Transcranial direct current stimulation efficacy in trigeminal neuralgia

Trigeminal neuralgia is a severe,disabling pain and its deafferentation remains a challenge for health providers.Transcranial direct current stimulation is a non-invasive stimulation technique which finds new utility in managing pain.There-fore,the introduction of alternative,non-invasive,safe,and effective methods should be considered in treating patients with trigeminal neuralgia unresponsive to conventional treatment.

Meta-analysis and sequential analysis of acupuncture compared to carbamazepine in the treatment of trigeminal neuralgia

BACKGROUND In this randomized controlled trial(RCT)comparing current acupuncture with carbamazepine for trigeminal neuralgia,meta-and sequential analyses were utilized.AIM To guide clinical decision making regarding the treatment of trigeminal neuralgia with carbamazepine.METHODS The RCT literature on needle comparison was searched in various Chinese biomedical databases including Chinese Biomedical Literature Database,Wanfang Data,VIP Database,as well as international databases such as Excerpt Medica Database,Cochrane Library,PubMed,and Web of Science,along with related clinical registration platforms such as World Health Organization International Clinical Trial Registry Platform,ChiCTR,and Clinical Trials up to 1 April 2020.Risk of bias was evaluated using the Cochrane Collaborative Risk Bias tool,primary outcome measures(pain reduction)were analyzed using STATA metaanalysis,outcome measures were analyzed using trial sequential analysis 0.9.5.10 Beta sequential analysis,GRADE was used to assess the evidence,and adverse reactions were documented.RESULTS This study analyzed 16 RCTs with a total of 1231 participants.The meta-analysis revealed a statistically significant difference in pain reduction between acupuncture and carbamazepine[standardized mean difference(SMD)=1.47;95%confidence interval(CI):0.99-1.95],although the quality of evidence was deemed to be of extremely low quality.Cumulative meta-analysis based on the year of publication indicated that carbamazepine treatment first demonstrated a statistically significant difference in pain reduction in 2014 and remained relatively stable over time[SMD=1.84;95%CI:0.22-3.47].Additionally,the number of adverse events associated with acupuncture was significantly lower compared to carbamazepine.CONCLUSION Acupuncture for trigeminal neuralgia is better than analgesia and safer than carbamazepine;however,firm conclusions still require a high-quality,multicenter,large-sample RCT to confirm these findings.

Analysis of the Degree of Psychological Distress of Elderly Patients with Recurrent Trigeminal Neuralgia and Its Influencing Factors

Objective:To analyze the degree of psychological distress among elderly patients with recurrent trigeminal neuralgia and its influencing factors.Methods:A single-center cross-sectional study was conducted on 126 elderly patients with recurrent trigeminal neuralgia who visited the Pain Department of our hospital from March 2022 to April 2024.Logistic regression analysis was employed to evaluate the factors influencing psychological distress,based on general patient data,the Distress Thermometer(DT),the Perceived Social Support from Family Scale(PSS-Fa),and the Pitsburgh Sleep Quality Index(PSQI).Results:Among the 126 elderly patients with recurrent trigeminal neuralgia,those with a DT score≥4(72 patients,57.14%)were more prevalent than those with a DT score<4(54 patients,42.86%).The average DT score for all patients was 4.35±1.72.Patients in the DT score≥4 group were older than those in the DT score<4 group(t=4.207,P=0.000),had lower PSS-Fa scores(t=5.925,P=0.000),and had higher PSQI scores(t=17.858,P=0.000).There were no statistically significant differences in gender,marital status,residence area,education level,disease type,or pain location(all P>0.05).Older age and poor sleep quality were identified as independent risk factors for psychological distress in elderly patients with recurrent trigeminal neuralgia(OR=1.258,OR=1.713,both P<0.05),while higher levels of family support were identified as a protective factor(OR=0.581,P=0.025).Conclusion:Elderly patients with recurrent trigeminal neuralgia experience psychological distress,and the degree of severity depends on age,quality of sleep,and level of family support.

