Cranial mononeuropathy III - diabetic typeDiabetic third nerve palsy; Pupil-sparing third cranial nerve palsy
Diabetes is a chronic disease in which the body cannot regulate the amount of sugar in the blood.
Ptosis (eyelid drooping) in infants and children is when the upper eyelid is lower than it should be. This may occur in one or both eyes. Eyelid dr...
Mononeuropathy means that only one nerve is damaged. This disorder affects the third cranial nerve in the skull. This is one of the cranial nerves that control eye movement.
Mononeuropathy is damage to a single nerve, which results in loss of movement, sensation, or other function of that nerve.
This type of damage may occur along with diabetic peripheral neuropathy . Cranial mononeuropathy III is the most common cranial nerve disorder in people with diabetes. It is due to damage to the small blood vessels that feed the nerve.
Diabetic peripheral neuropathy
Nerve damage that occurs in people with diabetes is called diabetic neuropathy. This condition is a complication of diabetes.
Cranial mononeuropathy III can also occur in people who don't have diabetes.
Cranial mononeuropathy III
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 ...
Symptoms may include:
- Double vision
- Drooping of one eyelid (ptosis)
- Pain in the head or behind the eye
Exams and Tests
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:
- Eyes that are not aligned
- Pupil reaction that is almost always normal
Your health care provider will do a complete examination to determine the possible effect on other parts of the nervous system. Depending on the suspected cause, you may need:
- Blood tests
Tests to look at blood vessels in the brain (
, CT angiogram,
Cerebral angiography is a procedure that uses a special dye (contrast material) and x-rays to see how blood flows through the brain.
CT scan of the brain
A head MRI (magnetic resonance imaging) is an imaging test that uses powerful magnets and radio waves to create pictures of the brain and surrounding...
- Spinal tap ( lumbar puncture )
You may need to be referred to a doctor who specializes in vision problems related to the nerves in the eye (neuro-ophthalmologist).
There is no specific treatment to correct the nerve injury.
Treatments to help symptoms may include:
- Close control of blood sugar level
- Eye patch or glasses with prisms to reduce double vision
- Pain medicines
- Surgery to correct eyelid drooping or eyes that are not aligned
Some people may recover without treatment.
Many people get better over 3 to 6 months. Some people have permanent eye muscle weakness.
Complications may include:
- Permanent eyelid drooping
- Permanent vision changes
When to Contact a Medical Professional
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.
Controlling your blood sugar level may reduce the risk of developing this disorder.
Brownlee M, Aiello LP, Cooper ME, Vinik AI, Plutzky J, Boulton AJM. Complications of diabetes mellitus. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology . 13th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 33.
Rucker JC, Thurtell MJ. Cranial neuropathies. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice . 7th ed. Philadelphia, PA: Elsevier; 2016:chap 104.
Central nervous system - illustration
The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.
Central nervous system
Review Date: 5/30/2016
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, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.