Access the full text.
Sign up today, get DeepDyve free for 14 days.
Trigeminal neuralgia is an idiopathic disorder of unilateral facial pain that is characterized by lancinating paroxysms of pain in the lips, gums, cheek, or chin. Pain in trigeminal neuralgia is associated with physical triggers. Much of the treatment has been unchanged for more than 10 years, with carbamazepine being the standard first-line treatment. There are several promising new medications available, such as pimozide, tizanidine hydrochloride, and topical capsaicin. Surgical management is also effective.Patients with trigeminal neuralgia (TN) often present first to their primary care provider. It is important for clinicians to keep this diagnosis in mind when seeing patients with facial pain. The following is an illustrative case report.REPORT OF A CASEA 50-year-old man was examined because of a 3-day history of left-sided "toothachelike" facial pain, located from the left midchin and lip to the preauricular area, including his left upper gums and teeth. The patient had a history of 2 similar episodes in the last year, which were treated as sinusitis. He had had cold symptoms with each of the previous episodes, and the pain resolved with the antibiotic treatment. He had had dental visits for both of his previous episodes, without any tooth or gum disease found. The results of the patient's physical examination were unremarkable. Cranial nerves were intact.One week later the patient returned to the clinic with worsening stabbing facial pain, which was unresponsive to a pain medication. He was unable to sleep, chewing and hot foods triggered pain, and his teeth were sensitive to touch. He had no other neurologic symptoms, and the examination results remained unremarkable. A presumptive diagnosis of TN was made, treatment was started with carbamazepine, and he had complete resolution of his pain within 2 days. The patient developed a rash while taking the carbamazepine, and the medication was discontinued. He remained pain free and the rash resolved.COMMENTTrigeminal neuralgia, or tic douloureux, is relatively uncommon but should be considered when facial pain is a part of a patient's complaint. It has an annual occurrence rate of 3 to 5 per 100,000 people.The pain is described as sudden, sharp, shocklike, or burning. The pain is found in the distributions of 1 or more of the branches of the trigeminal nerve, which supplies sensation to the skin of the face and anterior half of the head, and has a limited motor component supplying the masseter and pterygoid masticatory muscles. Trigeminal neuralgia is most commonly found in the maxillary and mandibular division or the maxillary branch alone. A small percentage of cases affect the ophthalmic division alone.Trigeminal neuralgia is found more often in women than in men (age-adjusted ratio, 1.74:1) and is most common from age 50 to 69 years, and attacks are more commonly seen on the right.The attacks can occur during the day or night but rarely during sleep.Attacks are usually triggered by nonpainful stimuli such as touch, movement, wind exposure, eating, brushing teeth, shaving, washing, talking, or swallowing.Patients have multiple clusters of pain that last from a few seconds to several minutes. Patients have often seen several providers, including dentists, before their diagnosis. The name tic douloureuxcomes from the ticlike muscle cramps caused by the pain.CAUSETrigeminal neuralgia is an idiopathic disorder, but several theories of neuropathological processes attempt to explain the symptoms. One theory is compression of the trigeminal root adjacent to the pons, causing demyelination of the nerve root. This may be caused by tortuous blood vessels in the posterior fossa, tumors, or arteriovenous malformations.However, these structural lesions are not found in all patients with TN. Other theories suggest that TN is a symptom of a central nerve disease or a disease of the trigeminal vascular system involving dysfunctional interplay between a trigeminal sensory plexus and blood vessels located in the pia and dura mater.DIFFERENTIAL DIAGNOSISThe diagnosis of TN is based on clinical findings, but a careful history and examination can distinguish between TN and other disorders that cause facial pain. The classification scheme of the International Headache Society divides facial pain into 2 groups—pain from local facial structures and pain from neuralgia (Figure 1).Figure 1.Differential diagnosis of facial pain (using the International Headache Society classification). HEENT indicates head, eyes, ears, nose, and throat; TMJ, temporomandibular joint.Local examination findings may