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SUNCT syndrome
SUNCT syndrome Case report and literature review Rafael Benoliel, BDS(Lond), LDS, RCS Eng, a and Y. Sharav, DMD, MS, b Jerusalem, Israel THE HEBREW UNIVERSITY The case of a woman with short neuralgiform paroxysmal pain of 2 years duration is described. Pain attacks were always accompanied by ipsilateral lacrimation and conjunctiva[ injection. Standard anti-neuralgic therapy, amitriptyline and indomethacin, failed to eliminate or reduce pain. At the end of a 30-month active period the patient seemed to have gone into remission. We believe this to be a case of short-lasting, unilateral, neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), the first reported in the dental literature and the 24th in the general medical literature. The differential diagnosis of the case and relevant literature are discussed. (Oral Surg Oral Med Oral Palhol Oral Radiol Ended 1998;85:158-61)
The syndrome known as SUNCT--shortlasting, unilateral, neuralgiform headache attacks with ,conjunctival injection and tearing--was first reported in 1978.1 It is a unilateral condition characterized by brief paroxysmal headaches and facial pain accompanied by ipsilateral local autonomic signs and usually by conjunctival injection and lacrimation as well. The similarities of this syndrome to t r i g e m i n a l neuralgia (TN) are marked, 2 and many professionals believe SUNCT to be a variant of TN. Autonomic signs are typical of vascular-type pains 3 and are not usually associated with neuralgias. 4 Therefore some clinicians believe SUNCT to be a subtype of cluster headache, which would explain the presence of ipsilateral autonomic signs. However, because of some particular features of SUNCT, many other clinicians believe it to be a separate disorder. 5 It has been included as a primary headache entity in the most recent classification of the International Association for the Study of Pain, 6 under the section dealing with neuralgias of the head and face.
Features of SUNCI Temporalpattern. Multiple attacks occur, usually during the daytime, 7 with less than 2% occurring at night. Each attack lasts from 15 to 120 seconds, 6 but longerlasting attacks of 250 seconds and even 2 to 3 hours have been reported. 7-9 Frequency ranges from several attacks per day to many per hour, 6,10 but a low frequency of one Or two attacks in 4 weeks has been reported. 11 aClinical Senior Lecturer, Orofacial Pain Clinic, Department of Oral Diagnosis, Oral Medicine and Oral Radiology, Hadassah School of Dental Medicine. bprofessor and chairman, Orofacial Pain Clinic, Department of Oral Diagnosis, Oral Medicine and Oral Radiology, Hadassah School of Dental Medicine. Received for publication June 5, 1997; returned for revision July 21, 1997; accepted for publication Oct. 29, 1997. Copyright © 1998 by Mosby, Inc. 1079-2104/98/$5.00 + 0 7/13/87431
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Attack frequency in a recent study was found to average 28 per day. 7 A "cluster-like" pattern with active and inactive episodes has been reported, 1° but this is variably present. Pareja et al. 12 reported on four patients with "SUNCT status" in whom pain lasted for the better part of the day for 1 to 3 days, but this is rare. Lowgrade background pain or discomfort may also be part of SUNCT. 12 Quality. Although less severe than in TN, the pain in S U N C T is quite strong. 6 It is non-pulsatile, usually stabbing, and sometimes electric or burning. 13 Triggering. As in TN, the pain in SUNCT may be triggered by light mechanical stimuli in the areas innervated by the trigeminal nerve, 1;6,1° but there is a short latency between trigger and pain onset. 8 Neck movements have also been shown to trigger attacks. 6,14 Alcohol has not been reported to worsen pain, 8,1° although this has been positively cited. 4 Location. Pain in SUNCT is unilateral; as yet, no side predilection has been identified. It typically appears in the ocular and periocular regions, corresponding to the area innervated by the first branch (ophthalmic) of the trigeminal nerve. 1,8,10 However pain may instead be felt in the temporal and auricular regions. 6 Accompanying phenomena. By definition SUNCT is accompanied by marked ipsilateral conjunctivai injection and lacrimation. 1,6 Nasal stuffiness, rhinorrhea, 6 and sweating 15 may also accompany attacks, but these symptoms are rarer and may be subclinical. 1° Associated phenomena. Respiratory studies 16 have indicated that patients with SUNCT hyperventilate during attacks. Heart rate was found to decrease during attacks in two SUNCT patients. 17 Some cardiovascular changes occurred before pain onset and were probably not in response to the pain. Increased intraocular pressure with increased facial temperature periocularly has been reported. 18 Orbital phlebography studies show abnormalities on the painful side 19 and may indicate
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Volume 85, Number 2 venous vasculitis. 2° Single photon emission computed t o m o g r a p h y 21 and magnetic resonance imaging 19 (MRI) studies during attacks are essentially normal, but cerebral blood flow may be abnormal in SUNCT. 22 Demographics. SUNCT is a rare syndrome and has been sparsely reported. The patients in most cases have been male, but female patients have also been found with SUNCT. In a recent review s 18 cases were presented; 2 of the patients were female and 16 were male. We found an additional five cases4,12,i4; all of the patients were male. Including the case we report in the present article, the total is 24 cases and the male:female ratio is 7:1. Treatment. A distinctive feature of S U N C T is its absolute resistance to both anti-neuralgic and anti-vascular drug therapies. 5 At times S U N C T is initially responsive to carbamazepine. 14 Some reduction in attack frequency and severity has also been reported with carbamazepine, 5,8 and SUNCT may also respond to steroids. 5'6'2° Many cases seem to be lost to followup or to go into remission. The importance of SUNCT in the differential diagnosis of orofacial pain is clear; moreover, there are cases of SUNCT that signal underlying disease. However, no cases of S U N C T appear in the dental literature. We describe the case of a w o m a n who was seen in the Orofacial Pain Clinic and review the relevant literature.
