Transcutaneous electrical nerve stimulation for neuropathic pain

This study examined the clinical effectiveness of high-frequency transcutaneous electrical nerve stimulation for reducing hypersensitivity of the hand. Nineteen patients suffering from hand hypersensitivity were randomly assigned into either a treatment or a placebo group. A visual analogue scale and the Downey Hand Centre Hand Sensitivity Test were used to measure the tactile tolerance of the hand. Grip strength was assessed by a grip dynamometer. Daily applications of electrical stimulation were provided for 2 weeks. Significantly lower pain scores were found in the treatment group than in the placebo group by Day 7 and Day 11. The ranking of ten dowel textures of the Downey Hand Centre Hand Sensitivity Test in the treatment group was significantly higher than in the placebo group by Day 7 and Day 11. However, no significant inter-group difference was found in grip strength.     

脑电刺激和外周电刺激治疗慢性非特异性腰痛的镇痛效果

目的 探讨经颅直流电刺激(tDCS)和经皮神经电刺激(TENS)治疗慢性非特异性腰痛(CNSLBP)的镇痛效果.方法 选择2018年3月～2020年3月在本院就诊的104例CNSLBP患者作为研究对象,采用随机数字表法分为TENS组、tDCS组和联合治疗组各34例.观察三组患者治疗后数字评分量表(NRS)、口述评分量表...     

Long term clinical outcome of peripheral nerve stimulation in patients with chronic peripheral neuropathic pain

BackgroundChronic neuropathic pain after injury to a peripheral nerve is known to be resistant to treatment. Peripheral nerve stimulation is one of the possible treatment options, which is, however, not performed frequently. In recent years we have witnessed a renewed interest for PNS. The aim of the present study was to evaluate the long-term clinical efficacy of PNS in a group of patients with peripheral neuropathic pain treated with PNS since the 1980s.MethodsOf an original series of 11 patients, 5 patients could be invited for clinical examination, detailed assessment of clinical pain and QST examination. The assessments were done both during habitual use of PNS and with the stimulator off.ResultsAverage pain intensity and pain unpleasantness ratings as assessed with visual analog and verbal rating scales showed significant beneficial effects of PNS. Quality of life measures (sleep and daily functioning) also showed positive effects. Quantitative Sensory Testing results did not show significant differences in cold pain and heat pain thresholds between the “ON” and “OFF” conditions.ConclusionIn selected patients with peripheral neuropathic pain PNS remains effective even after more than 20 years.     

Chronic peripheral nerve pain treated with direct electrical nerve stimulation

Chronic somatic peripheral nerve pain was treated prospectively in 24 nonrandomized patients by a program of direct electrical nerve stimulation. Patients qualified for the program if anesthetic (lidocaine) nerve block of the involved cutaneous zone of the peripheral nerve relieved symptoms and transcutaneous electrical nerve stimulation transiently improved and did not exacerbate somatic pain. Results were judged according to a pain score. Patients noted improved sleep and complete absence of the need for narcotic pain medication. On the basis of subjective and objective criteria, 18 patients had good or excellent results and 6 had implant failures. Of the six patients with failures, three failed the trial period and did not have implantation, and three had no significant pain relief and were judged as treatment failures. Three patients had late equipment failure after initial good results. Most patients had some relief of pain, which increased their quality of life and eliminated the need for narcotic analgesia. Direct electrical nerve stimulation should be considered for somatic peripheral nerve pain that has not been ameliorated with other methods. It will reduce, although not necessarily eliminate, pain and pain behavior in most patients.     

Management of acute traumatic pain by peripheral transcutaneous electrical stimulation.

Peripheral transcutaneous electrical stimulation has been used in an attempt to relieve the pain associated with fractured ribs. Sixty-two per cent of the patients considered their pain to be greatly relieved by this electro-analgesic technique and a further 28% gained some relief. Pain was assessed by means of a visual analogue scale. In most of the patients there was a clinical improvement in their condition, the degree of which correlated well with the pain relief. This trial indicated that transcutaneous electro-analgesia is a useful technique for producing analgesia in patients suffering from acute trauma, without some of the side-effects inherent in more conventional forms of therapy.     

Transcutaneous electrical nerve stimulation in chronic pain after peripheral nerve injury

Summary Transcutaneous electrical stimulation was tested in 24 patients with chronic pain following a peripheral nerve injury in an extremity, in 10 patients with a good effect. All of these 10 patients displayed signs of increased sympathetic activity in addition to hyperalgesia. Sympathetic block gave complete freedom from pain. In 14 patients with the same symptomatology but without an increased or with only very slightly increased sympathetic activity, no or an insignificant effect was obtained. Sympathetic block did not relieve the pain in this group. Transcutaneous electrical stimulation should be tried as an alternative to sympathectomy in causalgia major or minor.     

