Efficacy and safety of high concentration lidocaine for trigeminal nerve block in patients with trigeminal neuralgia

AIMS: Local anaesthetics, which act as neurolytics and Na(+) channel blockers, have been used for disrupting the neural firings in certain neuropathic pain conditions. This study was undertaken to investigate the clinical outcome of trigeminal nerve block with 10% lidocaine in the management of trigeminal neuralgia (TN). METHODS: Thirty-five patients with primary TN received trigeminal nerve blocks with 10% lidocaine. Success was defined as complete pain relief or mild pain without medication 1 day after the treatment. We followed the patients up every 2 months assessing for pain recurrence, sensory changes and other complications for a total of 37-45 months (median 43 months). RESULTS: Twelve of the 35 patients (34.3%) responded favourably to the treatment and were considered as success. Eleven patients experienced complete pain relief and one could tolerate pain without medication 1 day after the blocks, which lasted for 3-172 weeks. Four patients experienced mildly decreased sensation in the region of the face supplied by the nerve 1 day after the blocks; however, all recovered normal skin sensation in 6 months. There was neither allodynia nor other sensory discomfort. The pain intensity and current pain duration before treatment were significantly different between the two groups. CONCLUSION: Trigeminal nerve block with high concentration lidocaine (10%) is capable of achieving an intermediate period of pain relief, particularly in patients with lower pain intensity and shorter pain duration prior to the procedure.     

Subclinical sensory abnormalities in trigeminal neuralgia

Trigeminal neuralgia is considered as a paroxysmal single nerve phenomenon. Abnormal sensory perception has been previously described in 15-25% of patients with clinical examination. Quantitative sensory testing (QST) was used to evaluate sensory perception in patients with idiopathic trigeminal neuralgia (ITN). Nine patients and 10 normal control subjects were evaluated in all six trigeminal branches. QST abnormalities were found in the symptomatic division and in the other two branches on the same side. Minor contralateral changes were also found. Differences consisted of cold and warm hypoaesthesia and higher cold and heat pain thresholds in patients. All differences proved statistically significant. Our findings suggest that trigeminal neuralgia is not only a paroxysmal single nerve disorder, but also that other higher structures may be involved.     

Long-term pain control in trigeminal neuralgia with local anesthetics using an indwelling catheter in the mandibular nerve

OBJECTIVE: The authors sought to determine the usefulness of long-term continuous trigeminal nerve block with local anesthetics using an indwelling catheter in a patient with trigeminal neuralgia. DESIGN: The study design included pain control in a patient with trigeminal neuralgia until the time of neurosurgical operation. SETTING: The study was conducted in the Dental Hospital of Tokyo Medical and Dental University. PATIENT: The patient was a 78-year-old woman with trigeminal neuralgia in the right maxillary region. Her pain could not be controlled by carbamazepine and was unbearable. INTERVENTION: The authors estimated the patient's pain intensity, quality, and locality using a visual analog scale to determine the effectiveness of continuous nerve block. OUTCOME MEASURES: Visual analog scores were measured during treatment. The treatment term was divided into three periods according to the difference of the catheter location and injection protocol (premandibular nerve block, infuser injection, and patient-controlled analgesia [PCA] pump injection). The authors also examined the patient's general condition and blood concentration of drugs. RESULTS: The visual analog values were 44.8 +/- 3.6, 26.7 +/- 3.5, and 11.9 +/- 3.1 mm in each period, respectively. The value in the PCA pump infusion period was significantly lower than that in the other periods. No side effects of the local anesthetics were observed on the patient's systemic condition. CONCLUSIONS: The authors controlled trigeminal neuralgia pain by blocking the mandibular nerve with local anesthetics administered through an indwelling catheter. Because the continuous nerve block with local anesthetics is reversible and only mildly toxic, this method is beneficial for pain control in patients with trigeminal neuralgia scheduled to undergo microvascular decompression.     

