Trigeminal neuralgia is characterized by sudden and severe shock-like episodes of transient unilateral pain in the trigeminal nerve distribution. Most cases are idiopathic and are known to respond favorably to anticonvulsants. For patients who fail at least three drug trials or experience intolerable side effects, surgery may be warranted. First, a diagnostic block at the trigeminal nerve or Gasserian ganglion to confirm clinical diagnosis is performed. Surgical intervention can be either ablative or nonablative, each with its respective indications, contraindications, and risk-benefit profile. Most common are the percutaneous rhizotomies: conventional and pulsed radiofrequency ablation (RFA), chemical glycerol injections, and mechanical balloon compression. Stereotactic or gamma knife radiosurgery (GKRS) is the least invasive with only a moderate duration of pain relief, whereas microvascular decompression (VMD) is the most invasive, but associated with greatest long-term benefit. RFA has consistently shown favorable results and is the only modality with evidence of pain relief in ≥50% of patients treated 20 years postoperatively. Auxiliary interventional options such as peripheral neurectomy, botulinum toxin type-A (BTX-A) injections, and cryotherapy are available for those with contraindications to rhizotomies, radiosurgery, or neurosurgery. Ultimately, physicians must tailor their management of trigeminal neuralgia to the needs of the patient.
Part of the book: Peripheral Nerve Disorders and Treatment