Trigeminal neuralgia and other cranial neuralgias
Neuropathic facial pain can arise from the trigeminal, glossopharyngeal or greater occipital nerves—trigeminal neuralgia is most common.
Trigeminal neuralgia is recurrent, unilateral, shock-like pain in one or more divisions of the trigeminal nerve (see description in Facial pain types). It can be due to demyelination or neurovascular compression. Request imaging to exclude a structural cause, especially in the presence of sensory loss, which suggests trigeminal neuropathy. Request specific views of the trigeminal nerve and ganglion.
Drugs are first-line therapy for trigeminal neuralgia. There is stronger evidence for carbamazepine, but oxcarbazepine may be better tolerated. Use:
1 carbamazepine modified-release 100 mg orally, twice daily. If needed, gradually increase dose as tolerated and according to response every 7 days up to 400 mg twice daily1 carbamazepine
OR
2 oxcarbazepine 300 mg orally, twice daily. If needed, gradually increase dose after 7 days up to 600 mg twice daily trigeminal neuralgia oxcarbazepine
OR
3 baclofen 5 mg orally, twice daily. If needed, gradually increase dose every 4 days up to 10 to 20 mg 3 times daily trigeminal neuralgia baclofen
OR
3 gabapentin 300 mg orally, once daily at night. If needed, gradually increase dose every 3 to 7 days up to 600 to 1200 mg 3 times daily trigeminal neuralgia gabapentin
OR
3 lamotrigine 25 mg orally, once daily on alternate days for 14 days, then 25 mg once daily for 14 days, then 25 mg twice daily for 14 days. If needed, increase daily dose by 25 mg every 14 days up to 100 mg twice daily trigeminal neuralgia lamotrigine
OR
3 phenytoin 300 mg orally, once daily trigeminal neuralgia phenytoin
OR
3 pregabalin 75 mg orally, once daily at night. If needed, gradually increase dose every 3 to 7 days up to 150 to 300 mg twice daily. trigeminal neuralgia pregabalin
If the patient does not respond to an adequate dose of drug or does not tolerate it, or if the drug loses efficacy or the diagnosis is in doubt, refer to an expert. If drug therapy is not effective, patients may be considered for surgery (eg microvascular decompression of the trigeminal nerve, percutaneous rhizotomy, stereotactic radiotherapy [‘gamma knife’ therapy]).
Glossopharyngeal neuralgia is a rare facial pain syndrome characterised by paroxysmal pain in the throat, tonsillar fossa, base of tongue and ear (see description in Facial pain types). Exclude a structural cause (eg oropharyngeal malignancy, peritonsillar infection, vascular compression). Treat with drugs as for trigeminal neuralgia (see above).
Greater occipital neuralgia is characterised by shooting or stabbing pain (typically unilateral) over the occipital region (see description in Facial pain types). Initial treatment is a greater occipital nerve block. If effective, the nerve block can be repeated every 3 months (more frequent use risks local atrophy of skin and subcutaneous tissue). If a nerve block is not effective, drug therapy is an option. Use:
1 gabapentin 300 mg orally, once daily at night. If needed, gradually increase dose every 3 to 7 days up to 600 to 1200 mg 3 times daily occipital neuralgia gabapentin
OR
1 pregabalin 75 mg orally, once daily at night. If needed, gradually increase dose every 3 to 7 days up to 150 to 300 mg twice daily. occipital neuralgia pregabalin
Refer for expert advice if the diagnosis of greater occipital neuralgia is in doubt, a structural cause is identified or the patient does not respond to, or tolerate, the therapy.