The Effects of Streptomycin/Lidocaine Block on Trigeminal Neuralgia: A Double Blind Crossover Placebo Controlled Study

SYNOPSIS
This study investigated the long term effect of a peripheral sensory block using streptomycin sulphate on trigeminal neuralgia. A total of twenty subjects, thirteen with idiopathic trigeminal neuralgia (ITN) and seven with traumatic trigeminal neuralgia (TTN) were studied. A double-blind placebo controlled randomized design was used. After the clinical assessment subjects were randomly assigned to receive either 1 g of streptomycin with 3 ml 2% lidocaine, or 3 ml lidocaine alone. The injections were performed adjacent to the branches that served the painful site. These were intraoral injections, more specifically infraorbital and inferior alveolar blocks. Patients received five blocks of either streptomycin/lidocaine or lidocaine alone for a period of five consecutive weeks. On the sixth week they were crossed over. Measures of pain intensity and pain frequency were used to assess treatment outcome. Patients also recorded their side-effects. Repeated measures analysis of variance was used to compare the treatment outcomes between the active and placebo groups. There was no statistically significant differences in the treatment outcomes regarding frequency and intensity of pain attacks. The sensory function of the treated nerves was also not affected. Side effects including facial swelling and pain were a common finding in the patients receiving streptomycin. This study demostrated no beneficial effects of streptomycin blockade for idiopathic and traumatic trigeminal neuralgia.     

带状疱疹后三叉神经痛临床及病理分析

目的：探讨带状疱疹后三叉神经痛的临床及病理特点。方法：对34例带状疱疹后三叉神经痛进行临床分析,7例行Dandy氏手术并取病理检查。结果：发病年龄50～60岁20例（59%）。右侧21例（62%）。累及三叉神经I支24例（71%）。并发角膜溃疡12例,角膜炎10例。疱疹后三叉神经痛24例的病理所见,三叉神经感觉根肿胀、轴突变性、节段性脱髓鞘,神经纤维内见淋巴细胞及中性粒细胞浸润。结论：带状疱疹后三叉神经痛是带状疱疹病毒感染所致的三叉神经感觉根急、慢性炎症所致。该病多发生于中老年人,右侧I支较多,易并发角膜溃疡及角膜炎。Dandy氏手术是治疗带状疱疹引起的顽固性三叉神经痛的有效方法。     

实验性三叉神经痛慢性缩窄环术动物模型建立

目的 :为探讨三叉神经痛的发病机制及治疗等提供实验基础 ,建立一种可靠的三叉神经痛模型。方法 :将大鼠随机分为手术组及假手术组 ,手术组用两根铬线疏松环扎大鼠的眶下神经造成慢性缩窄损伤 ,而假手术组只暴露神经 ,但不结扎 ,观察术后不同时段大鼠对机械刺激的反应阈值及相关的痛觉行为变化。结果 :手术组术后 9～ 6 0天左右 ,在眶下神经支配区域内 ,大鼠出现痛觉超敏现象 ,与手术对侧、术前及对照组比较存在显著差异 (P <0 .0 1) ,极低的外在刺激即可激发强烈的疼痛行为反应 ,持续至术后 30天 ,然后逐渐恢复 ,术后 80天左右恢复术前水平。结论 :大鼠眶下神经的慢性环扎损伤可导致三叉神经痛出现 ,压迫解除后疼痛可缓解。该模型成功地模拟了临床因压迫导致三叉神经痛的情况 ,简单易行 ,成功率高。     

Diagnosis and treatment of trigeminal neuralgia

Trigeminal neuralgia is a disease affecting older individuals. The clinical hallmark of trigeminal neuralgia is a sudden, excruciating paroxysm of pain in the area of the trigeminal nerve. Drug therapy is considered the first line of treatment for trigeminal neuralgia. Anticonvulsant carbamazepine has been used. If relevant pharmacotherapy has been tried without any effect, other procedures are selected. These procedures are microvascular decompression(a radical technique), glycerol trigeminal rhizotomy, percutaneous trigeminal nerve decompression and nerve block. Nerve block with neurolytic solutions and radiofrequency thermocoagulation is a simple, less invasive therapy. In order to avoid hypesthesia and dysesthesia, nerve block using a high concentration of local anesthetics is recommended. In recent years, stereotactic radiosurgery for trigeminal neuralgia has emerged as a new therapeutic modality.     

