Overview
What the Disorder Is Doing to the Nerve
The trigeminal nerve, cranial nerve V, carries sensation from much of the face and also supplies the muscles used for chewing.
The trigeminal nerve, cranial nerve V, carries sensation from much of the face and also supplies the muscles used for chewing. In trigeminal neuralgia, abnormal excitability of this nerve produces sudden bursts of pain rather than the continuous aching expected from many inflammatory or dental conditions. A vascular contact, demyelinating process, or other lesion can disrupt the nerve’s insulation and allow nearby impulses to trigger one another. The result is a sensory nerve that fires excessively when it should be responding quietly. A stimulus as small as washing the face, brushing the teeth, chewing, speaking, or feeling cool air may provoke a severe discharge. The pain can be disproportionate to the stimulus because the problem is faulty nerve signalling, not tissue damage from the touch itself. Typical attacks are unilateral and brief—often seconds to a few minutes—with an electric-shock, stabbing, or lancinating quality. The patient may be comfortable between attacks. That pain-free interval is clinically useful: it separates trigeminal neuralgia from many causes of persistent facial pain.