Oculomotor Nerve Case Study

According to the symptoms expressed by my neighbor I would say it is very likely that she has damaged her oculomotor nerve. The oculomotor nerve innervates both the inferior rectus muscle and the levator palpebrae superioris. The inferior rectus muscle allows the eye to depress and abduct, if there were an injury to the oculomotor nerve it could cause the eye to retain this position. The levator palpebrae superioris allows the eyelid to elevate and damage to the nerve here would cause the inability to fully lift her right eyelid (Drake, Richard L., A. Wayne Vogl, and Adam W.M. Mitchell, 2012). Damage to this nerve causes a number of symptoms, including the symptoms of double vision or diplopia, a dilated right pupil, the inability to raise the eyelid or ptosis, and abduction and depression of the eye during straight forward staring (Rubin, 2016). Which are all of the symptoms mentioned by my neighbor. The oculomotor nerve begins in the brainstem,
as somatomotor and visceral motor nuclei. These cell bodies create axons that are then capable of leaving the brain stem as a nerve. It the passes through the dura mater of the brainstem and the cavernous sinus. Once through the cavernous sinus the oculomotor nerve exits through the superior orbital fissure. When this nerve enters the orbit it splits into superior and inferior divisions. The superior division innervates the levator palpebrae superioris, which my neighbor described as not functioning properly and allows elevation of the eyelid, and the superior rectus muscle, which allows the eye to abduct and elevate. The inferior division innervates the medial rectus, inferior rectus, and inferior oblique muscles. The medial rectus allows for adduction of the eye, the inferior rectus allows for abduction and depression, and is also injured, and the inferior oblique allows for adduction and elevation of the eye. The inferior division of the oculomotor nerve carries the parasympathetic component of this nerve. It has branches that enter and synapse with the ciliary ganglion (“Oculomotor nerve”, 2015). These ciliary ganglion cells then send fibers to the back of the eye which cause pupil constriction, or in the case of my neighbor and her injury fail to constrict and cause a dilated pupil. Considering the described symptoms I would say that this condition would not cause dry eye.
The entire lacrimal system, including the gland, lake, and sac are innervated by three separate nerves, but none of them are the oculomotor nerve. The lacrimal gland gets its sensory innervations from the ophthalmic nerve. The preganglionic parasympathetic innervation comes from the facial nerve, the postganglionic parasympathetic neurons go on to join the maxillary nerve and branch into the zygomatic nerve until it becomes the zygomaticotemporal nerve and finally joins the lacrimal nerve that innervates the lacrimal gland. The sympathetic innervation essentially follows the parasympathetic path of innervation and comes from the superior cervical ganglion. It travels along the plexus around the internal carotid artery until it joins the parasympathetic fibers (Drake, Richard L., A. Wayne Vogl, and Adam W.M. Mitchell, 2012). None of these connect or involve the oculomotor nerve and therefore this injury would not involve dry
eyes.