Introduction

Trigeminal neuralgia is a pain syndrome characterised by severe unilateral pain. The vast majority of cases are idiopathic but compression of the trigeminal roots by tumours or vascular problems may occur.

Epidemiology

  • Incidence: 15.00 cases per 100,000 person-years
  • Peak incidence: 60-70 years
  • Sex ratio: more common in females 2:1
Condition Relative
incidence
Trigeminal neuralgia1
Cluster headache0.67
Paroxysmal hemicrania0.01
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+

Clinical features

The International Headache Society defines trigeminal neuralgia as:
  • a unilateral disorder characterised by brief electric shock-like pains, abrupt in onset and termination, limited to one or more divisions of the trigeminal nerve
  • the pain is commonly evoked by light touch, including washing, shaving, smoking, talking, and brushing the teeth (trigger factors), and frequently occurs spontaneously
  • small areas in the nasolabial fold or chin may be particularly susceptible to the precipitation of pain (trigger areas)
  • the pains usually remit for variable periods

NICE Clinical Knowledge Summaries list the following as red flag symptoms and signs suggesting a serious underlying cause:
  • Sensory changes
  • Deafness or other ear problems
  • History of skin or oral lesions that could spread perineurally
  • Pain only in the ophthalmic division of the trigeminal nerve (eye socket, forehead, and nose), or bilaterally
  • Optic neuritis
  • A family history of multiple sclerosis
  • Age of onset before 40 years

Management

Management
  • carbamazepine is first-line
  • failure to respond to treatment or atypical features (e.g. < 50 years old) should prompt referral to neurology