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Neurology

Trigeminal neuralgia

Trigeminal neuralgia causes recurrent, brief, severe electric-shock-like facial pain triggered by innocuous stimuli; diagnose the phenotype clinically, investigate atypical or secondary features, offer carbamazepine first-line and refer early when treatment fails or procedures may be needed.

In a nutshell

Trigeminal neuralgia causes brief, unilateral, severe electric-shock-like facial pain triggered by light touch, chewing, talking or cold air. Diagnose the characteristic phenotype clinically, examine for sensory or other neurological signs, use MRI when secondary disease or procedural planning is relevant, and offer carbamazepine first-line. If pain is refractory, treatment is not tolerated or carbamazepine is contraindicated, seek specialist advice and consider early condition-specific referral; procedures require multidisciplinary selection.

Classic presentation

An older adult has repeated seconds-long electric shocks in the cheek or jaw, triggered by washing or chewing, with pain-free intervals and a normal cranial-nerve examination. Persistent numbness, bilateral pain or other neurological signs suggest secondary disease.

Key points

  • Typical pain is unilateral, paroxysmal, severe and shock-like, lasting seconds to about 2 minutes.
  • Touch, chewing, talking, tooth brushing and cold air can trigger attacks; V2 and V3 are common territories.
  • Offer carbamazepine as initial treatment and use current BNF monitoring and interaction advice.
  • Persistent facial numbness or another neurological sign needs urgent neuroimaging through the appropriate pathway.
  • MRI is often used to identify possible secondary causes and neurovascular contact, but a vascular contact may be incidental.
  • If carbamazepine fails, is not tolerated or is contraindicated, seek expert advice and refer early to a condition-specific service.
  • Microvascular decompression, percutaneous procedures and stereotactic radiosurgery are specialist options with different benefits and risks.

First-line investigation

Focused facial pain and cranial-nerve examination, with MRI when secondary disease is suspected or specialist planning requires it.

Management

Confirm phenotype and assess red flags

  • Identify brief triggered paroxysms, examine cranial nerves and facial sensation, check oral causes and assess hydration, nutrition and function.3,2

Offer carbamazepine

  • Offer carbamazepine as initial treatment and use current BNF advice for interactions, blood count, liver function, sodium, rash, pregnancy-related safety and tapering.4,5

Image and refer when atypical or refractory

  • Use MRI for suspected secondary disease or specialist planning, and refer refractory or medication-intolerant disease to a condition-specific service.3,4,2

Discuss specialist procedures

  • Discuss microvascular decompression, percutaneous procedures or stereotactic radiosurgery through an experienced multidisciplinary team, balancing pain relief, invasiveness, sensory risk, comorbidity and preference.1,7,6

Review safety and function

  • Review pain, eating, sleep, mood, adverse effects, neurological symptoms and recurrence; safety-net progressive numbness, weakness, visual symptoms or loss of oral intake.4,3,7

Exam traps

  • A continuous toothache is not the same as brief triggerable electric-shock pain; examine the teeth and jaw when appropriate.
  • Persistent numbness or abnormal neurological signs are not typical of classic disease and require neuroimaging.
  • Do not treat an incidental vascular contact on MRI as proof of causation without matching clinical features.
  • NICE CG173 specifically recommends carbamazepine for trigeminal neuralgia; do not substitute the generic neuropathic-pain ladder without specialist advice.
  • Stereotactic radiosurgery requires multidisciplinary selection and a specialist centre; microvascular decompression is invasive but may offer longer-lasting relief.

Illustrations

Specialist treatment options for trigeminal neuralgiaA balanced pathway diagram showing medication, specialist review, microvascular decompression, percutaneous procedures and stereotactic radiosurgery, with decision points for neurovascular contact, operative fitness, sensory-risk tolerance and patient preference.Luigi Berra, Wikimedia Commons · CC-BY-SA-4.0

Key sources

  1. NICE HTG608, Stereotactic radiosurgery for trigeminal neuralgia (NICE HealthTech guidance published 2 February 2022: specialist-centre stereotactic radiosurgery under standard governance, audit and multidisciplinary patient selection; includes comparison with microvascular decompression and percutaneous procedures)Updated 2 Feb 2022
  2. NHS, Trigeminal neuralgia: diagnosis (NHS diagnostic information last reviewed 27 January 2023: clinical symptom assessment, differential diagnosis and MRI use to identify possible multiple sclerosis, tumour or neurovascular contact)Updated 27 Jan 2023
  3. NICE NG127, Suspected neurological conditions: recognition and referral (NICE adult facial-pain recommendations: urgent neuroimaging pathway for persistent facial numbness or abnormal neurological signs, and referral of refractory unilateral facial pain triggered by touch)
  4. NICE CG173, Neuropathic pain in adults: pharmacological management in non-specialist settings (NICE guideline published 20 November 2013 and last updated 22 September 2020: offer carbamazepine as initial treatment for trigeminal neuralgia and seek specialist advice or early condition-specific referral if ineffective, not tolerated or contraindicated)Updated 22 Sept 2020
  5. BNF, current prescribing information for carbamazepine and trigeminal neuralgia (UK prescribing source for carbamazepine dosing, contraindications, interactions, blood-count/liver/sodium monitoring, serious skin reactions and withdrawal; direct access was restricted and the available browser session was unavailable, so unsupported doses were omitted)
  6. Royal College of Surgeons of England, Guidelines for the management of trigeminal neuralgia (UK Royal College of Surgeons guidance for specialist assessment and procedural options, including the need to weigh clinical phenotype, imaging, risks, outcomes and patient preference)Updated 1 Jan 2021
  7. NHS, Trigeminal neuralgia: treatment (NHS treatment information: carbamazepine, specialist referral when medicines fail or cause adverse effects, microvascular decompression, percutaneous procedures and stereotactic radiosurgery with risks and recurrence)

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.