TRIGEMINAL NEURALGIA ASSOCIATION CONFERENCE November 12 - 15, 1998: Orlando, Florida Summary of information by Jane Uitti Disclaimer: The following represents my understanding of the slides, presentations, and interchanges as I heard them. There may, be errors or incorrect information; I was writing as fast as I could in most of these sessions. Any errors or incorrect information is my own. There are differences of opinion among practitioners, however. Organization of this summary: This summary is organized as much as possible by topic area, rather than by presentation. Often, information about one topic (such as gamma knife) came up in numerous sessions. For reader clarity, they have been included in one section. Names of speakers are added, so that the reader may know to whom these statements were attributed. Dental aspects of facial pain Brian D. Fuselier, DDS, Clinical Assistant Professor in the Facial Pain Center at the University of Florida College of Dentistry: Jaw movement can be an occult (hidden) trigger of TN, because the trigeminal ganglion plays a role in jaw movement. Drugs that work for TN may also work for other facial pains that are not TN. A crack in a tooth can cause pain, and is often very hard to detect. Myofascial pain is seen as pain on jaw movement, pain on palpitation, taut muscle bands, and a twitch response. Jaw movement may aggravate jaw muscle spasms, which can in turn lead to more pain. Large-diameter nerve fibers in tooth pulp (A-beta) can cause a trigger of pain. TN is related to pain in cranial nerves V, VII, IX, and X. Diagnosis is made by analyzing the intensity, duration, frequency, location, and quality of pain. ("Quality" of pain means what it feels like; stabbing, throbbing, burning, aching, etc.) A trigger may come from the trigeminal ganglion. "Tugging" on the muscles can result in pain. The trigeminal ganglion may become mechanically sensitized; sodium, outside of the nerve, gets inside the nerve, where the potassium is. These are called "sodium channels" and the channels are increased through light touch or compression. Sodium channel accumulation, from hundreds of channels in the nerve to thousands, results in hypersensitivity of the nerve membrane. Also, there is sympathetic neuron sprouting, and neuron "crosstalk," whereby a stimulus in one area may cause pain in another area. The reasons that Tegretol and Lidocaine work is that they are sodium channel blockers. Because health providers only see what they know, and treat what they see, we need well-informed health providers. Henry A. Gremillion, DSS, Director of the Parker Mahan Facial Pain Center at the University of Florida College of Dentistry: Secondary TN is characterized by triggerable sharp episodes, moderate pain, and increased pain for 6 months or so that then stabilizes. There can be burning, throbbing background pain with sharp exacerbations of nerve pain. From 5 to 10% of patients may experience secondary TN after facial surgery; from 1 - 5% may experience secondary TN after extraction of teeth. -2- Elavil, an anti-depressant, can help with burning pain, as can Neurontin. However, too often dentists say: "If it's not dental, it's mental." Pre-TN is characterized by dull aching, which comes spontaneously with no specific trigger. It is sporadic with sharp lancinating pain which goes down with somatic (numbing) blocks. Pre-TN can precede TN. Somatic (numbing) anesthetic blocks can even put pre-TN into remission for up to several years. NICO (neuralgia-inducing cavitational osteonecrosis) is a bone infection in either arch, or a failure in the bony area. Pain persists even after the area is anesthetized. The most important aspect of care is diagnosis. Dental techniques of relief [Panel: Parker E. Mahan, DDS< PhD; Henry Gremillion, DDS; Michael Langan, DDS; Brian D. Fuselier, DDS] "Dysasthesia" means numbness and burning. Anesthesia dolorosa is more painful than dysasthesia. Dental work absolutely can cause TN, through nerve trauma; some people seem predisposed to nerve trauma through dental work, while others have the same type of work done and don't get TN. L Possibly TN would have developed anyway, in this population presumed to be predisposed. Dentists can do pre-emptive anesthesia, to prevent nerves from firing, before TN starts. They can also extend anesthesia post-op, to better transition the patient to when the anesthesia wears off; there are anesthetics that last 30 minutes, and others that last from 5 - 6 hours. Patients can have anesthesia to clean sensitive teeth, also. "Be proactive with oral hygiene" - though conference attendees responded that often they can't, because brushing, flossing, rinsing etc. sets off the TN. Implants in the