Radiofrequency percutaneous Gasserian ganglion lesions Results in 140 patients with trigeminal pain BURTON M .
ONOFRIO,M . D .
Mayo Clinicand Mayo Foundation, Rochester, Minnesota
v' Percutaneous radiofrequency ablation of the Gasserian ganglion or posterior root, or both, was performed in 140 patients. Of the 135 patients with trigeminal neuralgia, satisfactory analgesia was achieved in 121. Postoperative complications included unintentional first-division analgesia (10), transient sixth-nerve palsy (1), neuroparalytic keratitis (2), and anesthesia dolorosa (2). The phenomenon of facial blush may be helpful in avoiding unwanted first-division analgesia. In four of five patients with other forms of neuralgia, the procedure did not relieve pain; the fifth patient experienced significant relief from pain due to carcinoma of the mandible. KEy W o a o s 9 trigeminal neuralgia 9 Gasserian ganglion percutaneous lesion 9 radiographic coordinates
9
,E have analyzed the results of ra- face for a relatively long period, it helps him diofrequency ablation of the Gas- to tolerate permanent numbness following a serian ganglion in 140 patients, 135 subsequent radiofrequency ablation procewith trigeminal neuralgia and five with other dure. Before a patient was selected for the types of facial pain, and are reporting this ex- ablation procedure, any patient under 30 with face pain typical of trigeminal neuralgia perience. would undergo both angiography and Pantopaque rhombencephalography so that the Clinical Material and Methods possibility of mass lesions in and around Selection of Patients Meckel's cavity could be excluded. OtherOf the 135 patients suffering from tri- wise, age or complicating medical problems, geminal neuralgia, those who had had no other than those requiring anticoagulant previous medical treatment were treated with therapy, did not limit selection of patients for Dilantin or Tegretol. If this therapy was in- radiofrequency ablation. Table 1 shows the age distribution of the effective, patients were treated by alcohol blocks of the division or divisions affected 135 patients who were treated by radiofrebefore a definitive surgical procedure on the quency ablation for the first time. Table 2 ganglion was attempted. We believe that if a emphasizes the relative infrequency of patient actually experiences numbness of the isolated first-division pain, while corn-
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132
J. Neurosurg.
Volume42 / February, 1975
Radiofrequency percutaneous Gasserian ganglion lesions TABLE I Age factors in 135 patients with trigeminal neuralgia
Age at Onset Age at Time of Age Group of Trigeminal Radiofrequency (yrs) Neuralgia Lesion (No. of Cases) (No. of Cases) 10-20 21-30 31-40 41-50 51-60 61-70 71-80 81+
1 6 10 25 38 32 2O 3
9 14 33 36 36 7
TABLE 2 Divisions of fifth cranial nerve involved in 135 patients witit trigeminal neuralgia
Division Involved
No. of Cases
Vl v2 v8 vl, v2 v,, v~ Vl, v2, V3
2 22 25 28 47 11
binations of pain referred to the first and second or to all three divisions are common. The absence in this and other series of noncontiguous division pain (i.e., first and third divisions) is striking. Operative Technique
The patient is awake during the radiofrequency ablation procedure except for a brief period of unconsciousness produced by the administration of methohexital (Brevital) prior to the actual coagulation of the Gasserian ganglion and posterior root. Localization of the needle by roentgenography and stimulation with the electrode carries virtually no risk. The observation of certain precautions minimizes the possibility of untoward complications. The patient is admitted to the hospital the night before surgery, and the following morning is brought to the x-ray department and placed on the fluoroscopy table; a firm 4-inch pad is placed beneath the torso and legs so that the head and neck are hyperextended at J. Neurosurg. / Volume 42 / February, 1975
20 ~. Prior explanation of the entire procedure to the usually apprehensive patient facilitates verbal preparation for each step as it is carried out. After preparation of the involved side of the lower face and opposite forehead with an aqueous solution of thimerosal (Merthiolate), an 18-gauge spinal needle (the indifferent electrode) is placed in the subgaleal space of the opposite forehead. The radiothermistor needle 11 is then introduced through the skin 2.5 cm lateral to the labial commissure of the involved side. Its trajectory should bisect the pupil in the coronal plane, and pass through a point 3 cm anterior to the external auditory meatus in the sagittal plane. At this stage, the needle should have been advanced through the skin to a depth of only 4 to 5 cm. Fluoroscopic monitoring of the base of the skull is essential before the needle is introduced into a foramen because it is possible, in the cadaver specimen, to enter the foramen rotundum, foramen lacerum, internal auditory meatus, and the jugular foramen? ~ With the patient's neck hyperextended 20 ~ the face is gradually rotated away from the involved side while the area of the petrous ridge is monitored by fluoroscopy. Characteristically, the foramen ovale can be made to appear as a rising sun over the petrous ridge when lateral rotation is about 20 ~ with the neck in hyperextension (Fig. 1). Both of these variables are modified until the foramen ovale is well outlined (Fig. 2). The needle tip is then placed at the foramen ovale, and a lateral roentgenogram is taken. The trajectory of the needle must never bisect the floor of the sella as seen in the lateral x-ray. To achieve analgesia of the first division, the needle tip optimally should be at the junction of the petroclinoid ligament and posterior clinoid. For analgesia of the second division, the tip is introduced for a shorter distance through the foramen on this same trajectory. For third-division analgesia, a shallower middle fossa line is followed. If necessary, the preceding steps are repeated; the foramen ovale is not penetrated until the desired trajectory has been obtained (Fig. 3 upper). The patient tolerates this phase well because the fifth nerve has been manipulated very little. When the lateral roentgenogram confirms the proper trajectory, one determines the depth of insertion and introduces the needle to a position depending on the analgesia ]33
B. M. Onofrio
F~. 1. Position of patient for obtaining an optimal view of foramen ovale. Neck is in 20~ hyperextension and head is rotated 15 to 20~ away from side of pain.
