The optimal radiofrequency temperature in radiofrequency thermocoagulation for idiopathic trigeminal neuralgia: A cohort study

Analyzing the Effect of Intraoperative Stimulation Voltage on Facial Numbness Following Radiofrequency Thermocoagulation in the Treatment of Idiopathic Trigeminal Neuralgia

INTRODUCTION

Radiofrequency thermocoagulation (RFT) effectively alleviates idiopathic trigeminal neuralgia (ITN); however, postoperative facial numbness poses a significant challenge. This issue arises due to the close proximity of high-temperature thermocoagulation, which not only ablates pain-related nociceptive fibers but also affects tactile fibers. Intraoperative sensory stimulation voltage (SV), which reflects the distance between the RFT cannula and the target nerve, potentially possesses the ability to prevent tactile fiber injury. This study aimed to investigate the influence of SV on postoperative facial numbness and provide valuable insights to mitigate its occurrence.

METHODS

A retrospective analysis was performed on 72 ITN patients with maxillary division (V2) pain who underwent RFT between 2020 and 2022. Among them, 13 patients with SV ≤ 0.2 V constituted the low SV group. Subsequently, a matched-cohort analysis was conducted on the remaining 59 patients. The patients paired with the low SV patients were subsequently enrolled in the high SV group, adhering to a 1:1 match ratio. The primary outcome was the facial numbness scale assessment at 3 days, 3 months and 6 months post-surgery. The pain intensity and medication burden served as the secondary outcomes.

RESULTS

We successfully matched a cohort consisting of 12 patients in the low SV group and 12 patients in the high SV group. Each patient experienced various degrees of facial numbness at 3 days post-RFT. Notably, the low SV group exhibited a higher incidence of moderate numbness (66.7% vs. 16.67%, P = 0.036), whereas the high SV group had more cases of mild numbness at the 6-month follow-up (25% vs. 83.3%, P = 0.012). Both groups demonstrated significant decreases in pain intensity and medication burden compared to before the operation.

CONCLUSIONS

SV proved to be a reliable parameter for mitigating the degree of postoperative facial numbness in RFT treatment for ITN. A relatively high sensory SV ranging from 0.3 to 0.6 V during the RFT procedure results in less facial numbness in the treatment of ITN.

Comparison of the safety and efficacy of radiofrequency thermocoagulation with percutaneous balloon compression for treating trigeminal neuralgia: a systematic review and meta-analysis

Objective

This study aimed to systematically assess the efficacy and complications of radiofrequency thermocoagulation (RFT) and percutaneous balloon compression (PBC) for treating trigeminal neuralgia (TN).

Methods

Chinese and English studies on RFT and PBC in the treatment of TN were systematically searched using CNKI, Wanfang Data, VIP, PubMed, EMBASE, Cochrane Library, and until December 31, 2022. Further, the literature was strictly screened using specific inclusion and exclusion criteria. The RevMan 5.4 software was used for data processing and meta-analysis.

Results

Overall, 16 studies with 3,326 patients were included. The results of meta-analysis revealed that no significant difference was present between the two groups in terms of the rate of efficacy immediately after surgery, 1 month after surgery, and 3 months after surgery (odds ratio [OR] = 0.73, 95% confidence interval [CI] 0.35-1.54, p = 0.41; OR = 0.41, 95% CI 0.13-1.32, p = 0.13; OR = 0.40, 95% CI 0.10-1.60, p = 0.20); however, at 12 months after surgery, the difference was statistically significant (OR = 0.27, 95% CI 0.10-0.75, p = 0.01). Notably, there was no significant difference in the postoperative sleep quality index between the two groups immediately after surgery and 1 month after surgery (SMD = -0.01, 95% CI -2.47 to 2.44, p = 0.99; SMD = 0.14, 95% CI -3.95 to 4.22, p = 0.95). Further, statistically significant differences were observed between the two groups in the incidence of postoperative masticatory muscle strength decline and oral herpes (OR = 0.37; 95% CI 0.21-0.63, p = 0.0003; OR = 0.25, 95% CI 0.10-0.61, p = 0.003). In addition, a statistically significant difference was found in the recurrence rate at 1-year follow-up (OR = 2.23, 95% CI 1.03-4.81, p = 0.04); however, no statistically significant differences were found in the recurrence rate at the 2-year follow-up (OR = 1.95, 95% CI 0.33-11.59, p = 0.46).