Human trigeminal root evoked potentials during differential retrogasserian thermal and chemical rhizotomy

Human trigeminal root evoked potentials have been recorded using signal averaging techniques during radiofrequency trigeminal rhizotomy and lidocaine blocks in patients with trigeminal neuralgia. Both short and long latency trigeminal root potentials have been recorded which appear to represent fast- and slow-conducting fiber activity respectively. Long latency trigeminal root potentials appear in recordings at the noxious threshold as perceived by the awake patient and are relatively selectively abolished in a reversible fashion by lidocaine block and irreversibly by radiofrequency heat. Evaluation of these trigeminal root potentials provides an objective assessment of the results of pain surgery directed at differential destruction of slow-conducting fiber activity.     

Trigeminal Nerve Anatomy in Neuropathic and Non-neuropathic Orofacial Pain Patients

Trigeminal neuralgia, painful trigeminal neuropathy, and painful temporomandibular disorders (TMDs) are chronic orofacial pain conditions that are thought to have fundamentally different etiologies. Trigeminal neuralgia and neuropathy are thought to arise from damage to or pressure on the trigeminal nerve, whereas TMD results primarily from peripheral nociceptor activation. This study sought to assess the volume and microstructure of the trigeminal nerve in these 3 conditions. In 9 neuralgia, 18 neuropathy, 20 TMD, and 26 healthy controls, the trigeminal root entry zone was selected on high-resolution T1-weighted magnetic resonance images and the volume (mm³) calculated. Additionally, using diffusion-tensor images (DTIs), the mean diffusivity and fractional anisotropy values of the trigeminal nerve root were calculated. Trigeminal neuralgia patients displayed a significant (47%) decrease in nerve volume but no change in DTI values. Conversely, trigeminal neuropathy subjects displayed a significant (40%) increase in nerve volume but again no change in DTI values. In contrast, TMD subjects displayed no change in volume or DTI values. The data suggest that the changes occurring within the trigeminal nerve are not uniform in all orofacial pain conditions. These structural and volume changes may have implications in diagnosis and management of different forms of chronic orofacial pain.PerspectiveThis study reveals that neuropathic orofacial pain conditions are associated with changes in trigeminal nerve volume, whereas non-neuropathic orofacial pain is not associated with any change in nerve volume.     

头痛患者的电流感受阈值研究

目的：研究头痛患者头部位点的电流感受阈值(current perception threshold，CPT)变化，探讨电流感受阈值检测对头痛的辅助诊断意义。方法：头痛患者、正常对照各15人，对单侧耳前位点、乳突位点分别以2000Hz、250Hz、5Hz三种频率测定电流感受阈值，采用自动程序进行双盲检测，比较两组的异常率，将CFI、结果与影像学检查结果对比，分析头痛患者中器质性病变者与功能性头痛者的CPT结果差异。结果：头痛组与正常组CPT异常率分别为87％、26％，差异有显著意义。7名有器质性病变的头痛患者中有6名CPT结果异常，异常位点与受累的解剖结构具有一致性。所有受检者中4名CPT值增高者均证实有器质性病变。结论：头部位点各频率的CPT检测对头痛的定性有诊断价值，异常增高的CPT值提示头颈部器质性病变。     

