Percutaneous retrogasserian glycerol rhizotomy for tic douloureux: Part 2. Results nd implications of trigeminal evoked potential studies

Trigeminal evoked potentials were recorded before and 6 weeks after a percutaneous retrogasserian glycerol rhizotomy was performed in 22 patients with tic douloureux. The latency of the trigeminal evoked potential (TEP) N20 peak and the sensory threshold to electrical stimulation of the maxillary gum were measured in each patient. The N20 latency differences between normal and affected sides for each patient were reduced after glycerol injection. Sensory thresholds were significantly different between the normal and the affected sides both before and after rhizotomy. These results were interpreted to indicate that glycerol more specifically affects the damaged myelinated axons implicated in the pathogenesis of trigeminal neuralgia. Of the 22 patients, 82% were either pain-free or significantly improved after operation. Postoperative normal N20 latencies were associated with pain relief in most cases. Our preliminary experience suggests that recurrent pain is more likely to develop in those patients whose postoperative TEP remains abnormal, especially if the abnormality cannot be ascribed to a prior surgical deafferentiation procedure. In addition to providing insight into the mechanism of pain relief, TEP measurements may help to predict the likelihood of long term relief after percutaneous retrogasserian glycerol rhizotomy.     

Percutaneous retrogasserian glycerol rhizolysis in the management of trigeminal neuralgia

Sixty patients with trigeminal neuralgia or atypical facial pain were followed for an average of 1 year after percutaneous retrogasserian glycerol rhizolysis. The procedure was initially effective in relieving pain in 80% of the patients with typical trigeminal neuralgia and symptomatic trigeminal neuralgia secondary to multiple sclerosis. However, life-table analysis indicated that 50% of this group had persistence or recurrence of pain within 18 months after the operation. Percutaneous retrogasserian glycerol rhizolysis was ineffective in relieving atypical trigeminal neuralgia or atypical facial pain. Minor complications occurred in 23% of patients, and major morbidity was seen in 1.6%. Facial sensory loss which persisted for more than 1 month was found in 72% of patients, corneal hypesthesia occurred in 15%, and an additional 7% had corneal anesthesia. The data indicate that the success of percutaneous retrogasserian glycerol rhizolysis in relieving trigeminal neuralgia is directly related to the production of facial sensory loss.     

Percutaneous retrogasserian glycerol rhizotomy for trigeminal neuralgia. A prospective study of 100 cases

A prospective study of percutaneous retrogasserian glycerol rhizotomy (PRGR) with and without metrizamide trigeminal cisternography is reported in the treatment of the trigeminal neuralgia. A series of 100 patients with typical trigeminal neuralgia were allocated randomly to two treatment groups: Group I patients received PRGR with trigeminal cisternography (50 cases) and Group II patients received PRGR without trigeminal cisternography (50 cases). The results indicate that PRGR without trigeminal cisternography is a valid alternative to the original technique. Factors that assured the accurate performance of the modified technique proposed in this study were: spontaneous cerebrospinal fluid drainage; radiologically confirmed placement of the thin spinal needle at the clival edge into the trigeminal impression of the petrous apex and in the center of the foramen ovale; a positive response to the glycerol test; clinical control of the final glycerol injection; and an alert and cooperating patient throughout the entire procedure.     

Long-term results after percutaneous retrogasserian glycerol rhizotomy in patients with trigeminal neuralgia

Summary We have evaluated the long-term results of percutaneous retrogasserian glycerol rhizotomy (PRGR) in 60 patients with classical trigeminal neuralgia. Complete initial pain relief was achieved in 93% of the patients. Numbness was initially reported by 3/4 of the patients and at follow-up by 1/3, while long-lasting dysaesthesias were an important side effect in 38% of previously untreated patients. The half-life of the method was 47 months in our material, and this figure compares favourably with other previously reported series. The method carries a significant risk of long-lasting and troublesome sensory disturbances. Another disadvantage of the method, reported in the present long-term study, was the high incidence of recurrent neuralgia.We are unable to identify predictors of recurrent neuralgia after PRGR, although major recurrences were more common in patients with unchanged facial sensation postoperatively.In conclusion, PRGR offers safe and reliable relief of pain in patients with trigeminal neuralgia. In spite of the high incidence of recurrence and of long-lasting dysaesthesias it is, in our opinion, the method of choice in the elderly, and particularly suitable for patients at high risk.     