Effect of peripheral electrical stimulation on measures of tooth pain threshold and oral soft tissue comfort in children

The effect of peripheral electrical stimulation on tooth pain threshold and comfort of oral soft tissue was evaluated in 30 children, using a double-blind, crossover, study design. Tooth pain threshold was measured before and after 8 minutes of electrical or sham stimulation. Comfort of oral soft tissue during placement of a rubber dam clamp was evaluated 3 minutes after electrical or sham stimulation was begun. Comfort level was rated by each subject and by the investigator, using a visual analog scale (VAS). Heart rate was measured before and immediately following placement of the clamp. Electrical stimulation significantly increased tooth pain threshold and reduced the cardiovascular stress response without altering comfort levels during placement of the clamp. These findings suggest that peripheral electrical stimulation applied in a pediatric dental setting alters sensory aspects of pain but not affective aspects of comfort.     

Chronic precentral stimulation in trigeminal neuropathic pain

Summary The results of Deep Brain Stimulation in deafferentation pain syndromes, in particular in thalamic pain, indicate that excellent long-term pain relief can hardly ever be achieved. We report 7 cases using Motor-Cortex-Stimulation for treating severe trigeminal neuropathic pain syndromes, i.e., dysaesthesia, anaesthesia dolorosa and postherpetic neuralgia. The first implantation of the stimulation device for precentral cerebral stimulation was performed in June 1993, the last in September 1995. In all but one case the impulse-generator was implanted after a successful period of test stimulation. Successful means a pain reduction of more than 50% as assessed with a Visual Analogue Scale. Excluding one case, in whom a prolonged focal seizure resulting in a postictal speech arrest occurred during test stimulation, there have been no operative complications and the postoperative course was uneventful. In all the other patients the pain inhibition appeared below the threshold for producting motor effects. Initially these patients reported a good to excellent pain relief. In three of 6 patients a good to excellent pain control was maintained for a follow-up period of 5 months to 2 years. In the remaining three patients the positive effect decreased over several months.     

Conservative treatment of peripheral neuropathy and neuropathic pain

There are many types of peripheral nerve disorders that lead to peripheral neuropathy. Symptoms associated with peripheral neuropathy lack consistent, easy to treat qualities, and provide a constant challenge for physicians who encounter the sequelae of neuropathy. This review discusses medications, nutritional supplements, and topical and physical modalities that are effective in treating neuropathy associated with diabetes.     

Spinal cord stimulation does not change peripheral skin blood flow in patients with neuropathic pain

BACKGROUND AND OBJECTIVE: Spinal cord stimulation has been used successfully for many years in the management of neuropathic pain. Nociceptive pathways are closely integrated into many autonomic reflexes. The aim was to test the hypothesis that pain relief caused by spinal cord stimulation is related to changes in peripheral skin blood flow. METHODS: Twelve patients with spinal cord stimulators implanted as a treatment for neuropathic pain were entered into the study. Laser Doppler perfusion scanning was used as a direct method for selective measurement of changes in skin (peripheral) blood flow. Measurements were taken before and after the onset of spinal cord stimulation over the site of its sensory projection. The degree of pain relief due to spinal cord stimulation and the skin temperature of each patient were also recorded. RESULTS: Apart from one patient, spinal cord stimulation did not change skin blood flow in a statistically significant manner. CONCLUSIONS: Pain relief due to spinal cord stimulation is not related to changes of skin blood flow.     

Direct effect of electrical stimulation on peripheral nerve evoked activity: implications in pain relief.

Experiments were performed with a peripheral neurostimulator, used clinically for pain relief, on isolated cat cutaneous peripheral nerve to determine the effect of electrical stimulation on components of the compound action potential. The results show that neurostimulation alters the conduction velocity and the amplitude of both the A-alpha and beta and the A-delta waves with the more slowly-conducting A-delta component showing the greatest changes. This direct alteration of peripheral nerve activity distal to the first synapse in the spinal cord might contribute to the mechanism of pain relief.     

经皮神经电刺激技术对全髋关节置换术后疼痛影响的临床研究

背景:经皮神经电刺激(TENS)技术对全髋关节置换术(THA)后镇痛效果尚不明确。目的:初步探讨TENS对THA术后疼痛的影响。方法:前瞻性纳入2018年10月至2019年3月拟行初次单侧THA患者100例,采用信封法随机分为TENS组和对照组各50例。TENS组术后第1日开始应用TENS技术直至出院;对照组按同样时间应用,但不产生电流。观察指标:①术后24 h、术后48 h、术后72 h、术后1周及术后2周时患者静息及活动的视觉模拟评分(VAS);②住院期间镇痛补救药物(哌替啶)使用率;③TENS相关不良事件发生率。结果:TENS组4例,对照组3例于术后2周失随访。TENS组患者术后24 h、术后48 h的活动VAS评分明显低于对照组(P<0.05),两组术后72 h、术后1周、术后2周的活动VAS差异无统计学意义(P>0.05),两组术后各时间点的静息VAS差异无统计学意义(P>0.05);TENS组患者术后镇痛补救药物使用率明显低于对照组,差异有统计学意义(P<0.05);两组患者均未发生TENS相关不良事件。结论:TENS可有效减轻THA患者术后1~2 d的活动痛,并有效减少镇痛补救药物用量,是一种安全有效的THA辅助镇痛技术。     

Evaluation of the pain suppressive effect of different frequencies of peripheral electrical stimulation in chronic pain conditions.

