What happens if the oculomotor nerve is damaged?

Damage to any of these nerves or the muscle or muscles they innervate causes dysconjugate gaze, which results in characteristic patterns of diplopia (double vision). In addition, with oculomotor nerve damage, patients also lose their pupillary constriction to light as well as the elevation of their eyelid.

What is the nucleus of oculomotor nerve?

The Oculomotor Nerve The oculomotor nucleus is found at the level of the superior colliculus. It contains the somatic efferent fibers that control the medial rectus, inferior rectus, superior rectus, inferior oblique, and the striated muscle in the levator palpebrae superioris.

What is the function of oculomotor nucleus?

A nearby nucleus, the Edinger-Westphal nucleus lies dorsal to the main oculomotor nucleus. It is responsible for the autonomic functions of the oculomotor nerve, including pupillary constriction and lens accommodation….

What happens to pupil in oculomotor nerve paralysis?

The third cranial nerve “controls” the medial rectus, superior rectus, inferior rectus, inferior oblique muscle, the upper eyelid levator, iris sphincter and ciliary muscle, therefore if the affectation is complete, the eye is deviated outward and downward, the eyelid is droopy (ptosis), the patient will have a dilated …

Is 3rd nerve palsy a stroke?

An isolated third nerve palsy is a rare presentation of stroke. Historical features and risk factors can help distinguish the cause of third nerve palsy. A detailed neurological examination with attention to ‘neighboring’ signs is essential during the evaluation of individuals presenting with third nerve palsy.

What is the function of cranial nerve 3?

Cranial nerve 3, also called the oculomotor nerve, has the biggest job of the nerves that control eye movement. It controls 4 of the 6 eye muscles in each eye: Medial rectus muscle (moves the eye inward toward the nose) Inferior rectus muscle (moves the eye down)

Does third nerve palsy go away?

An acquired third nerve palsy may resolve, depending on the cause. Relief of pressure on the third nerve from a tumor or blood vessel (aneurysm) with surgery may improve the third nerve palsy. The ophthalmologist will usually wait at least 6 months after onset for possible spontaneous improvement.

What is the most common cause of third nerve palsy?

The most common causes of acquired third nerve palsy were: Presumed microvascular (42 percent) Trauma (12 percent) Compression from neoplasm (11 percent)

What is the treatment for vagus nerve disorders?

Vagus nerve stimulation involves the use of a device to stimulate the vagus nerve with electrical impulses. An implantable vagus nerve stimulator is currently FDA-approved to treat epilepsy and depression.

What are the symptoms of an oculomotor nerve lesion?

A lesion here will result in a contralateral tremor, due to damage to the superior rectus input, and the typical oculomotor nerve lesion symptoms: Deviation of the ipsilateral eye downward and outward (due to action of the intact superior oblique and lateral rectus muscles)

What are the two nuclei of the oculomotor nerve?

The anterior group consists of two nuclei, an antero-medial and an antero-lateral. The nucleus of the oculomotor nerve, considered from a physiological standpoint, can be subdivided into several smaller groups of cells, each group controlling a particular muscle.

Where does the crossing take place in the oculomotor nucleus?

The superior rectus weakness is bilateral because the crossing takes place within the nucleus, such that with a right oculomotor lesion, the right superior rectus neurons and also axons from the left superior rectus neurons are involved.

What does damage to the oculomotor nuclear complex mean?

Patients with damage to the oculomotor nuclear complex need not have ipsilateral pupillary dilation, but when involved, it may indicate dorsal rostral damage. often caused by ischemia, usually from embolic or thrombotic occlusion of small, dorsal perforating branches of the mesencephalic portion of the basilar artery.