Abstract
This study focuses on the analysis of cranial nerves, examining their function and paired relationships. The work examines and discusses the consequences of head trauma as a function of the nature of the injury. Procedures, processes, assessments, and assumptions are described, along with comparisons to a control patient to determine the extent of damage, diagnosis, and further treatment necessary to restore function. As a result of the observation, damage to the vestibulocochlear and facial nerves in the patient’s head trauma is determined.
Introduction
Cranial nerves transmit electrical signals from the brain to an individual’s head, neck, and torso. They are directly responsible for taste, hearing, smell, and facial muscle movements. Accordingly, based on the observed abnormalities in the functional areas of responsibility of these nerves, it is possible to identify the damaged areas of the brain in craniocerebral trauma. Thus, in contrast to the control patient, the impaired function of the facial and vestibulocochlear nerves is evident.
Purpose: Based on laboratory tests and examination, determine potential head trauma and nerve damage to the patient being observed.
Background
Cranial nerves are located closer to the back of the brain and are a vital factor in the nervous system. There are 12 cranial nerve pairs in the human brain, and they are distributed on both sides of the brain. The division of each pair allows for control of the left and right sides of the human body.
The first cranial nerve pair is the olfactory nerves, which contribute to the sense of smell. Second, the optic nerve enables vision (Marieb & Hoehn, 2018). Third, oculomotor nerves facilitate eye movement and blinking.
Fourth, the trochlear nerve enables specific eye movements, allowing up-and-down and back-and-forth motions. Fifth, the trigeminal nerve provides sensations and movement in the jaw, face, cheeks, and sense of taste. Sixth, the abducens nerve also contributes to the eye’s ability to move.
Seventh, the facial nerve corresponds with facial expressions and the sense of taste. Eighth, the auditory and vestibular nerves affect an individual’s sense of hearing and balance. Ninth, the glossopharyngeal nerve enables functions related to swallowing and taste perception.
Tenth, the vagus nerve controls heart rate and digestive function. Eleventh, the spinal accessory nerve facilitates movements of the shoulder and neck. Twelfth, the hypoglossal nerve enables the movement of the tongue.
These are all the primary functions of the cranial nerves and their specific effects on the human body’s capabilities. In general, they are the motivators of functions related to hearing, touch, taste, smell, and sight. As such, they provide abilities within the ranges of motor and sensory domains.
Hypothesis
The head trauma to the patient in the study suggests a likelihood of substantial damage to several cranial nerves. With additional tests that include sensory and motor input, there may be clarity about which nerves may have been damaged. The hypothesis suggests that damage to the vestibulocochlear and facial nerves is likely and consistent with the injuries to the patient’s cranial bones. Physical symptoms associated with nerve damage may include balance issues, hearing complications, and dizziness. Some of the patient’s symptoms included an inability to walk steadily and dizziness while walking.
Procedures
Vestibulocochlear nerve procedures and assessments primarily relate to hearing function. The initial analysis section includes several tests that determine an individual’s hearing capabilities. First, an initial auditory assessment includes covering one ear and whispering phrases, numbers, or other words at a distance from the patient’s open ear. If the patient experiences issues, additional assessments, such as Rinne’s and Weber’s tests, are performed to further evaluate the condition. Rinne’s test utilizes a 256 or 512 Hz tuning fork placed on the patient’s mastoid process and, later, the auditory meatus (Howard Community College, n.d.).
The relevant facial nerve assessments include motor and reflex tests. The motor assessment includes facial palsy appearance and asymmetries. Upper motor neuron lesions typically do not affect the forehead, and patients should be able to wrinkle their forehead and raise their eyebrows.
Lower motor neuron lesions may depict paralysis or paresis of the ipsilateral facial muscles. Weakness was the primary indicator of likely facial nerve damage and inability to taste. The reflex assessment observes abnormal reactions such as blinking when the forehead is poked or exaggerated jaw reflexes. Some facial nerve procedures were observed, such as removing connective tissues, which are replaced by sutures in the case of direct and acute trauma.
Results
Results are presented below, including all data collected from the assessment.
- Sense of Smell: Correctly identified vanilla odor.
- Eye Exam: Normal visual acuity and peripheral vision.
- Eye Movement Test: Both eyes tracked the light normally.
- Sensory Test: Able to feel a warm probe on the forehead, cheek, and chin.
- Facial Symmetry: Some weakness in eyelids, eyebrows, lips, and forehead on the right side.
- Taste Test: Unable to distinguish sweet and salty tastes on the anterior right side of the tongue.
- Hearing Test: Unable to hear clearly through the right ear; could hear the tuning fork on the left side only.
- Walking Test: Unsteady and complained of dizziness.
- Speech and Gag Reflex: Normal.
- Jaw Clenching Test: Strong and symmetrical contraction.
Discussion
In patients without nerve damage, vestibulocochlear nerve tests showed normal hearing function. The patient was able to repeat phrases used in the auditory assessment concisely. Moreover, they could hear the buzzing sound for an expected period and for longer without physical contact with their head.
Hearing in both ears was similar, with neither ear substantially weaker. The reflex assessment revealed good Symmetry and no weakness or paralysis in their facial muscles. The patient did not show rapid or other blinking when touching their forehead, and their jaw did not react when assessed.
On the other hand, the patient with head trauma depicted a variety of symptoms that correlated with damage to two nerves. The patient had an apparent hearing loss on the right side of their ear and could not hear the fork for extended periods when it was removed from the right ear.
The patient’s left facial side also showed noticeable weakness of the lip, eyebrow, eyelid, and, significantly, the forehead. Paralysis or paresis of the forehead is a notable feature of a damaged facial nerve. Additionally, the patient reported imbalance and dizziness during the motor assessments.
Conclusion
Therefore, the contrast of the control patient with the patient experiencing head trauma depicts the apparent symptoms of damage to the vestibulocochlear and facial nerves. The combination of a fragile balance and hearing complications may indicate a connection to the vestibulocochlear nerve, along with assessment evidence of abnormal reflex reactions. The symptoms of reduced taste and asymmetrical facial muscle weakness suggest a correlation with facial nerve issues. Additional examination of the balance trouble and dizziness hints at trauma to the vestibulocochlear nerve. However, it would be beneficial to examine additional variables that may have affected the patient, such as their largely unaffected eye movements and reflexes, despite the effects on the vestibulocochlear nerve affecting hearing.
References
Howard Community College. (n.d.). Human anatomy and physiology I. Bluedoor.
Marieb, E. N., & Hoehn, K. (2018). Human anatomy & physiology [11th ed.]. Pearson.