Intra-Oral Nerve Blocks for Trigeminal Neuralgia
The management of drug-resistant trigeminal neuralgia (TGN) includes peripheral injections of different chemical agents into the affected nerve. Historically, chloroform was the first substance used for this purpose. Later on, substances like glycerol, phenol, boiling water, high concentrations of tetracaine , and streptomycin [2, 3] were also used. Alcohol injections  are preferred at the initial presentation of TGN or in elderly patients with similar problem . Patients with significant medical co-morbidities who are not fit to undergo invasive surgeries safely, may also benefit from alcohol injection . Peripheral alcohol nerve block is associated with a variable duration of pain relief ranging from 6 to 16 months . There are two distinct techniques described for peripheral nerve blocks for TGN: (a) extra-oral or percutaneous nerve blocks and (b) intraoral nerve block; this chapter will focus on intraoral nerve block techniques involving mandibular and maxillary nerves, and their branches (Table 1). The preferred local anesthetic (LA) agents include lignocaine (1–2%) and bupivacaine (0.5%) with or without adrenaline (1:2,00,000). Currently, the use of ropivacaine (0.5%) has also been increased as it has minimal cardiovascular risks with a prolonged duration of action.