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Typical versus Atypical Trigeminal Neuralgia and Other Factors that may Affect Results of Neurosurgical Treatment
Perspectives Commentary on: The Long-Term Outcome Predictors of Pure Microvascular Decompression for Primary Trigeminal Neuralgia by Zhang et al. pp. 756-762.
Ronald Brisman, M.D. Department of Neurological Surgery College of Physicians and Surgeons Columbia University
Typical versus Atypical Trigeminal Neuralgia and Other Factors that may Affect Results of Neurosurgical Treatment Ronald Brisman
In this issue of WORLD NEUROSURGERY, Zhang et al. review their results of treating 154 consecutive patients with trigeminal neuralgia (without a defined cause such as brain tumor or multiple sclerosis) with pure microvascular decompression (MVD). Factors associated with complete pain relief without medications after 5 years were typical symptoms, preoperative magnetic resonance imaging (MRI) indicating vessel compression, and obvious vessel compression found at operation, which were present in 64%, 64%, and 53% of patients. Initial complete pain relief and 5-year complete pain relief were seen in 87% and 80% of patients with typical trigeminal neuralgia and 79% and 54% of patients with atypical trigeminal neuralgia. A prior ablative procedure did not influence the outcome after MVD. There were no major complications. Other neurosurgical procedures for trigeminal neuralgia, such as Gamma Knife radiosurgery (GKRS) and needle rhizotomy (radiofrequency, glycerol, and balloon microcompression) have also been shown to be more effective for typical trigeminal neuralgia than atypical trigeminal neuralgia. It is particularly important for neurosurgeons to recognize the difference between these two entities. In addition to paroxysmal, triggered, trigeminally distributed pain, atypical trigeminal neuralgia usually has constant or persistent pain, which is often aching, nagging, burning, or throbbing. However, it is not unusual for patients with typical trigeminal neuralgia to have throbbing, burning, nagging, or aching pains in addition to the shooting, stabbing, and sharp pains that are characteristic of typical trigeminal neuralgia. So how can one distinguish between atypical and typical trigeminal neuralgia, both of which can be associated with constant pain?
Key words 䡲 Cohort studies 䡲 Logistic models 䡲 Microvascular decompression 䡲 Postoperative complications 䡲 Prospective studies 䡲 Prognosis 䡲 Trigeminal neuralgia
Abbreviations and Acronyms GKRS: Gamma Knife radiosurgery MRI: Magnetic resonance imaging MVD: Microvascular decompression
WORLD NEUROSURGERY 79 [5/6]: 649-650, MAY/JUNE 2013
The constant pain that is consistent with typical trigeminal neuralgia has several features. Pain is often triggered by talking or moving the tongue and is relieved when the patient holds completely still even for a few minutes. It often develops in a patient who used to have typical paroxysmal, triggered pain without constant pain, who later develops constant pain in addition to typical paroxysmal, triggered pain. It is present during a flare-up of paroxysmal, triggered pain but subsides when the paroxysmal, triggered pain subsides. Constant pain is often exquisitely sensitive to carbamazepine or oxcarbazepine and responds very well, as does accompanying paroxysmal pain, to neurosurgical interventions, similar to cases of typical trigeminal neuralgia without this kind of constant pain. The constant pain that is characteristic of atypical trigeminal neuralgia is similar to the constant pain seen in persistent idiopathic facial pain (formerly called atypical facial pain). Pain is not triggered by talking, eating, or moving the mouth or tongue and is not relieved when the patient holds completely still; it is often made worse by such a maneuver. It was never absent during a period of paroxysmal triggered pain. It is present even when there is no paroxysmal, triggered pain. It does not respond to carbamazepine or oxcarbazepine and is less likely to respond to neurosurgical interventions. When such nontriggered constant pain exists in the absence of any paroxysmal triggered pain (chronic idiopathic facial pain), it is unlikely to respond to neurosurgical intervention. By failing to distinguish clearly between different kinds of constant pain and regarding the presence of any kind of constant pain, when associated with some paroxysmal triggered pain, as enough to diagnose atypical trigeminal neuralgia, some studies
Department of Neurological Surgery, College of Physicians and Surgeons, Columbia University, New York, New York, USA To whom correspondence should be addressed: Ronald Brisman, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2013) 79, 5/6:649-650. DOI: 10.1016/j.wneu.2012.02.047
www.WORLDNEUROSURGERY.org
649
PERSPECTIVES