FIG. 2. Radiothermistor needle entering most medial portion of left foramen ovale, in position for further insertion to achieve analgesia of first or second division, or both. For third-division analgesia, needle should be introduced into middle of foramen in this projection.
desired: through the most medial portion of the foramen for first- to second-division analgesia or through the middle of the foramen for third-division analgesia. Avoidance of penetration of the lateral third of the foramen ovale makes injury to the temporal lobe highly unlikely, and avoidance of bisec]34
tion of the floor of the sella turcica obviates possible injury to the extraocular nerves (Fig. 3 lower). Under fluoroscopic control, the needle can be kept out of the wrong foramen entirely and carotid injury should be virtually impossible. Once the proper trajectory has been accomplished, the patient is forewarned of the most unpleasant part of the procedure: piercing of the third division. The introduction of the needle into the foramen gives the operator a sensation of passing through fascia or tendon until the dura propria is penetrated; then a small "pop" is usually felt. Any resistance to deeper insertion is due either to penetration of the lateral cavernous sinus wall by the needle or, if the needle is in a low middle-fossa trajectory, abutment of the needle against the petrous ridge. In these circumstances, the needle must either be positioned so that it lies less deeply in the foramen at a point superficial to that at which the operator feels the second resistance or be totally replaced, starting from the skin puncture to achieve a different trajectory. If removal of the stylet is followed by the flow of cerebrospinal fluid and a permanent lateral roentgenogram shows proper final placement, the stimulating current is turned on. If placement of the exposed needle tip is optimal, stimulation with 0.1 V will cause facial pain. If more than 2 to 3 V are needed to induce pain, the needle placement is probably not satisfactory enough for the achievement of suitable analgesia postoperatively. This phase of the procedure is terminated when stimulation reproduces pain in the area affected in a typical attack of trigeminal neuralgia. At this juncture, an intravenous injection (3 to 8 ml) of methohexital (Brevital) is given. A coagulating current is delivered to a temperature of 80~ (as measured by a thermistor bead at the end of the coagulating needle) and maintained for 30 seconds. During the period of unconsciousness and during coagulation, dense erythema almost always appears, becoming more brilliant in the analgesic zones the longer the current is applied; in nearly every case it indicates a durable lesion and is always confined to the divisions or division undergoing sensory deprivation. The blush will not appear if the sensory root, the ganglion, or the sensory division of the fifth nerve has been subjected J. Neurosurg. / Volume 42 / February, 1975
Radiofrequency percutaneous Gasserian ganglion lesions
FIG. 3. Lateral roentgenogram with superimposed drawings. Upper: Posterior root, Gasserian ganglion, three divisions, and motor root of fifth nerve. Lower: Needle trajectories for obtaining first-, second-, and third-division analgesia. Analgesia for first division is obtained by using a steeper trajectory and that for third division by a shallow trajectory; second-division analgesia requires an intermediate slope. In sagittal insertion, first-division analgesia must be obtained with deepest penetration to junction of petroclinoid ligament and clivus; third-division analgesia requires shallower penetration through foramen ovale. To avoid injury to third, fourth, or sixth nerve, the needle must not enter shaded area. to section or injection and is associated with dense anesthesia in that part of the face. The phenomenon of the blush originally was considered to indicate involvement by heating of the sympathetic arteries around and near the cavernous part of the carotid artery or stimulation of the adjacent greater superficial petrosal nerve. As this finding was observed
J. Neurosurg. / Volume 42 / February, 1975
in more patients undergoing electrocoagulation, however, it became apparent that the limitation of the dense blush to a single division or to divisions rendered densely analgesic by operation probably indicated stimulation of an active vasodilator fiber system, the course of which was obscure. These interesting clinical observations have led to 135
B. M. Onofrio laboratory investigation elucidating the anatomical course of this vasodilating response and will be reported at a later date? The patient is then allowed to awaken fully and, if sensory testing shows the desired analgesia, the procedure is terminated. If not, the duration of coagulation is increased by 30 seconds and repeated until analgesia is obtained. To avoid a high incidence of recurrence, the area of analgesia must include the entire trigger zone. Like Sweet and Wepsicy 'xs Tew,~~ and others, we attempt to damage selectively A-delta and C fibers; to avoid neurokeratitis and anesthesia dolorosa, we try to leave the larger fibers, which subserve light touch, relatively intact. Others have found, as we have, that patients who have little if any loss of facial sensibility after operation have an extremely high recurrence rate, usually in the first 2 years. If dense analgesia is present, the expected recurrence rate varies between 18% and 25%. This rate is approximately the same as may be expected from the TaarnhCj decompression procedureTM and twice as high as that following the Spiller-Frazier procedure.' Whatever the recurrence rate, StSwsand and associates ~5 summarized the issue succinctly; they justified the 53% recurrence rate in their series following partial coagulation of the ganglion on the basis of the ease of repeating the procedure. Results
Relief of Trigerninal Neuralgia Of the 135 patients with trigeminal neuralgia undergoing radiofrequency surgery for the first time, nine had been treated previously by avulsion of the peripheral division, 16 had undergone subtemporal compression of the Gasserian ganglion or partial section, and two had been treated by posterior fossa subtotal root section. In 115 patients the first procedure produced good analgesia with no return of pain. In 16 patients the first stereotaxic procedure produced fair to good analgesia with initial pain relief but recurrence of pain 2 weeks to 14 months later. All of these patients had relatively slight postoperative analgesia, a fact reinforcing the observation that the less the loss of sensibility in a division or divisions the higher the recurrence rate. One patient, 136
who had undergone three previous subtemporal open procedures elsewhere, had a small island of preserved sensation over the right cheek; this area was involved in periodic bouts of typical trigeminal neuralgia. We were unable to enlarge the area of facial anesthesia to include this segment even with two radiofrequency procedures. Of the 16 patients, one requested repeat alcohol blocks; one started to take Tegretol again; seven currently have occasional infrequent light "phantom" attacks not yet severe enough to justify a further surgical procedure; and six underwent a second radiofrequency procedure which has to date been effective in causing total relief. Anesthesia dolorosa developed in two patients; in two others, both of whom had persistent pain, we were unable to produce any analgesia at all. They later underwent an open surgical procedure.