Percutaneous Radiofrequency Thermocoagulation for the Treatment of Different Types of Trigeminal Neuralgia:Evaluation of Quality of Life and Outcomes

Radiofrequency thermocoagulation(RFT) of the gasserian ganglion is a routine and effective technique for the treatment of classical trigeminal neuralgia(CTN).In this study we compared its efficacy in patients with CTN and atypically symptomatic or mixed trigeminal neuralgia(MTN).Fifty-seven patients were treated with RFT for trigeminal neuralgia from June 2006 to February 2009.Thirty patients had CTN,and 27 had MTN.Outcomes were measured by using the visual analog pain scale(VAS) and patients’ reports of quality of life(QOL),medication usage,and complications over a follow-up period of up to 3 years.Our results showed that the patients with MTN were younger,tended to have bilaterial involvement of the first division,and were unresponsive to treatment.All surgeries were completed smoothly.About 86.7% CTN patients and 48.1% MTN patients responded immediately to RFT.The VAS scores were significantly higher in the CTN group than in MTN group(P<0.05).Kaplan-Meier curves showed that 1-year,2-year,and 3-year pain relief rates were 76.7%,73.3%,and 73.3% in the CTN group and 46.6%,41.4%,and 41.4% in the MTN group,respectively.The rates of pain relief for both groups leveled off at 2 years.Complications included numbness,dysesthesia,and anesthesia dolorosa.RFT did not cause any deaths and complications were low.The treatment was very effective for CTN and,to some degrees,effective for MTN.If numbness,dysesthesia,and anesthesia dolorosa are limited to the trigger area,QOL will be greatly improved.

Therapeutic Effects of the Point-injection Therapy on Primary Trigeminal Neuralgia An Observation of 103 Cases

From 1996 to 1999, the author treated 103 cases of primary trigeminal neuralgia by point-injection with lidocaine, VB1 and VB12, and obtained quite good therapeutic results. A report follows.

THREE-DIMENSIONAL COMPUTED TOMOGRAPHY-GUIDED RADIOFREQUENCY TRIGEMINAL RHIZOTOMY FOR TREATMENT OF IDIOPATHIC TRIGEMINAL NEURALGIA

Objective To evaluate the effectiveness of three-dimensional computed tomography （3D-CT） guided radiofi＇equency trigeminal rhizotomy （RF-TR） in treatment of idiopathic trigeminal neuralgia （1TN）. Methods From 1999 to 2001, 18 patients with ITN were treated with percutaneous controlled RF-TR. Intraoperative 3D-CT scanning was performed to guide the trajectory of the puncture. After correction of the needle tip according to the CT scans and stimulation effects, 2 to 5 lesions were made for a duration of 60-90 seconds at a temperature of 60℃ to 75℃ depending on the pain distribution and the age of patient. The needles located in foramen ovale. Pain alleviated immediately with no serious complication in all patients. The patients were followed up for an average of 31.5 months （range 24-41 months）. Acute pain relief was experienced by 17 patients after the procedure, reaching an initial success rate of 94.4%. Early （〈 6 months） pain recurrence was observed in 2 patients （11.1%）, whereas late （〉 6 months） recurrence was reported in 3 patients （16.7%）. Thirteen patients had complete pain control, with no need for medication thereafter. Five cases experienced partial pain relief, but required medication at a lower dose than in the preoperative period. Conclusion 3D-CT foramen ovale locations can raise the successful rate of puncture, enhance the safety, and reduce the incidence rate of complication.

