13.1.1 Trigeminal neuralgia

Description:

A disorder characterized by recurrent unilateral brief electric shock-like pains, abrupt in onset and termination, limited to the distribution of one or more divisions of the trigeminal nerve and triggered by innocuous stimuli. It may develop without apparent cause or be a result of another diagnosed disorder. Additionally, there may be concomitant continuous pain of moderate intensity within the distribution(s) of the affected nerve division(s).

Previously used terms:

Tic douloureux, primary trigeminal neuralgia.

Diagnostic criteria:

Recurrent paroxysms of unilateral facial pain in the distribution(s) of one or more divisions of the trigeminal nerve, with no radiation beyond1, and fulfilling criteria B and C

  1. Pain has all of the following characteristics:
    1. lasting from a fraction of a second to 2 minutes2
    2. severe intensity3
    3. electric shock-like, shooting, stabbing or sharp in quality
  2. Precipitated by innocuous stimuli within the affected trigeminal distribution4
  3. Not better accounted for by another ICHD-3 diagnosis.
Notes:
  1. In a few patients, pain may radiate to another division, but it remains within the trigeminal dermatomes.
  2. Duration can change over time, with paroxysms becoming more prolonged. A minority of patients will report attacks predominantly lasting for >2 minutes.
  3. Pain may become more severe over time.
  4. Some attacks may be, or appear to be, spontaneous, but there must be a history or finding of pain provoked by innocuous stimuli to meet this criterion. Ideally, the examining clinician should attempt to confirm the history by replicating the triggering phenomenon. However, this may not always be possible because of the patient’s refusal, awkward anatomical location of the trigger and/or other factors.
Comments:

The diagnosis of 13.1.1 Trigeminal neuralgia must be established clinically. Investigations are designed to identify a likely cause.
Other than the triggering phenomenon, most patients with 13.1.1 Trigeminal neuralgia fail to show sensory abnormalities within the trigeminal distribution unless advanced methods are employed (eg, quantitative sensory testing). However, in some, clinical neurological examination may show sensory deficits, which should prompt neuroimaging investigations to explore possible cause.

Diagnosis of subforms such as 13.1.1.1 Classical trigeminal neuralgia, 13.1.1.2 Secondary trigeminal neuralgia or 13.1.1.3 Idiopathic trigeminal neuralgia is then possible.

When very severe, the pain often evokes contraction of the muscles of the face on the affected side (tic douloureux).

Mild autonomic symptoms such as lacrimation and/or redness of the ipsilateral eye may be present.

Following a painful paroxysm there is usually a refractory period during which pain cannot be triggered.