> Table of Contents > Trigeminal Neuralgia
Trigeminal Neuralgia
Noah M. Rosenberg, MD
image BASICS
  • Disorder of the sensory nucleus of the trigeminal nerve (cranial nerve [CN] V) that produces episodic, paroxysmal, severe, lancinating facial pain lasting seconds to minutes in the distribution of >1 divisions of the nerve
  • Often precipitated by stimulation of well-defined, ipsilateral trigger zones: usually perioral, perinasal, and, occasionally, intraoral (e.g., by washing, shaving)
  • System(s) affected: nervous
  • Synonym(s): tic douloureux; Fothergill neuralgia; trifacial neuralgia; prosopalgia
  • Women: 5.9/100,000/year
  • Men: 3.4/100,000/year
  • >70 years of age: ˜ 25.6/100,000/year
  • Predominant age:
    • >50 years; incidence increases with age
    • Rare: <35 years of age (consider another primary disease; see “Etiology”)
  • Predominant sex: female > male (˜2:1)
Pediatric Considerations
Unusual during childhood
Pregnancy Considerations
Teratogenicity limits therapy for 1st and 2nd trimesters.
  • Demyelination around the compression site seems to be the mechanism by which compression of nerves leads to symptoms.
  • Demyelinated lesions may set up an ectopic impulse generation causing erratic responses: hyperexcitability of damaged nerves and transmission of action potentials along adjacent, undamaged, unstimulated sensory fibers
  • Compression of trigeminal nerve by anomalous arteries or veins of posterior fossa, compressing trigeminal root
  • Etiologic classification:
    • Idiopathic (classic)
    • Secondary: cerebellopontine angle tumors (e.g., meningioma); tumors of CN V (e.g., neuroma, vascular malformations), trauma, demyelinating disease (e.g., multiple sclerosis [MS])
  • Sjögren syndrome; rheumatoid arthritis
  • Chronic meningitis
  • Acute polyneuropathy
  • MS
  • Hemifacial spasm
  • Charcot-Marie-Tooth neuropathy
  • Glossopharyngeal neuralgia
All exam findings typically are negative due to the paroxysmal nature of the disorder.
  • Other forms of neuralgia usually have sensory loss. Presence of sensory loss nearly excludes the diagnosis of TN (if younger patient, frequently MS).
  • Neoplasia in cerebellopontine angle
  • Vascular malformation of brain stem
  • Demyelinating lesion (MS is diagnosed in 2-4% of patients with trigeminal neuralgia.)
  • Vascular insult
  • Migraine, cluster headache
  • Giant cell arteritis
  • Postherpetic neuralgia
  • Chronic meningitis
  • Acute polyneuropathy
  • Atypical odontalgia
  • SUNCT syndrome (short-lasting, unilateral, neuralgiform pain with conjunctival injection, and tearing)
  • The International Headache Society diagnostic criteria for classic trigeminal neuralgia (TN) are as follows:
    • Paroxysmal attacks of pain lasting from a fraction of 1 second to 2 minutes, affecting ≥ 1 divisions of the trigeminal nerve
    • Pain has at least an intense, sharp, superficial, or stabbing characteristic; or is precipitated from trigger areas or by trigger factors.
    • Attacks are stereotyped in the individual patient.
    • No clinically evident neurologic deficit found.
    • Not attributed to another disorder
  • Secondary TN is characterized by pain that is indistinguishable from classic TN but is caused by a demonstrable structural lesion other than vascular compression.
    • Indicated in all first-time-presenting patients to rule out secondary causes
  • MRI versus CT scan: MRI, with and without contrast, offers more detailed imaging and is preferred, if not contraindicated.
  • Routine head imaging identifies structural causes in up to 15% of patients.
  • No positive findings are significantly correlated with diagnosis.
Test Interpretation
  • Trigeminal nerve: inflammatory changes, demyelination, and degenerative changes
  • Trigeminal ganglion: hypermyelination and microneuromata
  • Outpatient
  • Drug treatment is first approach.
