Sixth nerve palsy is a disorder affecting the sixth nerve, which supplies the lateral rectus muscle. This ocular muscle is responsible for turning the eyeball outward, away from the nose. When a person has sixth nerve palsy, the eye begins to point inward toward the nose, often resulting in double vision. Sixth nerve palsy is sometimes known as abducens nerve palsy or cranial nerve VI palsy.
The most common cause of sixth nerve palsy in older adults and senior citizens is stroke. When sixth nerve palsy is present in children, the most common cause is trauma.
In rare cases, it is present at birth.
Other causes for sixth nerve palsy include:
- viral illness
- inflammation of the brain caused by viral illness
- brain tumor
- multiple sclerosis
- diabetic neuropathy
- intracranial pressure
- migraine headaches
- diabetic neuropathy
- systemic hypertension
There does not appear to be any gender or age group that is significantly more at risk. However, when sixth nerve palsy is the result of another condition, risk factors for that condition play a role in the likelihood a person will have sixth nerve palsy.
The most common symptom of sixth nerve palsy is double vision. Less common symptoms include headaches and pain surrounding the affected eye.
Sixth nerve palsy has been known to resolve on its own, without treatment. If inflammation of the sixth nerve is causing the problem, a doctor may prescribe corticosteroids. If double vision continues as the sixth nerve heals, doctors suggest wearing an eye patch.
Another option for realigning a person’s eyesight is prism spectacles. If the prism spectacles have not properly aligned the patient’s sight, he or she can have strabismus surgery. This surgery corrects the misalignment of the eyes.
Prognosis for sixth nerve palsy depends on the underlying cause. When resulting from a viral infection, sixth nerve palsy usually resolves on its own.
When resulting from trauma, especially in children, sixth nerve palsy may not heal completely on its own. Improvement and recovery from sixth nerve palsy often take place during the first sixth months after onset.
When the underlying cause for the palsy cannot be determined, the chances are high that the patient will fully recover. However, there have been cases where an individual’s sight has been irreparably altered as a result of the palsy.