Trigeminal Neuralgia

Essentials of Diagnosis

• Brief episodes of stabbing facial pain

• Pain is in the territory of the second and third division of the trigeminal nerve

• Pain exacerbated by touch

General Considerations

• Trigeminal neuralgia (tic douloureux) is most common in middle and later life

• It affects women more frequently than men

• Pain may be due to an anomalous artery or vein impinging on the trigeminal nerve

Symptoms and Signs

• Momentary episodes of sudden lancinating facial pain

• Commonly arises near one side of the mouth and shoots toward the ipsilateral ear, eye, or nostril

• The pain may be triggered by touch, movement, drafts, and eating

• To prevent further attacks, many patients try to hold the face still

• Symptoms remain confined to the distribution of the trigeminal nerve (usually the second or third division) on one side only

• Neurologic examination shows no abnormality unless trigeminal neuralgia is symptomatic of some underlying lesion, such as multiple sclerosis or a brainstem neoplasm

Differential Diagnosis

• Atypical facial pain

  • Especially common in middle-aged women

  • Generally a constant burning pain that may have a restricted distribution at onset but soon spreads to the rest of the face on the affected side and sometimes involves the other side of the face, the neck, and the back of the head as well

• Temporomandibular joint dysfunction

  • Occurs with malocclusion, abnormal bite, or faulty dentures

  • May cause tenderness of the masticatory muscles

  • An association between pain onset and jaw movement

  • Diagnosis requires dental examination and x-rays

• Giant cell arteritis—may have pain on mastication

• Sinusitis and ear infections

• Glaucoma

• Multiple sclerosis

• Brainstem tumor

• Dental caries or abscess

• Otitis media

• Glossopharyngeal neuralgia

• Postherpetic neuralgia

Imaging Studies

• Brain MRI

  • Need only be obtained when a secondary cause is suspected

  • Usually normal in classic trigeminal neuralgia

Diagnostic Procedures

• The characteristic features of the pain in trigeminal neuralgia usually distinguish it from other causes of facial pain

• In a patient younger than 40 years presenting with trigeminal neuralgia, multiple sclerosis must be suspected even if there are no other neurologic signs

Medications

• Carbamazepine (200–600 mg twice daily orally or oxcarbazepine (300–600 mg twice daily orally) is most helpful (monitor blood cell counts and liver biochemical tests)

• Phenytoin 200–400 mg once daily orally is second choice

• Baclofen (10–20 mg three or four times daily orally), topiramate (50 mg twice daily orally), or lamotrigine (400 mg daily orally) may be helpful, alone or in combination with carbamazepine or phenytoin

• Gabapentin

  • Up to 3600 mg daily orally is given in divided doses

  • May relieve pain in patients refractory to conventional therapy and those with multiple sclerosis

Surgery

• Microvascular surgical decompression with separation of the anomalous vessel (usually not visible on CT scans, MRI, or arteriograms) from the nerve root produces long-term relief of symptoms in roughly 75% of patients

• Three less invasive techniques are based on destruction of nociceptive trigeminal nerve fibers, which will cause sensory loss in addition to symptom relief in half of patients

  • Radiofrequency rhizotomy produces long-term pain relief in 60% of patients

  • Percutaneous balloon compression of the trigeminal ganglion in 67%

  • Stereotactic radiosurgery to the trigeminal nerve root in 45%

• In elderly patients with a limited life expectancy, radiofrequency rhizotomy and stereotactic radiosurgery are sometimes preferred because both can be performed without general anesthesia and have few complications

• Surgical exploration is inappropriate in patients with trigeminal neuralgia due to multiple sclerosis

Prognosis

• Spontaneous remissions may occur for several months or longer

• Progression of the disorder

  • Episodes of pain become more frequent

  • Remissions become shorter and less common

  • A dull ache may persist between the episodes of stabbing pain