Question

"A patient is experiencing a possible neurological emergency from a blunt force closed head injury. He is found to have abnormal pupillary reactions to light and has lost the ability to move his eyes from side to side to follow your finger movements. He is also unable to identify the number of fingers you are holding up. He reports he is able to see the fingers but is not able to focus enough to identify how many fingers are present.

Which of the following cranial nerves should you suspect may be involved in his injury?

A. Cranial nerves I, V, and VI

B. Cranial nerves V and VII

C. Cranial nerves IX and X

D. Cranial nerves II, III, and IV"

Answer 1

The patient's symptoms indicate impairment of the cranial nerves responsible for eye movements and pupillary function, specifically the oculomotor (III), trochlear (IV), and abducens (VI) nerves, as well as the optic nerve (II), making option D (Cranial nerves II, III, and IV) the correct answer.

Step-by-step explanation:

The patient's inability to follow finger movements horizontally, abnormal pupillary reactions, and difficulty focusing suggests impairment of the cranial nerves responsible for eye movement and pupillary function. The oculomotor (III), trochlear (IV), and abducens (VI) cranial nerves are involved in controlling eye movements. The oculomotor nerve also controls pupillary constriction, while vision acuity and focus are primarily governed by the optic nerve (II). Thus, the correct answer to the question is D. Cranial nerves II, III, and IV. Testing for neurological function, particularly the function of these cranial nerves, involves asking the patient to track a visual target such as the tip of a pen through their visual field. The oculomotor, trochlear, and abducens nerves, connected by the medial longitudinal fasciculus (MLF), coordinate conjugate gaze movements, which are assessed during this examination.