Cranial mononeuropathy VI is a nerve disorder that causes double vision.
Alternative NamesAbducens palsy; Lateral rectus palsy
Cranial mononeuropathy VI is damage to the sixth cranial (skull) nerve. This nerve, also called the abducens nerve, helps controls eye movement.
Abducens nerve disorders are often associated with:
In some people, no cause is found.
Because there are common nerve pathways through the skull, the disorder may affect other cranial nerves (such as the third or fourth cranial nerve).
Symptoms may include double vision when looking to one side (unilateral injury). Pain or headaches may also occur.
Exams and Tests
Tests typically show that one eye has trouble looking to the side, while the other eye moves normally. An examination shows the eyes do not align -- either at rest, or when looking in the direction of the weak eye.
Your health care provider will perform a complete medical and neurological examination to determine the possible affect on other parts of the nervous system. Depending on the suspected cause, you may need blood tests, a head imaging study (such as an MRI or CT scan), and possibly a lumbar puncture (spinal tap).
If a health care provider identifies a cause, the symptoms may be treated and relieved with corticosteroids to reduce swelling and relieve pressure on the nerve. Sometimes, the condition may disappear without treatment. People with diabetes may benefit from close control of blood sugar levels.
Until the nerve heals, wearing an eye patch may alleviate double vision.
Treatment of the underlying cause may improve the condition. Improvement may occur even if the cause is never determined.
Complications may include permanent vision changes.
When to Contact a Medical Professional
Call your health care provider if double vision occurs.
No specific prevention is available, although patients with diabetes may reduce the risk by controlling their blood sugar.