脉冲射频治疗慢性神经病理性疼痛的临床新进展

脉冲射频利用间断发出的脉冲式电流在组织周围形成高电压,对神经元的突触活性、细胞因子等有一定影响.脉冲射频具有创伤小、操作便捷、安全性高、效果好等特点.     

脉冲射频治疗慢性疼痛的国外实验研究进展

脉冲射频是一种新颖的治疗技术.本文就国外近年来对脉冲射频治疗慢性疼痛的实验研究进展做一综述.     

Transcutaneous Application of Pulsed Radiofrequency Treatment for Shoulder Pain

We report a retrospective audit of transcutaneous pulsed radiofrequency treatment therapy (TCPRFT) for shoulder pain over a 4‐year period. Methods: Electronic and manual case review revealed that TCPRFT had been performed on 13 patients, with 15 painful shoulders, using a single treatment session between 2006 and 2010 in an outpatient setting. Results: Of the 15 shoulders treated, 10 (two‐thirds) had pain relief for over 3 months with an average pain score reduction of 6.1 of 10 and an average duration of pain relief of 395 days. Two experienced pain relief of < 3 months with an average reduction in pain score of 4.3 of 10 and an average duration of effect of 11 days. Three cases experienced no pain relief from the treatment. Summary: These results suggest TCPRFT may provide clinically useful pain relief and be another treatment modality for shoulder pain. Our findings justifies further research, and we are proceeding with a double‐blind placebo randomized controlled studies to determine the efficacy of TCPRFT in chronic shoulder pain.     

Pulsed Radiofrequency for Radicular Pain Due to a Herniated Intervertebral Disc—An Initial Report

Abstract: Pulsed radiofrequency (PRF) has been used for the treatment of radicular pain, due to a herniated intervertebral disc, but so far the data are anecdotal. This is a retrospective study on 13 consecutive patients with this type of pain, at levels L3 to S1. All patients had a diagnosis confirmed by imaging, all had neurological abnormalities, and all were scheduled for surgical intervention. All 12 patients who had a profession had stopped working. Treatment consisted of application of PRF to the dorsal root ganglion of the affected segmental nerve, or in the case of S1 to the segmental nerve at the level of the S1 foramen. One patient underwent disc surgery, and one other patient underwent a spinal fusion 1 year following PRF treatment. He had no leg pain at the time of operation. The remaining patients did not require surgical intervention. The numeric rating scale (NRS) score fell from 7.83 to 2.25 over the first 2 weeks, followed by a gradual further fall to 0.27 at the final follow‐up, 15.8 (11 to 23) months after the procedure. Compared with the initial NRS score the data were significant (P < 0.01) from 4 weeks after the procedure. Neurological abnormalities resolved except in one patient, who had decreased sensibility in a small area in the L3 dermatome at the last follow‐up. All professionally active patients went back to work after 0.49 months (0.1 to 1). It is concluded that PRF may potentially be a viable alternative for epidural steroid injections in the treatment of acute radicular pain, due to a herniated intervertebral disc, and that further studies, including a control group, should be carried out to establish the value of this method.     

Pulsed Radiofrequency of Pudendal Nerve for Treatment in Patients with Pudendal Neuralgia. A Case Series with Long-Term Follow-Up

Pudendal neuralgia (PN) is an impairing neuropathic disorder, affecting both men and women, involving a severe burning and sharp pain along the course of the pudendal nerve. Treatment is often insufficient, and options are limited. Pulsed radiofrequency (PRF) is a technique which might be useful in therapy. This case series aims to determine the effectiveness of PRF in patients with PN in the context of evaluation of care. Between 2010 and 2016, all female patients of University Medical Center Utrecht diagnosed with PN who experience insufficient pain relief after common treatment were offered PRF. Patient Global Impression of Improvement (PGI-I) scores were assessed at 3-month follow-up and at long-term follow-up (median 4 years). PGI-I scores were recorded to evaluate our quality of care. Twenty patients with PN consented to undergo PRF. We lost one patient in follow-up. Seventy-nine percent of the patients described their condition as “(very) much better” at 3-month follow-up. At long-term follow-up, 89% of the patients described their condition as “(very) much better.” No serious side effects were observed. In conclusion, PRF is a successful treatment option in patients not responding to standard treatment options, including pudendal nerve blocks. PRF of the pudendal nerve can be used for PN to provide relief in patients’ chronic pelvic pain.     

