Friedman neuro-ophthalmology

Question 1

What are optic nerve drusen?

Answer 1

superficial or buried hyaline bodies in the prelaminar optic nerve that have become calcified

Question 2

How do you confirm optic nerve drusen?

Answer 2

B-scan (with gain turned down)
CT scan
autofluroescence

Question 3

complications of optic nerve drusen

Answer 3

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

Question 4

NAION associations?

Answer 4

HTN, DM, ischemic heart dz, hypercholesterolemia, smoking

Question 5

GCA questions

Answer 5

headache
scalp tenderness
jaw claudication (pain with chewing)
weight loss
fever
anorexia
neck pain
eye pain
diplopia
joint pain (Sx of polymyalgia rheumatica)
anemia

Question 6

GCA testing

Answer 6

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

Question 7

GCA Rx

Answer 7

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

Question 8

Other complications of GCA

Answer 8

BRAO/CRAO
ophthalmic artery occlusion
anterior segment ischemia
CN palsy (esp CN6) and stroke

Question 9

Foster Kennedy dz and findings?

Answer 9

Foster Kennedy: Front lobe mass (usually meningioma)

Anosmia, ipsilateral ON atrophy 2/2 tumor compression, contralateral ON edema 2/2 elevated ICP

Question 10

pseudo-Foster Kennedy?

Answer 10

bilateral AION

Question 11

Questions to ask pt if concern of CN3 palsy

Answer 11

Headache?
trauma?
cancer?

Question 12

What do you need to R/O in young pt with CN3 pupil-involvement?

Answer 12

PCOM (posterior communicating artery aneurysm) - neurosurgical emergency
Use MRI, MRA/CTA or both

Question 13

CN3 pupil-SPARING older pt

Answer 13

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.

Question 14

CN6 etiologies

Answer 14

MCC: vasculopathic
Also: trauma, GCA, infection, MS, increased ICP, rarely tumors

Question 15

CN6 DDx

Answer 15

TED
orbital inflammatory pseudotumor (idiopathic orbital inflammation)
myasthenia gravis
convergence spasm
strabismus
medial orbital wall fracture
orbital myositis

Question 16

CN6 work-up

Answer 16

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)

Question 17

Multiple CN palsies DDx

Answer 17

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

Question 18

Orbital apex syndrome

Answer 18

decreased visual acuity (CN2) and color vision + CN palsies

(CN2, 3, 4, V1 and 6) - NOT V2 or sympathetics

Question 19

A-V fistulas

Answer 19

CN palsies +
proptosis
conjunctival injection
chemosis
increased IOP
bruit
retinopathy

Question 20

Cavernous sinus thrombosis

Answer 20

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

Question 21

Multiple CN palsies testing

Answer 21

CT/MRI-MRA

fasting blood glucose, CBC with diff, ESR, VDRL, RPR, FTA-ABS or MHA-TP, ANA, blood cultures
LP, Tensilon test

Question 22

orbital cellulitis organisms

Answer 22

MC 2/2 gram positive bacteria (strep and staph)

also - fungi (phycomycetes), mucor

Question 23

Mucormycosis

Answer 23

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.

Question 24

Lid Retraction DDx

Answer 24

Thyroid eye disease
Post surgery
Contralateral ptosis (Hering’s Law)
Congenital (rare)
Progressive supranuclear palsy
Parinaud’s syndrome
Aberrant regeneration of CN3
Proptosis

Question 25

Wener Classification of eye findings in TRO mnemonic

Answer 25

``` NO SPECS No signs or symptoms Only signs Sof tissue involvement Proptosis EOM involvement Cornea involvement Sight loss (optic nerve compression) ```

Question 26

TED findings

Answer 26

``` proptosis lid signs: lid retraction/lag on downgaze, lagophthalmos restricted EOM (strabismus) exposure (Conj hyperemia, keratopathy) ON compression (optic neuropathy) ```

Question 27

How long to wait for strabismus and TED

Answer 27

wait until strabismus stable for at least 6 months

Question 28

Other Rx for TED

Answer 28

punctal occulsion tarsorraphy orbital decompression (if causing keratopathy or optic nerve decompression) diplopia (prism glasses) steroids, XRT

Question 29

steps for TED for surgery

Answer 29

1) orbital decompression 2) strabismus 3) lid surgery

Question 30

DDx proptosis

Answer 30

V: orbital vasculitis, cavernous sinus thrombosis, AV fistula I: cellulitis, idiopathic orbital inflammation T: trauma A M I N: orbital/lacrimal gland tumors

Question 31

Leber’s Hereditary Optic Neuropathy demographic and VF deficit

Answer 31

Males, 10-30y/o VF deficit? Central or cecocentral

Question 32

Leber’s Hereditary Optic Neuropathy Fundus and FA appearance?