Conclusion

In the treatment of TN, both RFT and PBC can achieve good short-term efficacy, and no significant differences were noted between the outcomes of the two approaches. Compared with RFT, PBC may result in a lower pain score and recurrence rate in the medium and long terms, but it is a higher incidence of cold sores, and the decrease of masticatory muscle strength is more obvious.

Identification of Foramen Ovale With H-Figure Fluoroscopic Landmark Improves Treatment Outcomes in Idiopathic Trigeminal Neuralgia

BACKGROUND

Because it is traditionally difficult and time-consuming to identify the foramen ovale (FO) with fluoroscopy, we recently developed the H-figure method to acquire fluoroscopic view of FO with shorter procedure time and less radiation. However, the impact of such an H-figure approach on the clinical outcomes of trigeminal ganglion radiofrequency thermocoagulation (RFT) in treating idiopathic trigeminal neuralgia (ITN) remains unclear.

METHODS

In a 12-month follow-up retrospective cohort study, patients with ITN had fluoroscopy-guided RFT of trigeminal ganglion via either classic approach (n = 100) or H-figure approach (n = 136) to identify FO. Data of continuous variables were analyzed with a Shapiro-Wilk test for normality and subsequently with a Mann-Whitney test, and the binary data were analyzed with a χ 2 test. The primary outcome was the facial pain measured by a Visual Analog Scale (VAS) 1 year after the treatment. The secondary outcomes included the quality of the fluoroscopic FO views, the threshold voltage to provoke paresthesia, the procedure time, the number of fluoroscopic images, and the facial numbness VAS.

RESULTS

Compared with the classic approach group, the H-figure approach group was associated with better long-term pain relief after the procedure, with significantly fewer patients had pain 3 months (6.6% vs 17.0%, P = .012) and 12 months (21.3% vs 38.0%, P = .005) after the procedure, and among patients who had pain after the procedure, patients in the H-figure group had significantly less pain 6 months after the procedure (VAS median [interquartile range (IQR)]: 3 [2-6] vs 6 [4-7], P < .001). Moreover, compared to the classic approach, the H-figure approach provided better fluoroscopic view of FO, lower threshold voltage to elicit paresthesia (median [IQR]: 0.2 [0.2-0.3] vs 0.4 [0.4-0.5] V, P < .0001), with shorter procedure time (median [IQR]: 7.5 [6.0-9.0] vs 14.0 [10.0-18.0] min, P < .0001), and required fewer fluoroscopic images (median [IQR]: 4.0 [3.0-5.0] vs 8.0 [6.0-10.0], P < .0001).

CONCLUSIONS

RFT of the trigeminal ganglion using the H-figure approach is associated with superior longer term clinical pain relief than the classic approach in treating ITN.

Xper-CT combined with laser-assisted navigation radiofrequency thermocoagulation in the treatment of trigeminal neuralgia

Objective

Our objective was to study the clinical feasibility of Xper-CT combined with laser-assisted radiofrequency thermocoagulation in the treatment of trigeminal neuralgia.

Materials and methods

A retrospective analysis was made of 60 patients with trigeminal neuralgia who visited the Affiliated Hospital of Binzhou Medical University from January 2019 to May 2021. According to the different surgical methods, we were divided into C-arm X-ray group and laser navigation group. The operation time, operative complications, post-operative 24 h, post-operative 3 and 6 months Barrow Neurotics Institute (BNI) score were recorded and compared.

Results

Compared with the C-arm X-ray-guided puncture group, Xper-CT combined with laser-assisted navigation has the obvious advantages of shorter total puncture time, shorter surgical time, higher success rate of first puncture, and better surgical effect.

Conclusion

Radiofrequency therapy of trigeminal neuralgia with Xper-CT combined with laser-assisted navigation has a good clinical effect and can be promoted and applied.