The pain suppressive effect of low (2/s) and high (50-100/s) frequency electrical stimulation was studied in 12 patients with severe chronic pain in the back and/or the legs. All patients were subjected to a thorough physical examination before and 2-3 weeks after a series of stimulation sessions. The stimulation was applied via surface electrodes to areas both segmentally related and segmentally unrelated to the regions of chronic pain. Low frequency stimulation induced a partial pain relief in only one patient whereas stimulation with high frequency gave a suppression of pain in seven patients. The effect was short-lasting in most cases and the pain started to increase usually within 30 min. It is concluded that the observed pain suppression is not due to psychological factors but to more basic neurophysiological mechanisms. Augmentation of the effect after repeated stimulation sessions was not observed, neither was there any alteration in the neuro-orthopedic status nor any lasting pain relief in any patient.     

The effectiveness of intravenous ketamine and lidocaine on peripheral neuropathic pain

BACKGROUND: Neuropathic pain is often severe and resistant to pharmacological treatment. The aims of the present study were to assess the analgesic effect of ketamine and lidocaine and to investigate if measurement of different variables of sensibility could be used to identify responders. We also wanted to study if treatment resulted in changes of sensibility. METHODS: Twelve patients with long-lasting peripheral neuropathic pain of traumatic origin were included. The effects of ketamine hydrochloride (Ketalar, Parke Davis) 0.4 mg/kg and lidocaine hydrochloride (Xylocain, Astra) 2.5 mg/kg were investigated. Saline was used as placebo. The intensity of continuous pain was measured by a visual analogue scale (VAS). Warm and cold perception as well as heat and cold pain thresholds were assessed. Sensibility to touch was also tested. Systemic plasma concentrations of lidocaine and ketamine were assessed. RESULTS: The mean reduction in VAS-scores was 55%, 34% and 22% for ketamine, lidocaine and placebo, respectively. A significant difference was registered between ketamine and placebo (P = 0.009). Response to treatment (50% reduction in VAS-score during infusion) was recorded in 7/12 in the ketamine, 4/12 in the lidocaine and 2/12 in the placebo group. Quantitative sensory testing (QST) of thermal sensitivity and sensory tests for mechanical stimuli could not separate responders from non-responders and neither were the results from these assessments changed by the infusion of the drugs. Lidocaine and particularly ketamine were associated with frequent side-effects, the most common being somnolence and dizziness. CONCLUSION: Ketamine showed a significant analgesic effect. The clinical usefulness is, however, limited by disturbing side-effects.     

姜黄素对大鼠神经病理性痛的影响

目的 探讨姜黄素对大鼠神经病理性痛的影响.方法 健康雄性SD大鼠108只,体重220～250 g,随机分为6组(n=18):对照组(C组)、假手术组(S组)、慢性压迫性损伤组(CCI组)和不同剂量姜黄素组(Cur1组、Cur2组和Cur3组).C组腹腔注射二甲基亚砜4 ml·kg-1·d-1,持续14 d;S组只分离坐骨神经,然后腹腔注射二甲基亚砜4 ml·kg-1·d-1,持续至术后14 d;CCI组术后腹腔注射二甲基亚砜4 ml·kg-1·d-1,持续至术后14 d;Cur1组、Cur2组或Cur3组术后分别腹腔注射姜黄素30、100、300 mg·kg-1·d-1,持续至术后14 d,姜黄素以二甲基亚砜溶解.于术前2 d和术后1、3、5、7、10、14d时测定热缩足反应潜伏期(TWL)和机械缩足反应阚值(MWT).各组于术后3、7、14 d时各处死6只大鼠,免疫组化法测定脊髓背角和背根神经节中磷酸化c-jun氨基末端蛋白激酶(p-JNK)和c-jun的表达.结果 与CCI组比较,Cur1组和Cur2组术后MWT升高,背根神经节和脊髓背角p-JNK和c-jun表达下调,Cur2组术后TWL升高(P<0.05);与Cur1组比较,Cur2组术后TWL升高,背根神经节和脊髓背角p-JNK和c-jun表达均下调(P<0.05),MWT差异无统计学意义(P0.05).结论 姜黄素30、100mg/kg可减轻大鼠神经病理性痛,100 mg/kg效果更明显,其机制可能与抑制脊髓背角和背根神经节p-JNK和c-jun表达上调有关.     

