Trigeminal Neuralgia

Trigeminal neuralgia (TN) is a painful, chronic condition that affects the fifth (5th) cranial nerve. Also called tic douloureux, TN is a form of neuropathic pain, which affects a nerve due to injury or lesion. The 5th cranial nerve is the most widely distributed nerves in the head.

What are the types of trigeminal neuralgia?

The usual or classic type of trigeminal neuralgia (called type I) causes a sporadic, extreme, and sudden burning, searing, or shock-like facial pain sensation. This pain last for a few seconds to a few minutes. These painful attaches often occur in quick succession, which can last for 2-3 hours. The other type of TN is called type 2 TN or atypical TN. Type 2 is characterized by a burning, aching, stabbing pain of lower intensity than TN type 1.

What is the trigeminal nerve?

The fifth cranial nerve is one of 12 pairs of nerves attached to the brain. This nerve has three branches, and they conduct sensations from the upper, middle, and lower areas of the face to the brain. The various branches stimulate the upper jaw, cheek, teeth, side of nose, and gums. While more than one nerve branch is affected by TN, rarely is both sides of the face involved.

What causes trigeminal neuralgia?

TN may be caused by a blood vessel pressing on the nerve as it exits the brain stem. This pressure lead to erosion of the protective nerve coating (myelin sheath). TN symptoms occur in persons with multiple sclerosis, which is a disease that results in deterioration of the nerve’s myelin sheath. In rare cases, nerve compression occurs due to a tumor or from an arteriovenous malformation (arteries and veins in a tangled mass).

What symptoms are associated with trigeminal neuralgia?

The pain associated with TN varies from patient-to-patient, and it depends on the type of TN. Pain may range from severe, sudden, and stabbing to aching, burning, and constant. In addition, flashes of pain are triggered by vibration, contact with the cheek, brushing the teeth, eating, talking, and exposure to wind. The pain associated with TN occurs in clusters, with pain-free intervals in between episodes. TN is not fatal, but is debilitating, and many patients suffer the pain long-term.

Who is affected by TN?

Trigeminal neuralgia occurs more in people age 50 and older. However, it can occur at any age. TN caused by multiple sclerosis often affects young adults. The incidence of TN is reported as 12 per 100,000 people each year, and the disorder occurs more often in women than men.

How is TN treated?

The pain management specialist often uses a combination of treatments for TN. These include:

  • Anticonvulsants – These agents are used to block nerve signal transmission. These include oxcarbazepine, carbamazepine, topiramate, pregabalin, and gabapentin.
  • Tricyclic antidepressants – These medications include nortriptyline and amitriptyline. They often change how the brain perceives pain.
  • Rhizotomy (rhizolysis) – This procedure involves deactivation of nerve fibers associated with the trigeminal nerve. A small cannula is inserted through the cheek and positioned near the nerve. A balloon is used to compress the nerve. As an outpatient procedure, pain relief can last for 1-2 years. Another method involves radiofrequency energy, which is mild electric current applied to the nerve to destroy a portion of it.
  • Stereotactic radiosurgery – Called Cyber Knife, this procedure uses computer imaging to direct focused beams of radiation onto the area where the nerve exits the brain stem. This causes the slow formation of the lesion and disruption of nerve transmission.
  • Microvascular decompression (MVD) – This procedure involves making a small opening behind the ear. A small scope is inserted and the nerve is compressed using special tools.
  • Neurectomy – A partial nerve section involves cutting a portion of the nerve. Often done during MVD, this causes long-term numbness of a portion of the face.