Relief of Other Types of Facial Pain After we had established good anatomical coordinates for obtaining a reasonably selective lesion of the ganglion and posterior root we performed the radiofrequency procedure in five patients with other types of facial pain. In two patients who had undergone an open surgical procedure for trigeminal neuralgia elsewhere and who had anesthesia dolorosa when first seen at the Mayo Clinic, the radiofrequency procedure was totally ineffective. With respect to the two patients with atypical facial pain, anesthesia dolorosa developed in one and the condition was unchanged in the other. In the fifth patient, who had pain secondary to carcinoma of the mandible, the procedure produced good analgesia of the face and relief of pain.
Postoperative Sequelae Motor Weakness. Because of the trajectory of the fifth motor root, weakness of the masseter and pterygoids almost always occurs with first-division analgesia and is rare with the creation of isolated third-division analgesia. The unilateral weakness is well tolerated by most patients even when it is severe, as seen in Table 3. In completing the follow-up questionnaire patients rarely mentioned difficulty with mastication as a major complaint. Usually the motor weakness resolves in 6 to 9 months, although this is not uniformly true. The more bothersome side J. Neurosurg. / Volume 42 / February, 1975
Radiofrequency percutaneous Gasserian ganglion lesions TABLE
3
Motor weakness of fifth cranial nerve after 140 radioJhequency procedures*
Degree of Weaknesst -
1
-2 -3 -4 total
No. of Cases 6
30 17 3 56
No. of Cases with Symptoms --
1 -1 2
* Includes 135 patients with trigeminal neuralgia and five patients with other forms of facial pain. t On scale ranging from 0 (normal) to - 4 (absence of motor power). TABLE 4 "Unwanted" first-division analgesia in 135 patients with trigeminal neuralgia after radiofrequency lesions Divisions of Fifth No. of Patients Cranial Nerve No. of Patients with Postoperative with Trigeminal Operated On First-division Neuralgia* Analgesiat V2 V3 V2, V.~
22 25 47
5 0 5
* vl was excluded from consideration in this table. t The 10 patients in this group had first-division analgesia in addition to analgesia in divisions affected by trigeminal neuralgia.
effect of weakness of the fifth motor nerve is paralysis of the tensor veli palatini, which causes a failure of closure of the eustachian tube. A feeling of fullness in the ear with decreased hearing and ear ache are frequent complaints of patients with moderate to severe weakness of the motor division of the fifth nerve. Examination of the external auditory canal and eardrum reveals no abnormalities, and all of the symptoms tend to disappear when the patient bends far forward or lies down. Follow-up of these patients will determine whether this problem will resolve as the motor weakness clears. Unwanted First-Division Analgesia. Unwanted first-division analgesia has become less of a problem as our experience with the procedure has grown (Table 4). Among the 135 patients operated on for trigeminal neuralgia, first-division analgesia and absence of the corneal reflex developed in five of 22 J. Neurosurg. / Volume 42 / February, 1975
patients with second-division trigeminal neuralgia and in five of 47 with combined second- and third-division pain. The risk of creating first-division anesthesia with resulting absent corneal reflex diminished in the management of the last 50 cases. This results directly from watching the facial areas where a vasodilating blush occurs during the actual process of coagulation of the ganglion and posterior root; a dense blush in the face almost always indicates developing analgesia or anesthesia (Fig. 4). Before this became recognized, only formal sensory testing after the patient had recovered from the effects of methohexital could reveal the area and degree of sensory deprivation. Now we can either terminate the heating or withdraw to a shallower position in Meckel's cavity if a blush appears in the first division of the anesthetized patient. This has helped greatly to avoid unwanted first-division sensory loss. Sixth-Nerve Palsy. In the total of 140 radiofrequency procedures, there was only one case of profound sixth-nerve palsy and this resolved in 6 months. During insertion of the needle, a second resistance was encountered after Meckel's cavity had been entered, and heat was transmitted across a partially penetrated lateral cavernous sinus wall. Neuroparalytic Keratitis. Two patients developed neuroparalytic keratitis. One required a permanent lateral tarsorrhaphy; vision of 20/60 was preserved in the involved eye. The other patient did not need a tarsorrhaphy but the visual acuity was permanently decreased to 20//100. Anesthesia Dolorosa. Two patients developed anesthesia dolorosa with dense anesthesia in all three divisions after operation. Discussion
There are numerous forms of treatment of trigeminal neuralgia. These include medical treatment with drugs such as diphenylhydantoin (Dilantin) and carbamazepine (Tegretol), 1 temporary nerve blocks and avulsions peripherally, instillation of liquid agents such as boiling water and alcohol into Meckel's cavity, 3'a subtemporal extradural Gasserian ganglion and posterior root compression or decompression, 5'1~'19 partial or total section, 4 posterior fossa sensory root 137
B. M. Onofrio
