Ocular Motor Disorders Flashcards
What does the suffix “phoria” mean?
weakness, eye would drift but drifting is held in check by sensory fusion
What does the suffix “tropia” mean?
paralysis, eye drifts even when the person is focusing on a target
What does prefix “eso” mean?
eye is deviating inward
What does the prefix “exo” mean?
eye is deviating outward
What does the prefix hyper mean?
eye is deviating upward
What does the prefix hypo mean?
eye is deviating downward
What muscles does the third cranial nerve supply?
levator muscle of the eyelid, medial rectus, superior rectus, inferior rectus, and inferior oblique
What does the third cranial nerve do to the pupil?
constricts the pupil through its parasympathetic fibers that supply the smooth muscle of the ciliary body and the sphincter of the iris.
What is the clinical presentation of acquired CN III palsy?
Sudden onset of binocular horizontal, vertical, or oblique diplopia. Ptosis or a droopy eyelid
What is the clinical presentation of congenital CN III palsy?
Found in young children. May have ptosis or strabismus. Amblyopia is the major complication of 3rd nerve palsy in children
What would you find on an eye examination of CN III palsy?
partial or complete ptosis. The pupil may be dilated and poorly reactive to light. usually are associated with a large-angle exotropia and hypotropia
What is in the differential for CN III palsy?
HTN, Diabetes, Tumor, Congenital, Aneurysm
What diagnostic and treatment options are there for CN III palsy?
neuroimaging. treat underlying etiology
What does the trochlear nerve (CN IV) innervate?
superior oblique muscle
What types of injuries is CN IV susceptible to?
blunt head trauma or compression from changes in intracranial pressure, brain tumors, or swelling anywhere along its course.
What is the clinical presentation of CN IV palsy?
Binocular vertical diplopiaand/or subjective tilting of objects (torsional diplopia) that improves with head tilting to the side opposite the paralyzed muscle. Objects viewed in primary position or especially in down-gaze may appear double (when going down a flight of stairs so that the pt. does not know which step to select).
What is seen in an eye exam of someone with CN IV palsy?
Ipsilateral hypertropia. The deviation is greater when gaze is in the direction toward the weak muscle
What is the differential for CN IV palsy?
HTN, Diabetes, Tumor Congenital, Trauma
What are the diagnostic and treatments for CN IV palsy?
maybe neuroimaging. lumbar puncture in patients suspected of subarachnoid space lesions. treatment directed at underlying etiology
What muscle does the abducens nerve (CN VI) innervate?
lateral rectus muscle
What is the clinical presentation of CN VI palsy?
Binocular horizontal diplopia that worsens with gaze toward the defective lateral rectus muscle.
Strabismus may be present
What is seen on an eye exam with CN VI palsy?
esotropia (eye turned in “crossed eyed”), worse in gaze toward the paretic muscle (lateral incomitance), and an ipsilateral abduction deficit.
What is the differential for CN VI (6) palsy?
HTN, Diabetes, Tumor, Elevated cranial pressure, Temporal arteritis, Pseudotumor cerebri
What is treatment and diagnosis of CN VI palsy?
neuroimaging. treat underlying cause -alternate patching, prism therapy, strabismus surgery,andbotulinum toxin.
CN III palsy deviations?
down and out
CN IV palsy deviations?
nasal upshoot
CN VI palsy deviations?
cross eyed