Pulsed Mode Radiofrequency Lesioning to Treat Chronic Post-tonsillectomy Pain (Secondary Glossopharyngeal Neuralgia)

Abstract: Glossopharyngeal neuralgia (GPN) is an uncommon orofacial pain syndrome. Primary GPN is idiopathic, whereas secondary GPN has identifiable causes: tonsillectomy, peritonsillar abscesses, invasive cancer, and trauma. Despite these differences, both types of GPN present similarly and can recur. Pulsed mode radiofrequency lesioning is a safe, non‐destructive treatment method and hence, useful in neuropathic pain conditions. We present the first case of chronic post‐tonsillectomy pain (secondary glossopharyngeal neuralgia), that was successfully managed with pulsed radiofrequency lesioning.     

Unsuccessful Pulsed Radiofrequency of the Sphenopalatine Ganglion in Patients with Chronic Cluster Headache and Subsequent Successful Thermocoagulation

We present the results of pulsed and continuous radiofrequency (CRF) of the sphenopalatine ganglion in a case series of 3 patients with chronic cluster headache (CCH). Three patients were referred to our neurosurgical department because of CCH, which was refractory to pharmacological treatment. They underwent pulsed radiofrequency of the sphenopalatine ganglion (PRF‐SPG), and the procedure was performed through an infrazygomatic approach. In the PRF procedures, we applied 2 cycles of PRF at 42°C and 45 V for 120 seconds, with a pulse frequency of 2 Hz and a pulse width of 20 ms. In those procedures where thermocoagulation was carried out, 2 CRF lesions at 80°C for 90 seconds each were performed. Following corticosteroid and local anesthetic (40 mg of methylprednisolone and 1 mL of 1% lidocaine) injection, 2 patients had no pain relief at all, whereas the third one experienced a partial response, which lasted only 1 month and his pain then returned to its baseline level. Thus, this outcome was assessed as a nonsustained partial response. Therefore, all of them underwent a CRF lesioning of the SPG, and after this procedure, they achieved complete pain relief until the end of the follow‐up period. Furthermore, the associated autonomic manifestations disappeared. The 3 patients presented in this case series failed to achieve adequate pain relief after PRF‐SPG. However, these same patients subsequently underwent a successful CRF of the SPG.     

Pulsed Radiofrequency Ablation for Residual and Phantom Limb Pain: A Case Series

Residual limb pain (RLP) and phantom limb pain (PLP) can be debilitating and can prevent functional gains following amputation. High correlations have been reported between RLP and the stump neuromas following amputation. Many treatment methods including physical therapy, medications, and interventions, have been used with limited success. Pulsed radiofrequency ablation (PRFA) has shown promise in treating neuropathic pain because of the inhibition of evoked synaptic activity. We present 4 amputees who were treated with PRFA after failing conservative management for their RLP and PLP. All 4 patients underwent PRFA and demonstrated at least 80% relief of RLP for over 6 months. One patient reported a complete resolution of phantom sensation while another patient had significantly decreased frequency of spontaneous PLP and resolution of evoked PLP. In addition, all patients reported improved overall function including increased prosthetic tolerance and decreased oral pain medications. This case series suggests that PRFA is a viable treatment option which might be used for long‐term relief of intractable RLP and/or PLP.     