jaw are not recommended, with TN. Dental school pain programs should invite experts to talk about dentistry and pain. A neuropathic condition, such as TN, can create a TMJ (temporal mandibular joint) problem when the body responds to the TN-caused pain. The dentists recommend sticking to reversible approaches (i.e. be very cautious before pulling teeth, which is irreversible.) Medical Therapy, and when to refer for surgery Joanna M. Zakrzewska, MD, Head of the Department of Oral Medicine, London, UK; referred to as "Dr. Zak" at this conference: Studies for effective drugs must be random, controlled. People respond differently to different medications, which include Tegretol, Phenytan, baclofen, clonazepam, sodium valproate, oxcarbazepine, lamotrigtene, tizandine, pimozide, tocainide, chlormethiazole, capsaicin, gabapentin. The patient needs to ask if random controlled studies have been conducted; only 12 drugs for TN have had these tests. Neurontin has not had a randomized controlled study conducted. One out of 3 people will respond -3- positively to Tegretol. Phenytoin is not trial tested, and may be a good drug in addition to others being used. Baclofen is effective in mild, early stages of TN; not as many side effects as other meds. Clonazepam has not been subject to a randomized trial, and may cause lots of drowsiness. Trileptal (oxcarbazepine) has not been randomized in a study, but in tests on 20 patients there seem to be lower cognitive side effects. However, trileptal is not licensed for use in the USA. Stephen Nadeau, MD, researcher: He starts with Tegretol or Dilantin for previously-unsuccessful patients. He says that Dilantin can be immediately raised to therapeutic levels. He has only referred two people to surgery. John Susac, MD, says his approach and experience is the same, but feels that a lot of his patients have later breakthrough pain, even at therapeutic levels of meds, and later require surgery. Kim Burchiel, MD, FACS, Chair of the Department of Neurological Surgery at Oregon Health Sciences University: Patients should be referred to surgery "like voting; early and often." (He said this with a smile.) TN is progressive over one's lifetime, with less response to meds with more frequent attacks. "Given enough time, a majority of patients will require surgery." The causes and mechanism of TN are somewhat controversial, and still unknown. TN is an exception to the general rule that chronic pain is not amenable to surgery. Stephen Haines, MD, Chair of the Department of Neurological Surgery at The Medical University of South Carolina: Patients need careful evaluation of surgeries as well as of pharmacological interventions. We can do randomized trials of surgical procedures. We still have an absence of high-quality surveys. Initial treatment should be pharmaceutical, but surgery should be explained to the patient early on, as an option. Newer drugs are more rigorously tested than older drugs: "aspirin, if it were introduced today, would not receive approval from the FDA because it can cause stomach ulcers and bleeding." Selection of operation Ron Brisman, MD, member of the Neurological Institute of New York and Associate Professor of Clinical Neurosurgery at Columbia University (and member of the TNA Medical Advisory Board): Patients in pain don't have to wait for terrible side effects from meds, or agonizing pain, especially with the advent of non-invasive gamma knife, "if pains or meds are a bother." All surgeries are important, but none is perfect, including gamma knife, radiofrequency, glycerol, balloon decompression (good for 1st and 2nd division pain), and MVD. He favors a different procedure for a second operation, rather than repeating a surgical intervention that has failed before. TN patients with MS should have less invasive procedures. He recommends cutting facial nerves 9 or 10 for glossopharyngeal. [Note: I found this surprising. This should be checked for accuracy.] Albert Rhoton, Jr., MD, Professor and Chair of the Department of Neurological Surgery at the University of Florida: Gamma knife radiation for TN is often 4 to 5 times stronger than the GK amount -4- used for cancer. Results and complications of operations Kenneth F. Casey, MD, practices neurological surgery with a specialty of functional neurosurgery and pain, in the Philadelphia area: Complications are what either the patient or the physician didn't want as an outcome. The patient has to determine when, and how much risk, he/she wants to endure, and for that informed choice, they need adequate information. John M. Tew, Jr., MD (Medical Director of the Neuroscience Institute, University of Cincinnati Dept. of Neurosurgery): Outcomes after surgery include: For