Percutaneous retrogasserian glycerol rhizotomy for tic douloureux: Part 1. Technique and results in 112 patients

The technique and results of treatment of tic douloureux by percutaneous retrogasserian glycerol rhizotomy ( PRGR ) were assessed in a series of 112 patients. All patients were refractory to or intolerant of medical therapy. Many of these patients had recurrent pain despite such surgical treatment as microvascular decompression (21%) or one or more percutaneous radiofrequency thermal rhizotomies (19%). The follow-up duration after glycerol rhizotomy ranged from 4 to 28 months. At the final assessment, 67% had complete pain relief; 23% were improved, with pan relieved by minimal drug therapy; and 10% had poor results with unsatisfactory pain relief even with medications. Before the final assessment, 19 patients required a second PRGR because of an initially suboptimal injection (10%) or recurrent pain (16.9%). Seventy-three per cent had no demonstrable change in facial sensation after operation. H akanson 's original procedure based on anatomic verification by cisternography provided precise localization, required no intraoperative stimulation or lesion generators, and allowed varied anesthetic options during operation. In contrast to thermal rhizotomy, PRGR offers patients relief of painful tic douloureux without altering facial sensation in most cases.     

Percutaneous retrogasserian glycerol rhizotomy. Predictors of success and failure in treatment of trigeminal neuralgia

Eighty-five medically intractable trigeminal neuralgia patients treated by percutaneous retrogasserian glycerol rhizotomy (PRGR) were followed for 6 to 54 months. The median time to recurrence of symptoms refractory to medical therapy and requiring further intervention was 3 years (by Kaplan-Meier survival analysis). The median time to recurrence of symptoms requiring some form of medical treatment was 2 years. Following repeat PRGR for recurrent symptoms, the median time to recurrence was 1 year. Univariate log rank statistics and multivariate Cox proportional hazards modeling revealed significant associations between favorable outcome and female sex, absence of atypical features or associated cluster headache symptoms, success of prior carbamazepine therapy, duration of symptoms, and cerebrospinal fluid return during the procedure. A scoring system using prognostic factors has been developed based upon these findings. Assessment of published studies of PRGR and of other treatments for trigeminal neuralgia is made difficult by the variety of outcome measures employed and variable follow-up intervals. The present study attempts to address these issues by definition of endpoints, statistical analysis of the data, and identification of important prognostic factors in a manner useful to the clinician.     

Trigeminal neuralgia

Trigeminal neuralgia (TN) is the most common facial neuralgia, and is considered to be one of the most painful conditions to affect patients. The rate of occurrence of TN in men and women is 2.5 and 5.7 per 100,000 per year respectively. TN is generally characterized by lancinating, unilateral, paroxysmal pain occurring in the distribution of the fifth cranial nerve. The diagnosis of TN is made clinically by excluding other possible causes of facial pain and is based on signs and symptoms from the patient history such as a trigger zone, typical unilateral lancinating paroxysms following neural disturbance, and a refractory period. Generally, TN can be diagnosed by the typical patient history, a negative neurologic exam, and response to a trial of carbamazepine. Imaging studies should be considered if the diagnosis is uncertain or neurologic abnormalities are noted. Most cases are caused by compression of the trigeminal nerve root, usually within a few millimeters of entry into the pons. In a few cases, TN is caused by a primary demyelinating disorder. The treatment modalities for the management of TN may be divided into medical, surgical, and gamma-knife radiosurgery. Generally, response to drug therapy is good, with over 80% of patients responding to some of the anticonvulsants. Percutaneous approaches to trigeminal gangliolysis are considered to have less associated risk and less cost than open surgical procedures. Three different techniques may be used to perform percutaneous destruction of the ganglion: percutaneous radiofrequency trigeminal gangliolysis (PRTG), percutaneous balloon microcompression (PBM), and percutaneous retrogasserian glycerol rhizotomy (PRGR). Open surgical procedures used in the treatment of TN include microvascular decompression of the trigeminal root and retrogasserian rhizotomy. Additionally, because both of these procedures have greater associated risks, morbidity, and mortality, they are customarily applied only to younger patients in good health. Stereotactic radiosurgery has been established as an alternative treatment for patients who do not respond to optimal medical management.     

