J Neurosurg 72:955-958, 1990
Auriculotemporal syndrome (Frey's syndrome) presenting as tic douloureux Report of two cases GIUSEPPE DE BENEDITFIS, M.D. Pain Research and Treatment Unit, Institute of Neurosurgery, University of Milan, Milan, Italy ~," Two cases of auriculotemporal nerve syndrome (Frey's syndrome) presenting as trigeminal tic douloureux are reported. This condition, characterized by gustatory sweating and facial hyperemia, is occasionally associated with pain, which is usually described as aching or burning, and long-lasting. In these two cases, however, a tantalizing gustatory pain occurred in excruciating brief paroxysms. The pathophysiology of the syndrome, with particular reference to pain, and possible treatment modalities are discussed. KEY WORDS auriculotemporal syndrome trigeminal neuralgia ~
T
HE auriculotemporal nerve syndrome was first described by Baillarger 2 in 1853, but not until 1923 was it recognized as a distinct entity by Lucie Frey, 12 who first proposed a pathogenic hypothesis of this rather rare syndrome. Since then, the designation of auriculotemporal syndrome or "Frey's syndrome" has been internationally recognized, and innumerable cases have been described. 26,31 The disorder appears in the classic form o f hyperemia and sweating in the distribution of the auriculotemporal nerve. Sweating occurs almost immediately upon tasting foods, particularly spicy ones; hence the description of gustatory sweating. Pain in the distribution of the nerve is an u n c o m m o n finding, occurring in less than 10% of cases. 4 Such pain is usually described as of a constant aching or burning nature. Two cases of auriculotemporal syndrome are described here in which tic douloureux of the face was the presenting and p r o m i n e n t symptom. These two patients were seen at the Pain Research and Treatment Unit, Institute of Neurosurgery, University of Milan. Paroxysmal pain was the presenting and predominant feature. It was aggravated by mastication or motion of the jaw and was preauricular, radiating into the external ear canal. H y p e r e m i a of the affected side of the face was observed in both cases, whereas gustatory sweating was present in one case only. O u r initial working diagnosis o f an atypical presentation o f the auriculotemJ. Neurosurg. / Volume 72/June, 1990
9 Frey's syndrome
9 facial pain
9
poral nerve syndrome was confirmed in both cases by the immediate and continued relief of pain following a simple auriculotemporal nerve block, 2~ using 0.5% bupivacaine. At 1-year follow-up examination, one patient was pain-free and the other patient had been lost to follow-up review. Case Reports
Case 1 This 72-year-old m a n suffered a left "idiopathic" facial paresis in 1982. Several weeks later, he developed left preauricular pain which radiated into the external ear canal and the temporal region. H y p e r e m i a was present, but not gustatory sweating. The pain was characterized by brief episodes of paroxysmal lighteninglike sharp stabbing sensations, triggered by gustatory excitation and aggravated by jaw m o v e m e n t . Examination revealed no objective sensory deficit of the face. An auriculotemporal nerve block with 3 ml of 0.5% bupivacaine gave p r o m p t relief. Pain relief lasted for 1 year, after which the patient was lost to further review. Case 2 This 79-year-old w o m a n complained of left facial pain, which had begun "spontaneously" 3 m o n t h s before her referral to our Pain Service. T h e pain was distributed into the preauricular and mandibular re955
G. De Benedittis gion. It was o f a tic douloureux type on introduction of food into the mouth, followed by a deep steady pain lasting 5 to 6 minutes. She also complained of flushing and gustatory sweating on the left side o f the face occurring almost immediately upon tasting any food, but particularly some spicy foods. Neurological examination (including sensory examination) was within normal limits. Immediate and continued relief o f pain was obtained by a simple auriculotemporal nerve block, using 0.5% bupivacaine. At her 1-year follow-up examination, the patient was pain-free. Discussion Although pain in the distribution of the auriculotemporal nerve was not mentioned as an accompanying symptom in the original description o f the syndrome by Frey,12 it has been reported as an u n c o m m o n finding, occurring in less than 10% of cases. 4 Pain is usually described as aching or burning, and long-lasting. To our knowledge, this is the first report of two consecutive cases in which pain was the presenting and predominant symptom. Furthermore, pain occurred in very severe, excruciating paroxysms, lasting only a few seconds and never longer than a minute. This paradoxical, tantalizing gustatory pain reflex occurred when flavored foods were placed on the tongue. The physiopathology and the definitive etiology of Frey's auriculotemporal syndrome are still uncertain. In the opinion of m a n y authors, 1~ the auriculotemporal syndrome is always preceded by a lesion of the facial fibers in the parotid region. The symptoms may therefore be present after such insults as a severe attack of mumps, a penetrating lesion of the parotid region, surgical intervention upon the parotid gland, and abscesses of the angle of the jaws. However, sometimes (as in our Case 2) the etiology remains unknown. Pathogenesis The most c o m m o n l y accepted theory is that of misdirected regeneration suggested in 1938 by Ford and WoodhallJ 1 They proposed that the auriculotemporal syndrome derived from the anatomical disposition of the auriculotemporal nerve. Arising from the mandibular nerve just outside the foramen ovale, the auriculotemporal nerve courses close to the parotid capsule on its way to the skin of the temple. Postganglionic parasympathetic neurons in the otic ganglion send secretory fibers through the auriculotemporal nerve to the parotid gland. Postganglion sympathetic neurons in the superior cervical ganglion send fibers, also via the auriculotemporal nerve, to the parotid gland and to the sweat glands o f the skin supplied by the nerve. Any injury to the fibers o f this mixed nerve can create a considerable disturbance in the pathways of salivation and sweating, 2v whereby aberrant regeneration o f the parasympathetic vasodilator fibers to the parotid gland results in reafferentation of the sympathetic end-organs (sweat glands and cutaneous vessels).
