Anisicoria and Ptosis Part 1 Flashcards
_____ refers to unequal pupillary size. It may be physiologic or pathologic. Physiologic anisicoria is present in 20% of the patient. and it is usually
Aniscoria
Pathological anisocoria is always caused by a defect in the ____ pathway and the iris _____ is the most common.
efferent; sphincter.
What is the pathway of the sympathetic chain to dilate your eyes
Start in hypothalamus through brain stem down spinal cord preganglionic 1st order neuron. Then synapse within the spinal cord, exit, travel up around the apex of the lung and then synapse in superior cervical ganglion at the level of your jaw-2nd order neuron, still preganglionic. 3rd order is postganglionic that will wrap around internal carotid, through carotid canal, through cavernous sinusand distributed via V1 (long ciliary nerve)mueller’s muscle dilator. Long ciliary nerve goes to dilator
______ ciliary nerves get distributed to your sympathetics. The _____ ciliary nerves get distrubuted to your parasympethics (iris sphincter and ciliary muscle) to constrict your eye.
long; short (subdivisions of trigeminal nerves)
short: bring afferent from surface of cornea and eyelids thats going back to your trigeminal ganglion and distribute the post ganglionic para sympathetics.
short and long: distrubute the sympathetics.
PS lesion can be anywhere from:
EW nucleus, CN III, ciliary ganglion, short ciliary nerves.
Anisicoria greater in bright is due to ______ lesion. Anisicoria greater in dim is due to _____ lesion. Anisicoria equal in bright and dark is physiologic.
parasympathetic; sympathetic
An afferent lesion would indicate what?
the consensual will be better than direct.
An efferent lesion would indicate what?
Both direct and consensual will be absent.
What does pupil evaluation include?
- direct vs consensual response
- eyelid position
- slit lamp evaluation
What are the 6 pupillary disturbances
- Marcus Gunn pupil:
- Horners syndrome
- Postganglionic Denervation (Adies Tonic Pupil, Neurotrophic): something is happening after the ciliary ganglion
- Pupil in Midbrain Disease- Dorsal midbrain syndrome and Argyll Robertson pupils (teriary syphillis)
- Pupil in Third Nerve Palsy
- Pharmacologic Blockade: pupil is blown (scopalamine)
Marcus Gunn pupil shows a relative asymmetry in the _____visual pathway. It NEVER causes anisicoria. And is usually accompanied by a reduction in VA, color vision, contrast sensitivity, or visual field on the affected side.
afferent;
Horner’s syndrome is damage to the sympathetic chain. _____ is the NT at the muscular junction of the sympathetic system.
norepinephrine;
___ order neuron lesion will be due to ischemic stroke (bc still in brain tissue) or demyelinating in young patients. _____ order neuron lesion will be usually a lung tumor or a carotid artery dissection (tear within wall of artery) where all the blood gets rushed into tear instead of going up and into the eye. ______order neuron lesion is due to carotid artery dissection and other benign causes.
first; second
What are some signs of Horner’s Syndrome?
- anisicoria greater in dim light
- dilation lag of abnormal pupil
- smaller pupil is abnormal and ipsilateral to lesion
- normal pupillary light rxn (bc PS is in charge of this)
- ipsilateral upper eyelid ptosis and lower lid reversed ptosis
The cocaine test is confirmatory test for Horner’s syndrome. Describe how it works.
4-10% cocaine blocks reuptake of NE. NE is the NT at the NMJ, In this situation your eye is releasing NE, but not to a large extent. If you block the reuptake you get accumulation of NE at the NMJ, and the pupil starts dilating much better.
In _____ anisicoria the pupil will dilate because the sympathetic pathway is intact and the NE is being released. In ______ anisicoria there is no effect/minimal effect on the pupil because third order neuron is not being stimulated. Nothing is telling it to release NE therefore, no pupillary dilation and there is a lesion in your sympathetic chain.
physiologic; pathologic
What is the procedure for testing pathologic anisicoria
Place 10% diluted cocaine eyedropper into both eyes. Wait 45 mins. Examine the pupils in dark.
What are common and uncommon causes of acquired Horner’s syndrome in the first order neuron (central)
common: lateral medullary stroke
uncommon: hypothalamic, midbrain, or pontine injury, spinal cord lesion
What are common and uncommon causes of acquired Horner’s syndrome in the second order (preganglionic) neuron
common: pancoast tumor (lung) brachial plexus injury iatrogenic trauma neuroblastoma (kids) carotid artery dissection
uncommon: cervical disc disease
what are common causes of acquired Horners syndrome in third order (postganglionic) neuron
carotid artery dissection
cluster headache
cavernous sinus lesion