Current Applications of Ablative Therapies for Trigeminal Neuralgia.

Trigeminal neuralgia (TN) is a syndrome consisting of episodic neuropathic facial pain. Although the precise symptoms vary across individuals, TN is typically described as lancinating electrical shocks triggered by sensory stimuli (light touch, talking, eating, and brushing teeth) that improve with antiepileptic medication (especially carbamazepine), remit spontaneously for weeks to months (pain-free intervals), and do not involve any changes in baseline sensation. The etiology of TN has not been definitively established, but many cases are associated with compression of the trigeminal nerve by a blood vessel at the trigeminal root entry zone adjacent to the brainstem. Patients who do not respond to medical management and who are not candidates for microvascular decompression often benefit from focal therapeutic injury to the trigeminal nerve at some point along its course. Many lesions have been described, including peripheral neurectomies that target distal branches of the trigeminal nerve, rhizotomies of the Gasserian ganglion of the nerve within Meckel's cave, radiosurgery of the trigeminal nerve at its root entry zone, partial sensory rhizotomy at the root entry zone, tractotomy of the spinal nucleus of the trigeminal nerve, and DREZotomy of the trigeminal nucleus caudalis, Though the latter two interventions are seldom done for TN and more commonly performed for trigeminal neuropathic pain. This article reviews the relevant anatomy and lesioning procedures for the treatment of trigeminal neuralgia.