The nervous system is a very complex system which is vital to the functioning of the human body. The nervous system is comprised of the central nervous system (CNS) and peripheral nervous system (PNS). There are 31 pairs of spinal nerves and 12 pairs of cranial nerves. Below are the procedures for performing an assessment of the cranial nerves. Show
For more information about performing a nursing health assessment read the article Tips for A Better Nursing Health Assessment. This will help you proceed through an assessment including the nervous system as you move from head-to-toe. During a complete health assessment of the nervous system, you will perform an assessment of the cranial nerves, motor function, sensory function, and reflexes. Below is a complete assessment of the cranial nerves. Read our article 5 Tips for Performing a Nursing Health Assessment of the Nervous System for assessment of the motor function, sensory function, and reflexes.
Cranial Nerve I – Olfactory NerveThe olfactory nerve is the sensory nerve of smell. Before beginning, have some type of aromatic substance available such as coffee, toothpaste, peppermint or soap to use as part of the assessment.
Cranial Nerve II – Optic NerveNext, test the optic nerve. The optic nerve is responsible for visual processes. Assessment of the optic nerve involves the testing of visual acuity, visual fields, and the ocular fundi. Testing visual acuity involves testing near and distant vision. Visual fields are tested by confrontation. Confrontation measures peripheral vision. Test of the ocular fundi requires the use of an ophthalmoscope. Testing Near Vision
Testing Distant Vision
Normal vision is 20/20. This means the patient is 20 feet away from the chart and can read the line numbered 20. If the patient’s vision is 20/30 then the patient reads at 20 ft what a person with normal vision reads at 30 ft. Observe the patient while they are reading the chart. If a patient is unable to read more than one-half of the letters on a line record the number of the line above. Testing visual fieldsConfrontation
Test the ocular fundi.
Cranial Nerve III – Oculomotor, Cranial Nerve IV – Trochlear, and Cranial Nerve VI – Abducens.The oculomotor nerve, trochlear nerve, and abducens nerve (cranial nerves III, IV, and VI) all work together, therefore, are assessed together. During this test, you will assess direct and consensual pupillary reaction to light, convergence, accommodation of the eyes and the six cardinal points of gaze. Testing Consensual Pupillary Reaction to Light
Testing accommodation and convergence of pupil response.
Testing the six cardinal fields of gaze.There are two methods used for this assessment. The first is the “H” Method. The second is the “Wagon Wheel” Method. These procedures test eye movement and the muscles of the eye. During the procedure, you will be assessing the patient’s ability to follow your movement with their eyes. Assess the patient eyes while performing the procedure. You are looking for the presence of any abnormalities such as nystagmus in one or both eyes. Nystagmus is the rapid back and forth jerky movement of the eyeball with the rapid lateral movement of the eyeball. The “H” Method
The Wagon Wheel method
Cranial Nerve V – Trigeminal NerveThe trigeminal nerve is the main nerve of the face. You will be testing the sensory function of the nerve. You will be looking for a loss of sensation, pain or any fine rapid muscle movements called fasciculations. Test the sensory function of the nerve.
Next test the corneal reflex.
Next, test the motor function of the nerve.You are assessing for any pain, muscle spasms or deviation of the mandible.
Cranial Nerve VII – Facial NerveThe facial nerve is a motor nerve. This nerve supplies the motor fibers used for facial expressions and, also the salivary and lacrimal glands. First, you will be assessing the symmetry of facial movement.
Second, test the muscle strength of the upper and lower facial muscles.
Third, test the sense of taste.
Cranial Nerve VIII – Vestibulocochlear NerveThe vestibulocochlear nerve is a sensory nerve and is responsible for transmitting information about balance and hearing from the inner ear to the brain. Assess the vestibulocochlear nerve using the Rinne test, the Weber test, and the Romberg test. The Rinne test compares bone conduction with air conduction. It tests for tinnitus and deafness. The Weber test provides lateralization of the sound. Lateralization is roughly defined as localized to one side in the presence of another side. Also, it is used to check for hearing and if a person hears better in one ear than another. And the Romberg test assesses coordination and equilibrium. A tuning fork and your watch are used for the Weber and Rinne test. Performing the Rinne test.
Performing the Weber test.
Performing the Romberg test.
Cranial Nerve IX – Glossopharyngeal and Cranial Nerve X – Vagus NerveThe glossopharyngeal nerve is a mixed nerve. The motor fibers carry motor information from the throat to the brain. And the sensory fibers carry impulses from the pharynx and tongue (taste buds). The vagus nerve is the largest of the cranial nerves. This nerve provides sensation from the throat, as well as organs of the chest and abdomen, taste from the tongue and back of the throat, and muscle function of the palate. Testing the motor activity of these nerves.
Next, test the gag reflex.This test assesses the sensory aspect of cranial nerve IX and the motor activity of cranial nerve X.
Finally, test the motor activity of the pharynx.
Cranial Nerve XI – Accessory Nerve or Spinal Accessory NerveThe accessory nerve is a mixed nerve but mostly the motor nerve of the sternocleidomastoid and trapezius muscles. During this assessment, you will check the strength and movement of the patient’s sternocleidomastoid and trapezius muscle. First, test the trapezius muscle.
Second, test the sternocleidomastoid muscle.
Cranial Nerve XII – Hypoglossal NerveThe hypoglossal nerve supplies the muscles of the tongue. This assessment involves testing the movement of the tongue.
Next, test the strength of the tongue.
In conclusion, the tips above will help you with a nursing health assessment of the cranial nerves. Perform a comprehensive or complete neurological assessment when a neurological concern or dysfunction is suspected. A basic check or recheck of the neurological system is done during a normal head-to-toe assessment. Don’t forget to read 5 Tips for Performing a Nursing Health Assessment on the Nervous System for the additional portions of the comprehensive assessment. ReferenceBickley LS., Szilagyi PG., (2017). Bates Guide to
Physical Examination and History Taking. 12th ed. Philadelphia, PA. Wolters Kluwer/Lippincott Williams & Wilkins. Disclaimer: The information contained on this site is not intended or implied to be a substitution for professional medical advice, diagnosis or treatment. All content, including text, graphics,
images, and information, contained is provided for educational purposes only. You assume full responsibility for how you chose to use this information. Which technique will the nurse use to assess pupillary reflexes?Test pupillary reaction to light. Using a penlight, approach the patient from the side, and shine the penlight on one pupil. Observe the response of the lighted pupil, which is expected to quickly constrict. Repeat by shining the light on the other pupil.
How do you assess pupillary light reflex?Gently point the focal light into one eye, this is known as the direct pupillary light reflex. Then, withdraw the light for few seconds, followed by stimulating the same eye again but this time observe the indirect, or consensual, PLR in the opposite eye.
When assessing the pupillary light reflex The nurse should use which technique quizlet?Ask the patient to focus on a distant object. Then ask the patient to follow the penlight to approximately 7 cm from the nose. To test the pupillary light reflex, the nurse should advance a light in from the side and note the direct and consensual pupillary constriction.
How would a nurse assess a client for pupillary accommodation?Accommodation? Make the lights normal and have patient look at a distant object to dilate pupils, and then have patient stare at pen light and slowly move it closer to the patient's nose. Watch the pupil response: The pupils should constrict and equally move to cross.
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