The impact of needle location on clinical outcome of radiofrequency rhizotomy for trigeminal neuralgia

BACKGROUND

Radiofrequency thermocoagulation trigeminal rhizotomy (RT-TR) through the foramen ovale is a minimally invasive treatment for trigeminal neuralgia. Navigation of magnetic resonance imaging (MRI) and CT fusion imaging is a well-established method for cannulation of the Gasserian ganglion. In this study, we use the inline measurements from fusion image to analyze the anatomical parameters between the actual and simulation trajectories and compare the short- and intermediate-term outcomes according to determinable factors.

METHODS

The study included thirty-six idiopathic neuralgia patients who had undergone RT-TR with MRI and CT fusion image as a primary modality or repeated procedures.

RESULTS

Among thirty-six treated patients, the inline length of the trigeminal cistern was longer for the simulated trajectory (8.4 ± 2.4 versus 6.5 ± 2.8 mm; p < 0.05), and the predominant structure at risk extrapolated from the inline trajectory was the brainstem, which signified a more medially directed route, in contrast with the equal weighting of temporal lobe and brainstem for the actual trajectory. The preoperative visual analogue scale (VAS) was 9.3 ± 1.0, which decreased to 2.5 ± 2.6 and 2.9 ± 3.1 at first (mean, 3 months) and second (mean, 14 months) postoperative follow-up, respectively. The postoperative VAS scores at the two follow-ups were not statistically significant without a covariate analysis. After adjustment for covariate risk factors, the second follow-up sustained therapeutic benefit was evident in patients with no prior history of related treatment, an ablation temperature greater than 70 °C, and needle location within or adjacent to the trigeminal cistern.

CONCLUSIONS

This preliminary study demonstrated that the needle location between cistern and ganglion also plays a significant role in better intermediate-term results.

Global Trends and Hotspots in Trigeminal Neuralgia Research From 2001 to 2021: A Bibliometric Analysis

Background

In recent years, there have been an increasing number of studies on trigeminal neuralgia (TN). However, a scientific and comprehensive study of the current situation and trends in the field of TN research is lacking. The purpose of this study is to summarize and visualize the development, research hotspots, and future trends in TN based on a bibliometric approach.

Methods

Studies on TN published from 2001 to 2021 were obtained from the Web of Science Core Collection (WoSCC). Bibliometrics, CiteSpace, and VOSviewer tools were used for bibliometric analysis and visualization.

Results

In total, 4,112 documents were searched. The number of research articles in the field is generally on an upward trend, with the fastest growth in the number of articles from 2017 to 2020. Shanghai Jiao Tong University, Pittsburgh University, and Mayo Clinic are the three institutions with the most publications. Shiting Li and Zakrzewska JM are the most prolific author and top co-cited authors, respectively. The Journal of Neurosurgery is the most influential journal. The top 5 keywords in that time frame are TN, microvascular decompression, facial pain, stereotactic radiosurgery, and neuropathic pain.

Conclusion

This is the first comprehensive scientific bibliometric analysis of the global research field on TN over the past 21 years, providing a meaningful reference for further exploration of topical issues and research trends in the field.

Radiofrequency thermocoagulation for the treatment of trigeminal neuralgia

Although microvascular decompression (MVD) should be considered as the first-line treatment for classic trigeminal neuralgia (TN) owing to neurovascular compression of the trigeminal nerve, an increasing number of surgeons prefer radiofrequency thermocoagulation (RFT). RFT is a Gasserian ganglion-level ablative intervention that may achieve immediate pain relief for TN. It is used for emergency management when MVD is not suitable for the patient. As the gold surgical standard of classic trigeminal neuralgia, MVD has the advantage of longer efficacy. However, there are currently no high-quality controlled trials to evaluate the efficacy of MVD and RFT. For the present systematic review, the PubMed, Embase and Cochrane databases (all entries up until July 31, 2020) were searched to identify studies related to RFT in order to provide valuable information for clinical decision-making. The efficacy of the RFT method was evaluated in terms of the initial pain relief percentage, recurrence rate and follow-up time. Furthermore, the incidence rate of various postoperative complications was retrieved. RFT was used for a wider range of applications than MVD, including use for primary (owing to neurovascular compression of the trigeminal nerve), idiopathic and secondary (due to primary neurological diseases) TN, and provided a high rate of initial pain relief and long-term pain control. Although this method has several side effects, the incidence of complications could be reduced by precise cannulation. Furthermore, the complications that occurred were not permanent. Thus, RFT is a safe and effective minimally invasive method of pain relief for patients with TN.

