Cranial mononeuropathy III is a problem with the function of the third cranial nerve that causes double vision and eyelid drooping.
Third cranial nerve palsy; Oculomotor palsy; Pupil-involving third cranial nerve palsy; Mononeuropathy – compression type
Cranial mononeuropathy III is a
Causes may include:
Abnormal blood vessels (vascular malformations)
Tissue damage from loss of blood flow (infarction)
Trauma (from head injury or caused accidentally during surgery)
Tumors or other growths (especially tumors at the base of the brain and pituitary gland)
Rarely, people with
Double visionis the most consistent symptom
- Drooping of one eyelid (ptosis)
- Enlarged pupil that does not get smaller when a light shines on it
- Headache or eye pain
Other symptoms may occur if the cause is a tumor or swelling of the brain. Decreasing alertness is a serious sign, because it could be a sign of brain damage or impending death.
Exams and Tests
An eye examination may show:
Enlarged (dilated) pupil of the affected eye
Eye movement abnormalities
Eyes that are not aligned (dysconjugate gaze)
A complete medical and nervous system (neurological) examination is performed to find out if any other parts of the body are affected.
Other tests may include:
Tests to look at blood vessels to the brain (
cerebral angiogram, CT angiogram, or MR angiogram)
MRIor CT scan of the brain Spinal tap(lumbar puncture)
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 in many cases.
Treatment may include:
Corticosteroid medications to reduce swelling and relieve pressure on the nerve (when caused by a tumor or injury)
Eye patch or glasses with prisms to reduce double vision
Surgery to treat eyelid drooping or eyes that are not aligned
Some cranial nerve dysfunctions will respond to treatment. A few cases result in some permanent loss of vision or eye drooping.
Causes such as brain swelling due to a tumor or stroke or a
When to Contact a Medical Professional
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.
Quickly treating disorders that could press on the nerve may reduce the risk of developing cranial mononeuropathy III.