show that patients with atypical trigeminal neuralgia do worse than patients with typical trigeminal neuralgia after MVD, as in the present study. However, other studies showed that patients with atypical trigeminal neuralgia (6) or constant pain (5) do just as well as patients with typical symptoms. Confusing the issue of atypical trigeminal neuralgia further is the use of the TN2 classification, which some erroneously equate with atypical trigeminal neuralgia. TN2 is diagnosed when patients with facial pain of spontaneous onset have constant pain that they report as being present ⬎ 50% of the time (4). However, patients with TN2 respond to MVD depending on whether they have the constant pain of typical trigeminal neuralgia, atypical trigeminal neuralgia, or persistent idiopathic facial pain (where there is no paroxysmal triggered pain): very well (typical trigeminal neuralgia), not so well (atypical trigeminal neuralgia), or not at all (persistent idiopathic facial pain). The most reliable way to diagnose atypical trigeminal neuralgia is to have the diagnosis made by an experienced clinician (attuned to the different kinds of facial pain including constant pain), rather than relying on a percentage of time that the patient feels constant pain is present. Other characteristics that have been shown elsewhere to be associated with a smaller chance of long-term pain relief after MVD include female gender, venous compression of the trigeminal root entry zone, duration of preoperative symptoms of ⱖ 8 years, and lack of immediate postoperative relief (1). Similar to the results published in the current issue of WORLD NEUROSURGERY, other authors also showed that a history of an ablative procedure before MVD did not significantly increase the likelihood of recurrent tic pain (1). Although some authors have argued that MVD should be performed early because patients who have trigeminal neuralgia for a long time do less well than patients with a shorter history, the present study, which shows no unfavorable outcome with a
REFERENCES 1. Barker FG, Jannetta PJ, Bissonette DJ, Larkins MV, Jho HD: The long-term outcome of microvascular decompression for trigeminal neuralgia. N Engl J Med 334:1077-1083, 1996.
2. Brisman R, Khandji G, Mooij RBM: Trigeminal nerve-blood vessel relationship as revealed by highresolution magnetic resonance imaging and its effect on pain relief after gamma knife radiosurgery for trigeminal neuralgia. Neurosurgery 50:1261-1266, 2002.
650
www.SCIENCEDIRECT.com
longer history, casts doubt on this reasoning. Similarly, the argument that MVD should be done first because other ablative procedures worsen the outcome after MVD is also called into doubt by the present study and other studies (1). Preoperative MRI can be helpful in further selecting patients who are more likely to benefit from MVD. MRI evidence of vessel compression, which was seen in only 64% of patients, was more likely to be associated with a better prognosis for long-term pain relief. This percentage probably includes patients with a large tortuous vertebrobasilar artery, which is not a situation that is readily amenable to pure MVD because it is not easy to mobilize such a vessel away from the trigeminal nerve. In addition, this percentage probably includes patients with venous compression of the trigeminal nerve—another situation where pure MVD is less likely to work (1). MRI showing blood vessel contact with the trigeminal nerve may also indicate a particularly favorable response to GKRS (2). Pure MVD without denervation is not always possible or desirable, as in the following situations: a vessel, usually a vein, runs right through the trigeminal nerve; the compressing artery is very large and arteriosclerotic; the artery (usually superior artery of cerebellum) is very impacted into the trigeminal nerve; there is no vascular compression; or only a vein is in contact with the trigeminal nerve. Because denervating procedures such as GKRS and needle rhizotomy also have a very good chance of providing pain relief and do not have an impact on results of a subsequent MVD, these minimally invasive procedures before or instead of MVD are very attractive alternatives. Although MVD probably has the best chance of long-lasting pain relief without bothersome numbness (3), it is a major procedure and is associated with many complications. Zhang et al. have properly emphasized the need for a complete and frank discussion with the patient before surgery regarding risks, benefits, and alternatives.
3. Brisman R: Microvascular decompression vs. gamma knife radiosurgery for typical trigeminal neuralgia: preliminary findings. Stereotact Funct Neurosurg 85: 94-98, 2007.
geminal neuralgia (typical or atypical): long-term effectiveness on pain; prospective study with survival analysis in a consecutive series of 362 patients. Acta Neurochir (Wien) 148:1235-1245, 2006.
4. Burchiel KJ: A new classification for facial pain. Neurosurgery 53:1164-1167, 2003.
Citation: World Neurosurg. (2013) 79, 5/6:649-650. DOI: 10.1016/j.wneu.2012.02.047
5. Sandell T, Eide PK: Effect of microvascular decompression in trigeminal neuralgia patients with or without constant pain. Neurosurgery 63:93-99, 2008.
Journal homepage: www.WORLDNEUROSURGERY.org
6. Sindou M, Leston J, Howeidy T, Decullier E, Chapuis F: Micro-vascular decompression for primary tri-
Available online: www.sciencedirect.com 1878-8750/$ - see front matter © 2013 Elsevier Inc. All rights reserved.
