Understanding Trigeminal Neuralgia

Trigeminal Neuralgia (TN), or tic douloureux, is a neurological condition causing sudden episodes of stabbing facial pain that lasts a few seconds.  This pain is usually triggered by sensory stimuli such as chewing, shaving, smiling, touching the side of the face or brushing teeth. 

The trigeminal, or fifth cranial nerve, is the largest cranial nerve, and it divides into three branches once it reaches the face.  The pain can be in one or more of these branches but is only on one side of the face.  Most of the cases are caused by a normal artery near the brain stem in an abnormal position.  This artery has a loop which can press against the trigeminal nerve.  Each heart beat forces blood through the artery, which causes the artery to bump up against the nerve.  This repeat pressure rubs the insulation off the nerve, resulting in the nerve firing abnormal, painful electrical-like shocks. 

Diagnosing TN

A physician from the USC Neurosurgery team will conduct a thorough neurological evaluation.  Often, the exam findings are normal except for the ability to reproduce the pain by touching the trigger point.  In these cases, imaging studies, such as an MRI  scan will be performed in order to rule out a tumor prior to any treatment.

Treatment Options       

There are four types of treatment options available – medication, percutaneous non-surgical intervention,  surgery, and radiosurgery.

Medication

The initial treatment of choice is the medicine Carbamazepine (Tegretol) or Trileptal.  Both drugs provide complete or acceptable pain relief in 69% of patients with TN.  Neither of these drugs is a “pain pill” but rather provide relief of the symptoms.  There are several other medications that may be used in combination with the primary drug treatment. Patients should discuss all medication options with their USC neurologist to decide where to begin.  As with any medication, potential side effects should also be discussed.

Percutaneous Non-Surgical Treatment

Peripheral Nerve Block
A peripheral nerve block provides temporary relief of pain by injecting a medication around the trigeminal branch involved. This is typically performed by a pain management specialist, oral surgeon or dentist.

Balloon Compression
Balloon compression of the trigeminal nerve is performed in the angiography suite under mild sedation.  This procedure involves inserting a cannula through the facial cheek, into the opening in the skull where the trigeminal nerve exits.  A balloon tipped catheter is inserted into the cannula and once in position, the balloon is inflated.  This balloon inflation compresses the trigeminal nerve, thereby injuring it so that it is unable to fire the painful electric shocks.  As expected, most patients (74%) develop facial numbness after the procedure, and 85 – 90% report good pain relief.

Surgical Treatment

Craniotomy for Microvascular Decompression
The surgical procedure is called microvascular decompression (MVD).  It is recommended for patients who have not had good results with other medical treatment, and are in good health.  A highly skilled neurosurgeon from USC will remove a piece of bone from behind the ear on the affected side.  The neurosurgeon can identify the blood vessel that is pressing against the nerve, and move it by tacking it up away from the nerve with Teflon felt and fibrin glue.  The bone is then replaced, a plate is usually placed over the skull opening, and the skin is closed.

This procedure treats the problems instead of the symptoms.  There is an 85 – 90% initial success rate and 70% success 10 years after this treatment.  Complications are minimal but should be discussed with a neurosurgeon.

Trigeminal Nerve Stimulator
A new and promising technique for treating atypical trigeminal nerve pain is the implanted, peripheral nerve stimulator.

Implantation of a peripheral nerve stimulator is done in two stages.  Stage one is a trial.  A special tunneling needle is inserted into a tiny, behind the ear incision and directed, just under the skin, to the are of pain.  A wire-like electrode is inserted through the needle.  The needle is pulled out, leaving the electrode under the skin of the painful area.  A stitch secures the electrode in place.  Sometimes a second wire is inserted.  Within a couple of hours, the patient goes home with one or two wires discreetly exiting the skin behind the ear.

Over the next week, the patient tests the electrodes.  If a significant amount of relief is achieved, the test electrodes are removed by the pain management physician in their office.  A few weeks later, the surgery is repeated.  For this second stage, the wires don’t exit the skin, but are connected to a battery implanted under the skin of the abdomen.  Once the incisions are closed, no wires are outside the skin.  Healing and electrical adjustments of the stimulator occur over the next two to three months.  The patient is given a remote control that allows them to adjust the stimulator and to turn it on and off.  This technique does not eliminate the pain, but often the degree of relief can be very significant in up to 85% of the patients.

GammaKnife Radiosurgery (Radiation)

This procedure targets radiation to the trigeminal nerve, thereby injuring it enough to keep it from firing the painful electric shocks.  This is a good option for a patient who has multiple medical problems and cannot safely undergo surgery, or someone who has undergone brain surgery and no blood vessel was found pressing on the nerve.  With this treatment patients get a 70% success rate in reduction of pain, although there is a lag time of 5 weeks to 3 months before pain subsides.

Fight On!
Contact Us

Learn more about our neurosurgery physicians at Faculty.

Keck Hospital of USC
USC Department Neurosurgry Surgery
(323) 442-6290
nsmessage@med.usc.edu