Long-term Follow-up of Patients Treated with Percutaneous Radiofrequency Thermocoagulation via the Foramen Rotundum for Isolated Maxillary Nerve Idiopathic Trigeminal Neuralgia

OBJECTIVE

The purpose of this study is to evaluate the effectiveness and safety of percutaneous radiofrequency thermocoagulation (PRT) via the foramen rotundum (FR) for the treatment of isolated maxillary (V2) idiopathic trigeminal neuralgia (ITN) and assess the appropriate puncture angle through the anterior coronoid process to reach the FR.

METHODS

Between January 2011 and October 2016, 87 patients with V2 ITN refractory to conservative treatment were treated by computed tomography (CT)-guided PRT via the FR at our institution. The outcome of pain relief was assessed by the visual analog scale (VAS) and Barrow Neurological Institute (BNI) pain grade and grouped as complete pain relief (BNI grades I-III) or unsuccessful pain relief (BNI grades IV-V). Recurrence and complications were also monitored and recorded. The puncture angle for this novel approach was assessed based on intraoperative CT images.

RESULTS

Of the 87 treated patients, 85 (97.7%) achieved complete pain relief, and two patients (2.3%) experienced unsuccessful pain relief immediately after operation. During the mean follow-up period of 44.3 months, 15 patients (17.2%) experienced recurring pain. No severe complications occurred, except for hypoesthesia restricted to the V2 distribution in all patients (100%) and facial hematoma in 10 patients (11.5%). The mean puncture angle to reach the FR was 33.6° ± 5.7° toward the sagittal plane.

DISCUSSION

CT-guided PRT via the FR for refractory isolated V2 ITN is effective and safe and could be a rational therapy for patients with V2 ITN.

The treatment of V2 + V3 idiopathic trigeminal neuralgia using peripheral nerve radiofrequency thermocoagulation via the foramen rotundum and foramen ovale compared with semilunar ganglion radiofrequency thermocoagulation

OBJECTIVES

To compare the advantages and disadvantages of V2 + V3 idiopathic trigeminal neuralgia using peripheral nerve radiofrequency (RF) thermocoagulation (PRF) via the foramen rotundum (FR) and foramen ovale (FO) with those of semilunar ganglion RF thermocoagulation (GRF) under local anesthesia, for exploring a new and available surgical method for patients with V2 + V3 idiopathic trigeminal neuralgia.

PATIENTS AND METHODS

102 patients with V2 + V3 idiopathic trigeminal neuralgia were enrolled in this prospective randomized controlled clinical trial, and they were divided into the PRF and GRF group randomly (n = 51 in both groups). The outcome of pain relief was assessed using the Barrow Neurological Institute (BNI) pain score, and grouped as good (BNI Class I or II, no medication required) and bad (BNI Class III-V, medication required or failed). Recurrence was defined as a relapse to a previous lower level after attainment of any higher level of pain relief. The immediate effective rate, the 2-year postoperative effective rate, the 2-year postoperative recurrence rate, and the number of complications were observed and recorded.

RESULTS

Their basic conditions (age, gender ratio, side of pain, and disease duration) were similar. Furthermore, we found that the 2-year postoperative effective rate between them had no significant difference. By comparing the two groups, PRF group had the better immediate effective rate of the V2 branch and no severe complications such as corneal ulcer, however, GRF group had lower 2-year postoperative recurrence rate of the V3 branch and fewer facial swelling.

CONCLUSION

The PRF surgery, like GRF, is another prospective treatment for V2 + V3 idiopathic trigeminal neuralgia by virtue of its excellent immediate effect, accurate positioning and high safety.