WORLD NEUROSURGERY, DOI:10.1016/j.wneu.2012.02.047
Ronald Brisman, M.D. Department of Neurological Surgery College of Physicians and Surgeons Columbia University
Typical versus Atypical Trigeminal Neuralgia and Other Factors that may Affect Results of Neurosurgical Treatment Ronald Brisman
In this issue of WORLD NEUROSURGERY, Zhang et al. review their results of treating 154 consecutive patients with trigeminal neuralgia (without a defined cause such as brain tumor or multiple sclerosis) with pure microvascular decompression (MVD). Factors associated with complete pain relief without medications after 5 years were typical symptoms, preoperative magnetic resonance imaging (MRI) indicating vessel compression, and obvious vessel compression found at operation, which were present in 64%, 64%, and 53% of patients. Initial complete pain relief and 5-year complete pain relief were seen in 87% and 80% of patients with typical trigeminal neuralgia and 79% and 54% of patients with atypical trigeminal neuralgia. A prior ablative procedure did not influence the outcome after MVD. There were no major complications. Other neurosurgical procedures for trigeminal neuralgia, such as Gamma Knife radiosurgery (GKRS) and needle rhizotomy (radiofrequency, glycerol, and balloon microcompression) have also been shown to be more effective for typical trigeminal neuralgia than atypical trigeminal neuralgia. It is particularly important for neurosurgeons to recognize the difference between these two entities. In addition to paroxysmal, triggered, trigeminally distributed pain, atypical trigeminal neuralgia usually has constant or persistent pain, which is often aching, nagging, burning, or throbbing. However, it is not unusual for patients with typical trigeminal neuralgia to have throbbing, burning, nagging, or aching pains in addition to the shooting, stabbing, and sharp pains that are characteristic of typical trigeminal neuralgia. So how can one distinguish between atypical and typical trigeminal neuralgia, both of which can be associated with constant pain?
Key words 䡲 Cohort studies 䡲 Logistic models 䡲 Microvascular decompression 䡲 Postoperative complications 䡲 Prospective studies 䡲 Prognosis 䡲 Trigeminal neuralgia
Abbreviations and Acronyms GKRS: Gamma Knife radiosurgery MRI: Magnetic resonance imaging MVD: Microvascular decompression
WORLD NEUROSURGERY 79 [5/6]: 649-650, MAY/JUNE 2013
The constant pain that is consistent with typical trigeminal neuralgia has several features. Pain is often triggered by talking or moving the tongue and is relieved when the patient holds completely still even for a few minutes. It often develops in a patient who used to have typical paroxysmal, triggered pain without constant pain, who later develops constant pain in addition to typical paroxysmal, triggered pain. It is present during a flare-up of paroxysmal, triggered pain but subsides when the paroxysmal, triggered pain subsides. Constant pain is often exquisitely sensitive to carbamazepine or oxcarbazepine and responds very well, as does accompanying paroxysmal pain, to neurosurgical interventions, similar to cases of typical trigeminal neuralgia without this kind of constant pain. The constant pain that is characteristic of atypical trigeminal neuralgia is similar to the constant pain seen in persistent idiopathic facial pain (formerly called atypical facial pain). Pain is not triggered by talking, eating, or moving the mouth or tongue and is not relieved when the patient holds completely still; it is often made worse by such a maneuver. It was never absent during a period of paroxysmal triggered pain. It is present even when there is no paroxysmal, triggered pain. It does not respond to carbamazepine or oxcarbazepine and is less likely to respond to neurosurgical interventions. When such nontriggered constant pain exists in the absence of any paroxysmal triggered pain (chronic idiopathic facial pain), it is unlikely to respond to neurosurgical intervention. By failing to distinguish clearly between different kinds of constant pain and regarding the presence of any kind of constant pain, when associated with some paroxysmal triggered pain, as enough to diagnose atypical trigeminal neuralgia, some studies
Department of Neurological Surgery, College of Physicians and Surgeons, Columbia University, New York, New York, USA To whom correspondence should be addressed: Ronald Brisman, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2013) 79, 5/6:649-650. DOI: 10.1016/j.wneu.2012.02.047
www.WORLDNEUROSURGERY.org
649
PERSPECTIVES
