Overview
The Pain Pattern and Its Mechanism
Trigeminal neuralgia is a disorder of cranial nerve V that causes recurrent bursts of severe facial pain.
Trigeminal neuralgia is a disorder of cranial nerve V that causes recurrent bursts of severe facial pain. The classic attack is unilateral, electric-shock-like, shooting, or stabbing; it lasts from a fraction of a second to 2 minutes and remains within one or more trigeminal divisions. Light touch, chewing, talking, tooth-brushing, or cold air can trigger it. Patients may identify a small “trigger zone” on the face and may avoid washing, eating, or speaking because the next stimulus feels dangerous. The mechanism explains the dramatic mismatch between a harmless touch and disabling pain. In classical trigeminal neuralgia, a blood vessel—often the superior cerebellar artery near the nerve’s root entry zone—compresses the trigeminal root. Focal demyelination disrupts the nerve’s insulation, allowing impulses from adjacent fibers to cross-talk and fire abnormally. A gentle stimulus can therefore activate a synchronized volley of pain signals, much like exposed electrical wires touching when they should remain separate. Trigeminal neuralgia is classified by cause: - Classical: neurovascular compression with associated nerve changes. - Secondary: caused by an identifiable disorder, such as multiple sclerosis or a cerebellopontine-angle tumor;...