Treatment Outcomes in Trigeminal Neuralgia-A Systematic Review of Domains, Dimensions and Measures

BACKGROUND

Trigeminal neuralgia (TN) is a painful disorder characterized by sudden electric shock-like pain. It is a rare condition for which multiple treatments are available, including medical and surgical. The best treatment option is yet to be defined, and this is related to the lack of definition in the treatment outcomes and outcome measures. The aim of this systematic review was to summarize all the outcomes and outcomes measures that have been published to date and highlight variability in their use.

METHODS

We have conducted a literature search using a wide range of databases (1946-2019 for medical and 2008-2019 for surgical treatment), for all intervention studies in TN. Four hundred and sixty-seven studies were selected for data extraction on TN classification, data collection method, intervention, and treatment outcomes mapped to the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT guidelines).

RESULTS

Most studies collected data on pain (n = 459) and side effects (n = 386) domains; however, very few collected data on the impact of treatment on physical (n = 46) and emotional functioning (n = 17) and on patient satisfaction (n = 35). There was high variability on outcome measures used for pain relief (n = 10), pain intensity (n = 9), and frequency of pain episodes (n = 3).

CONCLUSIONS

A clear definition of what are the important outcomes for patients with TN is essential. The choice of standardized outcome measures allowing for consistent reporting in TN treatment will allow for comparison of studies and facilitate treatment choice for patients and clinicians thus, improving health outcomes and reducing health care cost.

Long-Term Efficacy and Complications of Radiofrequency Thermocoagulation at Different Temperatures for the Treatment of Trigeminal Neuralgia

Trigeminal neuralgia (TN) is a common neuropathic pain that seriously affects the daily life of patients. Many invasive treatments are currently available for patients who respond poorly to oral carbamazepine or oxcarbazepine. Among them, radiofrequency (RF) treatment is a viable option with reliable initial and long-term clinical efficacy. The long-term analgesic effects of radiofrequency thermocoagulation (RFT) at high temperatures (≥80°C) are not superior to those at relatively low temperatures (60–75°C). In contrast, the higher the temperature, the greater the risk of complications, especially facial numbness, masticatory muscles weakness, and corneal hypoesthesia. Some patients even experience irreversible lethal complications. Therefore, we recommend low-temperature RFT (60–75°C) for treatment of TN. The therapeutic effects of pulsed radiofrequency (PRF) are controversial, whereas PRF (≤75°C) combined with RFT can improve long-term effects and decrease the incidence of complications. However, large-scale clinical trials are needed to verify the efficacy of the combination of PRF and RFT.

Combined pulsed and thermal radiofrequency versus thermal radiofrequency alone in the treatment of recurrent trigeminal neuralgia after microvascular decompression: A double blinded comparative study

BACKGROUND

Recurrent trigeminal neuralgia (RTN) is a common clinical problem and pain recurs in many patients after microvascular decompression (MVD). We evaluated the effect of adding pulsed radiofrequency to radiofrequency thermocoagulation at 60°C compared to radiofrequency thermocoagulation at 70°C alone in the treatment of recurrent trigeminal neuralgia after microvascular decompression.

METHODS

40 patients with recurrent trigeminal neuralgia after microvascular decompression were randomly divided into two equal groups. Group A: received prolonged duration of pulsed radiofrequency followed by less destructive thermocoagulation, while group B: received sole thermocoagulation. Then patients followed up for 2 years to evaluate the success rate by the Barrow Neurological Institute Pain Intensity (BNI) Scale, complications, and the need to medical treatment.

RESULTS

The success rate was 100% in both groups at discharge (BNI < III). It was 83.3% and 78.7% after 6 months, 77.8% and 68.4% after 12 month, 72.2% and 68.4% after 18 months and 66.7% and 63.1% after 24 months in group A and B, respectively (p > .05). In group A 88.9% of patients stopped tegretol treatment after the procedure compared to 84.2% in group B (p = .32). 88.9% compared to 89.5% % in group A and B, respectively, did not use tricyclic antidepressant (p = .61). The overall complications in group A was 5.61%, while it was 36.8% in group B (p = .025).

CONCLUSION

Combined pulsed and thermal radiofrequency can significantly reduce the incidence of the side effects/complications with similar success rate than using thermal radiofrequency alone in treatment of recurrent trigeminal neuralgia after microvascular decompression.

