cranial nerve palsy
Pronunciation: KRAY-nee-al nerv PAWL-zee
Dysfunction of one or more cranial nerves controlling eye movement, often presenting with diplopia, ptosis, or pupillary abnormalities.
Full Definition
Cranial nerve palsies affecting the third (oculomotor), fourth (trochlear), or sixth (abducens) cranial nerves result in characteristic patterns of eye movement dysfunction. Third nerve palsy causes ptosis, pupil involvement, and inability to move the eye upward, downward, or medially. Fourth nerve palsy results in vertical diplopia and head tilt. Sixth nerve palsy causes horizontal diplopia and inability to abduct the eye. These palsies can result from ischemia, trauma, compression, or inflammation, and the pattern of involvement helps localize the lesion and determine urgency of workup.
Usage
Usage note: Specify which cranial nerve is affected and whether pupil involvement is present, as this impacts differential diagnosis.
In Context
- "The patient developed a complete third nerve palsy with pupil involvement, concerning for posterior communicating artery aneurysm." — Emergency consultation
- "Isolated sixth nerve palsy in an elderly diabetic patient was attributed to microvascular ischemia." — Clinical assessment