CASE REPORT A 63-year-old female appeared for treatment with pain in the periorbital region. The pain, which had begun 2 years earlier, had been resistant to all previous treatments and had recently been worsening. The quality of the pain was spasmotic or pressure-like, and attacks were multiple during the day (the minimum number was 10, but usually there were many more); however, they did not wake the patient from sleep. Each attack lasted for up to 3 minutes and could prevent continuation of normal activity. The pain could spread to the left temporal area and sometimes beyond and was always accompanied by ipsilateral lacrimation. The patient could induce an attack by mechanical stimulation around the lips and even by sneezing. Eating and face-washing were particularly strong inducers of headache. However, many of the attacks were spontaneous, with no clear trigger preceding their onset. Neurologic examination by a specialist had revealed nothing out of the ordinary, and a computed tomography scan of the brain (done 1 year previously) had been normal. The patient had received carbamazepine, baclofen, and amitriptyline in what should have been adequate doses, but she had experienced no pain relief. Intraoral and extraoral physical examination revealed nothing unusual. Blood pressure and heart rate were within normal limits. There were upper full dentures that were satisfactory; oral hygiene was poor, but no dental pathologic conditions were evident. Mouth opening was normal, and
there was no sign of musculoskeletal-system involvement. Results of requested blood chemistry and hematologic tests were within normal limits. A second computed tomography scan of the brain, this time with particular attention paid to the cerebellopontine angle, was normal. On the basis of these findings the patient was tentatively diagnosed as having SUNCT. A trial treatment with indomethacin at a dosage of 75 mg daily was initiated. Four weeks later, the patient returned complaining of strong pain and lacrimation; there was doubt about the early efficacy of the indomethacin. The dosage was therefore increased to 150 mg daily, but on recall the patient reported that pain severity and frequency were unaffected. The patient was then given clonazepam at a dosage of 0.5 mg daily, but this treatment too was unsuccessful. The patient was then instructed to begin taking corticosteroids, and an appointment was made for MRI. However, the patient did not return for the appointment. A telephone interview revealed that the patient seemed to have entered a period of remission and was pain-free without drug therapy. She declined further investigations and treatment.
DISCUSSION Unilateral headaches a c c o m p a n i e d by autonomic signs---cluster headache (CH), paroxysmal hemicrania (PH), cluster-tic syndrome (CTS), hemicrania continua, and S U N C T s y n d r o m e - - a r e headache entities that share a c c o m p a n y i n g local phenomena; accordingly, they have recently been grouped into a category known as trigeminal-autonomic cephalgias. 4 They probably have a common underlying pathophysiologic mechanism for autonomic activation. In the eye, nose, and upper lip, painful stimuli will generally cause lacrimation. 23,24 This is thought to be initiated by reflex activation of the cranial parasympathetic innervation. 4 There is evidence that central trigeminal-antonomic connections exist and cause parasympathetic activation after stimulation of the trigeminal ganglion. 25,26 This could account for the clinical p h e n o m e n a associated with SUNCT and other trigeminal-autonomic cephalgias.
DIFFERENTIAL DIAGNOSIS Trigeminal neuralgia There are great clinical similarities between TN and SUNCT. 2 At present, SUNCT, like TN, is distinguished by a high male predilection, a resistance to classical anti-neuralgic therapy, and the invariable presence of autonomic signs. Yet thermography shows different patterns for TN and SUNCT, I8'27 and so far no refractory p e r i o d - - a typical TN p h e n o m e n a - - h a s been clearly demonstrated in SUNCT. The location of S U N C T is usually periorbital; in contrast, isolated first-branch TN is rare. 28 (SUNCT is rare, too, however.) In addition, there are reports of TN with autonomic signs 29 and vascular activation. 3° Such cases m a y be
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February 1998 misdiagnosed as SUNCT, 2 but it has been predicted that autonomic signs will occur above a certain pain threshold (as seen in hemicrania continua)4; this may be the deciding factor in whether TN appears with o r without autonomic signs. A case of TN that reportedly 31 seems to have "metamorphosed" into S U N C T stresses the close relation between these entities. As further studies appear, the issue of whether SUNCT is a TN variant or a separate primary headache will be elucidated. As classifications stand at the moment, our case resembles SUNCT more than it does TN.