神经导航下三叉神经感觉根射频术治疗顽固性三叉神经痛

目的探讨神经导航下三叉神经感觉根射频术治疗顽固性三叉神经痛的有效性和安全性。方法回顾分析39例在局部麻醉下行神经导航下三叉神经感觉根射频术的顽固性三叉神经痛患者,观察术前和术后1d、7d、1个月、6个月、12个月、24个月疼痛视觉模拟评分（VAS）,统计手术成功率、并发症并计算各时间点治疗的有效率。结果除1例患者因解剖异常外,余38例均获得成功,随访36例术后1d、7d、1个月、6个月、12个月、24个月镇痛治疗有效率分别为88.89%、94.44%、94.44%、91.67%、86.11%、75%,VAS评分治疗前后有统计学意义（P〈0.01）。结论神经导航下三叉神经感觉根射频术治疗顽固性性三叉神经痛具有成功率高、创伤小、并发症少等优点。     

DZY-C型三叉神经立体定向仪治疗三叉神经痛的特点

背景经皮三叉神经半月穿刺损毁术是治疗原发性三叉神经痛的方法之一.因其穿刺技术操作上的难度,可导致误伤及一些严重的并发症.DZY-C型三叉神经立体定向仪治疗原发性三叉神经痛具有穿刺准确度高、并发症低等特点,可减少误伤周围血管、神经的机会.目的评价应用DZY-C型三叉神经立体定向仪治疗三叉神经痛的疗效.设计以患者为研究对象,前后对照研究.单位一所市级中医院的脑外科和一所市级医院.对象2001/2003佛山市中医院门诊或住院部就诊的原发性三叉神经痛患者90例,男39例,女51例;年龄21～90岁.干预所有患者按要求在DZY-C型三叉神经立体定向仪的引导下,经皮穿刺三叉神经半月节,注射甘油.疗效根据视觉模拟评分法(visual ana1ogue scale,VAS)在患者治疗前及治疗后30 min对疼痛程度进行评估.主要观察指标疗效评定结果.结果应用DZY-C型三叉神经立体定向仪,对90例原发性三叉神经痛患者进行三叉神经半月节穿刺,均一次穿刺成功,注射甘油后,原三叉神经疼痛消除90例,优良率达100%.结论DZY-C型三叉神经立体定向仪的结构设计合理,手术操作简易,调节灵活,组织损伤少,使用安全,可明显消除三叉神经痛.     

Neurosurgical therapy of facial neuralgias

INTRODUCTION: Neuralgias of the face, especially trigeminal neuralgia and glossopharyngeal neuralgia are indications for surgical interventions after failed medical therapy. In contrast to other forms of headache or atypical facial pain, where surgical measures are considered to be contraindicated, percutaneous procedures or microvascular decompression are able to produce immediate and longstanding pain relief. Careful preoperative evaluation is essential to confirm the clinical diagnosis and to rule out other causes as multiple sclerosis or tumors afflicting the cranial nerves. The following study will summarize the common surgical techniques and their role considering a mechanism-based therapy as well as document long-term results of these measures. METHODS: Between 1977 and 1997 316 thermo-controlled radiofrequency trigeminal rhizotomies (TK) and 379 microvascular decompressions (MVD) were performed in our hospital to treat trigeminal neuralgia; additional 6 MVDs for glossopharyngeal neuralgia and one MVD of the intermediate facial nerve were carried out. Questionnaires were sent out to all patients still living in 1981, 1982, 1992 and 1998. For all other patients, interviews with relatives or the general practitioners were conducted. A retrospective analysis of postoperative pain relief was performed using Kaplan-Meier curves at the latest follow-up. Additionally 80 patients underwent careful quantitative sensory testing with Von-Frey-hairs. RESULTS: 225 patients who underwent microvascular decompression and 206 with radiofrequency trigeminal rhizotomies were further analyzed. There was a 50% risk for pain recurrence two years after radiofrequency rhizotomy. On the other hand 64% of patients who underwent microvascular decompression remained painfree 20 years postoperatively. Patients with microvascular decompression without sensory deficit were painfree significantly longer than patients with postoperative hypesthesia. DISCUSSION: Etiology and pathogenesis of facial neuralgias are far from understood despite several hypotheses. Based on current models there is no explanation for the immediate pain relief especially after microvascular decompression. Some authors even discuss surgical trauma as the only cause for postoperative pain relief.     