MVD, after 7 years, 77% of patients are pain-free. For "numbing" procedures like balloon decompression, 75% are pain-free after 7 years. Painful numbness is highest with radiofrequency and balloon decompression; then glycerol has the next highest incidence of painful numbness, then MVD, and then radiosurgery. The highest morbidity is with MVD, with a 1% mortality and 16% minor complications; 3% have nerve palsy after MVD. A loss of feeling in the eye is experienced by 6% of those who have had radiofrequency; 5% of those who have had glycerol; and 1/2 of 1% of those who have had balloon decompressions. {Dr. Tew had very little information on outcomes after gamma knife; when asked about this lack of info in his presentation, he said that after 2 years post-GK, 50% experience a success rate. He doesn't include those still taking meds when he defines "success" which to him is being pain-free without meds.] For technical success (doing the procedure correctly), all have a high degree of success; the lowest degree of technical success is MVD, with 85% technical success. MVD has 10% post-op morbidity, and 1/2 of 1% post-op mortality. MVD also has the highest incidence of permanent cranial nerve problems, with 3% experiencing facial palsy, hearing loss, vision problems. 17% of MS patients have trigeminal neuralgia. The successful outcome of treatment declines with chronicity; repeat surgeries have higher risks and lower success rates. "Pain is a more terrible lord over mankind than even death itself." - Albert Schweitzer R.A. de los Reyes, MD, Vice-Chair of the Department of Neurosurgery at the Institute for Neurology and Neurosurgery at Beth Israel Medical Center in New York City: Patient needs to get medical assessment of the individual risks of complications, with any procedure. This requires competent neurosurgeons and neuroanesthesiologists, and monitoring to prevent hearing loss during surgeries. Realistic expectations should be discussed with the surgeon for any particular surgery being considered. William Friedman, MD, Assoc. Chair of the Neurosurgery Dept. at the University of Florida in Gainesville: Gamma knife focus cobalt beams on the same point. Particle beams are not often used. The Linac (linear accelerator) produces high-energy x-rays only uses 5 to 9 shots, contrasted with the 201 -5- with gamma knife. It is much cheaper than GK, and is available in Canada. The Linac is used on movement disorders, obsessive disorders, and tumors. Dr. Konziolka (Univ. Of Pitts. Med. Center) did a study in 1996 (Journal of Neurosurgery) of GK radiosurgery, and found that after 2 years, the pain free rate among patients was 54%, using 60 - 90 gy's of cobalt. Friedman does 250 radiosurgeries per year, referring patients to both GK and Linac, but considers them "a third or fourth tier option for TN" because the outcomes are not perceived by him as being great. Psychiatric and Psychological Aspects of facial pain Karen A. Stennie, MD (psychiatrist): Depression and anxiety are often unrecognized or under-treated. It can mask real psychiatric disorders. A patient may interpret a psychiatric referral as dismissive, as if the physician is implying that the pain is "all in one's head." However, depression is, in fact, the most common response to chronic pain, with an 80% incidence rate. This is especially true for chronic facial pain. 60% of psychiatric inpatient patients report chronic pain. Seeing a psychiatrist is NOT to find out whether the pain is "real" or not, but to address the very real blend of neurotransmitter disorders. Anti-depressants often help with chronic pain. Depression also decreases pain tolerance, creating a cycle of pain causing depression, which in turn results in less tolerance to more pain. Medical chronic disorders result in 50% of the completed suicides. Cynthia D. Belar, Ph.D. (psychologist): Pain is both sensory and emotional. Pain has the following components: * sensory * affective (anxiety, depression, feelings of loss of control all affecting the way pain is experienced) * cognitive (expectations such as with a placebo effect; source and meaning of pain; health beliefs) * behavioral (negative reinforcement or positive reinforcement, rewards for "well" behavior) Pain is a warning, a mobilizing signal. When it's chronic pain, it loses its warning function, acting like a constant false alarm. Then, chronic pain itself becomes the chronic stressor. Patients need acceptance and ownership of their pain. Goals relating to work, recreation, and relationships need to be realistically set. Patients need to be able to handle anger, depression, anxiety, helplessness. Anger at pain can be used constructively (such as the "strike back" design on the TNA