Cranial mononeuropathy III is a nerve disorder. It affects the function of the third cranial nerve. As a result, the person may have double vision and eyelid drooping.
Mononeuropathy means that only one nerve is affected. This disorder affects the third cranial nerve in the skull. This is one of the cranial nerves that control eye movement. Causes may include:
In rare cases, people with migraine headaches have a temporary problem with the oculomotor nerve. This is probably due to a spasm of the blood vessels. In some cases, no cause can be found.
People with diabetes may also develop a neuropathy of the third nerve.
Symptoms may include:
Other symptoms may occur if the cause is a tumor or swelling of the brain. Decreasing alertness is serious, because it could be a sign of brain damage or impending death.
An eye examination may show:
Your health care provider will do a complete examination to find out if other parts of the nervous system are affected. Depending on the suspected cause, you may need:
You may need to be referred to a doctor who specializes in vision problems related to the nervous system (neuro-ophthalmologist).
Some people get better without treatment. Treating the cause (if it can be found) may relieve the symptoms.
Other treatments to relieve symptoms may include:
Some people will respond to treatment. In a few others, permanent eye drooping or loss of eye movement will occur.
Causes such as brain swelling due to a tumor or stroke, or a brain aneurysm may be life threatening.
Call your provider if you have double vision and it does not go away in a few minutes, especially if you also have eyelid drooping.
Quickly treating disorders that could press on the nerve may reduce the risk of developing cranial mononeuropathy III.
Reviewed By: Amit M. Shelat, DO, FACP, Attending Neurologist and Assistant Professor of Clinical Neurology, SUNY Stony Brook, School of Medicine, Stony Brook, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.