If a patient has neck pain and develops symptoms related to hindbrain ischemia, which cranial nerve would likely not be involved?

• A. CN 1
• B. CN 3
• C. CN 5
• D. CN 10

Answer: (A)

In cases of hindbrain ischemia, several cranial nerves that originate in the brainstem may be affected due to their close anatomical proximity. The hindbrain includes the medulla oblongata, pons, and cerebellum, and it is where cranial nerves III, V, and X primarily emerge.

Cranial nerve III (oculomotor) is responsible for eye movement and the pupillary response and is likely to be involved in ischemic events affecting the hindbrain due to its location in the midbrain. Cranial nerve V (trigeminal) plays a crucial role in sensation in the face and motor functions such as biting and chewing, and it traverses through the pons, making it another candidate for potential involvement.

Cranial nerve X (vagus) provides autonomic control of the heart, lungs, and digestive tract and emerges from the medulla, also indicating its possible involvement in hindbrain ischemic events.

Conversely, cranial nerve I (olfactory) is not implicated in the hindbrain region; it originates directly from the olfactory bulbs on the ventral surface of the frontal lobe and does not share the same anatomical pathway as the other cranial nerves mentioned. Therefore, it