indicate otitis media, sinusitis, temporomandibular joint disease, herpes zoster, dental caries, or eye disease. Neurologic deficits, especially those involving the eye, are useful in diagnosis. Tolosa-Hunt syndrome is characterized by ocular pain and ophthalmoplegia, and is caused by nonspecific idiopathic granuloma in the area of the cavernous sinus or superior orbital fissure. Raeder paratrigeminal neuralgia (or Raeder syndrome) is a paroxysm of throbbing pain in the first division of the trigeminal nerve, associated with ptosis and miosis. Optic neuritis, which appears as acute loss of vision and mild pain with eye movement, may indicate multiple sclerosis. Two percent to 4% of patients with TN also have multiple sclerosis.Eye pain and third-nerve palsy may be seen with diabetes mellitus. Cluster headache can cause closely spaced attacks of headache, ptosis, lacrimation, and conjunctival congestion. With any neurologic deficit, there should be suspicion of a structural lesion, including aneurysm, neural fibroma, meningioma, or other intracranial lesion. Magnetic resonance imaging can be useful in examining patients with neurologic abnormalities.Patients with normal results of physical examination can be divided into those with persistent and those with episodic pain. Persistent pain can be caused by compression or distortions of a cranial nerve before nerve deficit. Intracranial lesions should be excluded in this case. Giant cell arteritis causes persistent temporal headache, and postherpetic neuralgia may cause persistent pain even after the characteristic herpetic rash is gone.The most frustrating type of persistent facial pain is atypical facial pain. Atypical facial pain does not follow a nerve distribution and often occurs after local trauma, such as tooth extraction. Atypical facial pain is far less responsive to treatment than TN.Finally, episodic pain is helpful in the history. Cluster headaches cause paroxysms of unilateral periorbital pain. Trigeminal neuralgia causes lancinating paroxysms of pain associated with triggers. Other neuralgias may cause episodic pain, may be associated with triggers, and can be differentiated by their distribution. Glossopharyngeal neuralgia causes severe pain in the tonsils, the base of the tongue, the ear, and the posterior pharynx. It can be triggered by swallowing, talking, yawning, or coughing. Occipital neuralgia causes less severe pain in the occipital area. Superior laryngeal neuralgia causes laryngeal pain triggered by swallowing. Geniculate neuralgia is characterized by pain deep within the ear.PROGNOSISSpontaneous remission of TN is common, but the disorder is often progressive.Remissions may last for months or even years,but as the attacks become more frequent, the patient may develop persistent pain between episodes. Attacks may come in clusters and can completely disrupt activities of daily living if left untreated.Medical treatment is often very effective (Table 1) in controlling pain symptoms; in fact, carbamazepine is so effective initially that lack of response is considered by some to call into question the diagnosis of TN. If patients fail to respond to first-line agents, there are promising newer agents that may be more effective. For patients with continued pain after medical therapy, there are surgical options that are also quite effective.Table 1. Pharmacological Treatment Options*DrugEfficacy, %Dosage, mg/dAdverse EffectsInitial ReliefPain RecurrenceMildSeriousCarbamazepine68-8042-50200-1200Drowsiness, dizziness, nystagmus, ataxia, rash, GI tract discomfortLeukopenia, aplastic anemia, hyponatremia, hepatotoxic reaction, SLE, agranulocytosisPhenytoin6075300-600Drowsiness, dizziness, ataxia, nystagmus, nausea, slurred speech, rash, hyperpigmentationAgranulocytosis, aplastic anemia, SLE, osteomalacia, seizures, hepatotoxic reactionBaclofen65-747050-60 (divided into 3-6 doses)Weakness, somnolence, nausea, headache, confusion, urinary frequencyHallucinations, palpitations, hyperglycemia*GI indicates gastrointestinal; SLE, systemic lupus erythematosus.TREATMENTPharmacologicalHistorically, the treatment of choice has been the anticonvulsant carbamazepine, but most of the evidence for medical treatment of TN is based on noncontrolled studies from the 1960s.Evaluation of medical treatments is difficult because of the high rate of spontaneous remission. The mechanism of action for these drug treatments is not clear. Common adverse effects are listed in Table 1.Carbamazepine is an effective and well-tolerated treatment. Initial dose of carbamazepine is 100 mg twice daily, then increased to 3 times per day. The dose may then be increased by 