Neuro-Ophthalmology Flashcards
Nerve fibers (of the nerve fiber layer) will respect ______
Horizontal line
Nerve fibers (of the nerve fiber layer) will travel _____ until the first synapse on the _______
12cm, LGB
Visual cortex cells are____
Simple vs Complex
Visual cortex cells - Simple cells function
Linear orientation of the visual field
Visual cortex cells - Complex cells function
Linear orientation of the visual field with the direction of movement (best for movement perception)
State the percentage of cells that decussate at the chiasm and the side that decussate.
53% and nasal
The macular diseases will usually present with:
Metamorphosis\ Microopsia (actual location change of photoreceptors)
The ON diseases will usually present with:
COLOR perception!
VA to some extent as well.
Ischemic optic neuropathy usually presents with what VF deficit?
Lower arc in the lower visual field
Examination of the ON includes
VA, Color perception, RAPD
Pupillary light reflex pathway - First neuron and its output and synapse.
Light —(via CN II)—>pretectal nuclei in the midbrain
Light —(via CN II)—>pretectal nuclei in midbrain—-(decussation)—->bilateral Edinger Westphal nuclei–(via CN III)–>Cilliary ganglion—->Ciliary sphincter
pupils constrict bilaterally (direct and consensual reflex).
Result: illumination of 1 eye results in bilateral pupillary constriction.
Pupillary light reflex pathway - Second neuron and its output and synapse.
pretectal nuclei in midbrain—-(decussation)—->bilateral Edinger Westphal nuclei
Light —(via CN II)—>pretectal nuclei in midbrain—-(decussation)—->bilateral Edinger Westphal nuclei–(via CN III)–>Cilliary ganglion—->Ciliary sphincter
pupils constrict bilaterally (direct and consensual reflex).
Result: illumination of 1 eye results in bilateral pupillary constriction.
Pupillary light reflex pathway - Third neuron and its output and synapse.
bilateral Edinger Westphal nuclei–(via CN III)–>Cilliary ganglion
Light —(via CN II)—>pretectal nuclei in midbrain—-(decussation)—->bilateral Edinger Westphal nuclei–(via CN III)–>Cilliary ganglion—->Ciliary sphincter
pupils constrict bilaterally (direct and consensual reflex).
Result: illumination of 1 eye results in bilateral pupillary constriction.
Pupillary light reflex pathway - Fourth neuron and its output and synapse.
Ciliary ganglion—->Ciliary sphincter
Light —(via CN II)—>pretectal nuclei in midbrain—-(decussation)—->bilateral Edinger Westphal nuclei–(via CN III)–>Cilliary ganglion—->Ciliary sphincter
pupils constrict bilaterally (direct and consensual reflex).
Result: illumination of 1 eye results in bilateral pupillary constriction.
Disc examination:
Color (usually yellow-orange), Size (edematous/atrophied?), Shape (Congenital anomaly?)
Swollen disc usually results from____ at ____
Axoplasmic transport obstruction, Lamina cribosa (narrowest place)
Reasons for the increase in ICP and Papiloedema:
SCHMOCE!
S - SOL C - Craniosynostosis H - Hydrocephalus M - Meningitis O - Obstruction of venous outflow (sinus vein thrombosis -CSF has nowhere to go) C - CSF secreting tumors E - Edema
Papilledema examination - describe normal finding
Oval shape, clear borders, and blood vessels exiting from it with a cup in the middle.
Papilledema examination - neurologically we care most for the ____
Rim
Papilledema examination - we look for _____
blurring of the borders, and blood vessels
Pseudotumor cerebri etiologies:
Femal TOAD
Female Tetracyclines Obesity/OSA Vitamin A overdose Danazol
Pseudotumor cerebri symptoms:
Headache, Photophobia, N/V, “DVT”
D - diplopa (horizontal - CN VI)
V - Visual obstruction (transient with position change)
T - Tinitus
Pseudotumor cerebri findings:
Field PACS
Field - VF has increased the blind spot
P - Papilledema
A - Acuity decrease (not in the early stage)
C - Color perception decrease (not in the early stage)
S - Symetric
Pseudotumor cerebri treatment:
CLaWS C - CAI L - LP (from week 16-20) a W - weight loss (6-10%) S - Steroids (when approaching surgery/catastrophic edema) S - Surgery
Pseudotumor cerebri treatment - surgery indications:
Sever optic neuropathy or lack of response to medical treatment.