Differences in individual susceptibility affect the development of trigeminal neuralgia

Trigeminal neuralgia is a syndrome due to dysfunctional hyperactivity of the trigeminal nerve, and is characterized by a sudden, usually unilateral, recurrent lancinating pain arising from one or more divisions of the nerve. The most accepted pathogenetic mechanism for trigeminal neuralgia is compression of the nerve at its dorsal root entry zone or in its distal course. In this paper, we report four cases with trigeminal neuralgia due to an unknown mechanism after an intracranial intervention The onset of trigeminal neuralgia after surgical interventions that are unrelated to the trigeminal nerve suggests that in patients with greater individual susceptibility, nerve contact with the vascular structure due to postoperative pressure and changes in cerebrospinal fluid flow may cause the onset of pain.

Oxcarbazepine for trigeminal neuralgia may induce lower extremity weakness: A case report

BACKGROUND Although few studies have reported hyponatremia due to carbamazepine or oxcarbazepine in patients with epilepsy,no study has investigated cases of carbamazepine-or oxcarbazepine-induced hyponatremia or unsteady gait in patients with neuropathic pain.Herein,we report a case of oxcarbazepineinduced lower leg weakness in a patient with trigeminal neuralgia and summarize the diagnosis,treatment,and changes of clinical symptoms.CASE SUMMARY A 78-year-old male with a history of lumbar spinal stenosis was admitted to the hospital after he experienced lancinating pain around his right cheek,eyes,and lip,and was diagnosed with trigeminal neuralgia at the right maxillary and mandibular branch.He was prescribed oxcarbazepine(600 mg/d),milnacipran(25 mg/d),and oxycodone/naloxone(20 mg/10 mg/d)for four years.Four years later,the patient experienced symptoms associated with spinal stenosis,including pain in the lower extremities and unsteady gait.His serum sodium level was 127 mmol/L.Assuming oxcarbazepine to be the cause of the hyponatremia,oxcarbazepine administration was put on hold and the patient was switched to topiramate.At subsequent visit,the patient’s serum sodium level had normalized to 143 mmol/L and his unsteady gait had improved.CONCLUSION Oxcarbazepine-induced hyponatremia may cause lower extremity weakness and unsteady gait,which should be differentiated from those caused by spinal stenosis.

Analgesic Effect of Diprospan in Rats with Trigeminal Neuralgia

This study examined the analgesic effect of diprospan in rats with trigeminal neuralgia.Rat model of trigeminal neuralgic pain was established by loosely ligating the left infraorbital branch of the trigeminal nerve.After allodynia developed,the rats were randomly divided into 2 groups（n=20 in each）：diprospan group,in which the rats received diprospan（7 mg/mL,0.1 mL） injected to the left infraorbital foramen area;control group,in which saline（0.1 mL） was administered as the same manner as the diprospan group.The pain threshold（PT） in the left infraorbital area was measured before and 2,6,and 8 weeks after the administration.The expression of neuropeptides [substance P,preprotachykinin A（PPTA）,calcitonin gene-related peptide（CGRP）] in the trigeminal nerve was detected at the same time points as the PT measurement by immunohistochemistry or in situ hybridization method.The results showed that in the diprospan group,the PT was 10.65±1.26,10.77±1.19 and 14.13±1.34 g 2,6,and 8 weeks after the administration respectively,significantly higher than that before the administration（PT value：0.36±0.11）（P0.05 for each）.In the saline group,the PT was 0.37±0.13,0.66±0.09,4.45±1.29 and 13.72±1.72 g before and 2,6,and 8 weeks after the administration respectively with differences being significant between before and 6,8 weeks after the administration（P0.01）.No significant difference existed in the PT between the diprospan group and the saline group at pre-administration（P0.05）.The PT in the diprospan group was significantly greater than that in the saline group 2 and 6 weeks post-administration（P0.05）.In the diprospan group,the expression levels of neuropeptides were significantly reduced as compared with those in the saline group 2 and 6 weeks post-administration（P0.05）.It was concluded that diprospan has an obvious analgesic effect on the trigeminal neuropathic pain partly by reducing the expression of neuropeptides in the trigeminal ganglia.