t-shirts). She suggests avoiding caffeine, which increases muscle tension and thus the pain response. Depression causes pain, and pain causes depression, in a cycle. Tools for dealing with pain include guided imagery, relaxation, biofeedback training. Pain is a family and community problem; families can increase feelings of helplessness and "victimization," for example. Meds: tricyclic anti-depressants are often used, including Efexir, serotinoric receptor drugs. -6- Gamma Knife William Friedman, MD: Out of 1300 patients, 8 have been treated with TN using the Linac machine. There is a 54% pain free rate, after 2 years. The biggest problem with radiosurgery (GK or Linac) is that it takes from 1 - 3 months for pain to fade away. It is much more expensive than radiofrequency or glycerol. He doesn't support GK because he thinks it only has a "modest" result of success. Ronald Brisman, MD: Linac is wrong for TN; GK is much better. There is a big difference between Linac and GK; GK can handle tiny structures like the TN nerves, which Linac can't. There are only 35 gamma knife machines in the country. Only 3 have large data bases of patients; New York, Long Island, and Pittsburgh. He has done 48 patients over the past 5 months, and 4 were redo's. 3 had multiple sclerosis. After the 5 months, 80 - 90% of TN patients (without MS) "do well" after GK, with lots of improvement, and reduced levels of meds. He says that GK does not work for atypical facial pain. There is an older model GK machine "U," and a newer "B" unit, ranging from 60 - 90 gy. Of cobalt. He uses B, with 75 gy, covering 4mm. In his study, 40 had typical TN, 8 had MS. 16 had no prior surgeries, 6 had MVD's, 26 had RF. 92% "all better or much improved, with no dysasthesias." (Jannetta disagrees; he says he has seen 20 patients with increased numbness, dysasthesias, following GK, and he's concerned abut it. Brisman thinks dysasthesia doesn't occur using 75gy, but is more likely when the person has a 2nd GK procedure.) Al Rhoton says that the GK dose for TN is much higher than when GK is used for cancerous tumors; 4 to 5 times as much, and more numbness post-GK. "It does cause numbness," he says. Balloon decompression Jeffrey Brown, MD, Professor and Chair of the Dept. of Neurological Surgery at the Medical College of Ohio in Toledo: He showed a video of a balloon decompression, and said it works best for first-division pain, where MVD doesn't tend to work as well. At 8 years after the procedure, 66% of balloon patients remain pain-free. There is a 25% recurrence rate, and the procedure can be redone, after other procedures or as a second balloon. A hollow needle is inserted into the face up to the nerve, and a tiny balloon is activated at the end, which crushes the nerve. There are more complications with a balloon decompression, than with RF. He said that TN has a continuum of pains, although not everyone experiences all of the phases in the continuum: Over time: intermittent shocks-----------more frequent shocks-------------more burning pain with burning pain than shocks Microvascular decompression Peter J. Jannetta, Dept. of Neurosurgery, University of Pittsburgh Medical Center: The problem is finding all of the blood vessels that are compressing a nerve or nerves. Very small blood vessels cause trouble. There are compressions in people who don't have TN, but they are only touching, and not as compressed or as obvious as when they do have TN, when the vessel is pushing on the nerve. The panel showed a fascinating video, very close-up, of the TN nerve being decompressed and of veins -7- being cauterized and sectioned. A repeat MVD has a 50 - 70% success rate. Dr. Casey says that when 51 redo's of MVD's were looked at, it was uncertain if there was an identifiable vessel. He said that redo-s of decompressions had a 50-60% success rate. There is a relationship between head injury (as a car accident, for example) and TN - it is often instant. Al Rhoton: Has heard of teflon granulomas, caused by a few little hairs of the teflon coming out and causing more pain; he uses a substance called Ivalon instead of Teflon. However, Ivalon is hard, and close off the superior vestibular nerve. [artery??] Teflon sticks, and can be molded into the area; the arachnoid tissue regrows over the teflon and holds it in place. The size of the opening for an MVD is a hole between the size of a nickel and a quarter. Surgery is done between the brain and the bone, where the nerve comes out of the brain. MVD is not technically brain surgery; it's actually on the surface of the brain rather than inside the brain. When the surgeons reach the right nerve, there's a slowing of the pulse. If a patient is on a high dose of Tegretol, they're