Radiofrequency thermocoagulation for V2/V3 idiopathic trigeminal neuralgia: effect of treatment temperatures on long-term clinical outcomes: 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.

Microvascular Decompression versus Radiofrequency Ablation in Trigeminal Neuralgia of the Maxillary and Mandibular Divisions

Background  Although medical treatment is the mainstay of therapy, in trigeminal neuralgia (TN), patients failing to respond to it make them candidates to ablative or nonablative procedures. Objective  The aim of this study was to compare the outcome of Microvascular decompression (MVD) and radiofrequency (RF) thermocoagulation in the management of TN affecting the mandibular and maxillary divisions. Materials and Methods  Retrospective analysis of the data of 40 patients suffering from intractable classical TN affecting the maxillary or mandibular divisions or both was carried out. Twenty patients were operated upon by MVD of the trigeminal nerve; and 20 had RF ablation of the maxillary or mandibular divisions of the trigeminal nerve or both. Results  In MVD the overall successful outcome was achieved in 16 patients (80%), while the failure was in 4 patients (20%) of which 3 had a fair outcome and 1 patient had a poor outcome. Whereas in RF the overall successful outcome was achieved in 17 patients (85%), while the failure was in 3 patients (15%) of which 2 had a fair outcome and 1 patient had a poor outcome. Outcome was insignificantly different between both groups ( p -value 0.806). Conclusion  MVD and RF ablation represent safe and efficacious surgical choices for addressing TN that encompasses both the mandibular and maxillary divisions. Long-term follow-up studies demonstrate that MVD consistently yields favorable outcomes, establishing it as the preferred primary surgical technique, unless contraindicated by the patient's general health and specific needs.

Comparison of microvascular decompression, percutaneous radiofrequency rhizotomy, and stereotactic radiosurgery in the treatment of trigeminal neuralgia: A long term quasi-experimental study

BACKGROUND

Microvascular decompression (MVD), radiofrequency rhizotomy (RFR), and stereotactic radiosurgery (SRS) are surgical techniques frequently used in the treatment of idiopathic trigeminal neuralgia (TN), although the results reported for each of these are diverse.

OBJECTIVE

This study aimed to compare long-term pain control obtained by MVD, SRS, and RFR in patients with idiopathic TN.

METHODS

To compare the results obtained by MVD, SRS, and RFR we chose a quasi-experimental, ambispective design with control groups but no pretest. A total of 52 participants (MVD n = 33, RFR n = 10, SRS n = 9) were included. Using standardized outcome measures, pain intensity, pain relief, quality of life, and satisfaction with treatment were assessed by an independent investigator. The TREND statement for reporting non-randomized evaluations was applied. Clinical outcomes were evaluated at the initial postoperative period and at 6 months, 1, 2, 3, 4, and 5 years postoperatively.

RESULTS

MVD has shown better results in pain scales compared to ablative procedures. Significant differences between groups were found regarding pain intensity and pain relief at the initial postoperative period (p < 0.001) and 6 months (p = 0.022), 1 year (p < 0.001), 2 years (p = 0.002), and 3 years (p = 0.004) after the intervention. Those differences exceeded the thresholds of the minimal clinically important difference. A higher percentage of patients free of pain was observed in the group of patients treated by MVD, with significant differences at the initial postoperative period (p < 0.001) and 6 months (p = 0.02), 1 year (p = 0.001), and 2 years (p = 0.04) after the procedure. Also, a higher risk of pain recurrence was observed in the RFR and SRS groups (HR 3.15, 95% CI 1.33-7.46; p = 0.009; and HR 4.26, 95% CI 1.77-10.2; p = 0.001, respectively) compared to the MVD group. No significant differences were found in terms of quality of life and satisfaction with treatment. A higher incidence of complications was observed in the MVD group.

CONCLUSION

Concerning pain control and risk of pain recurrence, MVD is superior to RFR and SRS, but not in terms of quality of life, satisfaction with treatment, and safety profile.

