Dorsal Root Entry Zone Lesions Research Articles

History and evolution of surgical treatment for spasticity: a journey from neurotomy to selective dorsal rhizotomy.

The evolution of neurosurgical approaches to spasticity spans centuries, marked by key milestones and innovative practitioners. Probable ancient descriptions of spasmodic conditions were first classified as spasticity in the 19th century through the interventions of Dr. William John Little on patients with cerebral palsy. The late 19th century witnessed pioneering efforts by surgeons such as Dr. Charles Loomis Dana, who explored neurotomies, and Dr. Charles Sherrington, who proposed dorsal rhizotomy to address spasticity. Dorsal rhizotomy rose to prominence under the expertise of Dr. Otfrid Foerster but saw a decline in the 1920s due to emerging alternative procedures and associated complications. The mid-20th century saw a shift toward myelotomy but the revival of dorsal rhizotomy under Dr. Claude Gros' selective approach and Dr. Marc Sindou's dorsal root entry zone (DREZ) lesioning. In the late 1970s, Dr. Victor Fasano introduced functional dorsal rhizotomy, incorporating electrophysiological evaluations. Dr. Warwick Peacock and Dr. Leila Arens further modified selective dorsal rhizotomy, focusing on approaches at the cauda equina level. Later, baclofen delivered intrathecally via an implanted programmable pump emerged as a promising alternative around the late 1980s, pioneered by Richard Penn and Jeffrey Kroin and then led by A. Leland Albright. Moreover, intraventricular baclofen has also been tried in this matter. The evolution of these neurosurgical interventions highlights the dynamic nature of medical progress, with each era building upon and refining the work of significant individuals, ultimately contributing to successful outcomes in the management of spasticity.

Dorsal root entry zone lesioning for brachial plexus avulsion - technical evolution and long-term follow-up.

Brachial plexus avulsion (BPA) injuries can cause severe deafferentation pain. This has been successfully treated with dorsal root entry zone (DREZ) lesioning. Distortions in anatomy following a BPA injury can make identifying neural structures challenging. We describe a modification to the operative technique that improves the surgical view and the advanced intraoperative neuromonitoring (IONM) employed to identify DREZ. We have analysed the long-term outcomes for pain, quality of life, and complications in patients undergoing DREZ lesioning. This is a single-centre retrospective case series including patients who underwent DREZ lesioning with IONM for brachial plexus avulsion between 2012 and 2022. Analysed data included pre- and postoperative pain (VAS), quality of life score for chronic pain, and complications. The evolution of the surgical approach is discussed. 44 consecutive patients underwent a DREZ lesioning procedure with intraoperative monitoring and mapping. In these patients the mean VAS score improved from 8.9 (7-10) to 1.87 (0-6) (p < 0.0001) at the time of discharge. 31 patients were followed-up for more than 12 months with a mean duration of follow-up of 41 months and their results were as follows: the mean VAS improved from 9.0 (7-10) to 4.1 (0-9) (p < 0.0001) at the last follow-up and the mean QOL values improved from 3.7 (2-6) to 7.4 (4-10) (p < 0.0001). The long-term outcomes were 'good' in 39%, 'fair' in 29% and 'poor' in 32% of patients. 55% of the patients were able to stop or reduce pain medications. Modifications of surgical technique provide better exposure of DREZ, and IONM aids in identifying DREZ in the presence of severe intra-dural changes. Long-term outcomes of DREZ lesioning indicate not only a reduction in pain but also a significant improvement in quality of life.

