Trigeminal Neuralgia

Trigeminal Neuralgia (Facial pain, tic douloureux)

  • Pain:  Paroxysmal stabbing pain affecting one or more divisions of the trigeminal nerve
  • rarely bilateral, and never on both sides at the same time
  • may last for days or weeks and patient may remain pain free for many months after pain subsides
  • Signs and symptoms:  usually no accompanying neurological problems, sometimes blunting of pinprick over affected region
  • Triggers: speaking, brushing teeth, washing face, eating, cold wind, touching a “trigger spot”
  • Mostly affects females and patients 50+ yrs of age

Investigation

  • CT or MR scan to exclude CPA lesion or demyelination

Acute Attack Treatment = Phenytoin 250 mg IV for relief for hours- 3 days

First line Agent =  Carbamazepine 100mg 1-2 times per day, with increase of 100-200mg every 3 days up to a maintenance dose of 400-800mg

This post will go into a bit more detail about causes and treatment options for managing patients with trigeminal neuralgia coming into the ED.

Causes

  • Root or root entry zone compression
    • Arteries impinging on trigeminal nerve root as it enters Pons
  • Tumors between the Pons and Cerebellum (the cerebellopontine angle or CPA) can compress CN V nerve roots

Management

  • Anticonvulsants: Carbamazepine, gabapentin
  • Tricyclic antidepressants: Amitriptyline
  • GABA-enhancing drug: Baclofen
  • Procedures
    • Nerve block
      • alcohol or phenol (temporary relief)
    • Avulsion of supraorbital or infraorbital nerves
      • more long-term relief, but permanent damage
    • Trigeminal root section
    • Microvascular decompression
      • separation of blood vessels in contact with trigeminal nerve root or root entry zone at cerebellopontine angle by inserting non absorbable sponge
      • no nerve damage necessary
    • Radiofrequency thermocoagulation
      • electrical stimulation of inserted needle at trigeminal ganglion identifies location of trigger spot when it matches site of tingling
      • radiofrequency thermocoagulation with general anesthetic creates permanent lesion
    • Balloon Gangliolysis

A 2011 Cochrane Intervention Review evaluated the “analgesic efficacy and adverse effects of carbamazepine for acute and chronic pain management (except headaches),” finding that carbamazepine is, in most cases, effective for short term pain relief:

“Carbamazepine is effective for relieving chronic pain caused by damage to nerves, either from injury or disease, although the data available to support this is limited. Anticonvulsants (also known as antiepileptics) are a group of medicines commonly used for treating ‘fits’ or epilepsy, but which are also effective for treating pain. The type of pain which responds well is neuropathic pain, e.g., postherpetic neuralgia (persistent pain experienced in an area previously affected by shingles), trigeminal neuralgia, and painful complications of diabetes. About two-thirds of patients who take carbamazepine for neuropathic pain can expect to achieve good pain relief in the short term, and two thirds can expect to experience at least one adverse event.”

Source:

Wiffen PJ, Derry S, Moore RA, McQuay HJ. Carbamazepine for acute and chronic pain in adults. Cochrane Database of Systematic Reviews 2011, Issue 1. Art. No.: CD005451. DOI: 10.1002/14651858.CD005451.pub2.

Another 2011 Cochrane Intervention Review assessed the various neurosurgical techniques commonly used in treating trigeminal neuralgia.  Their findings emphasize the need for more research in order to help guide patients with trigeminal neuralgia in choosing the best neurosurgical option:

“There is either no, or very low quality, evidence for most neurosurgical procedures for the treatment of trigeminal neuralgia because of the poor quality of the trials. All procedures result in some pain relief (with or without medications) and there is good evidence to show that ablative procedures result in sensory loss. There is no evidence to assess the effect of surgery on quality of life and no evidence of the economic costs. There are no RCTs on microvascular decompression which from observational data gives the longest pain relief periods. Thus there is little evidence to provide the patient with guidance as to the most effective surgical procedure for the management of trigeminal neuralgia and this is in line with the study by Spatz 2007 on decision making. Thus any future high quality trials in this area are likely to lead to a highly significant impact on practice.”

Source:

Zakrzewska JM, Akram H. Neurosurgical interventions for the treatment of classical trigeminal neuralgia. Cochrane Database of Systematic Reviews 2011, Issue 9. Art. No.: CD007312. DOI: 10.1002/14651858.CD007312.pub2.

Compiled by: Karl Echiverri, M1

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