Pseudotumor cerebri treatment - surgical options:
Shunts (VP or Lumopertoneal) - risk of obstruction in 50% of cases.
Optic nerve decompression - risk of injury to blood vessels. ON, Diplopia, infections.
Pseudotumor cerebri workup:
MRI/CT
LP opening pressure (normal is 80-200mm water, >250mm water is diagnostic for PTC)
Pseudotumor cerebri workup - atypical patient mandates ____ for worry of_____
MRI and CTV/MRV for risk of sinus vein thrombosis.
Anterior Ischemic Optic Neuropathy (AION) Pathophysiology:
Area affected
Ischemic damage to ON at the prelaminar area (close to exit location of the eye)
Anterior Ischemic Optic Neuropathy (AION) ocular signs, symptoms, and fundus exam findings:
Sudden painless vision loss with RAPD.
Edema and flame-shaped bleeds (on an exam)
Anterior Ischemic Optic Neuropathy (AION) types.
NAION (non-arteric AION) - usually over 50 y.o. and related to vasculitis (with compartment syndrome of the other eye disc)
AAION (Arteric AION) - Womwn over 70 y.o. and related to GCA.
NAION (non-arteric AION) - RF
HOLDS H - HTN/HTN drugs O - hypOtension L - Lipids (cholesterol) D - DM - S - smoking
NAION (non-arteric AION) - treatment:
Asprin
NAION (non-arteric AION) - prognosis:
1/3 stay the same
1/3 get worse
1/3 get better
10% chance of damage to the other eye in coming years.
AAION (Arteric AION) - RF
CRP
C - Choroidial ischemia
R - Retinal arterial obstruction (CRAO)
P - PION (damage to the nerve in the socket)
AAION (Arteric AION) - findings:
TAPPABLE: T - Thrombocytosis A - Acuity (VA) P - Palpable (Hard to touch) P - Pallid disc swelling A - Amaurosis fugax B - Bx has skip lesions\ bilateral in some cases L - Labs (positive ESR and CRP has 97% specificity) E - ESR
AAION (Arteric AION) - treatment:
Start treatment ASAP
Bx can be delayed by 7-10.
IV prednislone 1 gram/day for 3-5 days —> PO prednislone 1 mg/kg for a year
+- Aspirine
AAION (Arteric AION) - symptoms:
Headache, Kayclaudication, Polymyalgia Rheumatica
Optic neuritis - Etiology and epidemiology:
Demyelinating disease (idiopathic or MS)
Presents in 50% of MS patients, In 20% it’s the presenting symptoms
Usually young, caucasian, women.
Optic neuritis - signs, symptoms:
Acute PAINFUL decrease in VA
1/3 - papillitis
2/2 no papillitis (retrobulbar optic neuritis)
Optic neuritis - general signs and symptoms, and can be classified as____
Acute PAINFUL decrease in VA
1/3 - papillitis
2/2 no papillitis (retrobulbar optic neuritis)
Optic neuritis - imaging findings:
Oval lesions, >6 mm
Located at the lateral ventricle, BS, or dorsum fingers
Optic neuritis - treatment:
IV methylprednisolone 250mg x4\ 3 days —-> 1mg\kg\day PO Prednisolone for 11 days
Don’t start with PO Prednisolone - makes it worse
MS is diagnosed by presenting______
Two different attacks in two different locations at two different times.
Devic’s disease - treatment:
Steroids
Devic’s disease - findings:
MRI not suitable for MS with\without elongated spinal lesion on T2
NMO-IGg for aquaporin 4.
Devic’s disease - Pathophysiology:
Its like MS BUT_____
Optic neuritis + Transverse myelitis
Optic neuritis - worse than in MS
Transverse myelitis - Sensory + motor deficits with urine output issues.
Optic neuritis - findings:
Field CRAP
Field - damage to visual field C - Color perception decrease R - RAPD A - Acuity decrease (VA) P - Pain (also when moving the eye)
Describe the relationship of damage to the retina and the visual field result.
Inverse: Temporal inferior retinal damage -> Nasal superior VF deficit
Fovea represents the___________
Central VF
ON contains mostly
macular fibers
Damage to beyond chiasm will_______
respect vertical middle line.
Damage to ON leads to either ___or ____ scotomas.
Central or Centro-cecal (around blind spot and macula) scotomas
Nasal fibers will make _____before decussating.