Fl~. 4. Phenomenon of facial blush. Patient underwent radiofrequency procedure to alleviate right second-division trigeminal neuralgia. Dense erythema over malar eminence and right upper lip occurred during creation of lesion at 80~ over 60 seconds as measured by needle-tip thermistor. After patient recovered from methohexital anesthesia, there was marked analgesia in right second division with preserved tactile sensation; sensation was intact in first and third divisions. section, ~ and temporo-occipital craniotomy with transtentorial section of the fifth sensory root? Each procedure has its advocates, but the very multiplicity of choices indicates that none is totally satisfactory. Ideally, one would like to offer a drug or surgical procedure for trigeminal neuralgia that would give a high rate of permanent cure with no mortality, low morbidity, and as little sensory deprivation as possible. Kirschner TM introduced coagulation of the Gasserian ganglion in 1925, but technical problems and complications of the procedure caused it to fall into disrepute. In the last few years, 138
Hfibner, 7 Piotrowski, 1~ Schiirmann, et al., TM and, later, Sweet and Wepsic 17'18 repopularized electrocoagulation of the Gasserian ganglion by the percutaneous route; each considered that this procedure, with refinements in technique, had an extremely low complication rate and was an effective means of offering a permanent cure of trigeminal neuralgia. Our experience has shown radiofrequency coagulation of the Gasserian ganglion and posterior root to be a safe and effective mode of treatment for patients with severe facial pain, particularly trigeminal neuralgia. Neither age nor debility is an absolute conJ. Neurosurg. / Volume 42 / February, 1975
Radiofrequency percutaneous Gasserian ganglion lesions traindication for the procedure. With fluoroscopic monitoring of the foramen ovale and the use of carefully established anatomic coordinates, selective lesions can be made. Extracranial carotid injury should be virtually impossible, and any motor weakness of the fifth cranial nerve usually subsides. Among 140 cases in this series, there has been no mortality and only one case of extraocular muscle palsy, which resolved in 6 months. The n u m b e r of patients experiencing "unwanted" surgically induced first-division anesthesia as a result of the radiofrequency procedure has been significantly decreased by monitoring the facial blush that develops during coagulation of the Gasserian ganglion. We were able to preserve touch in the areas of surgically induced analgesia in approximately 80% of the patients; 112 of 140 patients had some preserved touch sensation.
References 1. Blom S: Tic douloureux treated with new anticonvulsant: experiences with G 32883. Arch Neurol 9:285-290, 1963 2. Dandy WE: Section of the sensory root of trigeminal nerve at the pons. Preliminary report of the operative procedure. Bull Johns Hopkins Hosp 36:105-106, 1925 3. Ecker A, Perl T: Alcoholic gasserian injection for relief of tic douloureux. Preliminary report of a modification of Penman's method. Neurology (Minneap) 8:461-468, 1958 4. Frazier CH: Radical operations for major trigeminal neuralgia. JAMA 96:913-916, 1931 5. Gardner W J, Miklos MV: Response of trigeminal neuralgia to "decompression" of sensory root. Discussion of cause of neuralgia. JAMA 170:1773-1776, 1959 6. Gonzalez G, Onofrio BM, Kerr FWL: A vasodilator system for the face. Unpublished data. 7. Hfibner B: Ist die Elektrokoagulation des Ganglion Gasseri bei der Trigeminusneuralgie noch zeitgem~iss? Bericht fiber 524 Operationen an 372 Patienten von 1952-1967. Langenbecks Arch Chir 322:577-581, 1968 8. Jaeger R: The results of injecting hot water into the gasserian ganglion for the relief of tic douloureux. J Neurosurg 16:656-658, 1959
J. Neurosurg. / Volume 42 / February, 1975
9. Jannetta P J, Rand RW: Transtentorial retrogasserian rhizotomy in trigeminal neuralgia by microneurosurgical technique. Bull Los Angeles Neurol Soc 31:93-99, 1966 10. Kirschner M: Zur Behandlung der Trigeminusneuralgie. Erfahrungen an 250 Fallen. Arch Kiln Chir 186:325-334, 1936 11. Onofrio BM: Stereotaxic gasserian ganglion ablation using a new stereotaxic probe. Mayo Clin Proc 47:196-198, 1972 12. Onofrio BM: Stereotaxic radiofrequency Gasserian ganglion surgery (movie script), 1973 13. Piotrowski W: Derzeitiger Standpunkt zur Elektrokoagulation des Ganglion Gasseri beim Gesichtsschmerz. Langenbecks Arch Chir 322:573-577, 1968 14. Schfirmann K, Butz M, Brock M: Temporal retrogasserian resection of trigeminal root versus controlled elective percutaneous electrocoagulation of the ganglion of Gasser in the treatment of trigeminal neuralgia. Report on a series of 531 cases. Acta Neurochir (Wien) 26:33-35, 1972 15. St8wsand D, Markakis E, Laubner P: Zur Elektrokoagulation des Ganglion Gasseri bei der idiopathischen Trigeminus-Neuralgie. Nervenarzt 44:44-47, 1973 16. Svien H J, Love JG: Results of decompression operation for trigeminal neuralgia four years plus after operation. J Neurosurg 16:653-655, 1959 17. Sweet WH, Wepsic JG: Relation of fiber size in trigeminal posterior root to conduction of impulses for pain and touch: production of analgesia without anesthesia in the effective treatment of trigeminal neuralgia. Trans Am Neurol Assoc 95:134-139, 1970 18. Sweet WH, Wepsic JG: Controlled thermocoagulation of trigeminal ganglion and rootlets for differential destruction of pain fibers. I. Trigeminal neuralgia. J Neurosurg 40:143-156, 1974 19. TaarnhCj P: Decompression of the trigeminal root and the posterior part of the ganglion as treatment in trigeminal neuralgia: preliminary communication. J Neurosurg 9:288-290, 1952 20. Tew J: Personal communication, 1974 Address reprint requests to: Burton M. Onofrio, M.D., Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55901.