Percutaneous retrogasserian glycerol rhizotomy for patients with idiopathic trigeminal neuralgia: a prospective analysis of factors related to pain relief

OBJECT: The goal of this study was to analyze prospectively factors associated with facial pain outcomes after percutaneous retrogasserian glycerol rhizotomy (PRGR) for patients with medically unresponsive idiopathic trigeminal neuralgia. METHODS: Between July 1999 and December 2003, 98 patients underwent PRGR in the manner described by H?kanson. The mean patient age was 72.1 years and the average pain duration prior to PRGR was 8.6 years. Fifty patients (51%) had previously undergone surgery. In six patients (6%), the trigeminal cistern could not be defined and the procedure was aborted; six patients were lost to follow-up review. An excellent facial pain outcome was defined as the absence of facial pain without medications. Thirty-two (35%) of 92 patients either received no benefit (17 patients) or experienced recurrent pain (15 patients) and required additional surgery at a mean of 7.5 months after PRGR; the mean duration of follow-up review in the other 60 patients was 28.7 months (range 3-52 months). Including patients who did not receive a glycerol injection, the 1- and 3-year chances of an excellent facial pain outcome were 61 and 50%, respectively. A multivariate analysis of clinical and surgical factors showed that the facial pain exhibited on glycerol injection correlated with excellent facial pain outcomes (relative risk [RR] = 1.02; 95% confidence interval [CI] 0.26-1.77; p < 0.01), whereas patients who experienced any constant pain less frequently had excellent outcomes (RR = 1.13; 95% CI 0.06-2.20; p = 0.04). Forty-six patients (53%) experienced either mild numbness/parathesias (39 patients) or dysesthesias (seven patients). New trigeminal deficits after PRGR were associated with excellent facial pain outcomes (RR = 1.25; 95% CI 0.56-1.93; p < 0.001). CONCLUSIONS: Percutaneous retrogasserian glycerol rhizotomy remains a good operation for patients with medically unresponsive trigeminal neuralgia who are considered poor candidates for posterior fossa exploration. Predictive factors for success include patients without any constant facial pain, patients with immediate facial pain during glycerol injection, and patients with new trigeminal deficits after PRGR.     

Microvascular decompression as treatment of trigeminal neuralgia in the elderly patient.

Elderly patients with idiopathic trigeminal neuralgia are commonly referred to percutaneous treatment if medical therapy has failed. Due to elaborated microsurgical techniques and perioperative care, minimal invasive neurosurgical operations like microvascular decompression (MVD) can be offered increasingly to elderly patients. We operated upon 8 elderly patients (median 70.5 years) suffering from trigeminal neuralgia using MVD in a one-year period (1995). Seven patients were free of pain at release. At a two year follow-up, 2 patients reported of slight dull pain in the trigeminal area, one of these had been pretreated with retrogasserian glycerol rhizolysis and an initial MVD procedure four years before this decompression. All patients were still off medication (analgetics and anticonvulsants), indicating that all patients experienced an excellent (6/8) or a good (2/8) result two years after MVD. One CSF fistula requiring reoperation was the only complication. After failure of medical therapy for symptomatic trigeminal neuralgia, we encourage elderly patients to undergo MVD if the general medical condition is stable and complete pain relief without medication is the requested aim of treatment.     

Percutaneous retrogasserian glycerol injection in the management of trigeminal neuralgia: long-term follow-up results

The results in 122 patients with trigeminal neuralgia who underwent percutaneous retrogasserian glycerol injection are presented. Eighty patients were followed from 38 to 54 months. The recurrence rate at 54 months was 72% (Kaplan-Meier analysis), and the median pain-free interval was 32 months. Complications associated with the procedure were significantly high: 63% of the patients had definite hypesthesia of the face and 29% had unpleasant dysesthesias, including two cases of anesthesia dolorosa. Sensory disturbances were most frequent in patients who had received a previous alcohol block procedure. Among the patients without previous peripheral procedures, 50% developed sensory disturbances. Because of the high rates of recurrence and sensory disturbances, the authors prefer microvascular decompression for the management of trigeminal neuralgia.     

