15A. Trigeminal neuralgia

Trigeminal neuralgia (TN) is a type of facial neuropathic pain restricted to one or more divisions of the trigeminal nerve. The pain is recurrent, abrupt in onset and termination, triggered by innocuous stimuli like soft touch and typically compared to an electric shock or described as shooting or stabbing. It usually affects elderly.

Etiology

• Primary
  • Classic type – due to neurovascular compression of the trigeminal nerve root by a vessel
  • Idiopathic
• Secondary
  • Multiple sclerosis
  • Tumour

Clinical features

The patient has attacks of very severe facial pain in the area of one or more branches of CN V. The pain is sharp and stabbing and lasts for seconds. They may experience many episodes each day (as many as 100).

The pain can occur at rest or in association with movements like chewing, talking, touching, etc. The patient is usually asymptomatic between the attacks. Long periods of remission, sometimes as long as a few years, where the patient experiences no attacks, are not unusual.

Diagnosis and evaluation

MRI is important to look for neurovascular contact or a cause of secondary TN.

Treatment

The treatment is most importantly carbamazepine and oxcarbazepine. Surgery can treat underlying neurovascular compression if present, or it can be used to ablate the nerve in an attempt to improve symptoms.