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Figure 1. The trigeminal
nerve is both a sensory and motor nerve supplying feeling and movement
to the face. It has three divisions that branch from the trigeminal ganglion:
ophthalmic division (V1) provides sensation to the forehead and eye, maxillary
division (V2) provides sensation to the cheek, and mandibular division
(V3) provides sensation to the jaw. Figure 2. A nurse administers anesthesia to a patient during PSR. The surgeon will adjust the current that destroys the pain-causing nerve fibers on a radiofrequency generator (A). The monitor (B) shows a view of the brain from the fluoroscope (C). The patient's arms are secured onto the narrow table and a grounding wire (D) is attached.
Figure 3. The surgeon inserts their finger into your mouth and guides the electrode introducer through the cheek and into the foramen ovale.
Figure 4. (Side view, same as figure 1) The introducer is inserted beyond the ganglion to the nerve root fibers. By advancing the introducer and rotating the curved tip, the surgeon locates the specific division of the trigeminal nerve causing pain.
Figure 5. Short controlled bursts of heat are applied to selectively destroy portions of the nerve. |
Percutaneous stereotactic radiofrequency rhizotomy (PSR) is a minimally invasive procedure performed to relieve pain caused by:
Medications often provide pain relief to patients with these conditions, but when medications become ineffective in pain control or cause serious side effects, one treatment option is PSR. What is PSR? Percutaneous stereotactic rhizotomy (PSR) is usually performed by a neurosurgeon as an outpatient procedure in a radiology department or an operating room. The procedure typically takes about 1 to 2 hours. PSR can relieve neuralgia (nerve pain) by destroying the part of the nerve that causes pain and by suppressing the pain signal to your brain. The surgeon passes an electrode introducer (hollow needle) through the skin of your cheek into the selected nerve at the base of the skull. A heating current, which is passed through the electrode, destroys some of the nerve fibers. The entire nerve is not destroyed. Who is a candidate for PSR? PSR can provide pain relief for many patients with trigeminal neuralgia, glossopharyngeal neuralgia, or other neurological diseases (e.g., cluster headache) when medications become ineffective. PSR can be effective in treating patients of all ages including those with multiple sclerosis and those with some types of tumors. Patients often choose to undergo PSR because it poses lower surgical risks than those of a major operation such as microvascular decompression (MVD). Although facial numbness results, PSR is one of the most effective procedures because it provides lasting pain relief with few risks of serious side effects. What happens before PSR? A history and physical is performed to assess your overall health condition.
Several routine tests (e.g., blood tests, electrocardiogram, chest
X-ray) may also be performed. In the doctors office you will sign consent
forms and complete paperwork to informthe surgeon about your medical history
(i.e., allergies, medicines, anesthesia reactions, previous surgeries).
Discontinue all non-steroidal anti-inflammatory medicines (Naproxin, Advil,
etc.) and blood thinners (coumadin, aspirin, etc.) 1 week before the procedure. Patients are admitted to the outpatient clinic several hours before the procedure.
No food or drink is permitted past midnight the night before undergoing
PSR. The surgeon will give you specific instructions about taking your
medications the day of the procedure. What happens during PSR? There are 5 steps of the procedure, which generally takes 1 to 2 hours. Step 1.Prepare
the patient Step 2. Insert the electrode For glossopharyngeal neuralgia, the surgeon inserts the introducer intothe skull
base at the jugular foramen where the glossopharyngeal nerve exits the
skull. Step 3. Find the source of your pain Step 4. Destroy the pain-causing fibers Step 5. Test for pain or numbness What happens after PSR? After the procedure, you will recuperate in a hospital room for 4 to 6 hours. An ice pack, placed on your jaw, reduces swelling caused by the operation. Patients go home the same day. While adjusting to the numbness, you should be careful when shaving, eating or drinking hot foods/liquids, and chewing. A soft diet is often recommended for the first few weeks. Dentures, if used, can be worn at any time. Patients taking anticonvulsant or pain medication for trigeminal neuralgia prior to PSR will be weaned offthe medications according to a schedule to decrease risk of withdrawal and side effects. Discharge instructions:
What are the results? For trigeminal neuralgia, 98% of patients have immediate pain relief after PSR. About 20% of those who undergo PSR experience some recurrence of pain within 15 years; about half of these patients will require medication or undergo another procedure to control pain. For glossopharyngeal neuralgia, 90% of patients have immediate pain relief after PSR. In patients with vagoglossopharyngeal neuralgia from cervicofacial tumors, 70% of patients can expect pain relief or improvement after PSR. Open rhizotomy is the treatment of choice for patients who experience vagoglossopharyngeal syncope. For cluster headache, almost all patients have somepain relief after PSR. Only 62% of those experience long-term pain relief and will require medication or another procedure to control pain. PSR works best in treating pain behind the eye, but is not as effectivein treating pain that radiates to the temple and ear region. Regardless of the surgery that is performed, good pain control rather than complete pain relief is expected. Recurrence What are the risks? For trigeminal neuralgia, numbness, the most commonside effect of PSR, is necessary for pain relief. Numbness usually occurs in the cheeks, gums, teeth, or tongue. Dysesthesia (troublesome numbness) is reported in 7% of patients after PSR. The loss of corneal reflexis reported in 6% of PSR procedures, primarily in patients with V-1 nerve pain. Complications (e.g., bleeding or infection) are rare. Other possible side effects include blurred or double vision, as well as weakness in the jaw (e.g., making chewing difficult); these symptoms usually resolve within 6 months. Some patients may develop fever blisters that will heal in 1–2 weeks. For glossopharyngeal neuralgia, common side effectsare hoarseness, vocal cord paralysis, and dysphagia (difficulty in swallowing). Controlled PSR for ninth and tenth cranial nerve neuralgia is more difficult than for trigeminal neuralgia. PSR should be restricted to patients with cancer pain who already have swallowing problems and vocal cord paralysis. For cluster headache, because the nerve pain originates in V1, major sensory loss is associated with increased risks of keratitis and dysesthesia that can be up to 12%. For this reason, balloon compression may be worthy of consideration for the treatment of cluster headache.
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