| Intractable headache pain can be treated with sphenopalatine ganglion (SPG) blocks and
radiofrequency rhizotomy. Initially a diagnostic block is performed utilizing sedation, and
placement of a needle into the SPG from the side of the face. The SPG is like a central
switching station for multiple nerves from the spine and brain which sometimes
malfunctions or at times the nerves leading into the SPG begin to transmit pain. Blocking
the pain signals at the SPG can be a useful way to interrupt headache pain, especially
from headaches in the front of the head. Cluster headaches are a special type of
headache which may respond to SPG blocks and radiofrequency (RF).
HOW IS THE SPG BLOCK PERFORMED?
Under the cheek bone on the side of the face is a small opening in the bone of the skull
that serves as an entryway to the SPG. With the mouth open, the access to this opening
called the pterygomaxillary fissue, is easier. For that reason, the patient will be asked to
open their mouth and a small gauze pad will be placed between the teeth to hold the
mouth open during the procedure. Once sedated, a needle is brought into the fissure and
advanced into the sphenopalatine fossa where the SPG lives. (see the pic on the left) The
SPG is injected with a local anesthetic, and the patient is awakened and goes home with a
6 hour pain assessment tool to follow any reduction in pain from the anesthetic block.
Any pain relief from this block is expected to be very temporary. If the patient does
derive significant relief from the block, then the next step would be RF rhizotomy. This is
done on a different day from the block. The RF rhizotomy involves the same approach to
the SPG, but after the needle is placed, the patient is awakened briefly for electrical
stimulation of the ganglion to assure proper placement. RF energy is then applied to the
ganglion in order to interrupt the pain signal for up to one year. The RF rhizotomy may be
repeated up to every 3-6 months if there is significant relief from the procedure.
WHAT ARE THE POTENTIAL COMPLICATIONS?
Bleeding, infection, nerve injury, worsening pain are all rare but may occur from this
relatively safe procedure.
WHAT ARE THE RESULTS?
If the SPG block demonstrates relief of pain, it is likely the SPG RF will do so also. There
are many case reports published and a few papers demonstrating relief in >60% of
Severe intractable facial pain can be effectively treated by trigeminal radiofrequency
rhizotomy (TGRF) after a successful trigeminal ganglion block (TGB). The trigeminal
ganglion is located deep inside the head and is the cell body for the nerves going to the
entire face for sensation purposes. The upper part of the nerve V1, gives sensation from
the top of the eyes to the forehead while the middle part of the nerve V2, gives sensation
to the area between the eyes and the mouth. Below the mouth and into the front of the
neck is the lower part of the nerve, V3. While it is possible to selectively block V2 and V3
by placing a needle in the side of the face, it is not possible to selectively block the nerves
at the level of the ganglion deep inside the head. For pain below the eyes, often selective
V2 and V3 blocks will be performed first, followed by a trigeminal gangion block. If the
block is temporarily successful (not expected to have long term reilef-this is a temporary
diagnostic block), then a radiofrequency rhizotomy may be performed to give much longer
HOW ARE THE BLOCK AND RF PERFORMED?
The patient is sedated lying on their back, and a thin needle is passed from the corner of
the mouth to the trigeminal gangion using x-ray (fluoroscopic) guidance. For the block,
the patient remains asleep. For the TGRF procedure, the patient is briefly awakened after
the needle is placed in order to electrically stimulate the trigeminal ganglion for needle
positioning purposes. Then the patient is resedated for the radiofrequency energy
application through the needle.
WHAT ARE THE POTENTIAL COMPLICATIONS?
Bleeding, infection, nerve injury, worsening facial pain, anesthesia of the face with
residual pain (anesthesia dolorosa-very uncommon), CSF leak, meningitis, brain injury
WHAT ARE THE SUCCESS RATES?
Typically for a person who responds to the TGB, the success rate of the TFRF is about
80-95%. The relief usually lasts from 6-18 months.
|Click on pics
below to enlarge
|Sphenopalatine and Trigeminal Blocks
and Radiofrequency Rhizotomy