Optic Neuropathies I Flashcards
CN II is myelinated by:
oligodendrocytes
What are the four anatomical segments of the optic nerve
- intraocular - vascular insults; inflammation and infection
- intraorbital - muscle engorgement/tumors
- intracanalicular - most susceptible to trauma; fractures an sinus inflammation
- intracranial - pituitary and circle of willis
______ blood supply includes the SPCA (peripapillary choroidal vessels). anastamoses between SPCA are scant, making this a _____ area
Prelaminar; watershed
Lamina _____ is supplied by the SPCA and circle of inn haller
cribrosa
_____ branches from the CRA, branches from pial vessels
retrolaminar
Prelaminar region includes the retina and the ____
choroid
what does pallor of the optic nerve mean
you’ve lost your prelaminar vasculature which includes SPCA
what does it mean when you can’t see the cup ?
obliteration of the nerve
round white globular dots within the optic cup =
optic nerve head drusen
optociliary shunt vessels deal with dilation of pre existing _____ beds due to compromised venous return in the _____ region of the optic disc. They develop as a response to congested blood flow.
capillary; prelaminar
what is etiology of optic nerve shunts
- optic nerve sheath meningioma
- CRVO
- Chronic glaucoma
ON dysfunction includes:
- VA loss
- RAPD
- dyschromatopsia
- VF defect
- reduced CS
- +/- normal optic disc appearance
- Abnormal VEP
ON disease can include:
- Glaucoma
- Ischemic
- Inflammatory
- Infectious
- Demylinating
- Hereditary
- Toxic/metabolic
- Compressive
- Traumatic
optic neuritis is inflammation of the optic nerve. There are two types: typical and atypical.
Typical: due to demyelinating lesion; autoimmune disease that causes antibodies to attack the myelin sheath
Atypical: systemic infectious/inflammatory causes
Describe characteristics of typical optic neuritis
- sudden VA loss - progresses for a week and then improves by a month
- Pain on EOMs
- +/- RAPD
- Dyschromatopsia and reduced CS is usually worse than VA
What is a typical presentation of optic neuritis
- unilateral
- retrobulbar
- age: 15-50 but avg age is 30
- mostly female
optic neuritis also presents with _____ deficits
VF
associated symptoms of optic neuritis may include _____ of hands, problems with bladder control, ______ phenomenon, which includes altered perception of moving objects. Lhermitte’s sign as well as Uthoff sign is also prevent.
numbness; pulfrich
what is lehrmittes sign
flexion of head causes unpleasant electric shock like discharge originating from neck and spreading down the spine
what is uthoff sign
worsening of neurologic symptoms with increased body temperature
what were the 3 treatment arms of ON
- IV methylprednisolone 250 mg QID x 3 days, followed by oral prednisolone 1 mg x 11 days
- Oral prednisolone 1 mg x 14 days
- Oral placebo x 14 days
In the study, oral steroid alone, _______rate of recurrence optic neuritis
increased
IV steroids reduced risk for development of MS after initial attack of ON for ____ years, no benefit after that. Brain MRI is extremely useful in identifying patients who are at a higher risk for dev MS
2
15 year overall risk in MS after ON is ____ in women.
75%
Initial MRI is the most _____ risk factor in developing MS. 0 lesions = _____%, 1 lesion = ______%, 3+ lesions = _____%
predictive; 25; 60; 78
what are other risk factors for MS
- white race
- family history of MS
- ill defined neurologic complaints
- previous episode of acute optic neuritis
what are low risk for MS?
- severe disc swelling
- no pain
- disc or PPA hemorrhage
- retinal exudates (infection)
- NLP vision
- Male sex
Dissemination in ____ means you have two separate events
time; new lesion when compared to previous scan irrespective of timing. also includes simultaneous prescene of enhancing and non enhancing T2 lesion on any one scan
Dissemination in _____. It includes greater than or equal to 1 enhancing_____lesion in greater than or equal to 2 locations.
space; look at multiple sections. different lesions in different parts of brain. Usually enhancing T2 lesion in 1+ locations.