  • Invasive procedures are reserved for patients who cannot tolerate, fail to respond to, or relapse after chronic drug treatment.
  • Avoid stimulation (e.g., air, heat, cold) of trigger zones, including lips, cheeks, and gums.
First Line
  • Carbamazepine (Tegretol) (1)[A]: Start at 100 to 200 mg BID; effective dose usually 200 mg QID; max dose 1,200 mg/day:
    • 70-90% of patients respond initially.
    • By 3 years, 30% are no longer helped (number needed to treat [NNT] = 1.7) (1)[A]
    • Most common side effect: sedation
  • Contraindications: concurrent use of monoamine oxidase inhibitors (MAOIs)
  • Precautions: caution in the presence of liver disease
  • Significant possible medication interactions: macrolide antibiotics, oral anticoagulants, anticonvulsants, tricyclics, oral contraceptives, steroids, digitalis, isoniazid, MAOIs, methyprylon, nabilone, nizatidine, other H2 blockers, phenytoin, propoxyphene, benzodiazepines, and calcium channel blockers
  • Oxcarbazepine (Trileptal): Start at 150 to 300 mg BID; effective dose usually 375 mg BID; max dose 1,200 mg/day:
    • Efficacy similar to carbamazepine
    • Faster, with less drowsiness and fewer drug interactions than carbamazepine
    • May cause hyponatremia
    • Most common side effect: sedation
Second Line
  • Antiepileptic drugs: Insufficient evidence from randomized, controlled trials to show significant benefit from antiepileptic drugs in TN (2)[A].
  • Phenytoin (Dilantin): 300 to 400 mg/day (synergistic with carbamazepine):
    • Potent P450 inducer (enhanced metabolism of many drugs)
    • Various CNS side effects (sedation, ataxia)
  • Baclofen (Lioresal): 10 to 80 mg/day; start at 5 to 10 mg TID with food (as an adjunct to phenytoin or carbamazepine); side effects: drowsiness, weakness, nausea, vomiting
  • Gabapentin (Neurontin): Start at 100 mg TID or 300 mg at bedtime; can increase dose up to 300 to 600 mg TID-QID. Can be used as monotherapy or in combination with other medications and reduces the cost of illness.
  • Lamotrigine: Titrate up to 200 mg BID over weeks; side effect: 10% experience rash
  • P.1063

  • Antidepressants, including amitriptyline, fluoxetine, trazodone:
    • Used especially with anticonvulsants
    • Particularly effective for atypical forms of TN
  • Clonazepam (Klonopin) frequently causes drowsiness and ataxia.
  • Sumatriptan (Imitrex) 3 mg SC reduces acute symptoms and may be helpful after failure of conventional medical therapy.
  • Capsaicin cream topically
  • Botulinum toxin injection into zygomatic arch
  • Valproic acid (Depakene, Depakote)
Initial treatment failure or positive findings on imaging studies
  • Radiotherapy
  • Stereotactic radiosurgery, such as gamma knife radiosurgery, has been shown to be effective after drug failure:
    • Produces lesions with focused gamma knife radiation
    • Therapy aimed at the proximal trigeminal root
    • Minimal clinically effective dose: 70 Gy
    • ˜ 60-80% of patients achieve complete relief within 1 year; by 3 years, ˜ 30-40% maintain complete relief (3)[B].
    • Most common side effect: sensory disturbance (facial numbness)
    • Failure rates are higher in patients with past TN-related invasive procedures.
  • Microvascular decompression of CN V at its entrance to (or exit from) brain stem:
    • 98% of patients achieve initial pain relief; by 20 months, 86% maintain complete relief (NNT = 2) (4)[B].
    • Surgical mortality across studies was 0.3-0.4%.
    • Most common side effect: transient facial numbness and diplopia, headache, nausea, vomiting
    • Pain relief after procedure strongly correlates with the type of TN pain: Type 1 (shocklike pain) results in better outcomes than type 2 (aching pain between paroxysms).