Cluster headache The marked autonomic activation and male preponderance in SUNCT are distinctly reminiscent of CH. 32 Orbital phlebography has also shown similarities between S U N C T and CH, 19 and the two conditions have a common location. However, their temporal patterns are very different. S U N C T is characterized by very frequent, extremely short attacks; in contrast, CH is characterized by longer-lasting attacks (15-180 minutes) of relatively low frequency. Moreover, CH is particularly noteworthy for its nocturnal appearance (approximately 50% o f CH attacks take place at night), 32 whereas SUNCT is rarely nocturnal. All these factors negated a diagnosis of CH in our case.
Combination syndromes The combination of CH and TN in CTS may cause particular diagnostic difficulties. In CTS the two types of headache coexist, so the differentiating factors that apply to CH and TN also apply to CTS. Neck movements also precipitate pain in CTS (40% of cases), and an atypical form of CTS has been described with very short attacks that make CTS disturbingly similar to PH and even to SUNCT. 33 In both CTS and SUNCT, carbamazepine alleviates but does not eliminate pain, and although CTS mainly affects females it is liable to cause diagnostic difficulties. PH has been associated with TN in a so-called "CPH-tic" syndrome34; mixed attacks differentiating this from SUNCT were not described, and CPH-tic syndrome is responsive to indomethacin. Our case involved attacks that were too short and too frequent to be CTS and too unresponsive to indomethacin to be CPH-tic syndrome.
Paroxysmal hemicrania PH attacks are of intermediate duration (1-45 minutes) and affect women more than men. The frequency is usually less than in SUNCT, and up to 30% of PH attacks may occur at n i g h t y Moreover, PH is characterized by an absolute response to indomethacin35; our case did not respond even after several weeks of treatment with indomethacin in doses from 75 to 150 mg.
Indomethacin-resistant PH cases that r e s p o n d e d to other drugs have been reported, 36 but the clinical parameters in our case still seemed to favor a diagnosis of SUNCT.
Dental pain At times, CH, 37 PH, 35 and TN 38 have all been misdiagnosed as dental pain, and this has led to unnecessarry dental interventions. SUNCT cases are typified by the triggering of attacks by oral stimuli, 2° and triggering as a result of drinking, tooth brushing, or tongue movements has also been reported. 8 Thorough dental evaluation should exclude dental pathologic conditions as a diagnosis, and the presence of ipsilateral autonomic signs should alert the practitioner.
Symptomatic SUNCT Cerebellopontine arteriovenous malformations 39,4° and cavernous h e m a n g i o m a of the brainstem 41 have been implicated in SUNCT. These lesions are diagnosable with MRI, and all S U N C T patients should be referred for MRI. Our patient did not have an initial MRI, and because she seems t o have gone into remission she has understandably been reluctant to have one.
CONCLUSION Our case meets the criteria for S U N C T syndrome, and we believe it to be an additional case of the condition.
REFERENCES 1. Sjaastad O, Russell D, Horven I, Bunaes U. Multiple neuralgiform, unilateral headache attacks associated with conjunctival injection and appearing in clusters: a nosological problem. Proceedings of the Scandinavian Migraine Society 1978:31. 2. Sjaastad O, Kruszewski R Trigeminal neuralgia and SUNCT syndrome: similarities and differences in the clinical pictures-an overview.Funct Neurol 1992;7:103-7. 3. Pareja JA, White LR, Sjaastad O. Pathophysiologyof headaches with a prominent vascular component. Pain Research and Management 1996;1:93-108. 4. Goadsby PJ, Lipton RB. A review of paroxysmal hemicranias, SUNCT syndrome and other short-lasting headaches with autonomic features, including new cases. Brain 1997;120:193-209. 5. Pareja JA, Kruszewski R Sjaastad O. SUNCT syndrome: trial of drugs and anesthetic blockades. Headache 1995;35:138-42. 6. Merskey H, Bogduk N, editors. InternationalAssociation for the Study of Pain's classification of chronic pain: descriptions of chronic pain syndromes and definition of pain terms. 2nd ed. Seattle: IASP Press; 1994. p. 68-71. 7. Pareja JA, Shen JM, Kruszewski P, Caballero V, Pamo M, Sjaastad O. SUNCT syndrome: duration, frequency, and temporal distribution of attacks. Headache 1996;36:161-5. 8. Pareja JA, Sjaastad O. SUNCT syndrome in the female. Headache 1994;34:217-20. 9. Pareja JA, Joubert J, Sjaastad O. SUNCT syndrome. Atypical temporal patterns. Headache 1996;36:108-10. 10. Sjaastad O, Sannte C, Salvesen R, Fredriksen TA, Seim A, Roe OD, et al. Short-lastingunilateral neuralgiform headache attacks with conjunctival injection, tearing, sweating, and rhinorrhea. Cephalalgia 1989;9:147-56.