Progress in Radiofrequency Therapy for Zoster-Associated Pain About Parameters, Modes, Targets, and Combined Therapy: A Narrative Review

Zoster-associated pain (ZAP) is a painful condition that significantly impacts a patient's quality of life, often leading to postherpetic neuralgia (PHN). Over 30% of patients with herpes probably experience PHN. However, the understanding and treatment of ZAP remain inadequate. Common interventional treatments include radiofrequency therapy, nerve blocks, epidural block, and spinal cord electrical stimulation. Among these, radiofrequency therapy is widely used for pain control in ZAP, but the standard pulsed radiofrequency technique can still be improved. Researchers have explored different radiofrequency parameters, modes, targets, and combined treatments to enhance the therapeutic effect. In this paper, we review the latest research findings and incorporate our own departmental investigations. We conclude that high-voltage, long-duration pulsed radiofrequency and radiofrequency thermocoagulation therapy have shown improved therapeutic outcomes, despite some remaining limitations. Emphasis is placed on safety in intercostal nerve and extracranial nerve radiofrequency treatments. Combination therapy is also safe and effective; however, many studies have a low grade of evidence. Further high-quality research and systematic reviews are needed.

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.

Percutaneous Radiofrequency Rhizotomy Is Equally Effective for Trigeminal Neuralgia Patients with or without Neurovascular Compression

BACKGROUND

Neurovascular compression (NVC) in patients with trigeminal neuralgia (TN) can be a factor of treatment outcome especially in microvascular decompression and stereotactic radiosurgery. No such effect has been reported in percutaneous radiofrequency rhizotomy (RF). This study is to investigate if NVC affects the efficacy of RF in patients with TN.

METHODS

We retrospectively reviewed patients with TN who received RF in our institution. Pre-treatment MRI was performed in every patient, and the presence of NVC was reviewed independently by two physicians. The patients were followed up at least for a year after the treatment. Pain severity was assessed with numerical rating scale (NRS).

RESULTS

Sixty-two patients were included in the study. All the patients had single-sided lesion, and 35 patients had NVC. There was no significant difference between these two groups of patients in terms of gender distribution, age, and pre-treatment pain severity. Comparable pain severity improvement was found in one-year follow-up between these two groups (NRS 7.93 ± 0.492 without compression vs. 7.57 ± 0.451 with compression, p = 0.600). No significant difference in post-treatment pain severity at one year between these two patient groups (NRS 1.37 ± 0.466 without compression vs. 1.66 ± 0.458 with compression, p = 0.667) was found.

CONCLUSIONS

For patients with TN treated by RF, the presence of NVC or not is not likely to affect the one-year pain control rate.

[A comparative analysis of clinical efficiency of laser and radiofrequency denervation in patients with primary trigeminal neuralgia]

OBJECTIVE

To compare the clinical efficacy of laser and radiofrequency denervation in patients with primary trigeminal neuralgia.

MATERIAL AND METHODS

The study included 50 patients with primary trigeminal neuralgia who were operated on by laser (group I, n=25) or radiofrequency denervation (group II, n=25) in the period from 2018 to 2019. To assess the clinical efficacy, we analyzed the dynamics of the pain syndrome level according to the scale of facial pain and the quality of life according to the Short Form Medical Outcomes Study (SF-36), as well as patient satisfaction with the operation according to the Macnab scale, the presence of postoperative surgical complications and adverse effects of anesthesia.

RESULTS

In the postoperative period, according to the scale of facial pain, a decrease in its intensity was noted in both study groups (p<0.001). Comparative analysis showed a comparable level of pain in the early postoperative period: at discharge (p=0.43) and 6 months after surgery (p=0.07). At the same time, after 12 months, lower scores on the scale of facial pain were noted in patients of group I (p=0.02). According to SF-36, a significant improvement in the physical and psychological components of health was determined in group I (p<0.001) and group II (p<0.05). Comparison of SF-36 scores in the long-term postoperative period revealed the best indicators in group I (p=0.02 and p=0.01, respectively). Comparative analysis verified a greater subjective satisfaction with the operation in group I, compared with group II (p<0.001). A comparable number of adverse effects of anesthesia was determined in both groups. Comparative analysis revealed a significantly greater number of postoperative surgical complications in group II (p=0.0017).