  • Peripheral nerve ablation (multiple methods):
    • Higher rates of failure and facial numbness than decompression surgery
    • Radiofrequency thermocoagulation
    • Neurectomy
    • Cryotherapy: high relapse rate
    • Partial sensory rhizotomy
  • 4% tetracaine dissolved in 0.5% bupivacaine nerve block (only a few case reports to date; ropivacaine)
  • Alcohol block or glycerol injection into trigeminal cistern: unpredictable side effects (dysesthesia and anesthesia dolorosa); temporary relief
  • Peripheral block or section of CN V proximal to Gasserian ganglion
  • Balloon compression of Gasserian ganglion
  • Evidence supporting destructive procedures for benign pain conditions remains limited (5)[A].
Acupuncture, moxibustion (herb): weak evidence for efficacy (6)[B]
Regular outpatient follow-up to monitor symptoms and therapeutic failure.
Patient Monitoring
  • Carbamazepine and/or phenytoin serum levels
  • If carbamazepine is prescribed: CBC and platelets at baseline, then weekly for a month, then monthly for 4 months, then every 6 to 12 months if dose is stable (regimens for monitoring vary)
  • Reduce drugs after 4 to 6 weeks to determine whether condition is in remission; resume at previous dose if pain recurs. Withdraw drugs slowly after several months, again to check for remission or if lower dose of drugs can be tolerated.
No special diet
  • Instruct patient regarding medication dosage and side effects, risk-to-benefit ratios of surgery, or radiation therapy.
  • Support organizations:
    • The Facial Pain Association (formerly the Trigeminal Neuralgia Association): www.fpa-support.org
    • Living with Trigeminal Neuralgia: www.livingwithtn.org
  • 50-60% eventually fail pharmacologic treatment.
  • After having microvascular decompression surgery, most patients wish they had undergone the procedure sooner.
  • Of those, relapse is seen in ˜ 50% of stereotactic radiosurgeries and ˜ 27% of surgical microvascular decompressions.
1. Wiffen PJ, Derry S, Moore RA, et al. Carbamazepine for chronic neuropathic pain and fibromyalgia in adults. Cochrane Database Syst Rev. 2014;(4):CD005451.
2. Zhang J, Yang M, Zhou M, et al. Non-antiepileptic drugs for trigeminal neuralgia. Cochrane Database Syst Rev. 2013;(12):CD004029.
3. Karam SD, Tai A, Wooster M, et al. Trigeminal neuralgia treatment outcomes following Gamma Knife radiosurgery with a minimum 3-year follow-up. J Radiat Oncol. 2014;3:125-130.
4. Sekula RF Jr, Frederickson AM, Jannetta PJ, et al. Microvascular decompression for elderly patients with trigeminal neuralgia: a prospective study and systematic review with meta-analysis. J Neurosurg. 2011;114(1):172-179.
5. Zakrzewska JM, Akram H. Neurosurgical interventions for the treatment of classical trigeminal neuralgia. Cochrane Database Syst Rev. 2011;(9):CD007312.
6. Liu H, Li H, Xu M, et al. A systematic review on acupuncture for trigeminal neuralgia. Altern Ther Health Med. 2010;16(6):30-35.
Additional Reading
  • Attal N, Cruccu G, Baron R, et al. EFNS guidelines on the pharmacological treatment of neuropathic pain: 2010 revision. Eur J Neurol. 2010;17(9):1113-e88.
  • Gronseth G, Cruccu G, Alksne J, et al. Practice parameter: the diagnostic evaluation and treatment of trigeminal neuralgia (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology and the European Federation of Neurological Societies. Neurology. 2008;71(15):1183-1190.
  • G50.0 Trigeminal neuralgia
  • B02.22 Postherpetic trigeminal neuralgia
Clinical Pearls
  • Patients with TN typically have a normal physical exam.
  • The long-term efficacy of pharmacotherapy for TN is 40-50%.
  • If pharmacotherapy fails, stereotactic radiosurgery or surgical microvascular decompression often is successful.