Overview of Trigeminal Neuralgia
Trigeminal neuralgia, also called tic douloureux, is a painful neurological condition that occurs as a result of damage to or pressure on the fifth cranial nerve, also called the trigeminal nerve. Trigeminal neuralgia causes sudden, severe pain, usually on one side of the face.
Contact with a stimulus (i.e., a touch) often can trigger a painful attack in patients who have tic douloureux. Triggers include the following:
- Brushing the teeth
- Changes in temperature (e.g., hot or cold foods or drinks, a cool breeze on the face)
- Chewing gum
- Combing the hair
- Washing the face
In trigeminal neuralgia, painful attacks may occur frequently over the course of a few hours to several weeks at a time, and then diminish for a period of weeks or months. Each attack can last from a few seconds to up to 2 minutes. Tic douloureux is not a life-threatening condition, but it can often be disabling.
Trigeminal Nerve Anatomy
The trigeminal nerve is actually a bundle of nerves that controls areas of sensation and movement in the face (e.g., facial skin, tongue, teeth, muscles used for chewing). Also called the fifth cranial nerve, it originates in the pons region of the brain (area in front of the brainstem) and is attached to the brainstem by two roots—one that controls movement (called a motor root) and another that controls sensation (called a sensory root).
Three large nerve branches stem from the sensory root. These branches are called the ophthalmic nerve, the maxillary nerve, and the mandibular nerve. Electrochemical signals are relayed from the brain along the branches of the trigeminal nerve.
The ophthalmic nerve is a sensory nerve that controls feeling in the skin on the top of the head, the lining (mucous membrane) of the nose and sinuses, the cornea (clear, transparent portion of the coating that surrounds the eyeball), and the conjunctiva (thin, transparent, mucous membrane that lines the eyelids and covers the front surface of the eyeball). In trigeminal neuralgia, damage to or pressure on the ophthalmic nerve can cause pain along the jaw line, to the eye, and back across the forehead.
The maxillary nerve controls sensation in the outer covering of the brain and spinal cord (the dura mater), the gums and teeth in the upper jaw, the upper lip, and the eye socket (orbit). If this nerve is affected, pain often radiates from the jaw to the upper lip, nose, and underneath the eye.
The mandibular nerve is the largest branch of the fifth cranial nerve. This nerve controls sensation in the lower jaw (including the gums and teeth), the tongue, the lower lip, and the skin of the cheek. It also controls the muscles that are used for chewing. In patients who have tic douloureux, damage to or pressure on the mandibular nerve can cause pain that radiates from the jaw and chin to the lower lip and tongue.
Incidence and Prevalence of Trigeminal Neuralgia
According to the National Institutes of Health (NIH), trigeminal neuralgia is more common in people over the age of 50, although the condition can occur at any age. Trigeminal neuralgia affects more women than men, and the disorder may have a genetic (inherited) link.