CONCLUSION

Laser denervation and radiofrequency denervation are highly effective methods of minimally invasive treatment of primary trigeminal neuralgia.

The comparison of efficacy and complications of coblation and radiofrequency thermocoagulation for V2/V3 idiopathic trigeminal neuralgia: a retrospective cohort study of 292 cases

Background

Coblation is a novel technique in respect of treating idiopathic trigeminal neuralgia. We aimed to identify the efficacy and complications between radiofrequency thermocoagulation (RFT) and coblation for V2/V3 idiopathic trigeminal neuralgia (ITN) and investigate the risk factors associated with postoperative facial numbness.

Methods: We retrospectively reviewed our cohort of 292 patients who had undergone RFT or coblation for V2/V3 ITN. The characteristics of the baseline were collected before surgery. Pain scores, the degree of facial numbness and other complications were evaluated at discharge and 1 month, 3 months, 6 months and 12 months after surgery.

Results

Postoperative pain intensity was apparently alleviated in both groups. The initial and 12-months remission rates were 94.0 and 75.3% in coblation group compared with 96.9 and 78.4% in RFT group (P = 0.462, P = 0.585). The degree of postoperative facial numbness tended to be more severe in RFT group at discharge, 1 month, 6 months and 12 months (P = 0.006, P = 0.026, P = 0.004, P = 0.003). Factors significantly associated with more severe facial numbness were procedure of RFT (OR = 0.46, 95%CI: 0.28–0.76, P = 0.002), history of previous RFT at the affected side (OR = 2.33, 95%CI: 1.21–4.48, P = 0.011), and ITN with concomitant continuous pain (OR = 0.36, 95%CI: 0.18–0.71, P = 0.004).

Conclusion

Coblation could reduce the degree of postoperative facial numbness for ITN, and the efficacy was no less effective than RFT. History of previous RFT at the affected side, procedure of RFT, ITN with concomitant continuous pain was identified as significant factors of the development of postoperative facial numbness.

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.

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.

Effects of Supraorbital Foramen Variations on the Treatment Efficacy of Radiofrequency Therapy for V1 Trigeminal Neuralgia: A Retrospective Study

Background

Primary V1 trigeminal neuralgia is a common refractory neuralgia in clinical practice, lacking effective treatments. Radiofrequency therapy has certain treatment efficacy, but its long-term efficacy remained poor and the disease might relapse.

Objective

To compare the effects of different types of supraorbital foramen variations on the treatment efficacy of radiofrequency therapy for V1 trigeminal neuralgia.

Methods

Data of 54 patients with V1 trigeminal neuralgia who underwent treatment in the First Hospital of Jiaxing, Zhejiang, were retrospectively analyzed. All these patients received CT-guided radiofrequency thermocoagulation of supraorbital nerve. According to the CT images, the supraorbital foramen of the patients was categorized as holes (hole group) or notches (notch group). The patient characteristics, including Numerical Rating Scale (NRS) score and effective treatment rates before and 1 d, 0.5 y, 1 y, and 2 y after operation, and numbness degree at day 1 and 2 y after the operation were compared. The short- and long-term complications during postoperative follow-up period were also recorded.

Results

Among the 54 patients, 25 patients were grouped into the hole group and 29 into the notch group. The NRS scores before and at 1 d, 0.5 y, 1 y, and 2 y after operation showed no significant differences between the two groups. However, the NRS scores at the remaining time points after operation were significantly decreased when compared with scores before operation (P < 0.05). The numbness and numbness degree after operation showed no significant differences between the two groups. The numbness degree at 2 y after operation was significantly lower than 1 d after operation (P < 0.05). The numbness and numbness degree after operation showed no significant differences between the two groups. The numbness degree at 2 y after operation was significantly lower than 1 d after operation (P < 0.05). The numbness and numbness degree after operation showed no significant differences between the two groups. The numbness degree at 2 y after operation was significantly lower than 1 d after operation (

Conclusion

The short- and long-term effective rates of radiofrequency therapy during V1 trigeminal neuralgia treatment are relatively high in patients with different types of supraorbital foramen variations. However, the effective rate is even higher in patients with hole-type supraorbital foramen. No other severe complications, except numbness, were found, and the acceptability rate remained high in patients.