芍药苷对小鼠神经病理性痛的影响

目的 探讨芍药苷对小鼠神经病理性痛(NP)的影响。方法 选择SPF级雄性BALB/c小鼠40只,4～6周龄,体重20～25 g。将小鼠随机分为四组：假手术组(S组)、坐骨神经套管结扎损伤组(C组)、坐骨神经套管结扎损伤+芍药苷50 mg/kg组(P50组)和坐骨神经套管结扎损伤+芍药苷100 mg/kg组(P100组),每组10只。S组仅分离坐骨神经,不进行套管结扎。C组、P50组和P100组行坐骨神经套管结扎术。P50组术后连续14 d腹腔注射芍药苷50 mg/kg, P100组术后连续14 d腹腔注射芍药苷100 mg/kg, S组和C组术后连续14 d腹腔注射相同容量的生理盐水。于术后1、2、5、7、10、14 d测定机械缩足阈值(MWT)和热回缩潜伏期(TWL),于术后13 d行蔗糖偏好实验(SPT)测定糖水消耗百分比,于术后14 d行强迫游泳实验(FST)和悬尾试验(TST)分别测定静止不动时间。于术后14 d取小鼠眼球血,采用ELISA法测定TNF-α、IL-6、IL-1β浓度。采用Western blot法检测海马组织MKP-1蛋白含量、p-ERK/ERK及p-p38/p...     

Chronic post-traumatic neuropathic pain of brachial plexus and upper limb: a new technique of peripheral nerve stimulation

The aim of the study was to evaluate the effect on pain relief in patients with peripheral neuropathic pain after brachial plexus injuries using an implanted peripheral nerve stimulator applied directly to the nerve branch involved into the axillary cavity. Seven patients with post-traumatic brachial plexus lesions or distal peripheral nerve complaining of severe intractable chronic pain were enrolled in a single-centre, open-label trial. Conventional drugs and traditional surgical treatment were not effective. Patients underwent careful neurological evaluation, pain questionnaires and quantitative sensory testing (QST). Surgical treatment consists of a new surgical technique: a quadripolar electrode lead was placed directly on the sensory peripheral branch of the main nerve involved, proximally to the site of lesion, into the axillary cavity. To assess the effect, we performed a complete neuroalgological evaluation and QST battery after 1 week and again after 1, 6 and 12 weeks. All patients at baseline experienced severe pain with severe positive phenomena in the median (5) and/or radial (2) territory. After turning on the neuro-stimulator system, all patients experienced pain relief within a few minutes (>75 % and >95 % in most), with long-lasting pain relief with a reduction in mean Numerical Rating Scale (NRS) of 76.2 % after 6 months and of 71.5 % after 12 months. No significant adverse events occurred. We recommend and encourage this surgical technique for safety reasons; complications such as dislocation of electrocatheters are avoided. The peripheral nerve stimulation is effective and in severe neuropathic pain after post-traumatic nerve injuries of the upper limbs.     

Failure of long-term nerve root stimulation to improve neuropathic pain

OBJECT: Stimulation of dorsal nerve roots or dorsal root ganglia was reported to alleviate neuropathic pain in selected patients during the early postoperative period. A prospective study was initiated to investigate long-term outcome in patients with neuropathic pain of the lower extremities or groin who were treated with selective nerve root stimulation. METHODS: The study included patients with dermatomally distributed neuropathic pain who were > 18 years of age and in whom the pain was refractory to medical treatment. The patients were prospectively evaluated using a visual analog scale (VAS) for pain and ratings for quality of life, activities of daily living, and depression preoperatively, and after defined intervals postoperatively. Implantation of electrodes was performed via foraminotomy or interlaminar fenestration in an awake procedure. An implantable pulse generator (IPG) was implanted in a second operation after successful test stimulation performed over several days. RESULTS: Three patients were included in the study before it was stopped. The mean maximum pain score preoperatively was 9.3. All patients had successful test stimulation with > 50% pain relief prior to implantation of the IPG (mean maximum VAS Score 3.6). The beneficial effect, however, was lost within the next few months despite adjustment of stimulation settings. With higher amplitudes, side effects such as pain attacks or motor phenomena occurred. They disappeared after stopping stimulation, but neuropathic pain recurred to its full extent. The study was stopped 18 months after the first implantation, when the third and last IPG of this series was explanted. Due to the overall short-term effect of stimulation, no relevant changes in ratings for quality of life, activities of daily living, or depression were detected. CONCLUSIONS: Spinal nerve root stimulation proved to be effective on short-term follow-up in 3 patients with neuropathic pain in a dermatomal distribution. Long-term stimulation, however, was disappointing because of the loss of effectiveness and the occurrence of side effects.