956
Both the initially innervated salivary glands and the later-innervated sweat glands are cholinergic, so there would be no compatibility between the regenerating fibers and their new effector organs, accounting for the gustatory sweating in the classic cases. The hyperemia can be explained by the direct innervation of the cutaneous vessels by parasympathetic vasodilatory vessels, which are known to exist in the nerves that supply the major salivary glands. Gustatory, but also exteroceptive (tactile), stimulP 4 may trigger the paradoxical gustatory-sweating reflex, the afferent portion o f the arc being mediated through the fifth, seventh, ninth, and 10th cranial nerves, particularly the ninth. The fibers which carry gustatory sensation terminate a t t h e solitary tract and its nucleus into the brain stem. The exteroceptive components of the facial, glossopharyngeal, and vagus nerves join into the descending spinal tract. Secondary neurons pass from these structures to the superior and inferior salivary nuclei from which efferent parasympathetic impulses reach the salivary glands mainly through the glossopharyngeal nerve. 15 Pain might be the result of an artificial synapse (ephapse) between the sympathetic efferents and the sensory afferents much like reflex sympathetic dystrophy, ~6'25although sympathetic nerve blocks are usually ineffective. Other theories postulate traumatic neuritis of the auriculotemporal nerve, 28 transaxonal activation of a regenerated nerve fiber by the action potential of a nerve fiber to a different end-organ, or reinnervation by axons which previously supplied different end-organs. 27 In our opinion, several kinds of indirect evidence support the hypothesis that pain secondary to the auriculotemporal syndrome might be due to partial deafferentation. 1) Pain is an u n c o m m o n finding in Frey's syndrome patients; only a small fraction (1 to 5%) of the patients with a specific injury to the nervous system will develop pain. 23 2) The pain syndrome characteristics are not correlated with the pathogenesis of the lesion. Although trauma (accidental or surgically induced) is the single most c o m m o n cause of pain associated with deafferentation, there are numerous examples of infection, degenerative disease, and demyelinating disease leading to different types of chronic pain, such as constant burning pain or tic douloureux. This is often the case with auriculotemporal syndrome. 3) It has long been recognized that pain caused by deafferentation frequently has a delayed onset, from weeks to months after injury. This particular onset pattern is also characteristic of Frey's syndrome. 4) Denervation hypersensitivity is a c o m m o n process set off by nerve lesions: some patients with auriculotemporal syndrome were also found to have hypersensitivity to acetylcholine. 8,~5'16 5) Alterations in the central nervous system following deafferentation have been correlated in experimental animals and humans with the emergence o f certain electrophysiological abnormal spiking activity at spinal and supraspinal levels that appears to resemble J. Neurosurg. / Volume 72~June, 1990
Frey's syndrome presenting as tic douloureux epileptic seizures. 1.30 On the other hand, some biopsy specimens of trigeminal posterior roots from patients with idiopathic trigeminal neuralgia demonstrated grossly abnormal fibers with poor myelin coverage. 3,7 Moveover, some symptomatic trigeminal neuralgias, such as multiple sclerosis and postherpetic neuralgia, produce the same pathophysiological milieu for the development o f paroxysmal facial pain observed in the typical idiopathic disorder. 29 According to Braus-Eltze, 5 "As it [the auriculotemporal nerve] turns back around the ascending part of the mandible it gives off one, or usually two, strong branches which, immediately adjacent to the bone, run over its outer surface and enter the tract of the facial nerve. This is how sensory auriculotemporal fibers get into the rami of the facialis . . . . . Following the same course, or else as fine branches o f their own, secretion fibers, which have been fed by the otic ganglion to the auriculotemporal nerve via a minute ramus, enter the parotid." Thus, a neural anastomosis exists between the auriculotemporal and the facial nerves, so there is no difficulty in accounting for the auriculotemporal syndrome in terms of defective regeneration at least in cases of idiopathic facial palsies, x~ Furthermore, the convergence of fibers from the cutaneous distributions of the fifth, seventh, ninth, and 10th cranial nerves and the cervical plexus (C-2 and C-3) into the subnucleus caudalis region of the fifth cranial nerve spinal tract provides a logical anatomical explanation for the phen o m e n o n of referred pain 6,21 (Fig. 1). Treatment
Most of the methods of treatment have been directed at the gustatory sweating and facial flushing rather than
Trigeminal ganglion ,
9
division
~
~ ~
-
#l
~
~'~/ Mandibular
o,v,=
......
