clinical features

Last reviewed 05/2023

Trigeminal neuralgia presents with brief electric shock-like pains, abrupt in onset and termination, limited to the distribution of one or more divisions of the trigeminal nerve (1).

  • site
    • pain is unilateral in the distribution of the trigeminal nerve, mandibular is singularly affected in 20% of cases; the mandibular and maxillary divisions together in 40% of cases; and all three affected in 15% of cases, it is rare for the ophthalmic division to be affected by itself
    • it is bilateral in only 3% of patients and rarely is the pain active on both sides at the same time
  • periodicity
    • episodic and sudden onset of pain, lasting a few seconds to minutes and stopping suddenly, with many attacks a day
    • there is a refractory period between each attack
    • pain might then go into remission for a few weeks or months; pain free intervals gradually shortens between episodes with time (pain often gets  longer with time)
  • character
    • electric shock like, sharp, shooting
  • severity
    • very severe attacks, pain may be so severe that the patient will only be able to point to the site of the pain and not be able to touch the site
    • can get milder when patients are given drug treatment
  • factors affecting pain
    • pain can be provoked by light touch to the face, eating, cold winds or vibrations
    • repeated stimulation may alleviate symptoms temporarily and permit pain free activity, e.g. to eat food
  • associated factors
    • rarely associated with history of other chronic pain or migraine. Some forms have more continued aching background pain after main attack. Rarely associated with autonomic features (1,2)

In some patients the pain does not match with the above criteria and may have a background pain of lower intensity for 50% of the time. These patients are said to have “atypical trigeminal neuralgia” or “type 2” or according to the new International Classification for Headache Disorders – “trigeminal neuralgia with concomitant persistent facial pain” (1).

Autonomic symptoms such as conjunctival injection, lacrimation, nasal congestion or rhinorrhoea, eye lid oedema, ptosis, or facial sweating may occur in some patients

  • a retrospective study has reported that up to 67% had one autonomic symptom and 14% had four or more, 
  • in these patients it will be difficult to determine whether this is still trigeminal neuralgia or a variant known as short unilateral neuralgiform pain with autonomic symptoms (SUNA) or short unilateral neuralgiform pain with conjunctival injection and lacrimation (SUNCT)
  • presence of autonomic features were more likely to have a poorer response to surgery

Patients may experience as few as three or four attacks a day but in some cases there can be as many as 70 per day.

Pain can occur at night in a third of patients.

A second episode is seen in 65% of newly diagnosed patients within 5 years and in 77% within 10 years (1).

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