| 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 patients. 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 pain relief. 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 (extremely rare) 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 |
