Friedman neuro-ophthalmology Flashcards
What are optic nerve drusen?
superficial or buried hyaline bodies in the prelaminar optic nerve that have become calcified
How do you confirm optic nerve drusen?
B-scan (with gain turned down)
CT scan
autofluroescence
complications of optic nerve drusen
cause VF defects (typically enlarged blind spot, arcuate scotoma, sectoral scotoma that is stable/nonprogressive)
- anterior ischmeic optic neuropathy
- choroidal neovascularization
- subretinal/vitreous hemorrhage
- vascular occlusion
NAION associations?
HTN, DM, ischemic heart dz, hypercholesterolemia, smoking
GCA questions
headache scalp tenderness jaw claudication (pain with chewing) weight loss fever anorexia neck pain eye pain diplopia joint pain (Sx of polymyalgia rheumatica) anemia
GCA testing
ESR: greater than age/2 for males and (age+10)/2
CRP: > 2.45 mg/dL
CBC (low hematocrit, high platelets)
FA: choroidal nonperfusion in arteritic form
temporal artery Bx w/in 2 weeks, at least 3 cm in length
GCA Rx
IV 1 gm qd x 3 days.
Rx does not improve outcome in affected eye but is necessary to prevent visual loss in fellow eye
>follow by an internist/rheumatologist to monitor therapy response and to slowly taper steroids
Other complications of GCA
BRAO/CRAO
ophthalmic artery occlusion
anterior segment ischemia
CN palsy (esp CN6) and stroke
Foster Kennedy dz and findings?
Foster Kennedy: Front lobe mass (usually meningioma)
Anosmia, ipsilateral ON atrophy 2/2 tumor compression, contralateral ON edema 2/2 elevated ICP
pseudo-Foster Kennedy?
bilateral AION
Questions to ask pt if concern of CN3 palsy
Headache?
trauma?
cancer?
What do you need to R/O in young pt with CN3 pupil-involvement?
PCOM (posterior communicating artery aneurysm) - neurosurgical emergency
Use MRI, MRA/CTA or both
CN3 pupil-SPARING older pt
can observe for pupil involvement during the 1st week, but generally such cases 2/2 microvascular dz (80% are pupil sparing) and resolve spontaneously in 3 months
Perform work-up if pupil becomes involved, history of cancer, other neurologic abnml or palsy does not resolve after 3 months.
CN6 etiologies
MCC: vasculopathic
Also: trauma, GCA, infection, MS, increased ICP, rarely tumors
CN6 DDx
TED orbital inflammatory pseudotumor (idiopathic orbital inflammation) myasthenia gravis convergence spasm strabismus medial orbital wall fracture orbital myositis
CN6 work-up
can monitor for 3 months if 2/2 DM
Other work-up to consider: check BP, lab tests (CBC, ESR, CDRL/RPR, FTA-ABS/MHA-TP, ANA, LP and tensilon)
Multiple CN palsies DDx
V: vascular lesions in the brain stem/subarachnoid space, cavernous sinus, orbital apex
I: infection/inflammation, meningitis
T
A: (mimickers: CPEO, myasthenia, MS, Guillian-Barre, PSP)
M
I
N: tumor
Orbital apex syndrome
decreased visual acuity (CN2) and color vision + CN palsies
(CN2, 3, 4, V1 and 6) - NOT V2 or sympathetics
A-V fistulas
CN palsies + proptosis conjunctival injection chemosis increased IOP bruit retinopathy
Cavernous sinus thrombosis
CN palsies (can see CN3, 4, V1 and V2, and 6 and sympathetic involvement with Horners)+
fever
lid edema
signs of facial infection
Key difference between orbital apex and cavernous sinus thrombosis is cavernous sinus thrombosis involves V2 and sympathetics
Multiple CN palsies testing
CT/MRI-MRA
fasting blood glucose, CBC with diff, ESR, VDRL, RPR, FTA-ABS or MHA-TP, ANA, blood cultures
LP, Tensilon test
orbital cellulitis organisms
MC 2/2 gram positive bacteria (strep and staph)
also - fungi (phycomycetes), mucor
Mucormycosis
aggressive infection from Mucor fungi that causes necrosis, vascular thrombosis, orbital invasion
histology: broad nonseptate fungae hyphae
Can cause retinal vascular occlusions and orbital apex syndrome
may extend intracranially to cause cavernous sinus thrombosis, meningitis, brain abscess, death.