weaned off in 10 days after MVD; if a low dose, right away. Percutaneous procedures There are several types of percutaneous (under the skin) procedures used to treat TN. All of them strip the myelin sheath off the nerve, leaving uninsulated nerves; the nerves are blocked and don't function. Eventually, the myelin regrows, which is why these are not permanent procedures There is a 50% recurrence rate of pain, within 1 1/2 to 3 years. In 15% of the cases, the corneal reflex is affected; in 7% of the cases, the corneal reflex is entirely absent, and the eye is numb. Anesthesia dolorosa results from too much numbing effect; corneal numbness also can result from too much numbing. The length of pain-free time after one of these procedures depends upon how much numbness there is; but numbness can cause problems, too. * Radiofrequency rhizolysis (RF) damages the nerve root. This does not work with atypical facial pain. It is not as good with MS, which shows a 50% recurrence rate of pain within 1 year. Generally, RF in non-MS patients lasts up to 3 years average relief. * Glycerol rhizolysis damages the nerve with glycerol. It last on average around 18 months. "TN is a permanent condition; glycerol is only temporary." * Balloon decompression lasts 18 months. Atypical TN J. Keith Campbell, MD, FRCP, Emeritus Professor of Neurology at Mayo Medical School and Clinic in -8- Rochester, Minnesota: "Typical" TN is severe, sharp, stabbing, intermittent, not continuous; each stab lasts a short type. Atypical is everything else. There can be "square" waves of pain, starting abruptly, lasting over time, and dropping off suddenly. Over time, following patients, maybe atypical or undiagnosed facial pain can get a diagnosis. Campbell does not believe, as Jannetta does, that ATF/ATN is a part of a continuum of TN. Parker Mahan, DDS, PhD, Distinguished Service Professor Emeritus at the University of Florida Facial Pain Center: Any pathology in nerves is a neuralgia. If it originates from outside the nerve, it's atypical (originating above the hyoid bone). Atypical TN is pre-TN. One can anesthetize with long-lasting results, from 6 months to a year. The difference between atypical TN and atypical facial pain is determined through a diagnosis of teeth, the temporal mandibular joint, muscles, mucosa, etc. Many are pains of unknown origin, but a series of clinical trials can help identify where pain is coming from. Atypical facial pain is sometimes treatable with immupramine (sp?), an anti-depressant. Myofascial pain dysfunction comes from large muscles, such as through teeth-clenching (bruxism). Pain refers up from the trigger point. Anesthesia injected into the "taut" muscle can help diagnose where the pain is coming from, if it releases the muscle and hence the pain. Myofascial pain dysfunction takes from 2 - 3 weeks for that muscle to heal; very accurate mouth splints can help. Peter Jannetta: TN is a continuum of one syndrome, and time and therapy change with the pain. 30% of TN sufferers have TN in the face. Atypical TN, or nervus intermedius neuralgia, and atypical facial pain most often happen in younger females, with no memorable onset, no sharp intermittent lancinating pain, and usually affect V2 and/or V3, with a lower likelihood of sensory loss. Jannetta has found that 1/2 of atypical TN patients have compressions. Many respond to tegretol. TMJ blends with atypical TN. TN, either constant or lancinating/jabbing, can become or be caused by trigeminal neurapathy; atypical TN; or cluster headaches - any of these can eventually become any of the others. The nervus intermedius is not one of the numbered nerves, but is with the 7th nerve that moves the face, and the 8th nerve. It controls saliva, tearing, autonomic and sympathetic functions. Parker Mahan says that the nervus intermedius can be cut without problems to the salivary or eye/tear glands. Cutting the nervus intermedius, according to Dr. Casey, has had a 90% success rate. John Susac, MD (neurologist in Florida): Antidepressants sometimes help with atypical TN. Dull aches with spikes of pain can sometimes be helped by Tegretol. Keith Campbell, MD: Antidepressants address pain, and not "just" psychological problems. The serotonen mechanism, when disordered, results in pain; antidepressants restore serotonen. Sometimes the dose of antidepressant meds has to be raised, because the liver has broken down the original dose, reducing the amount in the blood. Or, the patient can switch to another, similar drug. Excedrin and anything with caffeine can cause rebound headaches, for migraine sufferers. -9- General question and answer session with panel of physicians: General comments Paroxysmal (jabbing, on/off) pain