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.

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.

Radial Extracorporeal Shock Wave Therapy in an Individual With Primary Trigeminal Neuralgia: A Case Report and Literature Review

A patient with primary trigeminal neuralgia exhibited pain relief without medication after radial extracorporeal shock wave therapy. The 52-yr-old woman had a 3-yr history of primary trigeminal neuralgia, involving the right maxillary division (V2) and the mandibular division (V3). She became refractory to carbamazepine and exhibited hepatic dysfunction. She hence received 3000 to 6000 impulses of craniofacial radial extracorporeal shock wave therapy to the region centered on the surface projection of the trigeminal ganglion and pain areas at 10 Hz; the intensity ranged from 1.4 to 4.5 bars twice per week for 8 wks. At baseline, and 1, 2, and 5 mos after treatment, the Barrow Neurological Institute scores were IV, IIIa, II, and II, and the visual analog scale scores were 8, 3, 1, and 1, respectively. No complications or adverse effects were observed. The hepatic function returned to normal after the discontinuation of carbamazepine. This case report demonstrates the feasibility of radial extracorporeal shock wave therapy for primary trigeminal neuralgia without complications or adverse effects with careful regulation of the therapy intensity.

Therapeutic efficacy and safety of radiofrequency ablation for the treatment of trigeminal neuralgia: a systematic review and meta-analysis

Objective

The objective of this study was to summarize the effectiveness and safety of trigeminal neuralgia (TN) treatment via different radiofrequency approaches such as continuous radiofrequency (CRF), pulsed radiofrequency (PRF), and combined CRF and pulsed radiofrequency (CCPRF) treatments, thus providing high-quality clinical evidence for TN treatment.

Methods

A series of databases were searched for relevant articles published between January 1998 and April 2018. The modified Jadad scale was referred to evaluate the methodological quality of the included studies. Data were extracted independently, and the outcome and safety of different routes, temperatures, and guidance used in CRF, PRF, and CCPRF were compared. Meta-analysis and publication bias were calculated using Review Manager software.

Results

In total, 34 studies involving 3,558 participants were included. With regard to TN treatment, PRF had no difference in cured rate in comparison with CRF, while CRF was more effective than CCPRF (P<0.05). The comparison of complication rates showed that PRF and CCPRF were safer. For puncture guidance via CRF, three-dimensional-printed template was more accurate in success rate at first puncture than computed tomography guidance (P<0.05). For puncture route, foramen rotundum (FR) or pterygopalatine fossa (PPF) route had no significance in efficiency rate via CRF in comparison with foramen oval (FO) route, but PPF and FR routes were safer. For CRF treatment, low temperature (68°C-70°C) compared with high temperature (71°C-75°C) had no effect. Moreover, higher temperature (66°C-80°C) had a greater effect compared with lower temperature (55°C-65°C) on TN treatment (P<0.05), while the safety of which was decreasing.

Conclusion

CCPRF could achieve a greater effect and safety on TN treatment. FR and FO routes in TN puncture treatment via CRF are safer. Medium temperature range is better for CRF therapy, and higher temperature is recommended in PRF, especially for the elders. Further international multicenter trials are needed to confirm the evidence.

MicroRNA-9 regulates mammalian axon regeneration in peripheral nerve injury

Effective axon regeneration is achieved mainly by precise regulation of gene expression after peripheral nerve injury. MicroRNAs play an important role in controlling axon regeneration owe to its key epigenetic function in regulating gene expression. Here, we reveal that microRNA-9 (miR-9) may be a new suppressor of axon regeneration and FoxP1 is the functional target of miR-9. High level of endogenous miR-9 in sensory neurons inhibited axon regeneration in vitro and in vivo. In addition, the regulatory effect of miR-9 was mediated by changes in FoxP1 levels. Full rescuing effect of axon regeneration was achieved by FoxP1 up-regulation. Most importantly, we showed that miR-9-FoxP1 might be a new signaling pathway to regulate mammalian axon regrowth. Moreover, we provided the first evidence that maintaining a higher level of FoxP1 in sensory neurons by the microRNA is necessary for efficient axon regeneration.