Pulsed Radiofrequency Under Ultrasound Guidance for Persistent Stump‐Neuroma Pain

Limb amputation is a leading cause of pain and disability. Limb amputation can be associated with a myriad of symptoms, including phantom limb sensation, phantom limb pain, and stump pain. Treatment of phantom limb pain and stump pain, remains difficult, therefore optimal management must include a multidisciplinary approach. This case report describes the use of ultrasound for diagnosis and successful management, of persistent stump‐neuroma pain, using pulsed radiofrequency ablation.     

脉冲射频和射频热凝术对臂丛神经损伤的病理学观察

目的探讨脉冲射频和射频热凝术致神经损伤的病理变化。方法 55只Wistar雄性大鼠,5只为正常对照组(C组),另50只暴露臂丛神经后随机分为脉冲射频组和射频热凝组,每组25只。在术后即刻、1、7、14和28 d取臂丛神行HE染色及透射电镜观察。结果脉冲射频组术后神经功能正常,光镜下可见神经纤维间出现水肿,于术后1 d最重,随后逐渐恢复。电镜下可见髓鞘板层结构松散,并有髓鞘球形成,及超微结构的代偿性增生,并逐渐恢复。射频热凝组术后神经功能消失,并出现自噬行为,镜下表现为沃勒变性和神经再生等改变。结论脉冲射频和射频热凝术对神经均可产生损伤。脉冲射频损伤轻微,且恢复快;射频热凝术则损伤严重,毁损神经恢复慢。     

4. Cervical Radicular Pain

Cervical radicular pain is defined as pain perceived as arising in the arm caused by irritation of a cervical spinal nerve or its roots. Approximately 1 person in 1,000 suffers from cervical radicular pain. In the absence of a gold standard, the diagnosis is based on a combination of history, clinical examination, and (potentially) complementary examination. Medical imaging may show abnormalities, but those findings may not correlate with the patient's pain. Electrophysiologic testing may be requested when nerve damage is suspected but will not provide quantitative/qualitative information about the pain. The presumed causative level may be confirmed by means of selective diagnostic blocks. Conservative treatment typically consists of medication and physical therapy. There are no studies assessing the effectiveness of different types of medication specifically in patients suffering cervical radicular pain. Cochrane reviews did not find sufficient proof of efficacy for either education or cervical traction. When conservative treatment fails, interventional treatment may be considered. For subacute cervical radicular pain, the available evidence on efficacy and safety supports a recommendation (2B+) of interlaminar cervical epidural corticosteroid administration. A recent negative randomized controlled trial of transforaminal cervical epidural corticosteroid administration, coupled with an increasing number of reports of serious adverse events, warrants a negative recommendation (2B−). Pulsed radiofrequency treatment adjacent to the cervical dorsal root ganglion is a recommended treatment for chronic cervical radicular pain (1B+). When its effect is insufficient or of short duration, conventional radiofrequency treatment is recommended (2B+). In selected patients with cervical radicular pain, refractory to other treatment options, spinal cord stimulation may be considered. This treatment should be performed in specialized centers, preferentially study related.     

Pulsed Radiofrequency V2 Treatment and Intranasal Sphenopalatine Ganglion Block: A Combination Therapy for Atypical Trigeminal Neuralgia

Trigeminal neuralgia (TN) is a chronic condition affecting the fifth cranial nerve and resulting in sporadic intense burning and shock‐like pain lasting for seconds to minutes that can be incapacitating to patients. Atypical TN includes additional features such as continuous pain and sensory disturbances in the area innervated by one or more branches of the trigeminal nerve. Documented cases of TN have dated back to the 18th century. Today, there are roughly 140,000 people suffering with this condition in the U.S.A. Conventional treatments for this disorder include medical management with nonconvulsants such as carbamazepine, which decrease the nerves response to peripheral stimulation. These agents have good initial pain relief, but relief rates fall off dramatically over the long‐term. Recently, methadone has shown promise as a pharmacologic adjunct to patients with intractable neuropathic noncancer pain, including patients suffering from TN. Cases refractory to medical management can be treated with surgical microdecompression or minimally invasive procedures such as radiofrequency (RF) treatment. Pulsed RF (PRF) is a method gaining interest as it is delivered in pulses, allowing adequate time for dissipation of heat and energy resulting in less damage to surrounding structures. This case report describes the successful treatment of atypical V2 TN refractive to medical management requiring PRF treatment, a sphenopalatine block series, and low‐dose methadone.     