generally responds to therapeutic interventions; constant pain generally does not. If one holds still, and the pain goes away, it's more likely to be more "typical" TN. A pain measurement, called the McGill Pain Questionnaire, very accurately describes the type and intensity, and duration, of pains. Dr. Zak recommends that doctors use it, to standardize our language for describing and quantifying pain. Herpes simplex (not herpes zoster, which is shingles) is what people get in the area of the numbness, after a TN surgery. The virus lives in the ganglion. Burning pain is being treated in a study of motor cortex stimulation by electrodes, including a "pacemaker" device installed in a craniotomy operation. Jeffrey Brown says there is a "50% improvement in pain." Three to 4% of people with TN also have multiple sclerosis. TN is present in from 1 to 2% of people with MS. Hereditary nature of TN: Jannetta has seen very little indication (less than 5%) of intergenerational TN. However, there isn't much grant activity on the physiology of TN, and more research is needed (with funding). Henry Gremillion, DDS: We need to look at predisposition to de-mylenization of the nerve, to find out if there are nutritional implications. Kim Burchiel, MD: Progression of TN is fairly typical: identifiable start, even if subtle and not identified specifically. Pain-free intervals become shorter and disappear over time, and TN becomes more medically intractable over time, from episodic and lancinating to more "background" pain. It is a neuropathic pain progression. MVD is better at stopping lancinating pain, but sometimes MVD will also stop the "background" pain too. Pain memory, and pathological "learning" (nerve learning) may explain how numbness results in, or continues, to feel like pain. Costs of surgeries: around $25,000 for MVD, $20,000 for gamma knife, and $7-8000 for percutaneous procedures. These costs vary by region and hospital, however. Alternative procedures for TN Roger Hinson, DC: Chiropractic procedures on the upper cervical spine (joints in C-1 and C-2 area involved in movement) have helped some with TN. There is a correlation between TN and "short leg" on one side. He has found large rotational displacements in his 2 TN patients. There are fibrous connections between bone and the dura (covering of the skull) on C-2 and C-3. Specific chiropractors do this work on the upper cervical spine, for TN - Luella Harris, a patient, will send a free video on -10- this type of chiropractic and will refer TN patients to chiropractors in their areas that do this work {1-888-622-8221). Nutrition: No meat, no dairy, no sugar. Vitamin B12 in injections (2 to 3/week for 6 weeks) and vitamin B6 (pyridoxine), 100 - 200 mg/day for 3 weeks and then 25 to 200 mg/daily, recommended. Free radical damage to cartilage can affect TN. Anti-oxidants like vitamin C (1500 mg/day, spread out over the day), vitamin E (tocopherol) 400 to 1200 units/day, beta carotene 25,000 units/day, calcium 1000 to 1200 mg/day (calcium scorbate), and magnesium 500 to 600 mg/day can help. Magnesium has a calming effect on muscle, and on hyper-irritable neural tissue. Raising the high-density levels of cholesterols, and lowering triglycerides, can help TN. TN's future Parker Mahan: Keep up hope. Pain research in molecular biology is advancing very rapidly, and we're learning a lot about the mind/body interface. There is a lot involved in the patho-physiology of pain. We need more collaboration between medicine and dentistry. Keith Campbell: We need more research on pain transmitters and receptors through neurotransmitters, including Substance P (a pain transmitter). There is chemical as well as electrical impulse conduction of pain. Peter Jannetta - We need to educate and teach TN neurosurgical techniques. Currently, dentists and neurologists all speak with a nonstandardized vocabulary; we need a meaningful language to describe cranio-facial pain. We need work on the genetic aspects. Today's science fiction becomes tomorrow's science, or else tomorrow's fiction. Research in pain mechanisms needs to be synthesized, of information coming in now. We need prospective controlled studies. Procedures are becoming less and less ablative (destructive) and more precise, with less negative side effects. We are looking at endovascular ways of moving blood vessels (working on a binocular endoscope to see the blood vessels). Pipe dreams can become real pipes; new ideas can evolve. Al Rhoton: this is the "Decade (or century or millennium) of the brain," our greatest unexplored frontier. Molecular biology discoverers will help us with addiction, alcoholism, affective disorders/depression, anxiety, Alzheimer's disease, and AIDS.