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Volume 85, Number 2 11. Sjaastad O, Zhao JM, Kruszewski R Stovner LJ Short-lasting unilateral neuralgiform headache attacks with conjunctival injection, tearing, sweating, and rhinorrhea. (SUNCT), III: another Norwegian case. Headache, 1991;31:175-7. 12. Pareja JA, Caballero V, Sjaastad O. SUNCT syndrome: statuslike pattern. Headache, 1996;36:622-4. 13. Pareja JA, Pareja J, Palomo T, Caballero V, Pamo M. SUNCT syndrome: repetitive and overlapping attacks. Headache 1994;34:114-6. 14. Becser N, Berky M. SUNCT syndrome: A Hungarian case. Headache 1995;35:158-60. 15. Kruszewski E Zhao JM, Shen JM, Sjaastad O. SUNCT syndrome: forehead sweating pattern. Cephalalgia 1993;13:108-13. 16. Kruszewski P, White LR, Shen JM, Pareja JA, Zhao JM, Schaanning J, et al. Respiratory studies in SUNCT syndrome. Headache 1995;35:344-8. 17. Kruszewski R Fasano ML, Brubakk AO, Shen JM, Sand T, Sjaastad O. Short-lasting, unilateral, neuralgiform headache attacks with conjunctival injection, tearing, and subclinical forehead sweating ("Sunct" syndrome), II: changes in heart rate and arterial blood pressure during pain paroxysms. Headache 1991;31:399-405. 18. Sjaastad O, Kruszewski P, Fostad K, Elsas T, Qvigstad G. SUNCT syndrome, VH: ocular and related variables. Headache 1992;32:489-95. 19. Kruszewski R Short-lasting, unilateral, neuralgiform headache attacks with conjunctival injection and tearing (SUNCT syndrome), V: orbital phlebography. Cephalalgia 1992;12:387-9. 20. Hannerz J, Greitz D, Hansson P, Ericson K. SUNCT may be another manifestation of orbital venous vasculitis. Headache 1992;32:384-9. 21. Poughias L, Aasly J. SUNCT syndrome: cerebral SPECT images during attacks. Headache 1995;35:143-5. 22. Shen JM, Johnsen HJ SUNCT syndrome: estimation of cerebral blood flow velocity with transcranial Doppler ultrasonography. Headache 1994;34:25-31. 23. Hardebo JE. The involvement of substance P neurons in cluster headache: an hypothesis. Headache 1984;24:294-304. 24. Drummond PD. Lacrimation and cutaneous vasodilatation in the face induced by painful stimulation of the nasal ala and upper lip. J Auton Nerv Syst 1995;51:109-16. 25. Goadsby PJ, Edvinsson L, Ekman R. Release of vasoactive peptides in the extracerebral circulation of humans and the cat during activation of the trigeminovascular system. Ann Neurol 1988;23:193-6. 26. Goadsby PJ, Edvinsson L. Peripheral and central trigeminovascular activation in cat is blocked by the serotonin (5HT)-ID receptor agonist 311C90. Headache 1994;34:394-9.
27. Mongini F, Caselli C, Macfi V, Tettim C. Thermographic findings in cranio-facial pain. Headache 1990;30:497-504. 28. Fromm GH. Medical treatment of patients with trigeminal neuralgia. In: Fromm GH, Sessle BJ, editors. Trigeminal neuralgia: current concepts regarding pathogenesis and treatment. Boston: Butterworth-Heinemann; 1991. p. 131-44. 29. Rasmussen E Facial pain, IV: a prospective study of 1052 patients with a view of precipitating factors, associated symptoms, objective psychiatric and neurological symptoms. Acta Neurochir (Wien) 1991;108:100-9. 30. Dubner R, Sharav Y, Gracely RH, Price DD. Idiopathic trigeminal neuralgia: sensory features and pain mechanisms, Pain 1987;31:23-33. 31. Bouhassira D, Attal N, Esteve M, Chauvin M. SUNCT syndrome: a case of transformation from trigeminal neuralgia? Cephalalgia 1994;14:168-70. 32, Nappi G, Russell D. Cluster headache: clinical features. In: Olesen J, Tfelt-Hansen R Welch KMA, editors. The Headaches. New York: Raven Press; 1993. p. 577-84. 33. Alberca R, Ochoa JJ. Cluster-tic syndrome. Neurol 1994;44: 996-9. 34. Hannerz J. Trigeminal neuralgia with chronic paroxysmal hemicrania: the CPH-tic syndrome. Cephalalgia 1993;13:361-4. 35. Antonaci E Sjaastad O. Chronic paroxysmal hemicrania (CPH): a review of the clinical manifestations. Headache 1989;29:64856. 36. Evers S, Husstedt IW. Alternatives in drug treatment of chronic paroxysmal hemicrania. Headache 1996;36:429-32. 3% Brooke RI. Periodic migranous neuralgia: a cause of dental pain. Oral Surg Oral Med Oral Pathol 1978;46:511-6. 38. Terrence CF, Fromm GH. Trigeminal neuralgia and other facial neuralgias. In: Olesen J, Tfelt-Hansen R Welch KMA, editors. The Headaches. New York: Raven Press; 1993. p. 773-85. 39. Bussone G, Leone M, Dalla Volta G, Strada L, Gasparotti R, Di Monda V. Short-lasting unilateral neuralgiform headachee attacks with tearing and conjunctival injection: the first "symptomatic" case? Cephalalgia 1991 ;11:123-7. 40. De Benedittis G. SUNCT syndrome associated with cavernous angioma of the brain stem. Cephalalgia 1996;16:503-6. 41. Morales F, Mostacero E, Marta J, Sanchez S Vascular malformation of the cerebellopontine angle associated with "SUNCT" syndrome. Cephalalgia 1994;14:301-2.