]39
ONOFRIO,M . D .
Mayo Clinicand Mayo Foundation, Rochester, Minnesota
v' Percutaneous radiofrequency ablation of the Gasserian ganglion or posterior root, or both, was performed in 140 patients. Of the 135 patients with trigeminal neuralgia, satisfactory analgesia was achieved in 121. Postoperative complications included unintentional first-division analgesia (10), transient sixth-nerve palsy (1), neuroparalytic keratitis (2), and anesthesia dolorosa (2). The phenomenon of facial blush may be helpful in avoiding unwanted first-division analgesia. In four of five patients with other forms of neuralgia, the procedure did not relieve pain; the fifth patient experienced significant relief from pain due to carcinoma of the mandible. KEy W o a o s 9 trigeminal neuralgia 9 Gasserian ganglion percutaneous lesion 9 radiographic coordinates
9
,E have analyzed the results of ra- face for a relatively long period, it helps him diofrequency ablation of the Gas- to tolerate permanent numbness following a serian ganglion in 140 patients, 135 subsequent radiofrequency ablation procewith trigeminal neuralgia and five with other dure. Before a patient was selected for the types of facial pain, and are reporting this ex- ablation procedure, any patient under 30 with face pain typical of trigeminal neuralgia perience. would undergo both angiography and Pantopaque rhombencephalography so that the Clinical Material and Methods possibility of mass lesions in and around Selection of Patients Meckel's cavity could be excluded. OtherOf the 135 patients suffering from tri- wise, age or complicating medical problems, geminal neuralgia, those who had had no other than those requiring anticoagulant previous medical treatment were treated with therapy, did not limit selection of patients for Dilantin or Tegretol. If this therapy was in- radiofrequency ablation. Table 1 shows the age distribution of the effective, patients were treated by alcohol blocks of the division or divisions affected 135 patients who were treated by radiofrebefore a definitive surgical procedure on the quency ablation for the first time. Table 2 ganglion was attempted. We believe that if a emphasizes the relative infrequency of patient actually experiences numbness of the isolated first-division pain, while corn-
W
132
J. Neurosurg.
Volume42 / February, 1975
Radiofrequency percutaneous Gasserian ganglion lesions TABLE I Age factors in 135 patients with trigeminal neuralgia
Age at Onset Age at Time of Age Group of Trigeminal Radiofrequency (yrs) Neuralgia Lesion (No. of Cases) (No. of Cases) 10-20 21-30 31-40 41-50 51-60 61-70 71-80 81+
1 6 10 25 38 32 2O 3
9 14 33 36 36 7
TABLE 2 Divisions of fifth cranial nerve involved in 135 patients witit trigeminal neuralgia
Division Involved
No. of Cases
Vl v2 v8 vl, v2 v,, v~ Vl, v2, V3
2 22 25 28 47 11
binations of pain referred to the first and second or to all three divisions are common. The absence in this and other series of noncontiguous division pain (i.e., first and third divisions) is striking. Operative Technique
The patient is awake during the radiofrequency ablation procedure except for a brief period of unconsciousness produced by the administration of methohexital (Brevital) prior to the actual coagulation of the Gasserian ganglion and posterior root. Localization of the needle by roentgenography and stimulation with the electrode carries virtually no risk. The observation of certain precautions minimizes the possibility of untoward complications. The patient is admitted to the hospital the night before surgery, and the following morning is brought to the x-ray department and placed on the fluoroscopy table; a firm 4-inch pad is placed beneath the torso and legs so that the head and neck are hyperextended at J. Neurosurg. / Volume 42 / February, 1975
20 ~. Prior explanation of the entire procedure to the usually apprehensive patient facilitates verbal preparation for each step as it is carried out. After preparation of the involved side of the lower face and opposite forehead with an aqueous solution of thimerosal (Merthiolate), an 18-gauge spinal needle (the indifferent electrode) is placed in the subgaleal space of the opposite forehead. The radiothermistor needle 11 is then introduced through the skin 2.5 cm lateral to the labial commissure of the involved side. Its trajectory should bisect the pupil in the coronal plane, and pass through a point 3 cm anterior to the external auditory meatus in the sagittal plane. At this stage, the needle should have been advanced through the skin to a depth of only 4 to 5 cm. Fluoroscopic monitoring of the base of the skull is essential before the needle is introduced into a foramen because it is possible, in the cadaver specimen, to enter the foramen rotundum, foramen lacerum, internal auditory meatus, and the jugular foramen? ~ With the patient's neck hyperextended 20 ~ the face is gradually rotated away from the involved side while the area of the petrous ridge is monitored by fluoroscopy. Characteristically, the foramen ovale can be made to appear as a rising sun over the petrous ridge when lateral rotation is about 20 ~ with the neck in hyperextension (Fig. 1). Both of these variables are modified until the foramen ovale is well outlined (Fig. 2). The needle tip is then placed at the foramen ovale, and a lateral roentgenogram is taken. The trajectory of the needle must never bisect the floor of the sella as seen in the lateral x-ray. To achieve analgesia of the first division, the needle tip optimally should be at the junction of the petroclinoid ligament and posterior clinoid. For analgesia of the second division, the tip is introduced for a shorter distance through the foramen on this same trajectory. For third-division analgesia, a shallower middle fossa line is followed. If necessary, the preceding steps are repeated; the foramen ovale is not penetrated until the desired trajectory has been obtained (Fig. 3 upper). The patient tolerates this phase well because the fifth nerve has been manipulated very little. When the lateral roentgenogram confirms the proper trajectory, one determines the depth of insertion and introduces the needle to a position depending on the analgesia ]33
B. M. Onofrio
F~. 1. Position of patient for obtaining an optimal view of foramen ovale. Neck is in 20~ hyperextension and head is rotated 15 to 20~ away from side of pain.
