These Disorders Can Really Get On Your Nerves (Essay Example)

I would like you to close your eyes, and imagine you are on a beach on a private island. The birds are chirping, the waves are crashing, the smell of the salty water overwhelms you. You see a sailboat in the distance and watch as it approaches the setting sun. An ice cold margarita soothes your taste as your tongue filters through the frozen crystals. The bittersweet taste puckers your lips. Resting your hands comfortably behind your head as you start to close your eyes you believe to think, this is paradise. Just as you start to doze off reality smacks you right in the face because this is nursing school and you don’t have time for a trip to the beach. Instead you’re neck deep in your Med-Surg book learning what allows you to move, see, hear, feel, and taste these sensations. These structures are the cranial nerves, a part of a major body system known as the CNS. This complex division of the nervous system is composed of 12 unique nerves known as the Olfactory, Optic, Oculomotor, Trochlear, Trigeminal, Abducens, Facial, Auditory/Vestibular, Glossopharyngeal, and Vagus nerves that work together to process everything around you. 

The Olfactory, nerve number one, is known for the ability to smell and its influence on taste. These nerves originate from the olfactory mucosa, travel through the cribriform plate,  and into the brain. This nerve is considered unusual because of its unique ability to regenerate. There are very few disorders associated with the olfactory nerve, however those that do exist can cause other functional issues. Hyposmia, anosmia, parosmia, and phantosmia are four conditions that directly correlate to one's ability to smell. Hyposmia is the reduced ability to detect odors caused by allergies, nasal polyps, viral infections, and head trauma that impair the olfactory nerve. Anosmia is the end result of hyposmia if the defect is not corrected resulting in complete loss of smell. Parosmia is caused by swelling of or around the olfactory nerves resulting in distortion or misconception of smells. Phantosmia is described as smelling odors that aren’t actually present often caused by upper respiratory infections, migraines, dental problems, and exposure to neurotoxins.

The next group of cranial nerves work together as a group to perform eyesight. Cranial nerves two, three, four, and six as known as the Optic, Oculomotor, Trochlear, and Abducens work together to coordinate the process of vision. Each of these nerves perform a specific task that enables the eyes to sense, focus, and adjust. The Optic nerve or cranial nerve number two is perhaps the pathway of sight to the brain, it transfers visual information from the retina to the vision centers of the brain via electrical impulses. If this nerve becomes damaged it could potentially lead to blindness early on. Some of the more common Optic nerve disorders are glaucoma, optic neuritis, optic nerve atrophy, and optic nerve head drusen. Glaucoma is probably the best known optic disorder, and is the leading cause of blindness if left untreated. This condition is caused by an abundance of pressure that compresses the optic nerve causing visual disturbances that lead to blindness. Cranial nerve number 3, also known as the Oculomotor nerve functions to move the eye medially and superiorly. Manifestations of a damaged oculomotor nerve include, diplopia, ptosis, deviation of the eye either laterally or more inferior. These can be associated with disorders like Weber’s Syndrome, a midbrain lesion that leads to Supranuclear Paralysis and other defects that cause compression of the nerve resulting in loss of movement. The Trochlear and Abducens are specific to motor movement, therefore any inflammation or outside conditions limit eye movement resulting in an impaired field of vision.

The Trigeminal nerve name derives from each of the two nerves having three major branches: the ophthalmic nerve, the maxillary nerve, and the mandibular nerve. The Trigeminal is a work of art, this nerve complex is the largest of the cranial nerves and functions as the motor for our mouth and jaw, along with sensations of the face, and taste. Trigeminal Neuralgia is a major disorder with cranial nerve number five, it causes severe facial pain and impaired intake. The intense pain described as a “shocking pain” can be localized or travel across the face and can be accompanied with inadequate intake due to the unbearable pain. The episodes can last seconds to multiple minutes, extending from days to months. Conditions such as multiple sclerosis and other myelin sheath attacking conditions are seen to be in direct correlation alongside tumors and other constricting structures that impair the normal function of the trigeminal nerve. This condition can become chronic if unaddressed but can be controlled using medications and surgical procedures to lessen the nerve response or remove the restricting structure.

