The etiology of trigeminal neuralgia is about as well understood now as it was in the days of Fothergill. Even the site at which the pain originates in the trigeminal sensory system is uncertain. Two general sites have been proposed: either peripheral, anywhere from the posterior root to the terminal filaments of the trigeminal nerve,1 or central, especially the pontomedullary portion of the nerve but also including higher regions.2 The character of the pain indicates that a single lesion is responsible for the disorder. Unpredictable remissions and exacerbations, similar to the abrupt and violent discharges characteristic of epilepsy, suggest that the causative factor may be a reversible process of central origin. Conversely, limitation of the pain to one branch or even to a small portion of one branch of the nerve would most easily be explained by a peripheral lesion.
Investigation of the problem is difficult for several
ETIOLOGY OF TRIGEMINAL NEURALGIA. JAMA. 1965;194(5):553. doi:10.1001/jama.1965.03090180077020