Answer 32

``` 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

Question 33

Leber’s Hereditary Optic Neuropathy Inheritance and Rx?

Answer 33

``` 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)

Question 34

drugs that can cause toxic neuropathy

Answer 34

``` Ethambutol isoniazid chloramphenicol streptomycin methanol digitalis chloroquine quinine ```

Question 35

What tests to order if concern of optic nerve pathology

Answer 35

HVF or Goldman and color vision testing

Question 36

Junctional scotoma

Answer 36

lesion of optic nerve near the chiasm Central VA loss in ipsi/L eye and superotemporal field defect in the contralateral eye

Question 37

DDx for chiasmal syndrome

Answer 37

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) ```

Question 38

Optic neuritis findings:

Answer 38

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

Question 39

Workup if atypical optic neuritis (lasting > 1 month)?

Answer 39

ANA, anti-DNA, VDRL, FTA, CXR, ACE, ESR Prognosis for typical optic neuritis - Good (VA >20/40 in 95% untreated)

Question 40

ONTT

Answer 40

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

Question 41

CHAMPS

Answer 41

IM Interferon beta (Avonex) showed 44% decreased risk of progression to MS with first demyelinating event (includes optic neuritis) Patients treated with steroids also

Question 42

How to uncover functional visual loss

Answer 42

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 ```

Question 43

Causes of ipsi/L Horner's

Answer 43

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

Question 44

Horner's testing - apraclonidine

Answer 44

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

Question 45

Horner's testing - cocaine 10%

Answer 45

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

Question 46

MCC of transient diplopia

Answer 46

``` decompensated phoria, convergence, divergence insufficiency myasthenia gravis spasm of accommodation GCA (EOM ischemia) vertibrobasilar insufficiency superior oblique myokymia cyclic esotropia skew deviation ```

Question 47

Questions to ask patient with ptosis and diplopia

Answer 47

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?

Question 48

Characteristic ocular findings of MG and tests to confirm

Answer 48

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

Question 49

Work-up and Rx for MG

Answer 49

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

Question 50

swollen optic nerve DDx

Answer 50

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

Question 51

Testing swollen optic nerve in office

Answer 51

``` 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

Question 52

Work-up for swollen optic nerve (and IIH criteria)

Answer 52

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)

Question 53

IIH associations

Answer 53

``` Medications - tetracyclines, accutane, OCP, vitamin A, lithium COPD dural sinus thrombosis radical neck surgery recent weight gain pregnancy ```

Question 54

IIH Rx

Answer 54

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

Question 55

Orbital floor fracture w/entrapment - MC involves which bones?

Answer 55

maxillary bone and posterior medial floor (weakest point of the orbit)

Question 56

Other signs of blow-out fracture

Answer 56

``` limited supraduction (limited elevation and depression) subconj hemorrahge AC cell and flare globe ptosis infraorbital nerve hypesthesia lid emphysema ```

Question 57

Rx for blow-out fracture

Answer 57

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

Question 58

Indications for surgery - with entrapment or without entrapment

Answer 58

Any entrapment is an emergent reason for surgical intervention because of the chance for muscle necrosis, but without entrapment, we look at: 1. 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. 2. 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 3. 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

Question 59

Pediatric vs. adult floor fracture

Answer 59

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

Question 60

Globe displacement/dystopia DDx

Answer 60

``` 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

Question 61

horizontal gaze palsy with inability to ADDuct one eye DDx

Answer 61

INO MR palsy Myasthenia gravis

Question 62

Where is the INO lesion?

Answer 62

MLF - medial longitudinal fasiculus

Question 63

Etiology of INO

Answer 63

50 yo - usually vascular Other: trauma, infection, compression

Question 64

bilateral INO signs

Answer 64

inability to ADDuct either eye impaired convergence appearance of exotropia in primary gaze

Question 65

INO vs. one-and-a-half syndrome

Answer 65

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.