y//
]~
(~ -_ Brainstem "/" trigeminal '~ ,'~, ~ ~ ~s / / nuclearcomplex I I'~, [L/"
~
'
/ Chorda Auriculotemporaln. tympani
SpinaltractofV
Facialn. (VII)
FIG. 1. Schematic drawing showing neural anastomosis between the auriculotemporal and the facial nerves, as well as convergence of afferent fibers from the fifth, seventh, ninth, and 10th cranial nerves into the subnucleus caudalis region of the fifth cranial nerve spinal tract. Fibers from C-2 and C-3 are not shown.
J. Neurosurg. / Volume 72~June, 1990
at pain control. Local a n d systemic a n t i c h o l i n e r g i c agents a n d a n t i h i s t a m i n e s are effective only a g a i n s t the gustatory sweating a n d would be of no use in the t r e a t m e n t o f pain. 16 A n t i c o n v u l s a n t drugs, such as carb a m a z e p i n e a n d phenytoin, might be of s o m e benefit at least for p a r o x y s m a l pain; however, they were ineffective in o u r two patients. T r a n s i e n t a u r i c u l o t e m p o r a l nerve blocks 2~ with local anesthetic effect were b o t h diagnostic a n d t h e r a p e u t i c in o u r patients a n d c a r r i e d m i n i m a l risk, whereas neurolytic blocks (with alcohol) rarely i n d u c e p e r m a n e n t pain relief a n d s h o u l d be a v o i d e d in o r d e r not to d a m a g e n e a r b y nerves a n d / o r increase deafferentation. Ablative neurosurgical procedures, such as n e u r e c t o m y o f the a u r i c u l o t e m p o r a l nerve a n d section o f the glossopharyngeal nerve,15 often p r o d u c e o n l y t r a n s i e n t pain relief. R e f r a c t o r y cases might benefit f r o m p l a c e m e n t o f a caudalis d o r s a l r o o t entry zone lesion. 9 In conclusion, p a i n of a tic d o u l o u r e u x t y p e m a y be the p r e d o m i n a n t presenting s y m p t o m o f the F r e y ' s s y n d r o m e . A simple transient a u r i c u l o t e m p o r a l or m a n d i b u l a r nerve block m a y be a safe a n d effective t h e r a p e u t i c a p p r o a c h for pain control. References 1. Albe-Fessard D, Lombard MC: Use of an animal model to evaluate the origin of and protection against deafferentation pain, in Bonica J J, Lindblom U, Iggo A (eds): Advances in Pain Research and Therapy, Vol 5. New York: Raven Press, 1983, pp 691-700 2. Baillarger M: M6moire sur l'oblit6ration du canal de St6non. Gaz Med Paris 23:194-195, 1853 3. Beaver DL: Electron microscopy of the gasserian ganglion in trigeminal neuralgia. J Neurosurg 26:138-150, 1967 4. Bednarek J, Reid W, Matsumoto T: Frey's syndrome. Am J Surg 131:592-594, 1976 5. Braus-Eltze HC: Anatomie des Menschen, Band IV. Berlin: Springer-Verlag, 1940 6. Brodal A: Neurological Anatomy in Relation to Clinical Medicine, ed 3. Oxford: Oxford University Press, 1981 7. Calvin WH, Loeser JD, Howe JF: A neurophysiological theory for the pain mechanism of tic douloureux. Pain 3: 147-154, 1977 8. Daly RF: New observations regarding the auriculotemporal syndrome. Neurology 17:1159-1168, 1967 9. De Benedittis G" The spinal DREZ lesion and the caudalis DREZ lesion for intractable extra-facial and facial control: preliminary experience, in Montorsi M, Granelli P (eds): Surgical Updating. XXVI Congress of the International College of Surgeons. Lecture Book III. Bologna: Monduzzi Ed, 1988, pp 1531-1535 10. Ford FR: Paroxysmal lacrimination during eating as a sequel of facial palsy (syndrome of crocodile tears). Arch Neurol Psychiatry 29:1279-1288, 1933 11. Ford FR, Woodhall B: Phenomena due to misdirection of regenerating fibers of cranial, spinal and autonomic nerves. Arch Surg 36:480-496, 1938 12. Frey L" Le syndrome du neuf auriculo-temporal. Rev Nenroi 39:97-104, 1923 13. Fridberg OD: Das auriculo-temporale Syndrom. Dtsch Z Nervenheilk 121:225-239, 1931 14. Galli S, Bianchi A, Romani U, et al: La sindrome di Frey: considerazioni sui meccanismi patogenetici. Acta Otorhinolaryngul Ital 3:183-193, 1983 957