Surgical treatment of glossopharyngeal neuralgia and pain from cancer of the nasopharynx. A 20-year experience

The outcome is summarized for 14 cases operated on for glossopharyngeal neuralgia, with both open and percutaneous rhizotomy techniques, between 1960 and 1984. Four patients, all with primary neuralgia, underwent open surgery. Pain disappeared, leaving only a ninth nerve deficit in all but one patient; in that patient, paroxysms of pain recurred after 3 years, mediated by the nervus intermedius. Five other patients with idiopathic neuralgia and five patients with pain secondary to carcinoma underwent percutaneous procedures. Seven patients who had retrogasserian percutaneous rhizotomy for associated trigeminal neuralgia were also pain-free. No mortality or morbidity resulted from either type of procedure.     

Glycerol rhizolysis for treatment of trigeminal neuralgia

Percutaneous retrogasserian glycerol instillation was performed under local anesthesia for treatment of trigeminal neuralgia in 162 patients. A simplified technique that did not involve cisternography was used. Initial pain relief was achieved in 146 patients (90.1%). Recurrent pain was noted in 27 patients (18.5%) and was more frequent (50%) in patients who had undergone surgical treatments prior to glycerol injection than in those who had no previous surgical treatment (12.3%). A second glycerol injection was carried out in nine patients and a third injection in two patients. The follow-up period extended from 6 to 67 months and 77.8% of patients are totally pain-free after one or more glycerol injections. Another 8.6% experienced good pain relief with the addition of small doses of pharmacological agents. Thus, 140 (86.4%) of the original 162 patients experienced satisfactory pain control following glycerol rhizolysis. Initial sensory loss on the face occurred in 117 patients (71.6%) but at last follow-up examination only 46 patients (28%) experienced mild orofacial hypalgesia and 13 patients (8%) noted analgesia. The corneal reflex was absent in three patients (1.8%) and reduced in five (3.1%). No patients noted corneal ulceration or anesthesia dolorosa. Percutaneous retrogasserian glycerol rhizolysis offers a rapid, safe, reliable, and relatively inexpensive surgical approach to treatment of trigeminal neuralgia.     

Relation of hypesthesia to the outcome of glycerol rhizolysis for trigeminal neuralgia

The effects of percutaneous retrogasserian glycerol rhizolysis were observed in a population of 58 cases of classical trigeminal neuralgia. The follow-up period ranged from 7 to 52 months postoperatively. It was noted that 84% of the patients had immediate relief of pain. The overall recurrence rate was 29%. Based on Kaplan-Meier survival curves, the overall half-life (T1/2) of this procedure was 16 months. Although none of the patients developed anesthesia dolorosa or corneal ulceration, one group of patients developed either a clinical or subclinical persistent "minimal hypesthesia." In these there was a statistically significant difference in the T1/2 associated with this procedure (p = 0.01). This finding suggests that, contrary to the general belief, persistent hypesthesia after glycerol rhizolysis is a negative indicator of long-term success.     

Postural syncope and trigeminal neuralgia relieved by percutaneous rhizotomy with glycerol

A patient with typical trigeminal neuralgia experienced an episode of sudden loss of consciousness when she tried to sit up. Clinical neurological and neuroradiological studies revealed no known abnormalities. Percutaneous retrogasserian rhizotomy with glycerol with the patient in the prone position relieved the syncope and neuralgia.     

Bilateral trigeminal neuralgia

Bilateral trigeminal neuralgia occurred in 32 (11.9%) of 269 consecutive patients who were treated with radiofrequency electrocoagulation (RFE). This is a higher incidence than has been reported before and may be explained by the prospective nature of the present study, the long follow-up period, and the inclusion of patients with mild bilateral symptoms. Multiple sclerosis is the most common predisposing factor and occurred in 18% of those with bilateral trigeminal neuralgia. Although patients with bilateral trigeminal neuralgia were more likely to have had prior surgery than those with unilateral neuralgia, they did not have a higher recurrence rate following treatment. Percutaneous RFE of the retrogasserian rootlets and gasserian ganglion, with or without glycerol, is effective in managing patients whose pain is intractable to medical therapy. The preservation of most trigeminal sensory and motor functions, the low morbidity rate, and the ability to repeat the procedure are particularly advantageous for patients with bilateral involvement.     