FIG. 2. Radiothermistor needle entering most medial portion of left foramen ovale, in position for further insertion to achieve analgesia of first or second division, or both. For third-division analgesia, needle should be introduced into middle of foramen in this projection.
desired: through the most medial portion of the foramen for first- to second-division analgesia or through the middle of the foramen for third-division analgesia. Avoidance of penetration of the lateral third of the foramen ovale makes injury to the temporal lobe highly unlikely, and avoidance of bisec]34
tion of the floor of the sella turcica obviates possible injury to the extraocular nerves (Fig. 3 lower). Under fluoroscopic control, the needle can be kept out of the wrong foramen entirely and carotid injury should be virtually impossible. Once the proper trajectory has been accomplished, the patient is forewarned of the most unpleasant part of the procedure: piercing of the third division. The introduction of the needle into the foramen gives the operator a sensation of passing through fascia or tendon until the dura propria is penetrated; then a small "pop" is usually felt. Any resistance to deeper insertion is due either to penetration of the lateral cavernous sinus wall by the needle or, if the needle is in a low middle-fossa trajectory, abutment of the needle against the petrous ridge. In these circumstances, the needle must either be positioned so that it lies less deeply in the foramen at a point superficial to that at which the operator feels the second resistance or be totally replaced, starting from the skin puncture to achieve a different trajectory. If removal of the stylet is followed by the flow of cerebrospinal fluid and a permanent lateral roentgenogram shows proper final placement, the stimulating current is turned on. If placement of the exposed needle tip is optimal, stimulation with 0.1 V will cause facial pain. If more than 2 to 3 V are needed to induce pain, the needle placement is probably not satisfactory enough for the achievement of suitable analgesia postoperatively. This phase of the procedure is terminated when stimulation reproduces pain in the area affected in a typical attack of trigeminal neuralgia. At this juncture, an intravenous injection (3 to 8 ml) of methohexital (Brevital) is given. A coagulating current is delivered to a temperature of 80~ (as measured by a thermistor bead at the end of the coagulating needle) and maintained for 30 seconds. During the period of unconsciousness and during coagulation, dense erythema almost always appears, becoming more brilliant in the analgesic zones the longer the current is applied; in nearly every case it indicates a durable lesion and is always confined to the divisions or division undergoing sensory deprivation. The blush will not appear if the sensory root, the ganglion, or the sensory division of the fifth nerve has been subjected J. Neurosurg. / Volume 42 / February, 1975
Radiofrequency percutaneous Gasserian ganglion lesions
FIG. 3. Lateral roentgenogram with superimposed drawings. Upper: Posterior root, Gasserian ganglion, three divisions, and motor root of fifth nerve. Lower: Needle trajectories for obtaining first-, second-, and third-division analgesia. Analgesia for first division is obtained by using a steeper trajectory and that for third division by a shallow trajectory; second-division analgesia requires an intermediate slope. In sagittal insertion, first-division analgesia must be obtained with deepest penetration to junction of petroclinoid ligament and clivus; third-division analgesia requires shallower penetration through foramen ovale. To avoid injury to third, fourth, or sixth nerve, the needle must not enter shaded area. to section or injection and is associated with dense anesthesia in that part of the face. The phenomenon of the blush originally was considered to indicate involvement by heating of the sympathetic arteries around and near the cavernous part of the carotid artery or stimulation of the adjacent greater superficial petrosal nerve. As this finding was observed
J. Neurosurg. / Volume 42 / February, 1975
in more patients undergoing electrocoagulation, however, it became apparent that the limitation of the dense blush to a single division or to divisions rendered densely analgesic by operation probably indicated stimulation of an active vasodilator fiber system, the course of which was obscure. These interesting clinical observations have led to 135
B. M. Onofrio laboratory investigation elucidating the anatomical course of this vasodilating response and will be reported at a later date? The patient is then allowed to awaken fully and, if sensory testing shows the desired analgesia, the procedure is terminated. If not, the duration of coagulation is increased by 30 seconds and repeated until analgesia is obtained. To avoid a high incidence of recurrence, the area of analgesia must include the entire trigger zone. Like Sweet and Wepsicy 'xs Tew,~~ and others, we attempt to damage selectively A-delta and C fibers; to avoid neurokeratitis and anesthesia dolorosa, we try to leave the larger fibers, which subserve light touch, relatively intact. Others have found, as we have, that patients who have little if any loss of facial sensibility after operation have an extremely high recurrence rate, usually in the first 2 years. If dense analgesia is present, the expected recurrence rate varies between 18% and 25%. This rate is approximately the same as may be expected from the TaarnhCj decompression procedureTM and twice as high as that following the Spiller-Frazier procedure.' Whatever the recurrence rate, StSwsand and associates ~5 summarized the issue succinctly; they justified the 53% recurrence rate in their series following partial coagulation of the ganglion on the basis of the ease of repeating the procedure. Results
Relief of Trigerninal Neuralgia Of the 135 patients with trigeminal neuralgia undergoing radiofrequency surgery for the first time, nine had been treated previously by avulsion of the peripheral division, 16 had undergone subtemporal compression of the Gasserian ganglion or partial section, and two had been treated by posterior fossa subtotal root section. In 115 patients the first procedure produced good analgesia with no return of pain. In 16 patients the first stereotaxic procedure produced fair to good analgesia with initial pain relief but recurrence of pain 2 weeks to 14 months later. All of these patients had relatively slight postoperative analgesia, a fact reinforcing the observation that the less the loss of sensibility in a division or divisions the higher the recurrence rate. One patient, 136
who had undergone three previous subtemporal open procedures elsewhere, had a small island of preserved sensation over the right cheek; this area was involved in periodic bouts of typical trigeminal neuralgia. We were unable to enlarge the area of facial anesthesia to include this segment even with two radiofrequency procedures. Of the 16 patients, one requested repeat alcohol blocks; one started to take Tegretol again; seven currently have occasional infrequent light "phantom" attacks not yet severe enough to justify a further surgical procedure; and six underwent a second radiofrequency procedure which has to date been effective in causing total relief. Anesthesia dolorosa developed in two patients; in two others, both of whom had persistent pain, we were unable to produce any analgesia at all. They later underwent an open surgical procedure.