Lid Retraction DDx
Thyroid eye disease Post surgery Contralateral ptosis (Hering’s Law) Congenital (rare) Progressive supranuclear palsy Parinaud’s syndrome Aberrant regeneration of CN3 Proptosis
Wener Classification of eye findings in TRO mnemonic
NO SPECS No signs or symptoms Only signs Sof tissue involvement Proptosis EOM involvement Cornea involvement Sight loss (optic nerve compression)
TED findings
proptosis lid signs: lid retraction/lag on downgaze, lagophthalmos restricted EOM (strabismus) exposure (Conj hyperemia, keratopathy) ON compression (optic neuropathy)
How long to wait for strabismus and TED
wait until strabismus stable for at least 6 months
Other Rx for TED
punctal occulsion tarsorraphy
orbital decompression (if causing keratopathy or optic nerve decompression)
diplopia (prism glasses)
steroids, XRT
steps for TED for surgery
1) orbital decompression
2) strabismus
3) lid surgery
DDx proptosis
V: orbital vasculitis, cavernous sinus thrombosis, AV fistula
I: cellulitis, idiopathic orbital inflammation
T: trauma
A
M
I
N: orbital/lacrimal gland tumors
Leber’s Hereditary Optic Neuropathy demographic and VF deficit
Males, 10-30y/o
VF deficit?
Central or cecocentral
Leber’s Hereditary Optic Neuropathy Fundus and FA appearance?
Hyperemia and elevation of optic disc Peripapillary telangiectasia Tortuosity of medium arterioles Findings may precede visual loss (visual loss can lead to vision 20/200) May also appear normal
FA shows?
No leakage or staining of disc
2nd eye affected weeks - months later
Leber’s Hereditary Optic Neuropathy Inheritance and Rx?
Inheritance? Mitochondrial DNA (therefore maternal inheritance - ~50% sons affected) Most common = mt 11778
Treatment?
Coenzyme Q
Prognosis:
Based on mutation type
Associated conditions?
Cardiac conduction abnormalities (WPW)
drugs that can cause toxic neuropathy
Ethambutol isoniazid chloramphenicol streptomycin methanol digitalis chloroquine quinine
What tests to order if concern of optic nerve pathology
HVF or Goldman and color vision testing
Junctional scotoma
lesion of optic nerve near the chiasm
Central VA loss in ipsi/L eye and superotemporal field defect in the contralateral eye
DDx for chiasmal syndrome
MCC: mass lesion but possibly due to hemorrhage
V: aneurysm, pituitary apoplexy I: chiasmal neuritis T: trauma A: sarcoidosis M I N: tumors (i.e. meningioma)
Optic neuritis findings:
Central visual loss, APD, dyschromatopsia
Pain with eye movement (90%)
Uhthoff’s Phenomenon?
VA decrease with exercise / increased body temp
Pulfrich phenomenon?
Lateral motion of pendulum appear to have depth
Average time to nadir = 4.5 days
Workup if atypical optic neuritis (lasting > 1 month)?
ANA, anti-DNA, VDRL, FTA, CXR, ACE, ESR
Prognosis for typical optic neuritis - Good (VA >20/40 in 95% untreated)
ONTT
15-year risk of MS with MRI?