100 mg/d (on a 3-times-daily schedule) until pain relief is achieved or 1200 mg/d is reached. A serum level should be determined 2 to 3 weeks after beginning therapy, and again every 1 to 3 months. A complete blood cell count and liver function tests should be done periodically on patients treated for longer periods. After the pain has been controlled for 6 to 8 weeks, the dosage should be decreased to the lowest level that maintains pain control or withdrawn completely. Some drugs, such as erythromycin, cimetidine, diltiazem hydrochloride, and terfenadine, can increase the plasma concentration of carbamazepine. Carbamazepine may also interact with other anticonvulsants and can decrease the effectiveness of oral contraceptives.The anticonvulsant phenytoin has also been used to relieve TN pain.A form of phenytoin can be used intravenously in patients in acute neurologic crisis.Baclofen is a γ-aminobutyric acid receptor agonist that has the least serious adverse effects.A double-blind crossover study by Fromm et alshowed a significant decrease in the number of TN attacks when treated with baclofen, even in patients who had become unresponsive to carbamazepine.Several other medications with central nervous system effects have been used to treat TN, with varied success (Table 2).Table 2. Other Treatment Options*DrugDosagePimozide2-12 mg/d given BIDLamotrigine300-600 mg/d given TIDTizanidine hydrochloride2-4 mg/d given BIDValproate sodium600-1200 mg/d given PORacemic ketamine0.45 mg/kg given IMProparacaine hydrochlorideOphthalmic dropsCapsaicin creamTopical cream*None of these treatments has been shown to be more effective than carbamazepine. BID indicates twice daily; TID, 3 times daily; PO, orally; and IM, intramuscularly.Pimozide is a neuroleptic that has shown significant relief of pain when compared with carbamazepine in a double-blind crossover trial by Lechin et al.Patients in this study had been diagnosed as having TN for at least 2 years and were treated with carbamazepine or pimozide. Adverse effects were common with pimozide, but mild, and no patients stopped the treatment because of side effects.Lamotrigine is an anticonvulsant with an action similar to that of carbamazepine, but with fewer side effects. A small noncontrolled study of patients who could not tolerate carbamazepine showed response without the side effects associated with carbamazepine.A controlled trial is needed to confirm this benefit.Tizanidine hydrochloride has neurochemical activity similar to that of baclofen and carbamazepine. A double-blind crossover study by Fromm et alevaluated its efficacy in patients with TN who were not responding to carbamazepine and found short-term improvement, with recurrence of pain in 1 to 3 months.Other drugs include valproate sodium, racemic ketamine, proparacaine hydrochloride, and topical capsaicin cream. Valproate sodium was beneficial in a small group of patients studied by Peiris et al.Racemic ketamine, an anesthetic, showed some benefit when treating acute pain but was ineffective for pain lasting more than 5 years.The use of topical ophthalmic anesthetics, such as proparacaine, has been reported to relieve TN pain in some patients, but a randomized trial by Kondziolka et alshowed no change in the frequency or severity of attacks. Topical capsaicin cream showed improvement in 60% of patients using it in an open trial.If an initial trial of medications fails or the patient has atypical symptoms or any neurologic deficits, magnetic resonance imaging should be performed. This modality is preferred over computed tomography and cerebral angiography because of better resolution and visualization of the entire course of the trigeminal nerve.Figure 2is an algorithm with one approach to the evaluation and treatment of TN.Figure 2.Treatment and evaluation of trigeminal neuralgia (TN). MR indicates magnetic resonance.SurgicalFor patients who do not respond to pharmacological therapy or have worsening symptoms or more frequent recurrence, a surgical procedure may be appropriate. These procedures have variable success rates and different definitions of success; they have been reported as case series data and thus are difficult to compare objectively.Peripheral approaches, including cryotherapy and alcohol injection, act to block the peripheral branches of the trigeminal nerve. These are effective initially but have a high rate of pain recurrence. Repeated blocks are not recommended because of the risk of permanent facial anesthesia.Central procedures can be divided into percutaneous and open approaches. Percutaneous destruction of the trigeminal ganglion is accomplished through administration