A nurse is performing a neurological assessment for a client who has head trauma. Which of the following assessments will give the nurse information about the function of cranial nerve III?
A.
Ask the client to shrug his shoulders against passive resistance
B.
Instruct the client to look up and down without moving his head
C.
Observe the client’s ability to smile and frown
D.
Have the client stand with his eyes closed and touch his nose
The correct answer and Explanation is :
The correct answer is B. Instruct the client to look up and down without moving his head.
Explanation
Cranial nerve III, also known as the oculomotor nerve, is primarily responsible for eye movement and the constriction of the pupil. It innervates most of the extraocular muscles, which control movements of the eye. Specifically, cranial nerve III allows the eyes to move up, down, and medially, and it also controls the elevation of the upper eyelid.
When assessing cranial nerve III function, the nurse can ask the client to look up and down without moving their head. This assessment checks for any abnormalities in eye movement, such as diplopia (double vision) or ptosis (drooping of the eyelid), which may indicate dysfunction of the oculomotor nerve. The ability to perform these movements indicates intact motor function and coordination of the muscles innervated by cranial nerve III.
Let’s briefly analyze the other options:
- A. Ask the client to shrug his shoulders against passive resistance: This assesses cranial nerve XI (accessory nerve), which controls shoulder and neck movement.
- C. Observe the client’s ability to smile and frown: This evaluates cranial nerve VII (facial nerve), responsible for facial expressions.
- D. Have the client stand with his eyes closed and touch his nose: This assesses proprioception and balance, which involves multiple cranial nerves but is not specific to cranial nerve III.
In conclusion, assessing the ability to look up and down is crucial for determining the integrity of cranial nerve III. Any observed impairment could suggest possible issues related to head trauma, such as increased intracranial pressure or direct injury to the nerve. Prompt recognition and intervention are critical in managing potential complications.