Quantitative assessment of sensory functions after 3 surgical approaches for trigeminal neuralgia by current perception threshold measurement

Objective： To quantitatively identify and grade trigeminal sensory functions after 3 major surgical procedures of trigeminal neuralgia using a newly developed quantitative sensory testing technique, current perception threshold measurement （CPTM）. Methods： In the current study, there were 48 trigeminal neuralgia patients without history of prior surgical treatment. These patients received one of the following 3 surgical procedures, microvascular decompression （MVD）, peripheral nerve block with alcohol （PNB）, or percutaneous radiofrequency thermocoagulation （PRFT）. The quantitative sensory testing measurement, CPTM, and conventional qualitative sensory testing measurements were performed preoperatively and postoperatively to evaluate and grade the trigeminal sensory functions All 3 major cutaneous sensory fiber types, large myelinated fibers （A beta）, small myelinated fibers （A delta） and unmyelinated fibers（C） were allowed to quantitatively evaluate and grade by CPTM. The results of the measurements were statistically analyzed using a one-way analysis of variance （single factor）. Each subject was his/her own control for comparison of the preoperative to postoperative state on the asymptomatic and symptomatic sides. Subjects were tested 48 h preoperatively and 4 weeks postoperatively. Results： PNB with alcohol and PRFT caused significant sensory dysfunction postoperatively in every fiber type, indicating damage to all fibers. On the contrary, the sensory function in all 3 fiber types was unchanged after MVD management. Conclusion： Among the 3 major surgical procedures tested, only MVD preserves sensory function in trigeminal system. CPTM is of quantitative nature on the evaluation of sensory functions of nerve fibers

Current gamma knife treatment for ophthalmic branch of primary trigeminal neuralgia

AIM: To probe into problems existing in gamma knife treatment of ophthalmic branch of primary trigeminal neuralgia (TN), and propose a safe and effective solution to the problem. METHODS: Through sorting the literature reporting gamma knife treatment of refractory TN in recent years, this article analyzed the advantages and problems of gamma knife treatment of primary TN, and proposed reasonable assessment for existing problems and the possible solution. RESULTS: Gamma knife treatment of TN has drawn increasing attention of clinicians due to its unique non-invasion, safety and effectiveness, but there are three related issue; to be considered. The first one is the uncertainty of the optimal dose (70-90GY); the second one is the difference in radiotherapy target selection (using a single isocenter or two isocenters); and the third one is the big difference of recurrent pains (specific treatment methods need to be summarized and improved). CONCLUSION: For patients with refractory TN, gamma knife treatment can be selected when the medical treatment fails or drug side effects emerge. The analysis of a large number of TN patients receiving gamma knife treatment has shown that this is a safe and effective treatment method.

Expression of hNav1.8 sodium channel protein in affected nerves of patients with trigeminal neuralgia

Objective: To explore the pathogenesis of trigeminal neuralgia (TN) and to provide a new target for the drug treatment of TN by studying the expression of tetrodotoxin-resistant hNav1. 8 sodium channel protein in affected nerves of patients with TN. Methods: Twelve affected inferior alveolar nerves were obtained from patients with idiopathic TN, to whom the drug therapy was not effective. As negative control, one nonnal inferior alveolar nerve was obtained from patients who accepted the combined radical neck dissection with glossectomy and mandibulectomy. One muscle sample was obtained as normal control. One dorsal root ganglion from rat was as positive control. These tissues and prepared hNav1. 8 antibody were conducted immunohistochemistry response. Results: hNav1.8 channel protein was expresses in all the 12 specimens of the affected nerves of patients with TN, but not in the muscle sample and the normal inferior alveolar nerve. Conclusion: The abnormal expression of hNav1. 8 channel protein in the affected nerves of patients with TN may play an important role in the pathogenesis of TN.