of radiofrequency lesions (thermal rhizotomy), glycerol injection, or balloon microcompression. Thermal rhizotomy is most commonly performed but has the risk of corneal anesthesia, keratitis, masticatory weakness, and temporary oculomotor paresis. Glycerol injection (into the arachnoid cistern of Meckel cavern) and balloon microcompression are less painful procedures, simpler to perform than thermal rhizotomy, but also less effective (Table 3).Table 3. Comparison of Central Surgical ProceduresTreatmentLength of Follow-upInitial Pain Relief, %Pain Recurrence (2-9 y), %Adverse EffectsPercutaneousRadiofrequency thermal rhizotomy16 mo-9.3 y74-9810-20Facial numbness, trigeminal motor weakness, corneal anesthesia, keratitisGlycerol rhizotomy (or injection)2-6 y79-9610-91Facial numbness, corneal anesthesia, keratitisBallon microcompression6 mo-10 y90-10010-28Trigeminal motor weakness, facial numbnessOpenMicrovascular decompression4-5 y68-966-34Permanent cranial nerve deficit (hearing loss, facial weakness or anesthesia), perioperative morbidity (brainstem infarction, cerebellar injury, ataxia, meningitis), headaches, deathPartial trigeminal rhizotomy21 mo-5.2 y86-9514-49Facial numbness, corneal anesthesia, perioperative morbidity (same as above), deathOpen surgical treatments for TN include microvascular decompression and partial trigeminal rhizotomy. Microvascular decompression is very effective but involves a suboccipital craniotomy and has serious risks, such as hearing loss, permanent facial anesthesia, brainstem infarction, cerebellar injury, ataxia, meningitis, headaches, and death. A partial sensory trigeminal rhizotomy at the pons has shown success in some cases, but with similar operative risks.CONCLUSIONSTrigeminal neuralgia is the most common neurologic cause of facial pain. The first step is to make the correct diagnosis. Initial therapy should be low-dose carbamazepine, with upward titration of the dose to relief of pain. Baclofen is a good choice for second-line therapy. Most patients will respond to anticonvulsant therapy, but its effectiveness decreases with time. Newer medications have shown promise, but none has been shown to be more effective than carbamazepine and need not be used for first-line therapy. Effective surgical options are available for cases that do not respond to medical treatment. There are serious risks associated with the surgical procedures, which should be reserved for the most resistant cases of TN.FYoshimasuLTKurlandLRElvebackTic douloureux in Rochester, Minnesota, 1945-1969.Neurology.1972;22:952-956.SKatusicCMBeardEBergstralhLTKurlandIncidence and clinical features of trigeminal neuralgia, Rochester, Minnesota, 1945-1984.Ann Neurol.1990;27:89-95.MWGreenJESelmanReview article: the medical management of trigeminal neuralgia.Headache.1991;31:588-592.WPCheshireTrigeminal neuralgia: a guide to drug choice.CNS Drugs.1997;7: 98-110.JCTurpJPGobettiTrigeminal neuralgia versus atypical facial pain: a review of the literature and case report.Oral Surg Oral Med Oral Pathol Oral Radiol Endod.1996;81:424-432.GHFrommCFTerrenceJCMaroonTrigeminal neuralgia: current concepts regarding etiology and pathogenesis.Arch Neurol.1984;41:1204-1207.ZHRappaportMDevorTrigeminal neuralgia: the role of self-sustaining discharge in the trigeminal ganglion.Pain.1994;56:128-138.SSolomonRBLiptonFacial pain.Neurol Clin.1990;8:913-928.JPHoogeWKRedekopTrigeminal neuralgia in multiple sclerosis.Neurology.1995;45:1294-1296.RKPortenoyCDumaKMFoleyAcute herpetic and postherpetic neuralgia: clinical review and current management.Ann Neurol.1986;20:651-654.WHSweetThe treatment of trigeminal neuralgia (tic douloureux).N Engl J Med.1986;315:174-177.RHSturmanFHO'BrienNon-surgical treatment of tic douloureux with carbamazepine.Headache.April 1969:88-91.EHDavisClinical trials of tegretol in trigeminal neuralgia.Headache.April 1969:77-82.CFNicolA four year double-blind study of tegretol in facial pain.Headache.April 1969:54-57.HWKienastLDBoshesClinical trials of carbamazepine in suppressing pain.Headache.April 1968:1-5.BWRockliffEHDavisControlled sequential trials of carbamazepine in trigeminal neuralgia.Arch Neurol.1966;15:129-136.PWalsonCTrincaRBresslerNew uses for phenytoin.JAMA.1975;233: 1385-1389.LSteardoALeoEMaranoEfficacy of baclofen in trigeminal neuralgia and some other painful conditions.Eur Neurol.1984;23:51-55.GHFrommCFTerrenceASChatthaBaclofen in the treatment of trigeminal neuralgia: double-blind study and long-term follow-up.Ann Neurol.1984;15:240-244.FLechinBvan der DijsMELechinPimozide therapy for trigeminal neuralgia.Arch Neurol.1989;46:960-963.SCanaveroVBonicalziPFerroliSZemeEMontalentiPBennaLamotrigine