Foramen ovale cannulation guided by intraoperative computed tomography with magnetic resonance image fusion plays a role in improving the long-term outcome of percutaneous radiofrequency trigeminal rhizotomy

Background

Percutaneous radiofrequency trigeminal rhizotomy (RF-TR) is a well-established treatment for patients suffering from trigeminal neuralgia (TN) as a primary modality or for those refractory to medical treatment. However, few existing studies have identified intraoperative parameter or navigation technique that can be used to predict the rates of short-term or long-term pain relief. In this study, we analyzed patient characteristics, intraoperative parameters and technical factors, and postoperative changes in relation to immediate and long-term pain relief.

Method

This study included a total 252 patients in which 340 RF-TR were performed under the guidance of intraoperative computed tomography (iCT) alone or with magnetic resonance image (MRI) and iCT fusion imaging.

Result

The immediate pain relief of RF-TR with iCT alone and iCT with MR image guidance with or without cerebrospinal fluid (CSF) outflow were all above 90.4%. The 2-year pain relief rate of RF-TR using iCT alone and iCT with MR images guidance with or without CSF outflow were 47.8%, 39.8%, 71.7%, and 53.9% respectively. Significant factors for 2-year pain relief were CSF outflow, iCT with MR image fusion, non-recurrent TN, and presence of postoperative facial numbness.

Conclusion

This preliminary study demonstrated foramen ovale cannulation under the aid of iCT with MR image guidance could improve 2-year pain relief.

Microvascular decompression and radiofrequency for the treatment of trigeminal neuralgia: a meta-analysis

PURPOSE

Surgical treatments are used for trigeminal neuralgia (TN) when drug treatment fails. Surgical options can be divided into two categories: ablation (destructive) or non-ablation. Microvascular decompression (MVD) is primarily a non-ablation option, while radiofrequency thermocoagulation/rhizotomy (RF) is an ablation option. The aim of this study was to compare outcomes of MVD versus RF in the treatment of TN.

MATERIALS AND METHODS

This article evaluates the clinical results and economic effectiveness of trigeminal nerve RF and MVD for the treatment of TN. This review was conducted according to the methodological standards described in the Cochrane Handbook for Systematic Reviews of Interventions and the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement. The PubMed, Embase and Cochrane libraries were searched in January 2018. We have registered our review at the Review Registry.

RESULTS

Nine studies were included in this review. The sample size was 2163 participants. The results showed that compared with RF, MVD had a lower risk of requiring a secondary procedure. The MVD group also had a lower risk of facial numbness. There was no significant difference in postoperative medication use between the two groups. Compared to RF, MVD was more likely to increase the risk of hypacusis and hypesthesia and to decrease the risk of facial pain and dysesthesia. The total cost of MVD, including the operation, hospital stay and additional procedures, was much higher than that of RF.

CONCLUSION

MVD had a lower risk of requiring a secondary procedure and facial numbness after surgery. RF could be considered in patients who are unfit for MVD or refused invasive treatment.

Association Between Radiofrequency Rhizotomy Parameters and Duration of Pain Relief in Trigeminal Neuralgia Patients with Recurrent Pain

BACKGROUND

Radiofrequency rhizotomy (RFR) is a commonly used, effective procedure for trigeminal neuralgia (TN), but a subset of patients experiences pain recurrence and requires subsequent surgeries. Currently, the rhizotomy temperature and duration of application are empirically determined, and there is no consensus on what settings are most beneficial. In this study, we analyzed patients who underwent trigeminal RFR and had subsequent surgeries to identify whether rhizotomy parameters were associated with the duration of pain relief.

METHODS

Single-center, retrospective analysis of patients undergoing RFR for TN from 1995 to 2016. The primary endpoint was subsequent procedure. Associations with rhizotomy parameters and covariates were assessed using Cox regression analysis.

RESULTS

The study included 338 patients, average age 65 years; 61% were women. Temperature was significantly associated with both the degree of immediate postoperative pain relief and the duration of pain relief, and in subgroup analyses by multiple sclerosis status and RFR procedural count. Ablation duration was also independently significant, though not when analyzed alongside age, sex, and race. Duration of pain relief was generally shorter in patients with multiple sclerosis and in repeated RFR.