Computed tomography-guided percutaneous radiofrequency thermocoagulation for primary trigeminal neuralgia in older and younger patients

We evaluated the immediate and long-term clinical efficacy of computed tomography （CT）-guided radiofrequency thermocoagulation for primary trigeminal neuralgia （RTPTN） in 852 patients including 502 patients aged -〉 60 years and 350 patients aged 〈 60 years. After discharge, the incidence of complications was 1.0% and 0.9% in patients aged 〉 60 years and patients aged 〈 60 years, respectively. Over 3-year follow-up after CT-guided RTPTN, 96.8% of the patients aged 〉 60 years and 98.6% of the patients aged 〈 60 years were completely pain-free, and there was no significant difference between these two age brackets. In addition, there were no significant differences in quality of life scores and numbness scores between these two age brackets. These findings suggest that CT-guided RTPTN is a safe and effective method and is recommended for older and poor-risk patients.

TREATMENT OF 25 CASES OF TRIGEMINAL NEURALGIA WITH ABDOMINAL ACUPUNCTURE THERAPY

Trigeminal Neuralgia is often found in female between 40-60 years old, marked by sudden severe pain on the face (a feeling of knife cutting, electric shock), and it is characterized by sudden, paroxysmal and periodical attack and triggered by touch). The attack usually lasts for 1 to 2 minutes with different intervals. The patient’s life quality can be seriously affected. It is mainly treated with orally taken drugs in western internal department but without satisfactory result, and with local closing therapy in surgical department. The problem may reoccur half a year later in most patients complicated with facial paralysis, so western medicine is not likely to be accepted by the patients. The author has tried to apply abdominal acupuncture in the treatment of 25 cases of trigeminal neuralgia with good effect. The result is as follows.

Pathogenesis of trigeminal neuralgia

To the editor,I read with interest the article, ＂Dif- ferences in individual susceptibility affect the development of trigeminal neuralgia＂ by Duransoy et al. （2013）. The authors have analyzed the possible pathogenesis of trigeminal neuralgia, with illustrative case examples. They have drawn very important conclu- sions, which may have implications in management of trigeminal neuralgia.

Use of High Definition Multileaf Colimator for the Treatment of Trigeminal Neuralgia

In the present work, a treatment technique for trigeminal neuralgia (TN) using LINAC radiosurgery is shown. The technique is based on the optimization of ten static arcs in such a way as to minimize the overlapping of the treatment fields with the brainstem. We will call this technique brainstem-optimized (BO). The results are compared with another technique described in the literature known as a virtual cone (VC). The comparison of dosimetry results that have been carried out essentially shows that the doses in the brainstem V12Gy-brainstem, D0.5cm3-brainstem and D0.035 cm3-brainstem are lower in the BO versus VC technique, and with the parameters V50% (whole brain) and V12Gy-cerebrum higher in BO versus VC. Our goal is to keep the dose to the brainstem as low as possible and, if possible, at most between 12 Gy and 15 Gy. The BO technique meets our purposes and is considered clinically acceptable at our institution.

Fire needle combined with blood-letting therapy for a case of 20-year trigeminal neuralgia

Background： Trigeminal neuralgia （TN） is a neuropathic pain syndrome. It is the most frequent cranial neuralgia and defined as sudden, usually unilateral and lightning-like, knife-like or burning-like recurrent episodes of pain within the distribution area of one or more divisions of the trigeminal nerve. Here we reported that an 81-year-old woman with TN who complained of severe pain on her right face showed a complete clinical relief after comprehensive therapy containing fire needle, filiform needle and blood-letting therapy. Methods： The patient was applied fire needle combined with filiform needle therapy （3 times / week for 4 months） and three consecutive fire needle combined with blood-letting therapy （3 times / week for one week）. Fire needle was inserted into the back points of Du meridian, the first lateral line of bladder meridian, the right spreading area of the trigeminal nerve and the points around the pain radiation site. The filiform needle acupuncture was applied to the points on the right face including Yuyao （EX-HN4）, Yangbai （GB14）, Toulinqi （GB15）, et al; points on the abdomen including Xiawan （RN10）, Qihai （RN16）, Guanyuan （RN14） and the bilateral points including Tianshu （ST25）, Daheng （SP15）, Zusanli （ST36）, et al. Finally, the three-edged fire needle punctured the points of Yangbai （GB41）, Shangguan （GB3）, Jiache （ST6） on the right face accompanied by the cupping method on the bleeding points. Results： The patient reported the complete disappearance of pain and could open mouth and eat normally. The face was normal and no triggering pain recurred after one-month follow-up. Conclusions： The fire needle combined with blood-letting therapy can cure the TN and might provide an alternative non-drug therapy for those patients who still suffered from TN after other medical treatments or whom that refused surgical treatment.