show that patients with atypical trigeminal neuralgia do worse than patients with typical trigeminal neuralgia after MVD, as in the present study. However, other studies showed that patients with atypical trigeminal neuralgia (6) or constant pain (5) do just as well as patients with typical symptoms. Confusing the issue of atypical trigeminal neuralgia further is the use of the TN2 classification, which some erroneously equate with atypical trigeminal neuralgia. TN2 is diagnosed when patients with facial pain of spontaneous onset have constant pain that they report as being present ⬎ 50% of the time (4). However, patients with TN2 respond to MVD depending on whether they have the constant pain of typical trigeminal neuralgia, atypical trigeminal neuralgia, or persistent idiopathic facial pain (where there is no paroxysmal triggered pain): very well (typical trigeminal neuralgia), not so well (atypical trigeminal neuralgia), or not at all (persistent idiopathic facial pain). The most reliable way to diagnose atypical trigeminal neuralgia is to have the diagnosis made by an experienced clinician (attuned to the different kinds of facial pain including constant pain), rather than relying on a percentage of time that the patient feels constant pain is present. Other characteristics that have been shown elsewhere to be associated with a smaller chance of long-term pain relief after MVD include female gender, venous compression of the trigeminal root entry zone, duration of preoperative symptoms of ⱖ 8 years, and lack of immediate postoperative relief (1). Similar to the results published in the current issue of WORLD NEUROSURGERY, other authors also showed that a history of an ablative procedure before MVD did not significantly increase the likelihood of recurrent tic pain (1). Although some authors have argued that MVD should be performed early because patients who have trigeminal neuralgia for a long time do less well than patients with a shorter history, the present study, which shows no unfavorable outcome with a
REFERENCES 1. Barker FG, Jannetta PJ, Bissonette DJ, Larkins MV, Jho HD: The long-term outcome of microvascular decompression for trigeminal neuralgia. N Engl J Med 334:1077-1083, 1996.
2. Brisman R, Khandji G, Mooij RBM: Trigeminal nerve-blood vessel relationship as revealed by highresolution magnetic resonance imaging and its effect on pain relief after gamma knife radiosurgery for trigeminal neuralgia. Neurosurgery 50:1261-1266, 2002.
650
www.SCIENCEDIRECT.com
longer history, casts doubt on this reasoning. Similarly, the argument that MVD should be done first because other ablative procedures worsen the outcome after MVD is also called into doubt by the present study and other studies (1). Preoperative MRI can be helpful in further selecting patients who are more likely to benefit from MVD. MRI evidence of vessel compression, which was seen in only 64% of patients, was more likely to be associated with a better prognosis for long-term pain relief. This percentage probably includes patients with a large tortuous vertebrobasilar artery, which is not a situation that is readily amenable to pure MVD because it is not easy to mobilize such a vessel away from the trigeminal nerve. In addition, this percentage probably includes patients with venous compression of the trigeminal nerve—another situation where pure MVD is less likely to work (1). MRI showing blood vessel contact with the trigeminal nerve may also indicate a particularly favorable response to GKRS (2). Pure MVD without denervation is not always possible or desirable, as in the following situations: a vessel, usually a vein, runs right through the trigeminal nerve; the compressing artery is very large and arteriosclerotic; the artery (usually superior artery of cerebellum) is very impacted into the trigeminal nerve; there is no vascular compression; or only a vein is in contact with the trigeminal nerve. Because denervating procedures such as GKRS and needle rhizotomy also have a very good chance of providing pain relief and do not have an impact on results of a subsequent MVD, these minimally invasive procedures before or instead of MVD are very attractive alternatives. Although MVD probably has the best chance of long-lasting pain relief without bothersome numbness (3), it is a major procedure and is associated with many complications. Zhang et al. have properly emphasized the need for a complete and frank discussion with the patient before surgery regarding risks, benefits, and alternatives.
3. Brisman R: Microvascular decompression vs. gamma knife radiosurgery for typical trigeminal neuralgia: preliminary findings. Stereotact Funct Neurosurg 85: 94-98, 2007.
geminal neuralgia (typical or atypical): long-term effectiveness on pain; prospective study with survival analysis in a consecutive series of 362 patients. Acta Neurochir (Wien) 148:1235-1245, 2006.
4. Burchiel KJ: A new classification for facial pain. Neurosurgery 53:1164-1167, 2003.
Citation: World Neurosurg. (2013) 79, 5/6:649-650. DOI: 10.1016/j.wneu.2012.02.047
5. Sandell T, Eide PK: Effect of microvascular decompression in trigeminal neuralgia patients with or without constant pain. Neurosurgery 63:93-99, 2008.
Journal homepage: www.WORLDNEUROSURGERY.org
6. Sindou M, Leston J, Howeidy T, Decullier E, Chapuis F: Micro-vascular decompression for primary tri-
Available online: www.sciencedirect.com 1878-8750/$ - see front matter © 2013 Elsevier Inc. All rights reserved.
WORLD NEUROSURGERY, DOI:10.1016/j.wneu.2012.02.047