Knee of von weilbrand on contralateral side
Clinical correlate of Knee of von weilbrand is ______
Junctional Scotoma: damage to one eye’s ON will also damage the inferior nasal fibers of the contralateral eye.
presents with central scotoma in primary affected (ON damage), and superior temporal (inferior nasal fiber damage) scotomain secondary affected eye.
Clinical correlate of Knee of von weilbrand is ______
Junctional Scotoma: damage to one eye’s ON will also damage the inferior nasal fibers of the contralateral eye.
presents with central scotoma in primary affected (ON damage), and superior temporal (inferior nasal fiber damage) scotoma in secondary affected eye.
Clinical correlate of Knee of von weilbrand is ______
Junctional Scotoma: damage to one eye’s ON will also damage the inferior nasal fibers of the contralateral eye.
presents with central scotoma in primary affected (ON damage), and superior temporal (inferior nasal fiber damage) scotoma in secondarily affected eye.
Clinical correlate of Knee of von weilbrand is ______
Junctional Scotoma: damage to one eye’s ON will also damage the inferior nasal fibers of the contralateral eye.
presents with central scotoma in primary affected (ON damage), and superior temporal (inferior nasal fiber damage) scotoma in the secondarily affected eye.
The clinical correlate of Knee of von weilbrand is ______
Junctional Scotoma: damage to one eye’s ON will also damage the inferior nasal fibers of the contralateral eye.
presents with central scotoma in primary affected (ON damage), and superior temporal (inferior nasal fiber damage) scotoma in the secondarily affected eye.
Optic tract damage will present with:
Homonymous hemianopia, with RAPD, incongruous.
Why will optic tract damage will present with RAPD, and be incongruous?
Incongruous - different proportions of fibers (53%nasal, 47%temporal)
RAPD - different proportions of fibers (53%nasal, 47%temporal), before the thalamus.
Optic radiation damage will present with:
Lower fiber damage - Meyers loop -> “pie in the sky” homonymous hemianopia
After the thalamus - no RAPD.
parietal lobe damage will present with:
upper fiber damage - lower VF homonymous hemianopia
After the thalamus - no RAPD.
Occipital lobe damage will present with what in regards to the macula?
Macular splitting or macular sparing homonymous hemianopia.
What is a patient’s perception with macular splitting homonymous hemianopia?
As half of the macula is involved - patients see half of everything
Blood supply, degrees preserved and a patient’s perception with macular sparing homonymous hemianopia?
Central 5 degrees are preserved (Blood supply from ACA and PCA) - patients can read and perceive detail when looking at things up-close.
Internuclear ophthalmoplegia - Pathophysiology:
Damage to medial longitudinal fasciculus (MLF): pair of tracts that allows for crosstalk between CN VI and CN III nuclei
Frontal eye field-> PPRF-> nuc VI—(MLF)—>nuc III
Directional term (eg, right INO, left INO) refers to the eye that is unable to adduct.
INO = ipsilateral adduction failure, Nystagmus Opposite.
Internuclear ophthalmoplegia - Pathway:
Frontal eye field-> PPRF-> nuc VI—(MLF)—>nuc III
Directional term (eg, right INO, left INO) refers to the eye that is unable to adduct.
INO = ipsilateral adduction failure, Nystagmus Opposite.
One-eye movement is called:
Duction
Two-eye movement is called:
Version
Patients with diplopia will usually complain about ________
Binocular double vision (covering one eye will lead to a single vision perception)
Single eye diplopia is usually due to____and binocular diplopia is usually due to_____
Binocular diplopia - central etiology
Single eye diplopia - eye etiology (e.g. Keratoconus)
Binocular diplopia workup includes_____
asking direction of the diplopia (vertical, horizontal, oblquie) - corresponding to the muscles affected.
CN VI Passes through _____ in the cavernous sinus and advances to the orbit
Dorello’s canal
CN Ill damage etiologies and corresponding presentations:
CN III has both motor (central) and parasympathetic (peripheral) components.
Common causes include:
PU(peripheral)CIM(central)
P - PCom aneurysm - sudden-onset headache
U - Uncal herniation - coma
C - Cavernous sinus thrombosis - proptosis, involvement of CNs IV, V1/V2, VI
I - Ischemia - pupil sparing (motor fibers affected more than parasympathetic fibers)
M - Midbrain stroke - contralateral hemiplegia
In the orbit, CN Ill divides into the _____
Inferior and Superior decisions
Inferior and Superior divisions of CN Ill are responsible for_____
Superior divisions - Superior rectus and levator
Inferior divisions - rest of muscles (intra and extra ocular)