Reprint requests: Rafael Benoliel, BDS NIH/National Institute of Dental Research Building 49, Room 1WW25 Bethesda, MD 20892
The syndrome known as SUNCT--shortlasting, unilateral, neuralgiform headache attacks with ,conjunctival injection and tearing--was first reported in 1978.1 It is a unilateral condition characterized by brief paroxysmal headaches and facial pain accompanied by ipsilateral local autonomic signs and usually by conjunctival injection and lacrimation as well. The similarities of this syndrome to t r i g e m i n a l neuralgia (TN) are marked, 2 and many professionals believe SUNCT to be a variant of TN. Autonomic signs are typical of vascular-type pains 3 and are not usually associated with neuralgias. 4 Therefore some clinicians believe SUNCT to be a subtype of cluster headache, which would explain the presence of ipsilateral autonomic signs. However, because of some particular features of SUNCT, many other clinicians believe it to be a separate disorder. 5 It has been included as a primary headache entity in the most recent classification of the International Association for the Study of Pain, 6 under the section dealing with neuralgias of the head and face.
Features of SUNCI Temporalpattern. Multiple attacks occur, usually during the daytime, 7 with less than 2% occurring at night. Each attack lasts from 15 to 120 seconds, 6 but longerlasting attacks of 250 seconds and even 2 to 3 hours have been reported. 7-9 Frequency ranges from several attacks per day to many per hour, 6,10 but a low frequency of one Or two attacks in 4 weeks has been reported. 11 aClinical Senior Lecturer, Orofacial Pain Clinic, Department of Oral Diagnosis, Oral Medicine and Oral Radiology, Hadassah School of Dental Medicine. bprofessor and chairman, Orofacial Pain Clinic, Department of Oral Diagnosis, Oral Medicine and Oral Radiology, Hadassah School of Dental Medicine. Received for publication June 5, 1997; returned for revision July 21, 1997; accepted for publication Oct. 29, 1997. Copyright © 1998 by Mosby, Inc. 1079-2104/98/$5.00 + 0 7/13/87431
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Attack frequency in a recent study was found to average 28 per day. 7 A "cluster-like" pattern with active and inactive episodes has been reported, 1° but this is variably present. Pareja et al. 12 reported on four patients with "SUNCT status" in whom pain lasted for the better part of the day for 1 to 3 days, but this is rare. Lowgrade background pain or discomfort may also be part of SUNCT. 12 Quality. Although less severe than in TN, the pain in S U N C T is quite strong. 6 It is non-pulsatile, usually stabbing, and sometimes electric or burning. 13 Triggering. As in TN, the pain in SUNCT may be triggered by light mechanical stimuli in the areas innervated by the trigeminal nerve, 1;6,1° but there is a short latency between trigger and pain onset. 8 Neck movements have also been shown to trigger attacks. 6,14 Alcohol has not been reported to worsen pain, 8,1° although this has been positively cited. 4 Location. Pain in SUNCT is unilateral; as yet, no side predilection has been identified. It typically appears in the ocular and periocular regions, corresponding to the area innervated by the first branch (ophthalmic) of the trigeminal nerve. 1,8,10 However pain may instead be felt in the temporal and auricular regions. 6 Accompanying phenomena. By definition SUNCT is accompanied by marked ipsilateral conjunctivai injection and lacrimation. 1,6 Nasal stuffiness, rhinorrhea, 6 and sweating 15 may also accompany attacks, but these symptoms are rarer and may be subclinical. 1° Associated phenomena. Respiratory studies 16 have indicated that patients with SUNCT hyperventilate during attacks. Heart rate was found to decrease during attacks in two SUNCT patients. 17 Some cardiovascular changes occurred before pain onset and were probably not in response to the pain. Increased intraocular pressure with increased facial temperature periocularly has been reported. 18 Orbital phlebography studies show abnormalities on the painful side 19 and may indicate
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Volume 85, Number 2 venous vasculitis. 2° Single photon emission computed t o m o g r a p h y 21 and magnetic resonance imaging 19 (MRI) studies during attacks are essentially normal, but cerebral blood flow may be abnormal in SUNCT. 22 Demographics. SUNCT is a rare syndrome and has been sparsely reported. The patients in most cases have been male, but female patients have also been found with SUNCT. In a recent review s 18 cases were presented; 2 of the patients were female and 16 were male. We found an additional five cases4,12,i4; all of the patients were male. Including the case we report in the present article, the total is 24 cases and the male:female ratio is 7:1. Treatment. A distinctive feature of S U N C T is its absolute resistance to both anti-neuralgic and anti-vascular drug therapies. 5 At times S U N C T is initially responsive to carbamazepine. 14 Some reduction in attack frequency and severity has also been reported with carbamazepine, 5,8 and SUNCT may also respond to steroids. 5'6'2° Many cases seem to be lost to followup or to go into remission. The importance of SUNCT in the differential diagnosis of orofacial pain is clear; moreover, there are cases of SUNCT that signal underlying disease. However, no cases of S U N C T appear in the dental literature. We describe the case of a w o m a n who was seen in the Orofacial Pain Clinic and review the relevant literature.