357 Postoperative Outcomes and Decreases in Pain Medication Utilization Following Nucleus Caudalis DREZ Lesioning for Painful Trigeminal Neuropathy: A Case Series

INTRODUCTION: Painful trigeminal neuropathy is characterized by treatment-resistant trigeminal pain. Nucleus Caudalis Dorsal Root Entry Zone lesioning (NC-DREZ) has been utilized to treat this condition, but changes in medication utilization has not been studied in this population. METHODS: We retrospectively reviewed patients who underwent NC-DREZ at an academic medical center for the treatment of painful trigeminal neuropathy between March 2014 and December 2022, with a minimum 30-day follow-up. Postoperative complications, emergency department visits, readmissions, reoperations, changes in patients' subjective pain, and the longitudinal dosage of pain medications were collected as outcomes. The Fisher's exact and Kruskal-Wallis tests, with alpha set at 0.05, were used to compare the proportion and doses of medications used at each timepoint. RESULTS: Thirty-nine patients were included (mean age 55.7 years, 66.7% female) Prior interventions included trigeminal ablation (35.9%), microvascular decompression (59.0%), and stereotactic radiosurgery (41.0%).Twelve patients (30.8%) had postoperative complications, including five with transient ataxia and two with pseudomeningocele. Nine patients (23.1%) visited the ED after surgery, and 7 (17.9%) were readmitted. The rate of opioid use decreased from 56.4% at baseline to 32.3% six months following surgery (p = 0.03). Additionally, the use of carbamazepine, gabapentin, pregabalin, duloxetine, and amitriptyline decreased. One year after surgery, 11/26 patients (42.3%) reported sustained pain relief. CONCLUSIONS: In this case series of NC-DREZ patients, we demonstrated that postoperative complications and subjective pain outcomes were comparable to those previously reported in the literature. Importantly, we demonstrated a reduction in the use of opioids six months after surgery. This study's findings support the use of NC-DREZ as an alternative treatment for painful trigeminal neuropathy. Large scale prospective studies are needed to confirm these results.

The Safety and Efficacy of Dorsal Root Entry Zone Lesioning for Pain Management in Patients With Brachial Plexus Avulsion: A Systematic Review and Meta-Analysis.

Persistent neuropathic pain after brachial plexus avulsion (BPA) is common and generally nonresponsive to medical management. Dorsal root entry zone (DREZ) lesioning is the last resort for pain management in patients with BPA. This study aims to investigate and compare the outcomes and complications of DREZ procedures. A systematic literature search was conducted to identify all related studies. Comparisons were based on the number of patients with preoperative pain vs postoperative pain, with the effect size calculated using the risk ratio. Mean visual analog scale (VAS) scores were extracted and analyzed between interventions. A meta-regression analysis was performed to identify risk factors for final outcomes. The rates of complications were also assessed and analyzed between interventions. A total of 30 studies with 917 patients (90.0% male and 10.0% female, mean age: 42.9 ± 16.6) were included in this systematic review. Of the 917 patients who underwent surgery, 655 (71.4%) patients had significant pain reduction at the last follow-up ( P < .05). The weighted mean preoperative VAS score was 8.3 ± 1.3, compared with postoperative VAS scores (1.9 ± 2.2); a significant improvement was observed ( P < .05). The subgroup analysis showed that microsurgical DREZotomy (MDT) is associated with better outcomes in terms of VAS score improvements compared with radiofrequency (RF)-assisted DREZ lesioning ( P < .05). Meta-analysis showed that the relative risk of motor deficits was significantly lower in the MDT group, compared with the RF-assisted group ( P < .05). Meta-regression showed that older age is correlated with an elevated risk of postoperative motor deficits compared with the incidence of sensory loss. DREZ lesioning is effective for intractable pain alleviation after BPA. Compared with RF-assisted DREZ lesioning, MDT is associated with better VAS score improvements and a lower rate of postoperative motor weakness.

