Royal Australasian College of Physicians Examinations/Resources/Clinical Exam/Short Cases/Example Cases/3rd Nerve Palsy
The 3rd Nerve Palsy
Stem: This patient presents with a headache. Please examine his eyes.
- dilated pupil
- abducted and depressed eye with reduced movement
- ipsilateral ptosis
- IV nerve palsy (tilt head towards side of lesion)
- V nerve palsy (corneal reflex, sensation V1 / V2)
- VI nerve palsy (lateral rectus palsy)
- Contralateral UMN signs in Limbs = Weber's D
This patient has a left 3rd nerve palsy, evidenced by a dilated pupil, and an abducted and depressed globe, with paralysis of movement and ptosis. There are no other cranial nerve abnormalities. The cause may be a berry aneurysm, causing headache and compressing the nerve. I would also consider a diabetic 3rd nerve palsy, or hypertension – although these would spare the pupil; or also a stroke in the midbrain, which would usually be accompanied by contralateral pyramidal signs; or a lesion in the cavernous sinus.