neurologic disorders
Trigeminal Neuralgia
Treatment of Trigeminal Neuralgia
Usually antiseizure drugs Trigeminal neuralgia is treated withcarbamazepine200 mg orally 3 or 4 times a day, which is usually effective for long periods; it is begun at 100 mg orally twice a day, increasing the dose by 100 to 200 mg/day until pain is controlled (maximum daily dose 1200 mg). Ifcarbamazepineis ineffective or has adverse effects, one of the following oral drugs may be tried: Oxcarbazepine Lamotrigine Gabapentin Baclofen Phenytoin Amitriptyline Peripheral nerve block provides temporary relief. Botulinum toxin may be injected between the epidermis and the dermis at trigger points where pain is experienced or along the path of the nerve branches involved. This treatment may be beneficial, but data are limited. If pain is severe despite these measures, neuroablative treatments are considered; however, efficacy may be temporary, and improvement may be followed by recurrent pain that is more severe than the preceding episodes. Surgery that relieves pain may result in facial numbness. Painful numbness (anesthesia dolorosa) may also result; it occurs in 4% of patients after rhizotomy. In a posterior fossa craniectomy, a small pad can be placed to separate the pulsating vascular loop from the trigeminal root (called microvascular decompression, or the Jannetta procedure). In gamma knife radiosurgery, gamma radiation is focused on the proximal trigeminal nerve where it exits the brain stem; this procedure interrupts pain signals to the brain. Electrolytic or chemical lesions or balloon compression of the trigeminal (gasserian) ganglion can be made via a percutaneous stereotactically positioned needle. Occasionally, the trigeminal nerve fibers between the gasserian ganglion and brain stem are cut. Sometimes, as a last resort to relieve intractable pain, the trigeminal nerve is destroyed. Microvascular decompression can relieve pain due to vascular compression of the affected cranial nerve in trigeminal neuralgia, hemifacial spasms, or glossopharyngeal neuralgia. For trigeminal neuralgia, pressure is relieved by placing a sponge is placed between the 5th cranial (trigeminal) nerve and the compressing artery (Jannetta procedure). Usually, this procedure relieves the pain, but in about 15% of patients, pain recurs. 