![]() The oculomotor nucleus is a collection of neuronal somas (cell bodies) that is found anterior to the periaqueductal grey matter and cerebral aqueduct of the midbrain, at the level of the superior colliculus. The intracranial oculomotor nerve Motor fibres Cranial nerves and cranial foramina diagram. Most patients will continue to have eye misalignment when looking in other gaze directions.You might also be interested in our Anatomy Flashcard Collection which contains over 2000 anatomy flashcards in addition to advanced features such as spaced repetition. Multiple surgeries may be required to achieve good ocular alignment in straight-ahead gaze, and surgery on the uninvolved eye may be necessary. Residual diplopia can be quite bothersome for some patients. The more severe the third nerve palsy, the more difficult it is to re-establish eye movements and single vision when the patient is attempting to use both eyes together. If the palsy is present after 6 months, eye muscle surgery can be performed to realign the eyes so that the eyes are straight when the patient is looking straight ahead, and eyelid surgery can be done to help the ptosis in certain cases. Prism spectacles may relieve diplopia for some patients. During this observation period, patching one eye can alleviate double vision. The ophthalmologist will usually wait at least 6 months after onset for possible spontaneous improvement. Relief of pressure on the third nerve from a tumor or blood vessel (aneurysm) with surgery may improve the third nerve palsy. An acquired third nerve palsy may resolve, depending on the cause. Unfortunately, there is no treatment to re-establish function of the weak nerve if it is a congenital case. What can be done to correct third nerve palsy? A partial palsy can be associated with the development of binocular vision. An abnormal head posture may allow binocular vision. Children with severe third nerve palsy often do not have binocular vision (simultaneous perception with both eyes), and stereopsis (three-dimensional vision) is often absent. Patching may be necessary for several years, sometimes until age 12 years. Amblyopia can often be treated by patching the unaffected eye. What problems develop in children with third nerve palsy?Ĭhildren may develop amblyopia in the involved eye. Acquired third nerve palsy can be associated with head injury, infection, vaccination, migraine, brain tumor, aneurysm, diabetes, or high blood pressure. Figure 2 demonstrates the droopy eyelid.Ī third nerve palsy may be present at birth (congenital), and the exact cause may not be clear. In this case, the third nerve palsy is partial, so the eye is not deviated downward. Figure 1 demonstrates outward position of the eye underneath the droopy eyelid signifying the palsy. Young children usually do not complain of double vision. Ptosis of the eyelid or an enlarged pupil may be the first sign of a third nerve palsy. If a droopy eyelid ( ptosis) covers the pupil, diplopia may not be noticeable. Older children and adults with third nerve palsy usually have double vision (diplopia) due to misalignment of the eyes. What are the Symptoms of Third Nerve Palsy? A partial third nerve palsy affects, to varying degrees, any of the functions controlled by the third cranial nerve. The eye cannot move inward or up, and the pupil is typically enlarged and does not react normally to light. ![]() A complete third nerve palsy causes a completely closed eyelid and deviation of the eye outward and downward. The third cranial nerve also controls constriction of the pupil, the position of the upper eyelid, and the ability of the eye to focus. These muscles move the eye inward, up and down, and they control torsion (rotating the eye downward and toward the ear on the same side). The third cranial nerve controls the movement of four of the six eye muscles. ![]()
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