0 lesions: 16%
1 or more lesions: 72%
overall risk: 50%
PO prednisone increased recurrence
IV methylprednisolone (250 mg IV q6h x 3 days followed by pred 1 mg/kg day for 11 days then rapid taper) recovered vision faster if treated in first 2 weeks (BUT NO difference in final VA)
IV methylprednisolone in patients with CNS plaques had fewer recurrences within first 2 years, but equivocal at 3 years
CHAMPS
IM Interferon beta (Avonex) showed 44% decreased risk of progression to MS with first demyelinating event (includes optic neuritis)
Patients treated with steroids also
How to uncover functional visual loss
check distance and near vision
monocular and binocular vision
vary test distance fog red-green glasses with duochrome test or W4D test prism dissociation stereopsis startle reflex propioception name signing mirror tracking OKHN visual fields
Causes of ipsi/L Horner’s
Anisocoria greater in DARK (due to impaired sympathetic input to side of lesion)
DDx: Central causes (rarely causes isolated Horner's): Wallenberg syndrome (PICA stroke), neck trauma/tumor, cervical disc dz, demyelinating dz
Preganglionic: tumors (mediastinal, apical, thyroid), trauma, pneumothorax, cervical infection, brachial plexus syndrome, aneurysm, trauma
Postganglionic:
neck lesion, headache, migraine/cluster headache,
carotid dissection (3rd order), c-c fistula, internal carotid artery aneurysm, infection
Horner’s testing - apraclonidine
Anisocoria greater in dark. REVERSAL of anisocoria with apraclonidine.
Apraclonidine 1% (must give OU)
Alpha adrenergic receptor agonist ACTS MORE ON ALPHA 2 receptors (than alpha 1 receptors). @ ~ 36 hrs, upregulation of alpha-1 receptors 2/2 synaptic denervation.
Normal: mild constriction
Horner: dilates more
Normal pupil response to iopidine - mild constriction 2/2 action on alpha2 receptors (decreased norepi)
Horner pupil - upregulated alpha1 receptors –> dilation
Horner’s testing - cocaine 10%
Cocaine 10%: Blocks NE reuptake
at presynaptic cleft… therefore more NorEpi stimulates the pupillary dilator muscle
Normal pupil - DILATES
Horner pupil - poor (or none) dilation
2/2 decreased sympathetic tone (so no change with cocaine 2/2 already low NorEpi in synaptic cleft)
Physiologic anisocoria - both pupils dilate nearly equally leading to
MCC of transient diplopia
decompensated phoria, convergence, divergence insufficiency myasthenia gravis spasm of accommodation GCA (EOM ischemia) vertibrobasilar insufficiency superior oblique myokymia cyclic esotropia skew deviation
Questions to ask patient with ptosis and diplopia
Is ptosis worse on one side, does it vary (throughout the day, from day to day, when pt is tired)?
Prior diplopia?
Happen with other activities - reading, watching TV?
Associated with HA or other neuro Sx?
h/o eye or head trauma?
Any other medical problems, specifically autoimmune disorders?
Any weakness, difficulty in breathing, swallowing, hoarseness?
Characteristic ocular findings of MG and tests to confirm
Si/Sx:
asymmetric ptosis and variable strabismus
gaze-evoked nystagmus
NO pupil/ciliary muscle involvement
variability/fatiguability - worsening of ptosis with extended upgaze and improvement with rest/cold
Rest test: improvement in ptosis s/p closing eye for 30 min or ice test (improvement in ptosis s/p application of ice pack for 2 min)
NEGATIVE forced ductions
Tensilon can be administered but a negative test does not R/O MG
Dx lab test: ACh receptor antibodies
If tests are negative: definitive Dx by single fiber EMG of peripheral or orbicularis muscle
Work-up and Rx for MG
R/O thyroid dz, thymoma, other autoimmune disorders.