T2
_____ lesion is active and will light up. _____ lesion is an old lesion
T2, T1
lesions usually occur around the _____
ventricles
Pts in the CHAMPS study who had a demyelinating event AND an abnormal MRI had a 44% reduced rate of developing MS by taking _____ injection
avonex
_____ therapy is given to those high risk patients who have 1+ MRI lesions
Interferon
T/F, After diagnosing optic neuritis, you should order an MRI and refer to neurology for treatment initiation
true
______ bands, aka immunoglobulins are inflammation related proteins in blood serum and CSF. While present in CSF, it indicates inflammation of the CNS
oligoclonal; 80-90% of pts with MS have permanently observable oligoclonal bands
_____ is the first oral treatment for MS, but it can cause macular edema
gilenya
What are the different ways to treat MS
- Intramuscular
- IV
- Oral
______optic neuritis includes falling out of typical age range. They’re either less than 18 or greater than 50 yo. It will usually present ______, and won’t be painful. It will present with anterior/posterior ______, as well as retinal exudates, and hemorrhages. Severe optic nerve swelling. VA continues to worsen past 1 week. Recurrence within short interval or during steroid taper
Atypical; bilateral; uveitis
What do you have to do after you diagnosed your patient with atypical optic neuritis
- Bloodwork:
- CBC with differential: RBC, WBC, platelet levels, hemoglobin, and hematocrit
- ESR and CRP: inflammation
- ACE (sarcoid)
- RPR- VDRL, RTA-Abs (syphillis)
- ANA (looks for lupus)
- Lyme titers
- Chest xray
2. MRI
3. Lumbar puncture
T/F Other causes of optic neuritis include CT disease, infectious, or infiltrative
true
what are ex of CT disease
- lupus
- sjogrens
- bechets
what are ex of infectious disease
- viral: measles, mumps, HZV
- bacterial: lyme, syphillis
- parasitic: toxoplamsa, toxocariasis
what are ex of infiltrative
- sarcoidosis
2. cancer: lymphoma, leukemia
neuromyelitis optica can present as _____ disease which presents as acute optic neuritis and transverse myelitis which is inflammation of the spinal cord that causes weakening of the limbs
devic
Two diagnostic criteria of neuromyeltis optica requires 2 _____ and 2 ______
absolute; supportive
absolute includes optic neuritis and acute myletis. Supportive includes contagious spinal cord lesion greater than or equal to 3 vertebral segments on MRI, brain MRI not meeting diagnostic criteria for MS, and positive _____ IgG serology
NMO
what do the NMO antibodies target ?
aquaporin 4; nervous system’s main water channel protein. Inflammatory demyelination results in necrotic damage of white and grey matter…astrocyte damage, demylinationn, neuronal loss, and necrosis
NMO can affect children but median age of onset is _____. its relapsing or monophonic. Treatment is via ______ therapy which includes IV steroid, azathioprine, rituximab
39; immunosuppresive
NMO can cause _____ failure, which is not seen in MS. MRI brain lesions are normal/nonspecfic in NMO, CSF oligoclonal bands usually absent in NMO
respiratory
T/F NMO has higher incidence in asians and aa, carries poor prognosis with higher incidence of permanent paralysis, binocular blindness, and respiratory failure. rehab is similar to patients with spinal cord injuries
true
_____ myelitis is another inflammatory CNS condition that deals with focal inflammatory disorder of spinal cord ,and presents with numbness and paresthesias and may progress to MS. eyes are usually not involved but can progress to optic neuritis later
transerve
Acute disseminated encephalomyelitis (ADEM) is usually seen in children after viral injections or immunizations. pts will get fever, nausea, vomiting, positional vertigo. Treatment includes:
- high dose IV steroids for 3-5 days
2. oral taper for 4-6 weeks