Relief of Other Types of Facial Pain After we had established good anatomical coordinates for obtaining a reasonably selective lesion of the ganglion and posterior root we performed the radiofrequency procedure in five patients with other types of facial pain. In two patients who had undergone an open surgical procedure for trigeminal neuralgia elsewhere and who had anesthesia dolorosa when first seen at the Mayo Clinic, the radiofrequency procedure was totally ineffective. With respect to the two patients with atypical facial pain, anesthesia dolorosa developed in one and the condition was unchanged in the other. In the fifth patient, who had pain secondary to carcinoma of the mandible, the procedure produced good analgesia of the face and relief of pain.
Postoperative Sequelae Motor Weakness. Because of the trajectory of the fifth motor root, weakness of the masseter and pterygoids almost always occurs with first-division analgesia and is rare with the creation of isolated third-division analgesia. The unilateral weakness is well tolerated by most patients even when it is severe, as seen in Table 3. In completing the follow-up questionnaire patients rarely mentioned difficulty with mastication as a major complaint. Usually the motor weakness resolves in 6 to 9 months, although this is not uniformly true. The more bothersome side J. Neurosurg. / Volume 42 / February, 1975
Radiofrequency percutaneous Gasserian ganglion lesions TABLE
3
Motor weakness of fifth cranial nerve after 140 radioJhequency procedures*
Degree of Weaknesst -
1
-2 -3 -4 total
No. of Cases 6
30 17 3 56
No. of Cases with Symptoms --
1 -1 2
* Includes 135 patients with trigeminal neuralgia and five patients with other forms of facial pain. t On scale ranging from 0 (normal) to - 4 (absence of motor power). TABLE 4 "Unwanted" first-division analgesia in 135 patients with trigeminal neuralgia after radiofrequency lesions Divisions of Fifth No. of Patients Cranial Nerve No. of Patients with Postoperative with Trigeminal Operated On First-division Neuralgia* Analgesiat V2 V3 V2, V.~
22 25 47
5 0 5
* vl was excluded from consideration in this table. t The 10 patients in this group had first-division analgesia in addition to analgesia in divisions affected by trigeminal neuralgia.
effect of weakness of the fifth motor nerve is paralysis of the tensor veli palatini, which causes a failure of closure of the eustachian tube. A feeling of fullness in the ear with decreased hearing and ear ache are frequent complaints of patients with moderate to severe weakness of the motor division of the fifth nerve. Examination of the external auditory canal and eardrum reveals no abnormalities, and all of the symptoms tend to disappear when the patient bends far forward or lies down. Follow-up of these patients will determine whether this problem will resolve as the motor weakness clears. Unwanted First-Division Analgesia. Unwanted first-division analgesia has become less of a problem as our experience with the procedure has grown (Table 4). Among the 135 patients operated on for trigeminal neuralgia, first-division analgesia and absence of the corneal reflex developed in five of 22 J. Neurosurg. / Volume 42 / February, 1975
patients with second-division trigeminal neuralgia and in five of 47 with combined second- and third-division pain. The risk of creating first-division anesthesia with resulting absent corneal reflex diminished in the management of the last 50 cases. This results directly from watching the facial areas where a vasodilating blush occurs during the actual process of coagulation of the ganglion and posterior root; a dense blush in the face almost always indicates developing analgesia or anesthesia (Fig. 4). Before this became recognized, only formal sensory testing after the patient had recovered from the effects of methohexital could reveal the area and degree of sensory deprivation. Now we can either terminate the heating or withdraw to a shallower position in Meckel's cavity if a blush appears in the first division of the anesthetized patient. This has helped greatly to avoid unwanted first-division sensory loss. Sixth-Nerve Palsy. In the total of 140 radiofrequency procedures, there was only one case of profound sixth-nerve palsy and this resolved in 6 months. During insertion of the needle, a second resistance was encountered after Meckel's cavity had been entered, and heat was transmitted across a partially penetrated lateral cavernous sinus wall. Neuroparalytic Keratitis. Two patients developed neuroparalytic keratitis. One required a permanent lateral tarsorrhaphy; vision of 20/60 was preserved in the involved eye. The other patient did not need a tarsorrhaphy but the visual acuity was permanently decreased to 20//100. Anesthesia Dolorosa. Two patients developed anesthesia dolorosa with dense anesthesia in all three divisions after operation. Discussion
There are numerous forms of treatment of trigeminal neuralgia. These include medical treatment with drugs such as diphenylhydantoin (Dilantin) and carbamazepine (Tegretol), 1 temporary nerve blocks and avulsions peripherally, instillation of liquid agents such as boiling water and alcohol into Meckel's cavity, 3'a subtemporal extradural Gasserian ganglion and posterior root compression or decompression, 5'1~'19 partial or total section, 4 posterior fossa sensory root 137
B. M. Onofrio