Dorsal Root Entry Zone Lesioning Following Unresponsive Spinal Cord Stimulation for Post-Traumatic Neuropathic Pain

Spinal cord stimulation (SCS) and dorsal root entry zone (DREZ) lesioning are important therapeutic options for intractable post-traumatic neuropathic pain (PNP). However, surgical choice is controversial due to the need to maximize pain relief and reduce complications. This study aims to retrospectively analyze the effect and complications of DREZ lesioning for patients with PNP who were unresponsive to SCS and provide a surgical reference. Demographic data and surgical characteristics of patients with PNP who underwent DREZ lesioning after an unresponsive SCS were reviewed. Long-term outcomes including numeric rating scale, global impression of change, and long-term complications were assessed. Kaplan-Meier analysis was used to evaluate pain-free survival. Of 19 patients with PNP, 8 had brachial plexus injury (BPI), 7 had spinal cord injury, 2 had cauda equina injury, 1 had intercostal nerve injury, and 1 had lumbosacral plexus injury. All patients were unresponsive or had a recurrence of pain after SCS, with an average pain-relief rate of 9.3%. After DREZ lesioning, the mean numeric rating scale scores significantly decreased from 7.6 ± 1.5 to 1.8 ± 1.7, with an average pain-relief rate of 75.3%. Seven patients (36.8%) experienced worsened neurologic dysfunction at the last follow-up. Patients with BPI had a significantly better outcome than other pathologies (P < 0.001) after DREZ lesioning. DREZ lesioning is an effective alternative procedure to SCS for patients with PNP who have lost limb function. Particularly for those with BPI, DREZ lesioning has shown good efficacy and can be considered a preferred surgical option.

Retrospective Study of 57 Patients Submitted to Dorsal Root Entry Zone Lesioning by Radiofrequency for Brachial Plexus Avulsion Pain

Dorsal root entry zone (DREZ) lesioning may be used to treat neuropathic pain in patients with traumatic brachial plexus injuries. The clinical outcome after surgery is variable in the medical literature. We aimed to report the surgical outcome after DREZ lesioning by radiofrequency and to analyze prognostic factors such as the presence of a spinal cord injury identified before surgery. We conducted a retrospective study that included 57 patients who had experienced traumatic brachial plexus injuries and exhibited neuropathic pain that did not respond to conservative treatment methods. They were submitted to DREZ lesioning. We defined the inclusion and exclusion criteria, collected sociodemographic and clinical characteristics, and identified and classified spinal cord lesions based on magnetic resonance imaging. We applied statistical tests to evaluate the association between pain intensity after surgery and the radiological profile and sociodemographic characteristics. Immediately after surgery, the pain outcome was considered good or excellent in 50 patients (89.28%). At the last follow-up, it was good or excellent in 39 patients (68.43%). There was no association (p > 0.05) between the pain outcome and the variables analyzed (time interval between trauma and DREZ lesioning, presence of spinal cord injury, age, the number of avulsed roots, and the type of pain) CONCLUSIONS: DREZ lesioning using radiofrequency represents a significant therapeutic approach for managing neuropathic pain after a traumatic brachial plexus injury. Importantly, we found that the presence of a spinal cord injury is not associated with the surgical outcome.

The "banana splitting DREZotomy": an atraumatic method to improve pain relief after dorsal root entry zone lesioning in brachial plexus injuries. Case series and tenets for the treatment.

The treatment of neuropathic deafferentation pain due to avulsion injuries of the brachial plexus is a major problem, albeit rare, in the neurosurgical practice. The aim of the paper is to present step-by-step the main principles of a surgical upgrade of the well-known Dorsal Root Entry Zone lesioning, that we named banana splitting DREZotomy. A comparison is made among three groups of patients, two of which were treated following the classic techniques, while in the third no physical agent is applied to the spinal cord during surgery. The patients operated on following the well-established surgical procedures showed a short-term success rate around 70%, online with the data of the ongoing literature. The results with the banana-splitting technique, instead, have been astonishing both in terms of resolution of pain, absence of true complications and of unpleasant side effects. A purely dissective technical variant of the surgical procedure called DREZ lesioning has shown better results overcoming the 30% failures of all the reported series. The profound and permanent splitting of the posterior horn and the absence of any other component (heat propagation, radiofrequency, or dotted coagulation) are the major factors which may explain such outstanding results.