Herpes zoster and post-herpetic neuralgia

Pain associated with herpes zoster arise from the virul neuritis of the suffered trigeminal or spinal dorsal ganglion. Prolonged neuritis makes an irreversible nerve injury and continuous pain impulse develops a central sensitization. A post-herpetic neuralgia is thought to be a neuropathic pain due to the irreversible nerve injury and sensitization. It is important to treat herpetic pain completely before the development of the post-herpetic neuralgia, because there are few effective therapies to cure post-herpetic neuralgia. A sympathetic nerve block increases the nerve blood flow supply, and may improve the nerve injury. It is also known that some sympathetic mechanisms relate to the development of the sensitization. A sensory nerve block reduces pain impulse to the dorsal horn, and may interfere the sensitization. A cortico-steroid administrated with a nerve block can reduce the neuritis, and may improve the nerve injury.     

岩静脉显微解剖在三叉神经痛显微血管减压术中的应用

【目的】研究岩静脉显微解剖在三叉神经痛显微血管减压术中的应用。【方法】回顾分析本院547例三叉神经痛的患者经三叉神经显微血管减压术治疗的临床资料。【结果】547例中127例患者术中行岩静脉处理,其中5例死亡,1例术后出现小脑及脑干梗死。未处理岩静脉的420例患者中,无死亡病例。【结论】岩静脉压迫三叉神经是导致三叉神经痛的原因之一,在显微血管减压治疗三叉神经痛的手术中,岩静脉的保护与合理处理是降低死亡的重要原因,对于岩静脉的处理应该慎重。     

Gamma Knife Stereotactic Radiosurgery in the Management of Cluster Headache

Gamma knife stereotactic radiosurgery (SRS) has proven to be an effective management approach for trigeminal neuralgia and as a minimally invasive alternative management option for cluster headache (CH). In CH, patients undergo single-session focused irradiation of the trigeminal nerve root (TN), sometimes coupled with irradiation of the sphenopalatine ganglion (SPG) as well. SRS provides early pain relief in most patients, but is associated with trigeminal sensory dysfunction in some patients. In the future, a prospective trial that compares a single target of TN to dual targets of both the TN and SPG may provide further understanding of the value of SRS for CH.     

牛痘疫苗致炎兔皮提取物治疗三叉神经痛的作用机制研究

目的:观察牛痘疫苗致炎兔皮提取物(analgecine)对于三叉神经痛的效果及镇痛机制.方法:将大鼠制成单侧缩窄性三叉神经痛模型,在痛觉超敏期随机分为两组.牛痘疫苗致炎兔皮提取物组:腹腔内注入牛痘疫苗致炎兔皮提取物100u/kg;生理盐水组:腹腔内注入生理盐水10ml/kg.2周后,观察大鼠疼痛阚值(PT)变化及缩窄环区域神经组织的改变.结果:(1)术后2周,动物出现痛觉过敏,PT明显减低;牛痘疫苗致炎兔皮提取物组PT逐渐升高,与治疗前及生理盐水组相比存在显著差异性(P<0.01).(2)痛觉超敏期大量神经纤维肿胀变性、髓鞘脱失.2周后,生理盐水组髓鞘脱失明显,无髓纤维数目增多;牛痘疫苗致炎兔皮提取物组神经纤维肿胀消失,髓鞘板层结构致密,与正常结构类似.结论:动物实验表明,牛痘疫苗致炎兔皮提取物对于三叉神经痛的镇痛效果肯定,其作用机制部分是通过促进受损变性的神经纤维修复实现.     