G. De Benedittis 15. Gardner WJ, McCubbin JW: Auriculotemporal syndrome. Gustatory sweating due to misdirection of regenerated nerve fibers. J A M A 160:272-277, 1956 16. Hanowell S, Lees DE, M a c n a m a r a T: Auriculotemporal syndrome after combined modality therapy for cancer. South Med J 72:1116-1120, 1979 17. Higier S: Das auriculo-temporale Syndrom und seine Pathogenese. Z Neurol Psychiatry 106:114-119, 1926 18. Hogeman KE: The auriculo-temporal syndrome after surgical intervention for mandibular protrusion. A study of morbid physiology (a preliminary report). Acta Psychiatr Seand (Suppl) 74:106-107, 1951 19. Kahle KW, Westermann H: Das auriculotemporale Syndrom. Dtsch Z Nervenheilk 169:39-54, 1952 20. Katz J: Atlas of Regional Anesthesia. Norwalk, Conn: Appleton-Century-Crofts, 1985 21. Kerr FWL: The organization of primary afferents in the subnucleus caudalis of the trigeminal: a light and electron microscopic study of regeneration. Brain Res 23: 147-165, 1970 22. Laage-Hellman JE: Gustatory sweating and flushing after conservative parotidectomy. Acta Otolaryngol 48: 234-252, 1957 23. Loeser JD: Definition, etiology, and neurological assessment of pain originating in the nervous system following deafferentation, in Bonica J J, Lindblom U, Iggo A (eds): Advances in Pain Research and Therapy, Vol 5. New York: Raven Press, 1983, pp 701-711 24. Roger J, Bille J, Vigoureux RA: Multiple cranial nerve palsies, in Vinken P J, Bruyn G W (eds): Handbook of Clinical Neurology. Vol 2: Localization in Clinical Neurology. Amsterdam: North-Holland, 1975, pp 103-104
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25. Sadjadpour K: Postfacial palsy phenomena: faulty nerve regeneration of ephaptic transmission? Brain Res 95: 403-406, 1975 26. Schiffter R, Schliack H: Das sogenannte Geschmacksschwitzen. Fortsehr Neurol Psyehiatr 36:261-274, 1968 27. Schwarz GA: Dysautonomic syndromes in adults, in Vinken P J, Bruyn G W (eds): Handbook of Clinical Neurology. Voi 22, Part II. Systems Disorders and Atrophies. Amsterdam: North-Holland, 1975, pp 243-280 28. Storrs T J: A variation of the auriculotemporal syndrome. Br J Oral Maxillofac Surg 11:236-242, 1974 29. Sweet WH: Trigeminal neuralgias, in Ailing CC III, Mahan PE (eds): Facial Pain, ed 2. Philadelphia: Lea & Febiger, 1977, pp 71-93 30. Tasker RR, Tsuda T, Hawrylyshyn P: Clinical neurophysiological investigation of deafferentation pain, in Bonica J J, Lindblom U, Iggo A (eds): Advances in Pain Research and Therapy, Vol 5. New York: Raven Press, 1983, pp 713-738 31. Ztilch K J: Idiopathic facial paresis, in Vinken PJ, Bruyn GW (eds): Handbook of Clinical Neurology. Vol 8, Part II: Diseases of Nerves. Amsterdam: North-Holland, 1970, pp 275-277
Manuscript received June 15, 1989. Accepted in final form October 24, 1989. Address reprint requests to: Giuseppe De Benedittis, M.D., Pain Research and Treatment Unit, Institute of Neurosurgery, University of Milan, 35 via F. Sforza, 20123 Milan, Italy.
