Anisocoria Flashcards
Main things to worry about when someone has a dilated pupil
Dilated pupil + CN 3 palsy
-if pupil is involved, aneurysm, get to ER
If ONLY dilated pupil
- put diluted pilo in the eye
- constricts=Adies
- doesnt constrict=pharmacological (scopolamine, plants)
Side effects of topamax
Bialteral angle closure
Myopic shift
If aniso is > in light
CN III
Adies
Pharm
If aniso is > in light
Syphillis
Horners
Uveitis
What is the correct definition of sensitivity
The probability of a test giving a positive result in patients with the disease
Adies tonic pupil
Acute dilated pupil due to an idiopathic lesion in the CG or the ciliary nerves, causing decreased innervation to the iris sphincter muscle
Who gets Adies
Most common in young (20-40) females. Typically unilateral but becomes bilateral at a rate of 4% per year
Short posterior ciliary nerves and Adies
Innervates the ciliary muscle and also arise from the ciliary ganglion, thus patients with Adies may also have decreased accommodation, resulting in a complaint of blur at near
Adies signs
Patients will present with minimal to no constriction of the affected pupil in response to light, but with a slow constrict in response to a near object. Anisocoria will be greatest under bright illumination due to poor innervation to the iris sphincter muscle (unable to constrict)
The iris will have a vermiform movement when looked at under slit lamp.
-decreased cell in CG but there are still SOME
Argyle Robertson pupil
Miotic pupil due to a lesion in the tectotegmental tract, which carries information from both pretectal nuclei to their respective ipsilateral and contralateral EW nuclei.
ARP
- accommodative response present
- FEF still working
What is Argyll Robertson pupil associated
Neurosyphilis
DM
Alcoholism
Signs of argyll Robertson pupils
Light-near dissociation (the pupil does not react or constricts poorly to light, but constricts normally in response to convergence and accommodation). Pupil constriction in response to near objects is controlled by the FEF, which is not affected here
Anisocoria will be greatest in the dark
Horners syndrome
Miotic pupil due to a lesion in the sympathetic nervous system pathway. Aniso will be greater in dark.
Classic triad of mild ptosis (poor innervation to mullers), miosis (due to poor innervation of the iris dilator), and anyhdrosis (due to lack of innervation to sweat glands)
Some less common findings: heterochromia, LL reverse ptosis, conj hyperemia, increased amplitude of accommodation
Pre-ganglionic central lesion for horners
From the hypothalamus to the ciliospinal center of Budge. Causes -CVA -demyelinating disease -tumor
Pre-ganglionic lesion in horners
From the ciliospinal center of Budge to the superior cervical ganglion Causes -thyroid mass -neck trauma -Hx of thyroid or neck surgery
Post-ganglionic lesion for horners
From the superior cervical ganglion to the iris dilator
Causes
-head trauma
-cavernous sinus syndrome
-carotid dissection (pain and Hx of trauma)
-cavernous sinus fistula
-ICA aneurysm
Pancoast tumor and horners
The most common pre ganglionic lesion
Superior CN 3
Innervates levator and the SR
Inferior CN3 innervation
IR, MR, IO
Parasympathetic fibers also travel along this division
Complete CN3 palsy
Occurs when both divisions are impaired resulting in a lack of innervation to all 4 EOMs and the levator muscle; the eye will be directed down and out, with a significant ipsilateral ptosis. An incomplete CN 3 palsy is anything less than a complete 3 palsy
Why might someone with a complete CN palsy not complain of diplopia
Because of the huge ptosis
Most common causes of CN3 palsy
Microvascular infarcts, trauma, and aneurysms
Pupillary fibers and CN3
Pupillary fibers travel on the outside of CN3; thus a pupil involving CN 3 palsy is much more likely to be caused by a compressive lesion rather than a microvascular infarct. Any pupil involving CN 2 palsy warrants immediate imaging with an MRI/MRA to r/o a compressive tumor or aneurysm (most commonly involving the PCA)
Because the pupil can rarely become involved after the initial presentation, patients with pupil sparing CN3 palsys should be monitored closely for 1 week to ensure the pupil does not become involved
Topamax and its side effects
Indicated for the treatment of seizures, and is also RXed off label for the treatment of migraines and weight loss. It may result in superciliary fusion, causing an anterior shift in iris-lens diaphragm and subsequent angle closure (commonly within the first month or after an increase in the dosage). It will be bilateral
May also cause a myopic shift in refractive error