CASE REPORT A 63-year-old female appeared for treatment with pain in the periorbital region. The pain, which had begun 2 years earlier, had been resistant to all previous treatments and had recently been worsening. The quality of the pain was spasmotic or pressure-like, and attacks were multiple during the day (the minimum number was 10, but usually there were many more); however, they did not wake the patient from sleep. Each attack lasted for up to 3 minutes and could prevent continuation of normal activity. The pain could spread to the left temporal area and sometimes beyond and was always accompanied by ipsilateral lacrimation. The patient could induce an attack by mechanical stimulation around the lips and even by sneezing. Eating and face-washing were particularly strong inducers of headache. However, many of the attacks were spontaneous, with no clear trigger preceding their onset. Neurologic examination by a specialist had revealed nothing out of the ordinary, and a computed tomography scan of the brain (done 1 year previously) had been normal. The patient had received carbamazepine, baclofen, and amitriptyline in what should have been adequate doses, but she had experienced no pain relief. Intraoral and extraoral physical examination revealed nothing unusual. Blood pressure and heart rate were within normal limits. There were upper full dentures that were satisfactory; oral hygiene was poor, but no dental pathologic conditions were evident. Mouth opening was normal, and
there was no sign of musculoskeletal-system involvement. Results of requested blood chemistry and hematologic tests were within normal limits. A second computed tomography scan of the brain, this time with particular attention paid to the cerebellopontine angle, was normal. On the basis of these findings the patient was tentatively diagnosed as having SUNCT. A trial treatment with indomethacin at a dosage of 75 mg daily was initiated. Four weeks later, the patient returned complaining of strong pain and lacrimation; there was doubt about the early efficacy of the indomethacin. The dosage was therefore increased to 150 mg daily, but on recall the patient reported that pain severity and frequency were unaffected. The patient was then given clonazepam at a dosage of 0.5 mg daily, but this treatment too was unsuccessful. The patient was then instructed to begin taking corticosteroids, and an appointment was made for MRI. However, the patient did not return for the appointment. A telephone interview revealed that the patient seemed to have entered a period of remission and was pain-free without drug therapy. She declined further investigations and treatment.
DISCUSSION Unilateral headaches a c c o m p a n i e d by autonomic signs---cluster headache (CH), paroxysmal hemicrania (PH), cluster-tic syndrome (CTS), hemicrania continua, and S U N C T s y n d r o m e - - a r e headache entities that share a c c o m p a n y i n g local phenomena; accordingly, they have recently been grouped into a category known as trigeminal-autonomic cephalgias. 4 They probably have a common underlying pathophysiologic mechanism for autonomic activation. In the eye, nose, and upper lip, painful stimuli will generally cause lacrimation. 23,24 This is thought to be initiated by reflex activation of the cranial parasympathetic innervation. 4 There is evidence that central trigeminal-antonomic connections exist and cause parasympathetic activation after stimulation of the trigeminal ganglion. 25,26 This could account for the clinical p h e n o m e n a associated with SUNCT and other trigeminal-autonomic cephalgias.
DIFFERENTIAL DIAGNOSIS Trigeminal neuralgia There are great clinical similarities between TN and SUNCT. 2 At present, SUNCT, like TN, is distinguished by a high male predilection, a resistance to classical anti-neuralgic therapy, and the invariable presence of autonomic signs. Yet thermography shows different patterns for TN and SUNCT, I8'27 and so far no refractory p e r i o d - - a typical TN p h e n o m e n a - - h a s been clearly demonstrated in SUNCT. The location of S U N C T is usually periorbital; in contrast, isolated first-branch TN is rare. 28 (SUNCT is rare, too, however.) In addition, there are reports of TN with autonomic signs 29 and vascular activation. 3° Such cases m a y be
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February 1998 misdiagnosed as SUNCT, 2 but it has been predicted that autonomic signs will occur above a certain pain threshold (as seen in hemicrania continua)4; this may be the deciding factor in whether TN appears with o r without autonomic signs. A case of TN that reportedly 31 seems to have "metamorphosed" into S U N C T stresses the close relation between these entities. As further studies appear, the issue of whether SUNCT is a TN variant or a separate primary headache will be elucidated. As classifications stand at the moment, our case resembles SUNCT more than it does TN.
Cluster headache The marked autonomic activation and male preponderance in SUNCT are distinctly reminiscent of CH. 32 Orbital phlebography has also shown similarities between S U N C T and CH, 19 and the two conditions have a common location. However, their temporal patterns are very different. S U N C T is characterized by very frequent, extremely short attacks; in contrast, CH is characterized by longer-lasting attacks (15-180 minutes) of relatively low frequency. Moreover, CH is particularly noteworthy for its nocturnal appearance (approximately 50% o f CH attacks take place at night), 32 whereas SUNCT is rarely nocturnal. All these factors negated a diagnosis of CH in our case.