Everytime you smile, laugh, or frown, cranial nerve number seven known as the Facial nerve is there to help you express the emotions through manipulation of the face muscles. It also functions to sense taste on the anterior two thirds of the tongue. Facial spasms on part or across the entire face, Ramsay Hunt syndrome, facial schwannoma, and trauma are all common disorders associated with the facial nerve. Ramsay Hunt syndrome is a condition that occurs when the shingles virus affects the facial nerve. Another major facial nerve dysfunction is Bell’s Palsy, a condition that causes temporary weakness or paralysis of the muscles in the face. It causes paralysis on one side of the face, drooping face, headache, loss of taste, increased sensitivity to sound, dry eye and dry mouth. Treatments for facial nerve disorders stem from the causative agent, medications for inflammation, anticonvulsants for nerve activity, and surgical interventions to remove foriegn structures and clear nerve pathways can be a successful treatment for the facial nerve disorders.

The bird chirping, the waves crashing, these are sounds that most would relate to a relaxing situation. These sounds are processed by the Auditory or Vestibular nerve, cranial nerve number eight. The Auditory nerve functions as the hearing unit of the body transmitting signals from the ears into the brain and the Vestibular nerve is the control center for balance. Vestibular Schwannoma is sometimes also referred to as acoustic neuroma, a tumor that results in loss of hearing, tinnitus, dizziness, and vertigo. This is relieved primarily by surgical intervention and antiinflammatory measures. 

The Glossopharyngeal nerve, cranial nerve number nine, functions to receive taste on the posterior third of the tongue. Its secondary function includes swallowing by intervating the stylopharyngeus muscle, which is responsible for elevating the pharynx and larynx aiding the swallow reflex. Glossopharyngeal neuralgia is characterized by oropharyngeal pain that is triggered by swallowing, chewing, coughing, and yawning.  It is a sporadic condition related to hyperactivity of cranial nerve nine. Glossopharyngeal neuralgia  is treated with anti seizure medications, vitamin B12, and a Glossopharyngeal nerve block. Cranial nerve number twelve, the Hypoglossal nerve, works closely with the Glossopharyngeal by controlling the movement of the tongue and aiding in the swallowing process and it aids in speech articulation.

Cranial nerve 10, the Vagus nerve, is an essential mechanism that aids in digesting and controlling the heart rate. The Vagus nerve is the longest nerve in the autonomic nervous system. Common disorders of the Vagus nerve are gastroparesis and vasovagal syncope. Gastroparesis occurs when the food is not transported into the intestines, instead it remains in the stomach. Vasovagal syncope occurs when a vagus nerve to your heart overreacts to certain situations like extreme heat, anxiety, hunger, pain or stress. Blood pressure drops very quickly making you feel dizzy or faint. Medications to control nausea and vomiting, feeding tubes to nourish the bloodstream, increasing sodium, and where stockings to prevent blood from pooling are effective measures to help Vagus nerve disorders.

Cranial nerve number 11, the Accessory nerve, controls the movements of the neck and shoulders. The most common cause for accessory nerve injury is iatrogenic, such as lymph node biopsies that involve the posterior triangle of the neck, trauma, and neck surgeries. Any injuries to the Accessory nerve can lead to paralysis of the neck and the inability to manipulate the shoulders. Interventions to relieve the symptoms of Accessory nerve damage include electrical regeneration, NSAIDs, nerve blocks, and transcutaneous stimulation.

The human body is a masterpiece every muscle, tissue, and organ are innervated and communicated throughout the nervous system. The Cranial nerves are a specialized group that performs some of our most needed functions such as eye sight, chewing and swallowing, and motor movements. Without these structures the body would not be able to function. The next time you are on that beach enjoying the views, inhaling the scent, and feeling the warm summer sun just remember your Cranial nerves are working hard so you can relax.