Third cranial nerve disorder

Head | Neurology | Third cranial nerve disorder (Disease)


Description

The third cranial nerve, also called the oculomotor nerve, is one of three cranial nerves that control the movement of the eye. Oculomotor nerve palsy is a common problem in people with diabetes. This disorder can include a sudden onset of pain around the eye and double vision.

Affected eye turns downward or outward. Pupil continues to react normally, usually expanding to the dark and light by contracting. Upper eyelid is often a tendency to ptosis. These signs and symptoms are easily mistaken for a stroke - and in fact, this disorder is the result of temporary disruption of blood flow to the third pair of cranial nerve. This nerve controls the muscles that support the action of some of the eye normally.

The pain typically lasts a few days, and double vision usually resolves after 2-3 months. If you have double vision, eyelid fallen or pain in or around the eye, or if the eye does not move normally in all directions, consult an ophthalmologist. Common oculomotor nerve or cranial nerve III put into action following eye muscles: muscle as higher, lower right muscle, the muscle below the national and oblique muscle. It also innervate the striated muscle portion of the upper eyelid lifter. The vegetative branch innervating the circular muscle of the iris and ciliary body circular muscle. Cranial nerve III nucleus originated in deep ventral portion of the brainstem, the midbrain, as higher.

Causes and Risk factors

Third cranial nerve palsy is most frequent in persons older than 60 years and in those with prominent or long-standing atherosclerotic risk factors, such as diabetes or hypertension.

The most common cause of palsies that spare the pupil, particularly partial palsies, is ischemia of the 3rd cranial nerve (usually due to diabetes) or of the midbrain. Occasionally, a posterior communicating artery aneurysm causes complete oculomotor palsy and spares the pupil.

Diagnosis and Treatment

CT or MRI is required. If a patient has a dilated pupil and a sudden, severe headache (suggesting ruptured aneurysm) or is increasingly unresponsive (suggesting herniation), CT is done immediately. If ruptured aneurysm is suspected and CT does not show blood or is not available rapidly, other tests, such as lumbar puncture, magnetic resonance angiography, CT angiography, or cerebral angiography, are indicated. Cavernous sinus disease and orbital mucormycosis require immediate MRI imaging for timely treatment.

Medical management is actually watchful waiting, since there is no direct medical treatment that alters the course of the disease. Fortunately, nearly all patients undergo spontaneous remission of the palsy, usually within 6-8 weeks.

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