Efficacy and safety of continuous radiofrequency thermocoagulation plus pulsed radiofrequency for treatment of V1 trigeminal neuralgia: A prospective cohort study

Patients may develop serious eye complications after continuous radiofrequency thermocoagulation (CRF) for V1 (ophthalmic division) trigeminal neuralgia (TN) at a higher temperature. Therefore, the temperature of clinical CRF for V1 TN has long been disputed, but there have few reports been found about how to achieve satisfactory pain relief, reduce the incidence rates of complications, and shorten the recovery time after CRF for V1 TN.To observe whether pulsed radiofrequency (PRF) can lead to increased rate in pain relief, reduced rate of complications, or shortened recovery time after CRF is used to treat V1 idiopathic trigeminal neuralgia (ITN).The prospective cohort study enrolled 56 patients with V1 ITN from May 2012 to April 2015. The patients were randomized into 2 treatment groups as follows: CRF only (group A, n = 28) and CRF plus PRF (group B, n = 28). The patients were followed 3 years up for pain relief, complications, and health-related quality of life (HRQoL).All the patients in either group achieved satisfactory pain relief at discharge. After treatment, patients completely pain free in group A and group B accounted for 81.6%, 92.0% at 1 year, 68.4%, 92.0% at 2 years, and 68.4%, 83.6% at 3 years, respectively. The pain relief rate was higher in group B patients than in group A, but the difference was not statistically significant. During the follow-up period, 9 (32.1%) patients in group A and 2 (7.1%) patients in group B developed recurrence (P < 0.05). Eleven patients in group A occurred corneal hypoesthesia and with recovery time was 11.9 ± 7.5 (4-18) months versus 3 patients in group B with recovery time was 3.4 ± 2.5 (2-6) months, the differences of incidence rate and recovery times were all significant (P < 0.05) between groups A and B. The mean scores of HRQoL in group B patients were higher than that in group A patients (P < 0.05).PRF after CRF results in decreased recurrence of V1 TN, reduced numbers of corneal hypoesthesia, shortened recovery time, and increased HRQoL scores. Its clinical use is recommended.

Treatment of bilateral idiopathic trigeminal neuralgia by radiofrequency thermocoagulation at different temperatures

Radiofrequency thermocoagulation (RFT) is an effective treatment for trigeminal neuralgia, but consensus regarding an optimal treatment temperature is lacking. While treatment temperatures ranging from 60°C to 95°C have been reported, RFT at too high a temperature is often followed by serious complications, and comparative evaluations of RFT at different temperatures in a single study are rare.This current prospective cohort study was to compare immediate and long-term outcomes of RFT at varying temperatures in patients with bilateral idiopathic trigeminal neuralgia (ITN) of maxillary division of trigeminal nerve (V2), mandibular division of trigeminal nerve (V3), and V2+V3, including pain relief, complications, recurrence rate, and patient satisfaction. From May 2011 to April 2016, 62 consecutive patients with bilateral ITN of V2, V3, and V2+V3 were enrolled in the study. These patients underwent bilateral RFT at 68°C and 75°C, respectively, using the same RF parameters. Side-to-side results, including pain relief, complications, and patient satisfaction, were compared during a 5-year follow-up period.Overall pain relief was satisfactory after RFT. The rate of pain relief after treatment at 75°C was slightly higher than at 68°C (P > 0.05). The pain-free rate was 95.1% at 75°C and 93.5% at 68°C at 1 year, 84.3% and 78.1% at 3 years, and 80.7% and 74.4% at 5 years. There were 10 and 13 cases of recurrence, respectively, and 6 cases of bilateral recurrence. The incidence and severity of complications were greater at 75°C (P < 0.05) than at 68°C, and therefore the patient satisfaction at the higher temperature was lower (P < 0.05).Patients with bilateral ITN who underwent RFT at different temperatures had consistent pain relief after RFT at both 75°C and 68°C, but there were fewer and less severe complications at 68°C, which was accompanied by greater patient satisfaction. This suggests that RFT at lower temperatures may be preferable, and that a temperature of 68°C can be recommended.