Relation between sensory disturbance and outcome after retrogasserian glycerol rhizotomy

Summary The relation between postoperative sensory deterioration and surgical outcome in 54 patients treated by retrogasserian glycerol rhizotomy for trigeminal neuralgia was studied. The facial sensibility was assessed one day and three months postoperatively. Thresholds for perception and pain were determined quantitatively using transcutaneous electrical stimulation and clinically by light touch and pinprick tests. At a follow-up one year after surgery there was no significant difference in pain relief between patients who did show and patients who did not show sensory deterioration at the one day or three months evaluations. Nevertheless, there was a tendency for higher recurrence rate in patients with mild or no sensory disturbance.     

Percutaneous controlled radiofrequency trigeminal rhizotomy for the treatment of idiopathic trigeminal neuralgia: 25-year experience with 1,600 patients

OBJECTIVE: The objective of this study was to evaluate the effectiveness of percutaneous, controlled radiofrequency trigeminal rhizotomy (RF-TR). The outcome of 1,600 patients with idiopathic trigeminal neuralgia after RF-TR was analyzed after a follow-up period of 1 to 25 years. METHODS: A total of 1,600 patients with idiopathic trigeminal neuralgia underwent 2,138 percutaneous radiofrequency rhizotomy procedures between 1974 and 1999. Sixty-seven patients had bilateral idiopathic trigeminal neuralgia, and 36 of them were treated with bilateral RF-TR; 1,216 patients (76%) were successfully managed with a single procedure, and the remainder were treated with multiple procedures. Benzodiazepines and narcotic analgesics were used for anesthesia because patient cooperation during the procedures was essential so that the physician could create selective, controlled lesions. RESULTS: The average follow-up time was 68.1 +/- 66.4 months (range, 12-300 mo). Acute pain relief was accomplished in 97.6% of patients. Complete pain relief was achieved at 5 years in 57.7% of the patients who underwent a single procedure. Pain relief was reported in 92% of patients with a single procedure or with multiple procedures 5 years after the first rhizotomy was performed. At 10-year follow-up, 52.3% of the patients who underwent a single procedure and 94.2% of the patients who underwent multiple procedures had experienced pain relief; at 20-year follow-up, 41 and 100% of these patients, respectively, had experienced pain relief. No mortalities occurred. After the first procedure was performed, early pain recurrence (<6 mo) was observed in 123 patients (7.7%) and late pain recurrence was observed in 278 patients (17.4%). Complications included diminished corneal reflex in 91 patients (5.7%), masseter weakness and paralysis in 66 (4.1%), dysesthesia in 16 (1 %), anesthesia dolorosa in 12 (0.8%), keratitis in 10 (0.6%), and transient paralysis of Cranial Nerves III and VI in 12 (0.8%). Permanent Cranial Nerve VI palsy was observed in two patients, cerebrospinal fluid leakage in two, carotid-cavernous fistula in one, and aseptic meningitis in one. CONCLUSION: Percutaneous, controlled RF-TR represents a minimally invasive, low-risk technique with a high rate of efficacy. The procedure may safely be repeated if pain recurs.     

