Cranial mononeuropathy VI is a nerve disorder that causes people to see two of the same image (double vision).
Alternative NamesAbducens palsy; Lateral rectus palsy
Causes, incidence, and risk factorsCranial mononeuropathy VI is damage to the sixth cranial (skull) nerve. This nerve, also called the abducens nerve, helps control eye movement.
Disorders of this nerve can occur with:
In some people, there is no obvious cause.
Because there are common nerve pathways through the skull, the disorder may affect other cranial nerves (such as the third or fourth cranial nerve).
SymptomsSymptoms may include:
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 line up -- either at rest, or when looking in the direction of the weak eye.
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:
You may need to be referred to a Doctor Who specializes in visual problems related to the nervous system (neuro-ophthalmologist).
TreatmentIf the health care provider finds a cause, medications called corticosteroids can 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 relieve double vision.
Expectations (prognosis)Treating the cause may improve the condition. Even if the cause is never found, the condition may improve.
ComplicationsComplications may include permanent vision changes.
Calling your health care providerCall your health care provider if you have double vision.
PreventionThere is no way to prevent this condition. However, people with diabetes may reduce the risk by controlling their blood sugar.
Cranial mononeuropathy VI is a nerve disorder. It prevents some of the muscles that control eye movements from working well. As a result, people may see two of the same image (double vision).
Alternative NamesAbducens palsy; Lateral rectus palsy; Vith nerve palsy; Cranial nerve VI palsy
Causes, incidence, and risk factorsCranial mononeuropathy VI is damage to the sixth cranial (skull) nerve. This nerve, also called the abducens nerve, helps control eye movement to the left or right.
Disorders of this nerve can occur with:
In some people, there is no obvious cause.
Because there are common nerve pathways through the skull, the same disorder that damages the sixth cranial nerve may affect other cranial nerves (such as the third or fourth cranial nerve).
SymptomsSymptoms may include:
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 line up -- either at rest, or when looking in the direction of the weak eye.
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:
You may need to be referred to a doctor who specializes in visual problems related to the nervous system (neuro-ophthalmologist).
TreatmentIf your health care provider diagnoses swelling or inflammation of, or around the nerve, medications called corticosteroids will be used.
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 will relieve double vision.
Expectations (prognosis)Treating the cause may improve the condition. Most people in whom no cause is found recover completely.
ComplicationsComplications may include permanent vision changes.
Calling your health care providerCall your health care provider if you have double vision.
PreventionThere is no way to prevent this condition. However, people with diabetes may reduce the risk by controlling their blood sugar.
ReferencesBaloh RW. Neuro-ophthalmology. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 450.
Reviewed ByReview Date: 06/15/2010
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
Pons.
lateral rectus
Cranial nerves III (oculomotor), IV (trochlear), VI (abducens), XI (accessory), and XII (hypoglossal) are motor nerves only.
Eye movement is controlled by cranial nerves III, IV, and VI (Oculomotor, Trohlear, and Abducens, respectively). CN III innervates most of the muscles of the eye and is responsible for most eye movements.
There are three cranial nerves that innervates muscle to move the eye. The main cranial nerve that controls eye movement is occulomotor nerve (CN III). It is responsible for inferior rectus, superior rectus, medial rectus, and inferior oblique. Lateral rectus muscle is innervated by abducens nerve (CN VI). Superior oblique muscle is innervated by trochlear nerve (CN III).
cranial nerve I: olfactory:smell cranial nerve II:optic:vision cranial nerve III: oculomotor: 4 of 6 eye muscles cranial nerve IV: trochlear: cranial nerve V: Trigeminal cranial nerve VI: Abducens cranial nerve VII: Facial cranial nerve VIII: Vestibulochlear: hearing cranial nerve IX: Grosspharnxgeal: saliva formation cranial nerve X: Vegus cranial nerve XI: Acessory Spinal: trapizious movement cranial nerve XII: Hypoglosseal: toungue movement
four cranial nerves (V or trigeminal, VI or abducens, VII or facial, & VIII or vestibulocochlear)
Each eye has one nerve for vision, the optic nerve, Cranial Nerve II. Nerves are actually bundles of many nerve fibers. There are nerves that supply impulses for the muscles associated with the eyeballs so they can move are the Cranial Nerve III, Oculomotor, Cranial Nerve IV, Trochlear, and Cranial Nerve VI, the Abducens nerve.
abducens nerve
Superior oblique is controlled by cranial nerve VI (Trochlear nerve). This muscle depresses the eye and moves it laterally. A person with damage to this cranial nerve will have difficulty looking down and to the side.
The main nerve required would be the optic nerve (II), although you would also use the ocular motor nerve (III) to move the eyes. Other cranial nerves involved are: Trochlear nerve (IV) and Abducens nerve (VI).
Cranial nerve #2 - optic nerve - special sensory for vision Cranial nerve #3 - occulomotor nerve - motor for extraoccular muscles & parasympathetic to ciliary ganglion Cranial nerve #4 - trochlear nerve - motor for extraoccular muscle (superior oblique) Cranial nerve #6 - abduscens nerve - motor for extraoccular muscle (lateral rectus)