Application of Radiofrequency Energy in Surgical and Interventional Procedures:

During surgical and interventional procedures, interference may occur between ICDs and electrical cautery or with the application of RF energy. This may lead to the false induction of ICD therapies or could even result in device malfunction, which represents a potential perioperative hazard for the patient. This study analyzed the intraoperative interactions in 45 consecutive ICD patients in reference to different surgical and interventional procedures. A total of 33 surgical operations (general surgery [n = 14], urologic [n = 5], abdominal [n = 10], gynecological [n = 2], thoracic [n = 1], neurosurgical [n = 1]) and 12 interventional therapies (RF catheter ablation [n = 10], endoscopic papillotomy [n = 2]) were performed. The ICD devices were all located in left pectoral position and consisted of 25 single and 20 dual chamber defibrillators. During the procedure, tachyarrhythmia detection (VF 296 +/- 20 ms, VT 376 +/- 49 ms) of the devices was maintained active (monitoring mode), only ICD therapies were inactivated. The indifferent electrode of the electrical cauter/RF generator was placed in standard positions (right/left mid-femoral position [n = 27/8], thoracic spine area [n = 10]). After the procedure, the ICD memory was checked for detections and for changes in the programming. There was no oversensing, reprogramming, or damage of any defibrillator caused by RF energy. Despite the lack of undesired interactions, ICDs should be inactivated preoperatively to assure maximum patient safety. However, should inactivation not be possible, or the achievement uncertain, electromagnetic interference is highly unlikely.     

Trans-facet Joint Approach to Pulsed Radiofrequency Ablation of the L5 Dorsal Root Ganglion in a Patient with Degenerative Spondylosis and Scoliosis

▪ Abstract:   Mechanical low back pain secondary to degenerative facet joint changes is a common reason for referral to pain clinics. When these changes cause encroachment into the intervertebral foramen, radicular pain may result. While pulsed radiofrequency of the dorsal root ganglion can be used in this setting, the anatomic deformity may make the transforaminal approach difficult. We report a case where a trans-facet approach was used successfully and describe the technique. ▪     

Pulsed Radiofrequency of Suprascapular Nerve for Chronic Shoulder Pain: A Randomized Double‐Blind Active Placebo‐Controlled Study

Background: The suprascapular nerve block is frequently implemented to treat chronic shoulder pain. Although effective the nerve blockade provides only a short‐term relief, and more compelling apaproaches have been investigated. Pulsed radiofrequency (pRF) has been anecdotally reported as safe and reliable method. However, formal efficacy study has not been published. Ostensibly evidence‐based validation of a new method is necessary for both scholastic and practical purposes. Methods: This study was designed as a randomized active placebo‐control double‐blind trial. Because of encountered difficulties in recruitment and high rate of dropout, the study was redesigned as to allow a smaller sample size and statistical analyses were performed utilizing the last observation carry forward method. Lidocaine injections alone or with combination of the pRF were performed. Participants were followed up during 6 months, and multiple subjective and objective outcome variables were recorded. Results: Thirteen of 22 participants completed 6 months follow‐up. Dropout rate was higher in the lidocaine group. A significant linear trend (P < 0.05) for improvement on the numeric rating scale, Shoulder Pain and Disability Index and Constant‐Murley score was observed in the pRF group, but not in the lidocaine group. Patients in the pRF group were on average more satisfied than the lidocaine group at 1 month (P = 0.041) and at 3 months (P = 0.035). Discussion: Considering limitations of the study design and statistics, it seems plausible to attribute better results in the pRF group to unique properties of this physical modality.