EOM
The 3rd cranial nerve controls all EOM except
SO4LR6
Horner syndrome causes ptosis and miosis due to over/under activity of sympathetic/parasympathetic..?
underactivity of the sympathetic fibers
A patient with DM HTN HLD wakes up with double vision and based on the eye exam, you suspect she has a CN3 palsy. How is the CN3 palsy classically described?
A patient with MS has vision issues.
when looking to the right, left eye does not adduct and right eye has nystagmus.
where is the lesion
L MLF
Adie tonic pupils affects sympathetic or parasympathetic?
How do patients present?
Parasympathetic
affected pupil is dilated, eye pain, blurry vision, loss of accommodation and light response
The superior oblique has these two actions
intorsion and depression
Name all 5 symptoms of Horner syndrome
upper eyelid ptosis, lower eyelid becomes elevated, enophthalmos, miosis and anhidrosis
A patient with DM HTN HLD wakes up with double vision and the ED tells you they think it's a CN3 palsy due to vascular risk factors. But when you see her, you notice the affected pupil is not reacting to light (is dilated). What is the true etiology of her CN3 palsy?
ANEURYSM "rule of the pupil"
A patient has a R MLF, what is the eye movement abnormality they will have on movement
R MLF= R eye cannot adduct= R INO
Adie tonic pupils has a very specific and early finding on exam
Sectoral palsy of the iris
The inferior oblique has these two actions
extorsion and elevation
Name the muscle affected in Horner that causes the ptosis
Muller muscle
CN3 has subnuclei in the midbrain. All of them innervate the ipsilateral designated muscle EXCEPT for two nuclei
SR (contralateral) and LPS (midline one)
When looking left--> L eye abducts, R eye stays midline
Where is the lesion
BL MLF and R LR/CN6 affected
How can 0.125% Pilocarpine help diagnose Adie tonic pupil
Affected pupil is now supersensitive to Ach.
Diluted Pilocarpine doesn't affect the normal pupil much but causes BIG constriction
A patient with suspected L. trochlear nerve palsy will compensate for the double vision by doing what?
They classically have trouble doing this simple activity
Head tilt to the right
Going down stairs
A patient with suspected Horner syndrome comes in and you use cocaine eye drops to help diagnose him. How does cocaine affect the pupils and what is the MOA?
Cocaine inhibits reuptake of NE at the NMJ of the dilator muscle--> dilation if sympathetic is working.
Normal eye--> dilation
Affected eye--> does not dilate
CN4 innervates the ipsi or contralateral SO?
Does it exit the midbrain dorsally or ventrally?
Contralateral and dorsally
A MS patient comes in with blurry vision, decreased red saturation and vision loss in the right eye. You do a swing test. What will you observe on the swing test on this patient?
RAPD R eye.
What does chronic Adie tonic pupil look like on exam? Is it miotic/mydriatic and how is the light and accommodation response?
It is miotic
Accommodation is better but light response is still slow--> light near dissociation (accommodate but do not react)
How does Hydroxyamphetamine eye drops help determine where the lesion is in suspected Horner syndrome?
Hydroxyamphetamine releases the stored NE in 3rd order neurons (only ones that have it).
Affected eye dilates--> 3rd neuron working--> 1st or 2nd neuron affected
Affected eye doesn't dilate--> 3rd neuron not working
List 4 common aneurysm locations that would affect CN3
PCA, SCA, PCOMM, Basilar tip
A patient with MS comes in for suspected optic neuritis. The ED want to discharge her on oral prednisone taper but Dr. Abbas says to admit the patient and start IV steroids.
Who do you believe is right and WHY?
ONTT
If you have an Adie tonic pupil PLUS absent DTR you have this specific syndrome
Holmes Adie Syndrome