TREATMENT OF 18 CASES OF TRIGEMINAL NEURALGIA WITH ELONGATED NEEDLE

In this paper, a total of 18 cases of primary trigeminal neuralgia were treated with elongated needle. Of the 18 cases, 5 were male and 15 female, ranging in age from 27 to 58 years and in disease duration from 3 days to 8 years. Main acupoints used were Taiyang (EX-HN 5) to Xiaguan (ST 7, for penetration needling), Xiajiache, Fengchi (GB 20), Yanglingquan (GB 34) and Taichong (LR 3). The treatment was given once daily, with 12 sessions being a therapeutic course. After 2 courses of treatment, of the 18 cases, 10 cases were cured, 7 experienced improvement in pain and one failed in the treatment, with an effective rate of 94.4%. The key point for treating trigeminal neuralgia is applying penetrative needling from EX-HN 5 to ST 7 to achieve ideal needling sensations.

CLINICAL STUDY ON TREATMENT OF TRIGEMINAL NEURALGIA BY NEEDLING MENTAL AND MANDIBULAR FORAMINA

In the present paper, 126 patients with neuralgia involving the mandibular branch of trigeminal nerve were treated mainly by puncturing the mental foramen and the mandibular foramen. The two foramina are both located in the focus through which the Stomach Channel of Foot Yangming passes. Among the 126 patients, 42 were attributed to the light type, 61 to the moderate type one and the other 23 to serious type. Acupuncture treatment was given once daily, 30 min every time, with 10 days being a therapeutic course. After 3 courses of treatment, results showed that 29 (69.1%) light type cases, 35(57.4%) moderate type cases and 6 (26.1%) serious type cases were cured. It displays that the less serious the symptom, the higher is the cure rate, and the shorter the duration of disease, the better is the therapeutic effect.

The progress in diagnosis and treatment of trigeminal neuralgia

Trigeminal neuralgia(TN)is characterized by recurrent facial acupuncture like,electric shock like,burning like pain and other common clinical cranial nerve diseases in the trigeminal nerve distribution area.Around the world,people who are 40 or more are at risk.The incidence rate of TN of female is slightly higher than that of male and most of the affecting areas are on the right side unilaterally,which affects maxillary nerve and mandibular nerve,yet seldom ophthalmic nerve.Although controversy exists in the pathogenesis of TN,the most accepted theory is microvascular compression,which forces on the demyelination of the sensory axon of the trigeminal nerve root.Additionally,slight touch,conversation and chewing may cause intolerable pain.The diagnosis of TN mainly depends on clinical manifestation.The treatment mainly includes medicine,operation,and some supplementary methods.Among them,antiepileptics and tricyclic antidepressants are the first-line treatment.Surgical treatment is mainly used for patients with TN who have failed in drug treatment or have intolerable side effects.The methods of operation include destructive or non-destructive operation.Deep brain stimulation(DBS)and motor cortex stimulation(MCS)are new therapeutic techniques emerged recently.This method is expected to alleviate the refractory TN with poor drug control or ineffective conventional surgical treatment.At present,this method has not been approved for clinical treatment.Of course,more clinical data collection processes are in progress.