion - upbeat nystagmus
Medulla
Where is the lesion - downbeat nystagmus
Cervico-medullary junction (rule out arnold-chiari malformation)
Where is the lesion - ocular bobbing
bilateral pontine hemorrhage
Where is the lesion - oculopalatal myoclonus
Cerebellar flocculus to medullary olive
Where is the lesion - PAN
Always watch any nystagmus for >2 min to see if it becomes PAN
- cerebellar Nodulus (paN = Nodulus)
Where is the lesion - oculomasticatory myoryhtmia
Whipple’s dz (duodenal bx)
Where is the lesion - convergence retraction nystagmus
Lateral medulla
Where is the lesion - Brun’s nystagmus
Brun’s = gaze evoked + vestibular
- when looking towards lesion, its low-freq
- when looking away, its high freq
- think CPA tumor, or CPA infarct
Where is the lesion - opsoclonus
Paraneoplastic.
Kids = metastatic neuroblastoma
Adults = breast, lung, ovaries
Where is the lesion - pendular nystagmus
Not localising
General ddx for nystagmus
Lesions (tumor, AVM) Infarct MS Encephalitis Syphillis Drugs (anti-convulsants, EToh, lithium) Nutritional (Wernicke's, parenteral feding)
What can you treat nystagmus with
Clonazepam, baclofen, gabapentin
same as for muscle spasms/myokymia
Features of dorsal midbrain syndrome
Light-near dissociation Upgaze palsy Eyelid retraction (Collier's sign) Tonic downgaze (setting sun sign) Convergence retraction nystagmus (with OKN moving up) Convergence paralysis (?)
Causes of dorsal midbrain syndrome
PINEAL tumor stroke AVM encephalitis syphillis drugs (lithium, etoh, anti-convulsants) nutritional (wernicke's, parenteral feeding) hydrocephalus
Features of congenital nystagmus
CONGENITAL
- better with Convergence
- no Opsoclonus
- have a Null point
- same in all positions of Gaze
- Equal in both eyes
- Near vision better than distance (because dampens with converence)
- Inversion of OKN
- head Turn often present
- Absent during sleep
- they have Latent nystagmus
Features of PSP
No Bell’s, yes VOR (ie yes Doll’s head)
Often have progressive dementia
Eventually get frozen globe, can’t blink
CN3 syndromes
Nothnagel: ipsilateral 3 + ataxia
BenediKT: 3+ Kontralateral Tremor (cerebral peduncle)
Weber: contralateral hemiparesis (red nucleus)
Claude: nothnagel + benedikt (cerebral peduncle)
- don’t quote me on these. Different sources define them differently.
What can you see in AR
- either miosis or lid retraction
- either with adduction or downgaze
(i.e. 4 things that could happen)
Causes of AR
Tumor
Trauma
AVM
Congenital (marcus-gunn)
NOT ischemic
Unique features of CN 4
- only CN to decussate
- only CN to exit brainstem dorsally
- longest course (most suspectible to trauma)
Features of bilat CN 4 palsy
hyper reverses on lateral gaze and head tilts
>10 degrees of torsion
V-pattern ET (usually ET > 25D)
Features of congenital CN 4 palsy
Head tilt on old photos
Large vertical fusional amplitudes (>10D (?))
Unique features of CN 6
Most suspectible to compression with high ICP - non-lateralising sign of high ICP
Second most common cause of CN6 palsy = trauma
CN 7 palsy - different causes
Idiopathic = Bell’s
HSV = Ramsy Hunt (often have facial rash, hearing loss)
Sarcoid = bilateral
Miller-Fisher = ophthalmoplegia + ataxia
Melkerson Rosenthal = children, recurrent facial swelling & CN 7 palsy. Furrowed tongue.
2 types of childhood aberrant regeneration
Marcus Gunn jaw wink (CN3/5) Crocodile tears (CN7 aberrant regen after Bell's)
CN’s in marcus-gunn jaw wink
CN 3 and 5
Pathology affecting cavernous sinus or SOF
Tolosa Hunt Thyroid Mucor, bacterial orbital abscess Retro-orbital hemorrhage Meningioma
Cavernous sinus thrombosis
ICA anneurysm
Mets
Pituitary tumors, apoplexy
What is Hutchinson’s
unilateral CN3 palsy (with blown pupil) in a coma due to a supratentorial mass
DDx of 2nd order Horners
Lung tumor (pancoast, neuroblastoma) Carotid dissection
DDx of 3rd order Horners
Cavernous sinus lesion, ICA dissection
Orbital apex
Ciliary ganglion
DDx of 1st order Horners
Hypothalamus lesion
Down through brainstem
Lateral medullary syndrome
Features of lateral medullary syndrome (ocular and systemic)
Ipsilateral Horner’s (miosis, ptosis, peri-ocular anhidrosis)
Nystagmus
Skew
Ipisilateral decreased pain and temp to face
Contralateral decreased pain and temp to trunk
Ataxia
Dysphagia, dysphonia, dysarthria
Ocular (4) and systemic (3) features of myotonic dystrophy
Ocular:
- Decreased EOM
- Ptosis
- Xmas-tree cataract
- Light-near dissociation
Systemic:
- MR
- Frontal baldness
- Testicular atrophy
What tests for MG
- Tensilon
- Ice pack
- rest
- ACH- receptor antibodies
- EMG
- Mestinon trial
What on history for MG
- alternating and variable ptosis
- variable diplopia
- symptoms worse at the end of the day
- symptoms worse with prolonged use
Always rule out with MG
thymoma (chest CT)
thyroid (TSH, free T3, T4)
Hereditary Optic Neuropathies
LHON (15-30 yo) - mitochondrial
Behr (
Mutations in LHON
11778 - most common
14484 - best prognosis
3460
You suspect hereditary optic neuropathy. What do you do?
FA
Maybe CT. Have to rule out other causes.
Genetics Avoid toxins (smoking, etoh, etc)
Causes of IIH
OCP Vitamin A compounds (e.g. retinoic acid) Tetracyclines Steroid use/withdrawal (Addison's dz) Young, overweight females Pregnancy
How do you treat IIH
Mild, no vision loss: lose weight and treat headaches Some vision loss: diamox Severe vision loss: - Optic nerve fenestrations - therapeutic LP's - VP shunt