三叉神经周围支撕脱术联合阿霉素神经干注射治疗三叉神经痛的疗效观察

目的探讨三叉神经周围支撕脱术联合阿霉素神经干注射治疗三叉神经痛的临床效果。方法对26例三叉神经痛患者采用手术方法游离出三叉神经周围支,将神经干切断后对近中枢段行阿霉素注射,对远中枢段采用神经撕脱术。结果26例患者中25例于术后7d内三叉神经痛症状消失或明显减轻,1例于术后2周疼痛消失,近期疗效满意。结论对三叉神经痛患者采用三叉神经周围支撕脱术联合阿霉素神经干注射治疗可取得较好的治疗效果。     

恩再适治疗三叉神经痛的实验研究

目的:观察恩再适对三叉神经痛(TN)的镇痛效果。方法:将30只大鼠制成单侧缩窄环三叉神经痛模型(ION-CCI)大鼠,在痛觉超敏期随机分为三组,恩再适组、卡马西平组、生理盐水组。观察用药后大鼠行为反应及机械刺激疼痛阈值(PT)变化。结果:术后2周,在ION支配区域内,大鼠出现痛觉超敏现象,疼痛阈值明显下降(P<0.01)。恩再适组用药后动物的疼痛阈值逐渐升高,痛觉超敏现象消失,与治疗前及生理盐水组相比存在显著差异性(P<0.01),用药2周后与卡马西平组的最大镇痛阈值相比无显著差异性(P>0.05)。结论:恩再适对三叉神经痛有明显的缓解疼痛效果,且安全。     

核磁共振成像诊断三叉神经痛的价值分析与研究

目的：研究探讨MRI检查在三叉神经痛诊断中的价值。方法：100例拟行微血管减压术的原发性三叉神经痛患者,于术前行MRI检查,分别采集三维快速稳态自由梯度（three dimensional- fast imaging employing steady state acquisition,3D-FIESTA）、三维时间飞跃（three dimensional-time of flight,3D-TOF）序列图像,判断神经血管接触压迫情况。以手术诊断结果为参照,计算和比较3D-FIESTA、3D-TOF术前诊断三叉神经痛患者神经血管接触压迫的灵敏度、特异度、准确率,分析2种序列成像诊断结果与手术诊断结果之间的一致性,并计算和比较3D-FIESTA、3D-TOF对不同责任血管的显示率。结果：100例三叉神经痛患者中,有75例经手术诊断证实存在神经血管接触压迫患侧三叉神经脑池段及邻近脑干组织的情况。以手术诊断结果为参照,3D-FIESTA、3D-TOF诊断三叉神经痛患者神经血管接触压迫的灵敏度（97.33%比94.67%）、特异度（92.00%比96.00%）、准确率（96.00%比95.00%）比较,差异均无统计学意义（P>0.05）。一致性分析显示,3D-FIESTA、3D-TOF对三叉神经痛患者神经血管接触压迫的诊断结果与手术诊断结果之间的一致性均保持在良好水平（Kappa值均>0.7）。3D-FIESTA、3D-TOF对1级、2级、3级、4级、5级神经血管压迫程度的诊断符合率比较,差异均无统计学意义（P>0.05）。3D-FIESTA、3D-TOF对小脑上动脉、小脑前下动脉、椎动脉、基底动脉等责任血管的显示率均为100.00%,二者对2支以上动脉、动脉+静脉的显示率未达到100.00%,3D-FIESTA分别为94.74%、75.00%,3D-TOF分别为89.47%、50.00% ,但二者比较差异无统计学意义（P>0.05）。结论：术前行MRI检查可对原发性三叉神经痛患者的神经血管接触压迫情况予以清晰显示,尤其是采用3D-FIESTA、3D-TOF这2种序列成像 ,不仅可作为三叉神经痛的主要诊断手段,还可作为三叉神经痛手术定位的辅助手段。