J. Neurosurg. / Volume 72/June, 1990
Auriculotemporal syndrome (Frey's syndrome) presenting as tic douloureux Report of two cases GIUSEPPE DE BENEDITFIS, M.D. Pain Research and Treatment Unit, Institute of Neurosurgery, University of Milan, Milan, Italy ~," Two cases of auriculotemporal nerve syndrome (Frey's syndrome) presenting as trigeminal tic douloureux are reported. This condition, characterized by gustatory sweating and facial hyperemia, is occasionally associated with pain, which is usually described as aching or burning, and long-lasting. In these two cases, however, a tantalizing gustatory pain occurred in excruciating brief paroxysms. The pathophysiology of the syndrome, with particular reference to pain, and possible treatment modalities are discussed. KEY WORDS auriculotemporal syndrome trigeminal neuralgia ~
T
HE auriculotemporal nerve syndrome was first described by Baillarger 2 in 1853, but not until 1923 was it recognized as a distinct entity by Lucie Frey, 12 who first proposed a pathogenic hypothesis of this rather rare syndrome. Since then, the designation of auriculotemporal syndrome or "Frey's syndrome" has been internationally recognized, and innumerable cases have been described. 26,31 The disorder appears in the classic form o f hyperemia and sweating in the distribution of the auriculotemporal nerve. Sweating occurs almost immediately upon tasting foods, particularly spicy ones; hence the description of gustatory sweating. Pain in the distribution of the nerve is an u n c o m m o n finding, occurring in less than 10% of cases. 4 Such pain is usually described as of a constant aching or burning nature. Two cases of auriculotemporal syndrome are described here in which tic douloureux of the face was the presenting and p r o m i n e n t symptom. These two patients were seen at the Pain Research and Treatment Unit, Institute of Neurosurgery, University of Milan. Paroxysmal pain was the presenting and predominant feature. It was aggravated by mastication or motion of the jaw and was preauricular, radiating into the external ear canal. H y p e r e m i a of the affected side of the face was observed in both cases, whereas gustatory sweating was present in one case only. O u r initial working diagnosis o f an atypical presentation o f the auriculotemJ. Neurosurg. / Volume 72/June, 1990
9 Frey's syndrome
9 facial pain
9
poral nerve syndrome was confirmed in both cases by the immediate and continued relief of pain following a simple auriculotemporal nerve block, 2~ using 0.5% bupivacaine. At 1-year follow-up examination, one patient was pain-free and the other patient had been lost to follow-up review. Case Reports
Case 1 This 72-year-old m a n suffered a left "idiopathic" facial paresis in 1982. Several weeks later, he developed left preauricular pain which radiated into the external ear canal and the temporal region. H y p e r e m i a was present, but not gustatory sweating. The pain was characterized by brief episodes of paroxysmal lighteninglike sharp stabbing sensations, triggered by gustatory excitation and aggravated by jaw m o v e m e n t . Examination revealed no objective sensory deficit of the face. An auriculotemporal nerve block with 3 ml of 0.5% bupivacaine gave p r o m p t relief. Pain relief lasted for 1 year, after which the patient was lost to further review. Case 2 This 79-year-old w o m a n complained of left facial pain, which had begun "spontaneously" 3 m o n t h s before her referral to our Pain Service. T h e pain was distributed into the preauricular and mandibular re955
G. De Benedittis gion. It was o f a tic douloureux type on introduction of food into the mouth, followed by a deep steady pain lasting 5 to 6 minutes. She also complained of flushing and gustatory sweating on the left side o f the face occurring almost immediately upon tasting any food, but particularly some spicy foods. Neurological examination (including sensory examination) was within normal limits. Immediate and continued relief o f pain was obtained by a simple auriculotemporal nerve block, using 0.5% bupivacaine. At her 1-year follow-up examination, the patient was pain-free. Discussion Although pain in the distribution of the auriculotemporal nerve was not mentioned as an accompanying symptom in the original description o f the syndrome by Frey,12 it has been reported as an u n c o m m o n finding, occurring in less than 10% of cases. 4 Pain is usually described as aching or burning, and long-lasting. To our knowledge, this is the first report of two consecutive cases in which pain was the presenting and predominant symptom. Furthermore, pain occurred in very severe, excruciating paroxysms, lasting only a few seconds and never longer than a minute. This paradoxical, tantalizing gustatory pain reflex occurred when flavored foods were placed on the tongue. The physiopathology and the definitive etiology of Frey's auriculotemporal syndrome are still uncertain. In the opinion of m a n y authors, 1~ the auriculotemporal syndrome is always preceded by a lesion of the facial fibers in the parotid region. The symptoms may therefore be present after such insults as a severe attack of mumps, a penetrating lesion of the parotid region, surgical intervention upon the parotid gland, and abscesses of the angle of the jaws. However, sometimes (as in our Case 2) the etiology remains unknown. Pathogenesis The most c o m m o n l y accepted theory is that of misdirected regeneration suggested in 1938 by Ford and WoodhallJ 1 They proposed that the auriculotemporal syndrome derived from the anatomical disposition of the auriculotemporal nerve. Arising from the mandibular nerve just outside the foramen ovale, the auriculotemporal nerve courses close to the parotid capsule on its way to the skin of the temple. Postganglionic parasympathetic neurons in the otic ganglion send secretory fibers through the auriculotemporal nerve to the parotid gland. Postganglion sympathetic neurons in the superior cervical ganglion send fibers, also via the auriculotemporal nerve, to the parotid gland and to the sweat glands o f the skin supplied by the nerve. Any injury to the fibers o f this mixed nerve can create a considerable disturbance in the pathways of salivation and sweating, 2v whereby aberrant regeneration o f the parasympathetic vasodilator fibers to the parotid gland results in reafferentation of the sympathetic end-organs (sweat glands and cutaneous vessels).
