The trigeminal nerve is the fifth of the twelve pairs of cranial nerves in the head; it is the nerve responsible for providing sensation to the face.
One trigeminal nerve runs on the right side of the head, while the other runs on the left. After the trigeminal nerve leaves the brain and travels inside the skull, it divides into three smaller branches (hence the name trigeminal).
- The first branch controls sensitivity in the eye, upper eyelid and forehead.
- The second in the lower eyelid, cheek, nostril, upper lip and upper gum.
- The third branch controls the sensations of the jaw, lower lip, lower gum and some muscles used for chewing.
Irritation of the trigeminal nerve produces what is sometimes described as one of the most excruciating pains one can experience; it typically involves the lower part of the face, although it sometimes affects the area around the nose and above the eye.
Seizures are usually brief, sudden, and without apparent cause; they tend to recur at progressively smaller intervals until they cause a state of tension and continuous fear.