Combination syndromes The combination of CH and TN in CTS may cause particular diagnostic difficulties. In CTS the two types of headache coexist, so the differentiating factors that apply to CH and TN also apply to CTS. Neck movements also precipitate pain in CTS (40% of cases), and an atypical form of CTS has been described with very short attacks that make CTS disturbingly similar to PH and even to SUNCT. 33 In both CTS and SUNCT, carbamazepine alleviates but does not eliminate pain, and although CTS mainly affects females it is liable to cause diagnostic difficulties. PH has been associated with TN in a so-called "CPH-tic" syndrome34; mixed attacks differentiating this from SUNCT were not described, and CPH-tic syndrome is responsive to indomethacin. Our case involved attacks that were too short and too frequent to be CTS and too unresponsive to indomethacin to be CPH-tic syndrome.
Paroxysmal hemicrania PH attacks are of intermediate duration (1-45 minutes) and affect women more than men. The frequency is usually less than in SUNCT, and up to 30% of PH attacks may occur at n i g h t y Moreover, PH is characterized by an absolute response to indomethacin35; our case did not respond even after several weeks of treatment with indomethacin in doses from 75 to 150 mg.
Indomethacin-resistant PH cases that r e s p o n d e d to other drugs have been reported, 36 but the clinical parameters in our case still seemed to favor a diagnosis of SUNCT.
Dental pain At times, CH, 37 PH, 35 and TN 38 have all been misdiagnosed as dental pain, and this has led to unnecessarry dental interventions. SUNCT cases are typified by the triggering of attacks by oral stimuli, 2° and triggering as a result of drinking, tooth brushing, or tongue movements has also been reported. 8 Thorough dental evaluation should exclude dental pathologic conditions as a diagnosis, and the presence of ipsilateral autonomic signs should alert the practitioner.
Symptomatic SUNCT Cerebellopontine arteriovenous malformations 39,4° and cavernous h e m a n g i o m a of the brainstem 41 have been implicated in SUNCT. These lesions are diagnosable with MRI, and all S U N C T patients should be referred for MRI. Our patient did not have an initial MRI, and because she seems t o have gone into remission she has understandably been reluctant to have one.
CONCLUSION Our case meets the criteria for S U N C T syndrome, and we believe it to be an additional case of the condition.
REFERENCES 1. Sjaastad O, Russell D, Horven I, Bunaes U. Multiple neuralgiform, unilateral headache attacks associated with conjunctival injection and appearing in clusters: a nosological problem. Proceedings of the Scandinavian Migraine Society 1978:31. 2. Sjaastad O, Kruszewski R Trigeminal neuralgia and SUNCT syndrome: similarities and differences in the clinical pictures-an overview.Funct Neurol 1992;7:103-7. 3. Pareja JA, White LR, Sjaastad O. Pathophysiologyof headaches with a prominent vascular component. Pain Research and Management 1996;1:93-108. 4. Goadsby PJ, Lipton RB. A review of paroxysmal hemicranias, SUNCT syndrome and other short-lasting headaches with autonomic features, including new cases. Brain 1997;120:193-209. 5. Pareja JA, Kruszewski R Sjaastad O. SUNCT syndrome: trial of drugs and anesthetic blockades. Headache 1995;35:138-42. 6. Merskey H, Bogduk N, editors. InternationalAssociation for the Study of Pain's classification of chronic pain: descriptions of chronic pain syndromes and definition of pain terms. 2nd ed. Seattle: IASP Press; 1994. p. 68-71. 7. Pareja JA, Shen JM, Kruszewski P, Caballero V, Pamo M, Sjaastad O. SUNCT syndrome: duration, frequency, and temporal distribution of attacks. Headache 1996;36:161-5. 8. Pareja JA, Sjaastad O. SUNCT syndrome in the female. Headache 1994;34:217-20. 9. Pareja JA, Joubert J, Sjaastad O. SUNCT syndrome. Atypical temporal patterns. Headache 1996;36:108-10. 10. Sjaastad O, Sannte C, Salvesen R, Fredriksen TA, Seim A, Roe OD, et al. Short-lastingunilateral neuralgiform headache attacks with conjunctival injection, tearing, sweating, and rhinorrhea. Cephalalgia 1989;9:147-56.
