Third nerve palsy affects the oculomotor nerve, which controls most eye movements and eyelid elevation. Symptoms can be dramatic.
Typical signs and symptoms
The affected eye often turns outward and downward because opposing muscles are unbalanced. Double vision is common.
- Drooping upper eyelid ptosis
- Eye turned outwards and slightly down
- Double vision that improves when one eye is covered
- Possible enlarged pupil that reacts poorly to light
Why urgent assessment is crucial
Some third nerve palsies are caused by aneurysms or other serious brain problems. Early diagnosis can be life-saving.
- Sudden-onset palsy with a large pupil is especially concerning
- Severe headache or other neurological symptoms add urgency
- Imaging of the brain and blood vessels is usually required
- Diabetes-related palsies may spare the pupil but still need evaluation
