Cranial mononeuropathy III is a problem with the function of the third cranial nerve, which is located behind the eye.
Cranial mononeuropathy III - compression type is a mononeuropathy, which means that only one nerve is affected. It affects the third cranial (oculomotor) nerve, one of the cranial nerves that controls eye movement. Local tumors or swelling can press down on and damage the nerve.
Causes may include:
Rarely, people with migraine headaches may 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.
Other symptoms may occur if the cause is a tumor or trauma. Decreasing consciousness is a serious sign, because it could indicate brain damage or death.
An eye examination may show:
A complete medical and nervous system (neurological) examination can show whether any other parts of the body are affected.
Other tests may include:
Some cases may get better without treatment. Treating the cause (if it can be found) may relieve the symptoms in many cases.
Treatment may include:
Some cranial nerve dysfunctions will respond to treatment. A few cases result in some permanent loss of function. If the problem is caused by brain swelling due to a tumor or stroke, those conditions may be life-threatening.
Call the local emergency number (such as 911) or go to the emergency room if you have:
Quickly treating disorders that could press down on the nerve may reduce the risk of developing cranial mononeuropathy III.
Cranial mononeuropathy III is a complication of diabetes that involves double vision and eyelid drooping.
Cranial mononeuropathy III - diabetic type is a mononeuropathy, which means that only one nerve is damaged. It involves the third cranial (oculomotor) nerve, which is one of the cranial nerves that controls eye movement. This type of damage usually occurs with diabetic neuropathy.
Cranial mononeuropathy III is the most common cranial nerve disorder in people with diabetes.
An examination of the eyes will determine whether only the third nerve is affected or if other nerves have also been damaged. Signs may include:
In some cases, it may not be clear if the nerve damage is due to diabetes or some other cause, such as an aneurysm. Tests to rule out other causes may include:
There is no specific treatment to correct the nerve injury.
Treatments may include:
Many patients get better over time, although some have permanent eye muscle weakness.
Call your health care provider if you have double vision and it doesn't go away in a few minutes, especially if you also have eyelid drooping.
Control of blood sugar levels in people with diabetes may reduce the risk of developing this disorder.
The fourth cranial nerve supplies the superior oblique muscle, which is the eye muscle responsible for lower the eye and tilting the eye in when the head is tilted.
Causes
Causes of a fourth nerve palsy include:
Symptoms
Exams and Tests
An eye examination specifically for eye misalignment and motility is required. Other tests may be ordered, such as:
Treatment
Depending on the cause of the fourth nerve palsy, treatments may include:
Outlook (Prognosis)
The underlying cause must be treated. The time to recovery will depend on the cause.
The sixth nerve supplies the lateral rectus muscle, which is the eye muscle responsible for turning the eye out when looking to the side.
Symptoms
Symptoms of a sixth nerve palsy include:
Causes, examination, treatment, and prognosis are similar to fourth nerve palsy.