control of idiopathic trigeminal neralgia [letter].J Neurol Neurosurg Psychiatry.1995;59:646.GHFrommDAumentadoCFTerrenceA clinical and experimental investigation of the effects of tizanidine in trigeminal neuralgia.Pain.1993;53:265-281.JBPeirisGLPereraSVDevendraNDLionelSodium valproate in trigeminal neuralgia.Med J Aust.1980;2:278.LCMathisenPSkjelbredLASkoglundIOyeEffect of ketamine, an NMDA receptor inhibitor, in acute and chronic orofacial pain.Pain.1995;61:215-220.DKondziolkaTLemleyJRWKestleLDLunsfordGHFrommPJJannettaThe effect of single-application topical ophthalmic anesthesia in patients with trigeminal neuralgia.J Neurosurg.1994;80:993-997.JBEpsteinJHMarcoeTopical application of capsaicin for treatment of oral neuropathic pain and trigeminal neuralgia.Oral Surg Oral Med Oral Pathol.1994;77:135-140.LADarlowMLBrooksPDQuinnMagnetic resonance imaging in the diagnosis of trigeminal neuralgia.J Oral Maxillofac Surg.1992;50:621-626.JMTahaJMTew JrComparison of surgical treatments for trigeminal neuralgia: reevaluation of radiofrequency rhizotomy.Neurosurgery.1996;38:865-871.BFraioliVEspositoBGuidettiGCruccuMManfrediTreatment of trigeminal neuralgia by thermocoagulation, glycerolization, and percutaneous compression of the gasserian ganglion and/or retrogasserian rootlets: long-term results and therapeutic protocol.Neurosurgery.1989;24:239-245.GBroggiAFranziniGLasioCGiorgiDServelloLong-term results of percutaneous retrogasserian thermorhizotomy for "essential" trigeminal neuralgia: considerations in 1000 patients.Neurosurgery.1990;26:783-787.RFYoungSSVermeulenPGrimJBlaskoAPosewitzGamma knife radiosurgery for treatment of trigeminal neuralgia.Neurology.1997;48:608-614.SSSainiRetrogasserian anhydrous glycerol injection therapy in trigeminal neuralgia: observations in 552 patients.J Neurol Neurosurg Psychiatry.1987;50:1536-1538.MJAriasPercutaneous retrogasserian glycerol rhizotomy for trigeminal neuralgia: a prospective study of 100 cases.J Neurosurg.1986;65:32-36.TFujimakiTFukushimaSMiyazakiPercutaneous retrogasserian glycerol injection in the management of trigeminal neuralgia: long-term follow-up results.J Neurosurg.1990;73:212-216.LDLunsfordMHBennettPercutaneous retrogasserian glycerol rhizotomy for tic douloureux, part 1: technique and results in 112 patients.Neurosurgery.1984;14:424-430.GDieckmannVBockermannCHeyerJHenningMRoesenFive-and-a-half years' experience with percutaneous retrogasserian glycerol rhizotomy in treatment of trigeminal neuralgia.Appl Neurophysiol.1987;50:401-413.RFYoungGlycerol rhizolysis for treatment of trigeminal neuralgia.J Neurosurg.1988;69:39-45.TLichtorJFMullanA 10-year follow-up review of percutaneous microcompression of the trigeminal ganglion.J Neurosurg.1990;72:49-54.RDLobatoJJRivasRSarabiaELamasPercutaneous microcompression of the gasserian ganglion for trigeminal neuralgia.J Neurosurg.1990;72:546-553.RIApfelbaumSurgery for tic douloureux.Clin Neurosurg.1983;31:353-368.JBBedersonCBWilsonEvaluation of microvascular decompression and partial sensory rhizotomy in 252 cases of trigeminal neuralgia.J Neurosurg.1989;71:359-367.BKlunMicrovascular decompression and partial sensory rhizotomy in the treatment of trigeminal neuralgia: personal experience with 220 patients.Neurosurgery.1992;30:49-52.JHPiatt JrRHWilkinsTreatment of tic douloureux and hemifacial spasm by posterior fossa exploration: therapeutic implications of various neurovascular relationships.Neurosurgery.1984;14:462-471.AKondoFollow-up results of microvascular decompression in trigeminal neuralgia and hemifacial spasm.Neurosurgery.1997;40:46-51.PJJannettaMicrosurgical management of trigeminal neuralgia.Arch Neurol.1985;42:800.Accepted for publication June 4, 1998.Corresponding author: John E. Delzell, Jr, MD, Department of Family and Community Medicine, University of Missouri–Columbia School of Medicine, MA303 Health Sciences Center, Columbia, MO 65212 (e-mail: DelzellJ@health.missouri.edu).
Archives of Family Medicine – American Medical Association
Published: May 1, 1999
Read and print from thousands of top scholarly journals.
Already have an account? Log in
Bookmark this article. You can see your Bookmarks on your DeepDyve Library.
To save an article, log in first, or sign up for a DeepDyve account if you don’t already have one.
Copy and paste the desired citation format or use the link below to download a file formatted for EndNote
Access the full text.
Sign up today, get DeepDyve free for 14 days.
All DeepDyve websites use cookies to improve your online experience. They were placed on your computer when you launched this website. You can change your cookie settings through your browser.