956
Both the initially innervated salivary glands and the later-innervated sweat glands are cholinergic, so there would be no compatibility between the regenerating fibers and their new effector organs, accounting for the gustatory sweating in the classic cases. The hyperemia can be explained by the direct innervation of the cutaneous vessels by parasympathetic vasodilatory vessels, which are known to exist in the nerves that supply the major salivary glands. Gustatory, but also exteroceptive (tactile), stimulP 4 may trigger the paradoxical gustatory-sweating reflex, the afferent portion o f the arc being mediated through the fifth, seventh, ninth, and 10th cranial nerves, particularly the ninth. The fibers which carry gustatory sensation terminate a t t h e solitary tract and its nucleus into the brain stem. The exteroceptive components of the facial, glossopharyngeal, and vagus nerves join into the descending spinal tract. Secondary neurons pass from these structures to the superior and inferior salivary nuclei from which efferent parasympathetic impulses reach the salivary glands mainly through the glossopharyngeal nerve. 15 Pain might be the result of an artificial synapse (ephapse) between the sympathetic efferents and the sensory afferents much like reflex sympathetic dystrophy, ~6'25although sympathetic nerve blocks are usually ineffective. Other theories postulate traumatic neuritis of the auriculotemporal nerve, 28 transaxonal activation of a regenerated nerve fiber by the action potential of a nerve fiber to a different end-organ, or reinnervation by axons which previously supplied different end-organs. 27 In our opinion, several kinds of indirect evidence support the hypothesis that pain secondary to the auriculotemporal syndrome might be due to partial deafferentation. 1) Pain is an u n c o m m o n finding in Frey's syndrome patients; only a small fraction (1 to 5%) of the patients with a specific injury to the nervous system will develop pain. 23 2) The pain syndrome characteristics are not correlated with the pathogenesis of the lesion. Although trauma (accidental or surgically induced) is the single most c o m m o n cause of pain associated with deafferentation, there are numerous examples of infection, degenerative disease, and demyelinating disease leading to different types of chronic pain, such as constant burning pain or tic douloureux. This is often the case with auriculotemporal syndrome. 3) It has long been recognized that pain caused by deafferentation frequently has a delayed onset, from weeks to months after injury. This particular onset pattern is also characteristic of Frey's syndrome. 4) Denervation hypersensitivity is a c o m m o n process set off by nerve lesions: some patients with auriculotemporal syndrome were also found to have hypersensitivity to acetylcholine. 8,~5'16 5) Alterations in the central nervous system following deafferentation have been correlated in experimental animals and humans with the emergence o f certain electrophysiological abnormal spiking activity at spinal and supraspinal levels that appears to resemble J. Neurosurg. / Volume 72~June, 1990
Frey's syndrome presenting as tic douloureux epileptic seizures. 1.30 On the other hand, some biopsy specimens of trigeminal posterior roots from patients with idiopathic trigeminal neuralgia demonstrated grossly abnormal fibers with poor myelin coverage. 3,7 Moveover, some symptomatic trigeminal neuralgias, such as multiple sclerosis and postherpetic neuralgia, produce the same pathophysiological milieu for the development o f paroxysmal facial pain observed in the typical idiopathic disorder. 29 According to Braus-Eltze, 5 "As it [the auriculotemporal nerve] turns back around the ascending part of the mandible it gives off one, or usually two, strong branches which, immediately adjacent to the bone, run over its outer surface and enter the tract of the facial nerve. This is how sensory auriculotemporal fibers get into the rami of the facialis . . . . . Following the same course, or else as fine branches o f their own, secretion fibers, which have been fed by the otic ganglion to the auriculotemporal nerve via a minute ramus, enter the parotid." Thus, a neural anastomosis exists between the auriculotemporal and the facial nerves, so there is no difficulty in accounting for the auriculotemporal syndrome in terms of defective regeneration at least in cases of idiopathic facial palsies, x~ Furthermore, the convergence of fibers from the cutaneous distributions of the fifth, seventh, ninth, and 10th cranial nerves and the cervical plexus (C-2 and C-3) into the subnucleus caudalis region of the fifth cranial nerve spinal tract provides a logical anatomical explanation for the phen o m e n o n of referred pain 6,21 (Fig. 1). Treatment
Most of the methods of treatment have been directed at the gustatory sweating and facial flushing rather than
Trigeminal ganglion ,
9
division
~
~ ~
-
#l
~
~'~/ Mandibular
o,v,=
......