CONCLUSIONS

Higher temperatures may be necessary to achieve pain relief in some patients, given the progressive nature of the facial pain, but they are not associated with longer duration of pain relief in patients who have recurrent pain. Modulation of the ablation duration does not seem to affect the short-term or long-term outcomes.

Nerve coblation for treatment of trigeminal neuralgia: A case report

BACKGROUND

Trigeminal neuralgia (TN) is a severe type of neuropathic pain which is often inadequately managed using conventional therapies. In this report, we present the first case of TN treated with gasserian ganglion nerve coblation (NC).

CASE SUMMARY

A 58-year-old man presented with right facial pain, mostly localized in the right zygomatic zone, alveolar region, and jaws. Similar to acupuncture and shock pain, the pain lasted about five seconds after each attack before resolving unaided. A diagnosis of TN was made, after which treatment with acupuncture therapy and oral carbamazepine was given. However, the pain was not satisfactorily controlled. Subsequently, gasserian ganglion NC of the right trigeminal nerve guided by computed tomography (CT) was performed on the patient. Following this procedure, the right zygomatic, alveolar, submandibular, and cheek pain disappeared completely. The right zygomatic and alveolar areas experienced mild numbness (level II). At 1-, 2-, 3-, and 6-mo follow-ups after surgery, the patient was painless and the numbness score was level I.

CONCLUSION

CT-guided gasserian ganglion (NC) is an effective treatment for TN and is associated with less or no postoperative numbness or hypoesthesia in comparison with current standard-of-care approaches.

Trigeminal somatosensory-evoked potential: A neurophysiological tool to monitor the extent of lesion of ganglion radiofrequency thermocoagulation in idiopathic trigeminal neuralgia: A case-control study

To reflect the extent of thermolesion of ganglion by testing the change of trigeminal somatosensory-evoked potential (TSEP) before and after ganglion radiofrequency thermocoagulation surgery (GRT), and evaluate long-term clinic effect by follow-up visiting of 1 year.Patients with idiopathic trigeminal neuralgia (TN) in the second division were enrolled between October 2014 and October 2015. They were treated with computed tomography-guided GRT and a follow-up visiting of 1 year. Bilateral TSEP measurements were performed 1 day before and 2 days after the GRT surgery. The latency and peak-to-peak amplitude of W2 and W3 were recorded.Immediate postprocedure pain relief (grades I-III) was 100% and 92.5% 1 year later. Facial numbness rate of grades III and IV was 70%, 40%, and 12.5%, respectively, at immediate, 2 days, and 1 year after GRT. No sever complications happened. The latency of W2 and W3 of patients who had no pain no numbness after 1 year of GRT was 1.74 ± 0.24 and 3.84 ± 0.66 ms, respectively, of TN side, and 1.71 ± 0.39 and 3.63 ± 0.85 ms of the healthy side before GRT. The amplitude of W2 and W3 was 1.13 ± 0.50 and 1.99 ± 1.09 uv, respectively, of TN side and 1.24 ± 0.40 and 1.89 ± 0.81 uv of the healthy side before GRT. There was no statistical difference of the latency and amplitude between 2 sides of W2 and W3 before surgery (P > 0.05). The latency of W2 and W3 delayed and the amplitude reduced especially in TN side after surgery comparing before (P < 0.001). And, comparisons of the latency and amplitude of W2 and W3 between TN side and the healthy side after surgery showed the latency of W2 and W3 delayed (W2: P = 0.02; W3: P = 0.01) and the amplitude of W2 reduced (P = 0.003), but the amplitude of W3 had no statistical difference (P = 0.22). The mean delayed latency and 95% confident interval of W2 and W3 were 0.22 ± 0.35 (0.1-0.34) ms and 0.35 ± 0.64 (0.14-0.57) ms, respectively. The mean decreased amplitude and 95% confident interval of W2 and W3 were 22 ± 24 (14-30)% and 23 ± 32 (12-34)%, respectively.GRT can make the latency delay and the amplitude decrease of TSEP. And the latency and amplitude of W2 and W3 can be considered reliable and safe reference for monitoring the extent of thermolesion.