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Volume 85, Number 2 11. Sjaastad O, Zhao JM, Kruszewski R Stovner LJ Short-lasting unilateral neuralgiform headache attacks with conjunctival injection, tearing, sweating, and rhinorrhea. (SUNCT), III: another Norwegian case. Headache, 1991;31:175-7. 12. Pareja JA, Caballero V, Sjaastad O. SUNCT syndrome: statuslike pattern. Headache, 1996;36:622-4. 13. Pareja JA, Pareja J, Palomo T, Caballero V, Pamo M. SUNCT syndrome: repetitive and overlapping attacks. Headache 1994;34:114-6. 14. Becser N, Berky M. SUNCT syndrome: A Hungarian case. Headache 1995;35:158-60. 15. Kruszewski E Zhao JM, Shen JM, Sjaastad O. SUNCT syndrome: forehead sweating pattern. Cephalalgia 1993;13:108-13. 16. Kruszewski P, White LR, Shen JM, Pareja JA, Zhao JM, Schaanning J, et al. Respiratory studies in SUNCT syndrome. Headache 1995;35:344-8. 17. Kruszewski R Fasano ML, Brubakk AO, Shen JM, Sand T, Sjaastad O. Short-lasting, unilateral, neuralgiform headache attacks with conjunctival injection, tearing, and subclinical forehead sweating ("Sunct" syndrome), II: changes in heart rate and arterial blood pressure during pain paroxysms. Headache 1991;31:399-405. 18. Sjaastad O, Kruszewski P, Fostad K, Elsas T, Qvigstad G. SUNCT syndrome, VH: ocular and related variables. Headache 1992;32:489-95. 19. Kruszewski R Short-lasting, unilateral, neuralgiform headache attacks with conjunctival injection and tearing (SUNCT syndrome), V: orbital phlebography. Cephalalgia 1992;12:387-9. 20. Hannerz J, Greitz D, Hansson P, Ericson K. SUNCT may be another manifestation of orbital venous vasculitis. Headache 1992;32:384-9. 21. Poughias L, Aasly J. SUNCT syndrome: cerebral SPECT images during attacks. Headache 1995;35:143-5. 22. Shen JM, Johnsen HJ SUNCT syndrome: estimation of cerebral blood flow velocity with transcranial Doppler ultrasonography. Headache 1994;34:25-31. 23. Hardebo JE. The involvement of substance P neurons in cluster headache: an hypothesis. Headache 1984;24:294-304. 24. Drummond PD. Lacrimation and cutaneous vasodilatation in the face induced by painful stimulation of the nasal ala and upper lip. J Auton Nerv Syst 1995;51:109-16. 25. Goadsby PJ, Edvinsson L, Ekman R. Release of vasoactive peptides in the extracerebral circulation of humans and the cat during activation of the trigeminovascular system. Ann Neurol 1988;23:193-6. 26. Goadsby PJ, Edvinsson L. Peripheral and central trigeminovascular activation in cat is blocked by the serotonin (5HT)-ID receptor agonist 311C90. Headache 1994;34:394-9.
27. Mongini F, Caselli C, Macfi V, Tettim C. Thermographic findings in cranio-facial pain. Headache 1990;30:497-504. 28. Fromm GH. Medical treatment of patients with trigeminal neuralgia. In: Fromm GH, Sessle BJ, editors. Trigeminal neuralgia: current concepts regarding pathogenesis and treatment. Boston: Butterworth-Heinemann; 1991. p. 131-44. 29. Rasmussen E Facial pain, IV: a prospective study of 1052 patients with a view of precipitating factors, associated symptoms, objective psychiatric and neurological symptoms. Acta Neurochir (Wien) 1991;108:100-9. 30. Dubner R, Sharav Y, Gracely RH, Price DD. Idiopathic trigeminal neuralgia: sensory features and pain mechanisms, Pain 1987;31:23-33. 31. Bouhassira D, Attal N, Esteve M, Chauvin M. SUNCT syndrome: a case of transformation from trigeminal neuralgia? Cephalalgia 1994;14:168-70. 32, Nappi G, Russell D. Cluster headache: clinical features. In: Olesen J, Tfelt-Hansen R Welch KMA, editors. The Headaches. New York: Raven Press; 1993. p. 577-84. 33. Alberca R, Ochoa JJ. Cluster-tic syndrome. Neurol 1994;44: 996-9. 34. Hannerz J. Trigeminal neuralgia with chronic paroxysmal hemicrania: the CPH-tic syndrome. Cephalalgia 1993;13:361-4. 35. Antonaci E Sjaastad O. Chronic paroxysmal hemicrania (CPH): a review of the clinical manifestations. Headache 1989;29:64856. 36. Evers S, Husstedt IW. Alternatives in drug treatment of chronic paroxysmal hemicrania. Headache 1996;36:429-32. 3% Brooke RI. Periodic migranous neuralgia: a cause of dental pain. Oral Surg Oral Med Oral Pathol 1978;46:511-6. 38. Terrence CF, Fromm GH. Trigeminal neuralgia and other facial neuralgias. In: Olesen J, Tfelt-Hansen R Welch KMA, editors. The Headaches. New York: Raven Press; 1993. p. 773-85. 39. Bussone G, Leone M, Dalla Volta G, Strada L, Gasparotti R, Di Monda V. Short-lasting unilateral neuralgiform headachee attacks with tearing and conjunctival injection: the first "symptomatic" case? Cephalalgia 1991 ;11:123-7. 40. De Benedittis G. SUNCT syndrome associated with cavernous angioma of the brain stem. Cephalalgia 1996;16:503-6. 41. Morales F, Mostacero E, Marta J, Sanchez S Vascular malformation of the cerebellopontine angle associated with "SUNCT" syndrome. Cephalalgia 1994;14:301-2.
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