Question

A patient presents with a unilateral throbbing headache, photophobia, and excessive lacrimation. He also complains of hemifacial pain on the clenching of teeth. On examination, pupillary reaction, light reflex, and accommodation reflex are normal. Which of the following marked nerves is involved in the above scenario?

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

The Correct Option is A

The scenario described is consistent with involvement of a specific cranial nerve. Let's break down each symptom in relation to cranial nerve functionality:

• Unilateral throbbing headache and hemifacial pain: These symptoms suggest trigeminal nerve involvement, which is responsible for facial sensation and muscle movement for chewing. The trigeminal nerve is the fifth cranial nerve (CN V), which has three major branches: ophthalmic (V1), maxillary (V2), and mandibular (V3).
• Photophobia: While photophobia is commonly associated with various conditions, in the context of this case, it supports nerve involvement that influences autonomic nervous control over the eyes. However, since the pupillary examination is normal, it is less likely to be directly due to parasympathetic nerve involvement.
• Excessive lacrimation: Lacrimation can be influenced by autonomic fibers associated with the trigeminal nerve, particularly through its branches connected to the lacrimal gland.
• Normal pupillary reaction, light reflex, and accommodation reflex: This indicates no direct parasympathetic or sympathetic involvement that would affect the pupil, ruling out the oculomotor (III) and other cranial nerves directly affecting eye muscles.

Given the symptoms align predominantly with issues in facial feeling and sensory disruptions, the trigeminal nerve, especially branches V1 (ophthalmic) and V2 (maxillary), are likely candidates:

• Ophthalmic branch (V1): This branch covers the forehead, scalp, and upper eyelid area, all of which could explain the headache and associated photophobia.
• Maxillary branch (V2): This branch covers the lower eyelid, cheek, and upper lip, which correlates to the hemifacial pain upon teeth clenching.

Considering the presented symptoms and the examination results, the most logical nerve involved is the ophthalmic branch (V1) of the trigeminal nerve (CN V), denoted by option 1 in the provided image.