y//
]~
(~ -_ Brainstem "/" trigeminal '~ ,'~, ~ ~ ~s / / nuclearcomplex I I'~, [L/"
~
'
/ Chorda Auriculotemporaln. tympani
SpinaltractofV
Facialn. (VII)
FIG. 1. Schematic drawing showing neural anastomosis between the auriculotemporal and the facial nerves, as well as convergence of afferent fibers from the fifth, seventh, ninth, and 10th cranial nerves into the subnucleus caudalis region of the fifth cranial nerve spinal tract. Fibers from C-2 and C-3 are not shown.
J. Neurosurg. / Volume 72~June, 1990
at pain control. Local a n d systemic a n t i c h o l i n e r g i c agents a n d a n t i h i s t a m i n e s are effective only a g a i n s t the gustatory sweating a n d would be of no use in the t r e a t m e n t o f pain. 16 A n t i c o n v u l s a n t drugs, such as carb a m a z e p i n e a n d phenytoin, might be of s o m e benefit at least for p a r o x y s m a l pain; however, they were ineffective in o u r two patients. T r a n s i e n t a u r i c u l o t e m p o r a l nerve blocks 2~ with local anesthetic effect were b o t h diagnostic a n d t h e r a p e u t i c in o u r patients a n d c a r r i e d m i n i m a l risk, whereas neurolytic blocks (with alcohol) rarely i n d u c e p e r m a n e n t pain relief a n d s h o u l d be a v o i d e d in o r d e r not to d a m a g e n e a r b y nerves a n d / o r increase deafferentation. Ablative neurosurgical procedures, such as n e u r e c t o m y o f the a u r i c u l o t e m p o r a l nerve a n d section o f the glossopharyngeal nerve,15 often p r o d u c e o n l y t r a n s i e n t pain relief. R e f r a c t o r y cases might benefit f r o m p l a c e m e n t o f a caudalis d o r s a l r o o t entry zone lesion. 9 In conclusion, p a i n of a tic d o u l o u r e u x t y p e m a y be the p r e d o m i n a n t presenting s y m p t o m o f the F r e y ' s s y n d r o m e . A simple transient a u r i c u l o t e m p o r a l or m a n d i b u l a r nerve block m a y be a safe a n d effective t h e r a p e u t i c a p p r o a c h for pain control. References 1. Albe-Fessard D, Lombard MC: Use of an animal model to evaluate the origin of and protection against deafferentation pain, in Bonica J J, Lindblom U, Iggo A (eds): Advances in Pain Research and Therapy, Vol 5. New York: Raven Press, 1983, pp 691-700 2. Baillarger M: M6moire sur l'oblit6ration du canal de St6non. Gaz Med Paris 23:194-195, 1853 3. Beaver DL: Electron microscopy of the gasserian ganglion in trigeminal neuralgia. J Neurosurg 26:138-150, 1967 4. Bednarek J, Reid W, Matsumoto T: Frey's syndrome. Am J Surg 131:592-594, 1976 5. Braus-Eltze HC: Anatomie des Menschen, Band IV. Berlin: Springer-Verlag, 1940 6. Brodal A: Neurological Anatomy in Relation to Clinical Medicine, ed 3. Oxford: Oxford University Press, 1981 7. Calvin WH, Loeser JD, Howe JF: A neurophysiological theory for the pain mechanism of tic douloureux. Pain 3: 147-154, 1977 8. Daly RF: New observations regarding the auriculotemporal syndrome. Neurology 17:1159-1168, 1967 9. De Benedittis G" The spinal DREZ lesion and the caudalis DREZ lesion for intractable extra-facial and facial control: preliminary experience, in Montorsi M, Granelli P (eds): Surgical Updating. XXVI Congress of the International College of Surgeons. Lecture Book III. Bologna: Monduzzi Ed, 1988, pp 1531-1535 10. Ford FR: Paroxysmal lacrimination during eating as a sequel of facial palsy (syndrome of crocodile tears). Arch Neurol Psychiatry 29:1279-1288, 1933 11. Ford FR, Woodhall B: Phenomena due to misdirection of regenerating fibers of cranial, spinal and autonomic nerves. Arch Surg 36:480-496, 1938 12. Frey L" Le syndrome du neuf auriculo-temporal. Rev Nenroi 39:97-104, 1923 13. Fridberg OD: Das auriculo-temporale Syndrom. Dtsch Z Nervenheilk 121:225-239, 1931 14. Galli S, Bianchi A, Romani U, et al: La sindrome di Frey: considerazioni sui meccanismi patogenetici. Acta Otorhinolaryngul Ital 3:183-193, 1983 957