Fl~. 4. Phenomenon of facial blush. Patient underwent radiofrequency procedure to alleviate right second-division trigeminal neuralgia. Dense erythema over malar eminence and right upper lip occurred during creation of lesion at 80~ over 60 seconds as measured by needle-tip thermistor. After patient recovered from methohexital anesthesia, there was marked analgesia in right second division with preserved tactile sensation; sensation was intact in first and third divisions. section, ~ and temporo-occipital craniotomy with transtentorial section of the fifth sensory root? Each procedure has its advocates, but the very multiplicity of choices indicates that none is totally satisfactory. Ideally, one would like to offer a drug or surgical procedure for trigeminal neuralgia that would give a high rate of permanent cure with no mortality, low morbidity, and as little sensory deprivation as possible. Kirschner TM introduced coagulation of the Gasserian ganglion in 1925, but technical problems and complications of the procedure caused it to fall into disrepute. In the last few years, 138
Hfibner, 7 Piotrowski, 1~ Schiirmann, et al., TM and, later, Sweet and Wepsic 17'18 repopularized electrocoagulation of the Gasserian ganglion by the percutaneous route; each considered that this procedure, with refinements in technique, had an extremely low complication rate and was an effective means of offering a permanent cure of trigeminal neuralgia. Our experience has shown radiofrequency coagulation of the Gasserian ganglion and posterior root to be a safe and effective mode of treatment for patients with severe facial pain, particularly trigeminal neuralgia. Neither age nor debility is an absolute conJ. Neurosurg. / Volume 42 / February, 1975
Radiofrequency percutaneous Gasserian ganglion lesions traindication for the procedure. With fluoroscopic monitoring of the foramen ovale and the use of carefully established anatomic coordinates, selective lesions can be made. Extracranial carotid injury should be virtually impossible, and any motor weakness of the fifth cranial nerve usually subsides. Among 140 cases in this series, there has been no mortality and only one case of extraocular muscle palsy, which resolved in 6 months. The n u m b e r of patients experiencing "unwanted" surgically induced first-division anesthesia as a result of the radiofrequency procedure has been significantly decreased by monitoring the facial blush that develops during coagulation of the Gasserian ganglion. We were able to preserve touch in the areas of surgically induced analgesia in approximately 80% of the patients; 112 of 140 patients had some preserved touch sensation.
References 1. Blom S: Tic douloureux treated with new anticonvulsant: experiences with G 32883. Arch Neurol 9:285-290, 1963 2. Dandy WE: Section of the sensory root of trigeminal nerve at the pons. Preliminary report of the operative procedure. Bull Johns Hopkins Hosp 36:105-106, 1925 3. Ecker A, Perl T: Alcoholic gasserian injection for relief of tic douloureux. Preliminary report of a modification of Penman's method. Neurology (Minneap) 8:461-468, 1958 4. Frazier CH: Radical operations for major trigeminal neuralgia. JAMA 96:913-916, 1931 5. Gardner W J, Miklos MV: Response of trigeminal neuralgia to "decompression" of sensory root. Discussion of cause of neuralgia. JAMA 170:1773-1776, 1959 6. Gonzalez G, Onofrio BM, Kerr FWL: A vasodilator system for the face. Unpublished data. 7. Hfibner B: Ist die Elektrokoagulation des Ganglion Gasseri bei der Trigeminusneuralgie noch zeitgem~iss? Bericht fiber 524 Operationen an 372 Patienten von 1952-1967. Langenbecks Arch Chir 322:577-581, 1968 8. Jaeger R: The results of injecting hot water into the gasserian ganglion for the relief of tic douloureux. J Neurosurg 16:656-658, 1959
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9. Jannetta P J, Rand RW: Transtentorial retrogasserian rhizotomy in trigeminal neuralgia by microneurosurgical technique. Bull Los Angeles Neurol Soc 31:93-99, 1966 10. Kirschner M: Zur Behandlung der Trigeminusneuralgie. Erfahrungen an 250 Fallen. Arch Kiln Chir 186:325-334, 1936 11. Onofrio BM: Stereotaxic gasserian ganglion ablation using a new stereotaxic probe. Mayo Clin Proc 47:196-198, 1972 12. Onofrio BM: Stereotaxic radiofrequency Gasserian ganglion surgery (movie script), 1973 13. Piotrowski W: Derzeitiger Standpunkt zur Elektrokoagulation des Ganglion Gasseri beim Gesichtsschmerz. Langenbecks Arch Chir 322:573-577, 1968 14. Schfirmann K, Butz M, Brock M: Temporal retrogasserian resection of trigeminal root versus controlled elective percutaneous electrocoagulation of the ganglion of Gasser in the treatment of trigeminal neuralgia. Report on a series of 531 cases. Acta Neurochir (Wien) 26:33-35, 1972 15. St8wsand D, Markakis E, Laubner P: Zur Elektrokoagulation des Ganglion Gasseri bei der idiopathischen Trigeminus-Neuralgie. Nervenarzt 44:44-47, 1973 16. Svien H J, Love JG: Results of decompression operation for trigeminal neuralgia four years plus after operation. J Neurosurg 16:653-655, 1959 17. Sweet WH, Wepsic JG: Relation of fiber size in trigeminal posterior root to conduction of impulses for pain and touch: production of analgesia without anesthesia in the effective treatment of trigeminal neuralgia. Trans Am Neurol Assoc 95:134-139, 1970 18. Sweet WH, Wepsic JG: Controlled thermocoagulation of trigeminal ganglion and rootlets for differential destruction of pain fibers. I. Trigeminal neuralgia. J Neurosurg 40:143-156, 1974 19. TaarnhCj P: Decompression of the trigeminal root and the posterior part of the ganglion as treatment in trigeminal neuralgia: preliminary communication. J Neurosurg 9:288-290, 1952 20. Tew J: Personal communication, 1974 Address reprint requests to: Burton M. Onofrio, M.D., Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55901.
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