A 20-year review of percutaneous balloon compression of the trigeminal ganglion

OBJECT: The aim of this study was to investigate outcomes and complication rates associated with percutaneous balloon compression (PBC) of the trigeminal ganglion over a long follow-up period. METHODS: This retrospective review was conducted in 496 patients with typical symptoms of unilateral trigeminal neuralgia who underwent 531 PBCs of the trigeminal ganglion between 1980 and 1999. The mean length of follow up was 10.7 years. The treatment used was a modification of that first described by Mullan and Lichtor in 1983. There were nine technical failures. Of the 522 successful procedures, prompt pain relief ensued in all patients except one. Recurrence of pain was found in 95 patients (19.2%) within 5 years and in 158 patients (31.9%) over the entire study period. Symptomatic dysesthesias occurred in 19 patients (3.8%), but corneal anesthesia and anesthesia dolorosa did not. CONCLUSIONS: In this review the authors present data on the largest cohort of patients with the longest follow up for this procedure in the current literature. The balance between the recurrence rate and troublesome sensory complications achieved in this series is favorable when compared with previously published studies on outcomes of PBC and the two alternative percutaneous methods, radiofrequency thermocoagulation and glycerol rhizolysis. The PBC procedure has additional advantages in that it is relatively straightforward and quick, and can be performed during a brief period of general anesthesia with no discomfort to the patient. This makes it an attractive first choice in the treatment of trigeminal neuralgia.     

Treatment of idiopathic trigeminal neuralgia: comparison of long-term outcome after radiofrequency rhizotomy and microvascular decompression

OBJECTIVE: To evaluate the long-term outcome of patients after either percutaneous trigeminal rhizotomy or microvascular decompression (MVD) for idiopathic trigeminal neuralgia at a single institution. METHODS: From 1977 to 1997, 316 radiofrequency lesion procedures and 378 MVDs were performed. Questionnaires were sent to all patients who were alive in 1981, 1982, 1992, and 1998. For all other patients, interviews were conducted with their relatives and general practitioners. A retrospective comparative analysis was performed with Kaplan-Meier probability curves as of the latest follow-up date. In addition, 80 patients who underwent MVD were examined postoperatively with quantitative sensory measurements by use of von Frey hairs. RESULTS: Two hundred twenty-five patients who underwent MVD and 206 patients who underwent radiofrequency could be analyzed retrospectively in detail. Overall, there was a 50% risk for recurrence of pain 2 years after percutaneous radiofrequency rhizotomy. Conversely, 64% of patients who underwent MVD remained completely pain free 20 years postoperatively. Patients without sensory impairment after MVD were pain free significantly longer than patients who experienced postoperative hypesthesia or partial rhizotomy. CONCLUSION: Because it is curative and nondestructive, MVD is considered the treatment of choice for trigeminal neuralgia in otherwise healthy people. In our study, it proved to be a more effective and long-lasting procedure for patients with typical trigeminal neuralgia than radiofrequency rhizotomy. Patients without postoperative sensory deficit remained pain free significantly longer, which is a strong argument against the "trauma" hypothesis of this procedure.     

Evaluation of microvascular decompression and partial sensory rhizotomy in 252 cases of trigeminal neuralgia

Outcome after 252 posterior fossa explorations for the treatment of trigeminal neuralgia was determined by a retrospective review. Patients with distortion of the fifth nerve root caused by extrinsic vascular compression underwent microvascular decompression, those with no compression underwent partial sensory rhizotomy, and those with vascular contact but no distortion of the nerve root underwent decompression and rhizotomy. The mean follow-up period was 5.1 years. An excellent (75%) or good (8%) clinical outcome was achieved in 208 patients; 13 patients (5%) experienced little or no pain relief. Thirty-one patients (12%) suffered recurrent trigeminal neuralgia an average of 1.9 pain-free years after operation; recurrence continued at a rate of approximately 2% per year thereafter. Reoperation for recurrent or persistent pain provided excellent or good results in 85% of reoperated patients, but partial sensory rhizotomy was required in most of these patients. Outcome was affected by previous surgical procedures. A previous percutaneous radiofrequency lesion was associated with a significantly greater incidence of fifth nerve complications and a worse outcome after posterior fossa exploration. Because of this finding, the authors recommend that percutaneous radiofrequency rhizolysis be reserved for patients who have failed posterior fossa exploration or who are not candidates for surgery. Patients with compressive nerve root distortion and a short duration of symptoms before surgery had a significantly better outcome than patients with a longer duration of symptoms. In contrast, there was no relationship between the duration of symptoms and outcome of patients without nerve root distortion. Vascular decompression may cause dysfunction of the trigeminal system in tic douloureux, but in patients who remain untreated for long periods an intrinsic abnormality develops that may perpetuate pain even after microvascular decompression. Posterior fossa exploration is recommended as the procedure of choice for patients with trigeminal neuralgia who are surgical candidates.