G. De Benedittis 15. Gardner WJ, McCubbin JW: Auriculotemporal syndrome. Gustatory sweating due to misdirection of regenerated nerve fibers. J A M A 160:272-277, 1956 16. Hanowell S, Lees DE, M a c n a m a r a T: Auriculotemporal syndrome after combined modality therapy for cancer. South Med J 72:1116-1120, 1979 17. Higier S: Das auriculo-temporale Syndrom und seine Pathogenese. Z Neurol Psychiatry 106:114-119, 1926 18. Hogeman KE: The auriculo-temporal syndrome after surgical intervention for mandibular protrusion. A study of morbid physiology (a preliminary report). Acta Psychiatr Seand (Suppl) 74:106-107, 1951 19. Kahle KW, Westermann H: Das auriculotemporale Syndrom. Dtsch Z Nervenheilk 169:39-54, 1952 20. Katz J: Atlas of Regional Anesthesia. Norwalk, Conn: Appleton-Century-Crofts, 1985 21. Kerr FWL: The organization of primary afferents in the subnucleus caudalis of the trigeminal: a light and electron microscopic study of regeneration. Brain Res 23: 147-165, 1970 22. Laage-Hellman JE: Gustatory sweating and flushing after conservative parotidectomy. Acta Otolaryngol 48: 234-252, 1957 23. Loeser JD: Definition, etiology, and neurological assessment of pain originating in the nervous system following deafferentation, in Bonica J J, Lindblom U, Iggo A (eds): Advances in Pain Research and Therapy, Vol 5. New York: Raven Press, 1983, pp 701-711 24. Roger J, Bille J, Vigoureux RA: Multiple cranial nerve palsies, in Vinken P J, Bruyn G W (eds): Handbook of Clinical Neurology. Vol 2: Localization in Clinical Neurology. Amsterdam: North-Holland, 1975, pp 103-104
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25. Sadjadpour K: Postfacial palsy phenomena: faulty nerve regeneration of ephaptic transmission? Brain Res 95: 403-406, 1975 26. Schiffter R, Schliack H: Das sogenannte Geschmacksschwitzen. Fortsehr Neurol Psyehiatr 36:261-274, 1968 27. Schwarz GA: Dysautonomic syndromes in adults, in Vinken P J, Bruyn G W (eds): Handbook of Clinical Neurology. Voi 22, Part II. Systems Disorders and Atrophies. Amsterdam: North-Holland, 1975, pp 243-280 28. Storrs T J: A variation of the auriculotemporal syndrome. Br J Oral Maxillofac Surg 11:236-242, 1974 29. Sweet WH: Trigeminal neuralgias, in Ailing CC III, Mahan PE (eds): Facial Pain, ed 2. Philadelphia: Lea & Febiger, 1977, pp 71-93 30. Tasker RR, Tsuda T, Hawrylyshyn P: Clinical neurophysiological investigation of deafferentation pain, in Bonica J J, Lindblom U, Iggo A (eds): Advances in Pain Research and Therapy, Vol 5. New York: Raven Press, 1983, pp 713-738 31. Ztilch K J: Idiopathic facial paresis, in Vinken PJ, Bruyn GW (eds): Handbook of Clinical Neurology. Vol 8, Part II: Diseases of Nerves. Amsterdam: North-Holland, 1970, pp 275-277
Manuscript received June 15, 1989. Accepted in final form October 24, 1989. Address reprint requests to: Giuseppe De Benedittis, M.D., Pain Research and Treatment Unit, Institute of Neurosurgery, University of Milan, 35 via F. Sforza, 20123 Milan, Italy.
J. Neurosurg. / Volume 72/June, 1990
