Surgical procedures
The
goal of a number of surgical procedures is to either damage or destroy
the part of the trigeminal nerve that's the source of the pain. Because
the success of these procedures depends on damaging the nerve, one side
effect is facial numbness of varying degrees. These procedures involve:
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Alcohol injection.
Alcohol injections under the skin of your face at the areas of pain
may offer temporary pain relief by numbing the areas for days or
months. Because the pain relief isn't permanent, you may need
repeated injections.
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Glycerol injection.
This procedure is called percutaneous glycerol rhizotomy (PGR),
Percutaneous means through the skin. Your doctor inserts a
needle into the trigeminal cistern (a small sac of spinal fluid that
contains the trigeminal nerve ganglion and part of its root). Images
are made to confirm that the needle is in the proper location. Once
the location is confirmed, your doctor injects a small amount of
sterile glycerol. After 3 or 4 hours, the glycerol damages the
trigeminal nerve and blocks pain signals.
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Initially, PGR relieves pain in most people. However, many people
have a recurrence of pain, and many experience mild facial numbness
or tingling.
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Balloon compression.
In a procedure called percutaneous balloon compression of the
trigeminal nerve (PBCTN), your doctor inserts a hollow needle
through your face and into an opening in your skull. Then a thin,
flexible tube (catheter) with a balloon on the end is threaded
through the needle. The balloon is inflated with enough pressure to
damage the nerve and block pain signals.
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PBCTN successfully controls pain in most people. Only a small number
of people experience a recurrence of pain. Most people undergoing
PBCTN experience facial numbness of varying degrees, and more than
half experience nerve damage, resulting in a temporary weakness in
the muscles used to chew.
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Electric current.
A procedure called percutaneous stereotactic radiofrequency thermal
rhizotomy (PSR) selectively destroys nerve fibers associated with
pain. Your doctor threads a needle through your face and into an
opening in your skull. Once in place, an electrode is threaded
through the needle until it rests against the nerve root.
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The
electrode is positioned so that you experience numbness or pain. An
electric current is passed through the tip of the electrode until it
is heated to the desired temperature for about 70 seconds. This
damages the nerve fibers and creates an area of injury (lesion). If
your pain isn't eliminated, your doctor may create additional
lesions.
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PSR
successfully controls pain in most people. A common side effect of
this type of treatment is mild to severe facial numbness.
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Radiation.
Gamma knife radiosurgery (GKR) involves delivering single high doses
of radiation to the root of the trigeminal nerve. The radiation
damages the trigeminal nerve and eliminates the pain. GKR is
successful in eliminating pain more than half of the time. The
procedure is painless and typically is done without anesthesia.
Because it's relatively new, the long-term risks of this type of
radiation are not yet known.
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Severing the nerve.
Your doctor may work through a small incision to cut the branch of
the trigeminal nerve that's causing the pain as that nerve branch
leaves your skull and before it reaches your facial area.
Microvascular decompression (MVD)
A
procedure called microvascular decompression (MVD) doesn't damage or
destroy part of the trigeminal nerve. Instead, MVD involves relocating
or removing blood vessels that have contact with the trigeminal root and
separating the root and vessels with a small pad.
During MVD, your doctor makes a small incision behind one ear. Then,
through a quarter-sized hole in your skull, part of your brain is lifted
to expose the trigeminal nerve. If your doctor finds an artery in
contact with the nerve root, he or she directs it away from the nerve
and places a pad between the nerve and the artery. Doctors usually
remove an artery that is found to be compressing the trigeminal nerve.
MVD
can successfully eliminate or reduce pain almost all of the time, but as
with every other surgical procedure for trigeminal neuralgia, pain can
recur in some people.
While
MVD has a high success rate, it also carries risks. There are small
chances of decreased hearing, facial weakness, facial numbness, double
vision and even a stroke or death.