thyroid function tests, ANA, RF
Chest CT or MRI scan
Refer to neurologist/internist for systemic Rx
Manage strabismus with prism and potentially surgery when stable for at least 6 months
swollen optic nerve DDx
Meaty - pseudotumor, diabetic papillitis
Mass or Mass shift - tumor, intracranial infection/hemorrhage (DURAL VENOUS SINUS THROMBOSIS)
Medications - tetracyclines, accutane, OCP, vitamin A, lithium
Malignant HTN
Testing swollen optic nerve in office
RAPD color vision visual field EOM (consider forced ductions) lid position and presence of proptosis and resitance of globes to retropulsion
Check BP to R/O HTN
check serum blood glucose level
Work-up for swollen optic nerve (and IIH criteria)
MRI/MRV
LP with opening pressure
IIH criteria:
1) Normal neuro-imaging
2) Normal neuro exam except possible CN6 palsies
3) high CSF pressure (> 250 mm H2O) with normal composition
4) si/sx of increased ICP (i.e. HA, vomitting, papilledema)
IIH associations
Medications - tetracyclines, accutane, OCP, vitamin A, lithium COPD dural sinus thrombosis radical neck surgery recent weight gain pregnancy
IIH Rx
weigh loss, d/c medications that can cause swollen optic nerves
Vision loss, VF, intractable headache - Rx with diamox or LASIX
If progressive vision loss: ON sheath fenestration, LP shunt
Orbital floor fracture w/entrapment - MC involves which bones?
maxillary bone and posterior medial floor (weakest point of the orbit)
Other signs of blow-out fracture
limited supraduction (limited elevation and depression) subconj hemorrahge AC cell and flare globe ptosis infraorbital nerve hypesthesia lid emphysema
Rx for blow-out fracture
ice compress
nasal decongestant
avoid blowing nose
PO antibiotics and steroids for 10 days
re-eval for surgery in 7-10 days to allow for reduction of swelling
Indications for surgery - with entrapment or without entrapment
Any entrapment is an emergent reason for surgical intervention because of the chance for muscle necrosis, but without entrapment, we look at:
- Diplopia within 25 degrees of primary gaze
This is the softest of the 3 indications- there often is diplopia that meets this criteria due to bruising of the extraocular muscles. But if it is improving, we often will watch it for a bit to see if it resolves. - Enophthalmos > 2mm
Enophthalmos tends to worsen over time both because swelling decreases and because there is a phenomenon known as late fat atrophy that occurs within the orbit. Enophthalmos >2mm is both cosmetically noticeable and likely to cause diplopia because the eyes are too disparate in position to allow fusion of images - Greater than 50% of floor involved in fracture (assessed by eyeballing scan)
If greater than 50% of floor is involved in fracture, then there is a very large chance that pt will develop significant enophthalmos
Pediatric vs. adult floor fracture
pediatric floor fractures are different b/c bones are pliable and trapdoor situation may occur in which inferior rectus or surrounding tissue can become entrapped
>nausea and bradycardia occur owing to the oculocardiac reflex
>referred to “white-eyed blow-out fracture” b/c eye is usually quiet but requires emergent surgery to prevent premanent damage to entrapped tissue
Globe displacement/dystopia DDx
Adult orbital tumros: cavernous hemangioma meningioma neurilemmoma (spingle cells in Antoni A pattern) fibrous histocytoma lymphoid lesion lacrimal gland sinus tumor mtz
Use pt age, direction of globe displacement, presence/absence of pain to narrow DDx
Most lesions are intraconal masses that cause proptosis
Lacrimal/sinus tumors tend to displace globe DOWN
Down and out - consider sinus mucocele* - MC from frontoethmoid sinus
*CT: opacification of ethmoid sinus with erosion into orbit
horizontal gaze palsy with inability to ADDuct one eye DDx
INO
MR palsy
Myasthenia gravis
Where is the INO lesion?
MLF - medial longitudinal fasiculus
Etiology of INO
50 yo - usually vascular
Other: trauma, infection, compression
bilateral INO signs
inability to ADDuct either eye
impaired convergence
appearance of exotropia in primary gaze
INO vs. one-and-a-half syndrome
one-and-a-half syndrome: lesion of PPRF (paramedian pontine reticular formation) or CN6 nucleus and ipsi/L MLF = ipsi/L gaze palsy AND INO (only eye movement = ABduction of contra/L eye with nystagmus)
Etiology: stroke, MS, basilar artery occlusion, pontine tumors.