Dorsal root entry zone lesioning for brachial plexus avulsion pain: a case series.

Retrospective case series. Dorsal root entry zone (DREZ) lesioning can be performed in patients with intractable pain following brachial plexus avulsion (BPA). However, post-operative outcomes are variable and it is uncommonly used. We sought to determine the pain outcomes and complication profile of DREZ lesioning for BPA. Quaternary neurosurgical centre. All patients that had undergone DREZ lesioning for BPA pain over a 13-year period were included. Patients were assessed for outcome with regard to degree of pain relief and presence of complications. Fourteen patients were reviewed, with a median post-operative follow-up duration of 27 months (1-145 months). Of these, ten were contactable for long-term telephone review, with a median post-operative duration of 37 months (11-145 months). At earliest review post-operatively, 12 of 14 patients (86%) had some level of pain relief: complete pain relief in four patients (29%) and partial pain relief in eight patients (57%). At most recent post-operative review, ten of 14 patients (71%) reported lasting significant pain relief: four (29%) had complete pain relief, six (43%) had partial pain relief and four (29%) had insignificant pain relief. Complications were predominantly sensory, including ataxia, hypoaesthesia and dysaesthesia. Four patients (29%) reported persistent motor complications at final follow-up. DREZ lesioning is uncommonly performed. It remains a reasonable option for relief of refractory BPA pain in selected cases, though there is a significant complication rate. Future prospective studies may enable quantification of pre- and post-lesioning analgesic use, another important determinant of procedure success.

Is dorsal root entry zone lesioning effective and safe for managing continuous versus paroxysmal pains post-brachial plexus avulsion?

Patients with brachial plexus avulsion (BPA) experience chronic deafferentation pain characterized by two patterns: continuous background pain and electrical shooting paroxysmal attacks. The authors' aim was to report the effectiveness and safety of dorsal root entry zone (DREZ) lesioning in relieving the two forms of pain over short and long periods. All patients who underwent DREZ lesioning performed by the senior author for medically refractory BPA-related pain between July 1, 2016, and June 30, 2020, in Johns Hopkins Hospital were followed up. The intensity levels for continuous and paroxysmal pains were evaluated using the numeric rating scale (NRS) preoperatively and at 4 time points postsurgery, including the day of discharge, with a mean hospital stay of 5.6 ± 1.8 days; first postoperative clinic visit (33.0 ± 15.7 days); short-term follow-up (4.0 ± 1.4 months); and long-term follow-up (3.1 ± 1.3 years). The percent of pain relief according to the NRS was categorized into excellent (≥ 75%), fair (25%-74%), and poor (< 25%). A total of 19 patients were included, with 4 (21.1%) lost to long-term follow-up. The mean age was 52.7 ± 13.6 years; 16 (84.2%) were men, and 10 (52.6%) had left-sided injuries. A motor vehicle accident was the most common etiology of BPA (n = 16, 84.2%). Preoperatively, all patients had motor deficits, and 8 (42.1%) experienced somatosensory deficits. The greatest pain relief was observed at the first postoperative and short-term follow-up visits, with the lowest proportions of patients having continuous pain (26.3% and 23.5%, respectively) and paroxysmal pain (5.3% and 5.9%, respectively). Also, the highest reductions in mean NRS scores were observed for first postoperative and short-term follow-up visits (continuous 1.1 ± 2.1 and 1.1 ± 2.3; paroxysms 0.4 ± 1.4 and 0.5 ± 1.7, respectively) compared to the preoperative symptomatology (continuous 6.7 ± 3.0; paroxysms 7.9 ± 4.3) (p < 0.001). Most patients had excellent relief of continuous pain (82.4% and 81.3%) and of paroxysms (90.9% and 90.0%) at the first postoperative visit and short-term follow-up visit, respectively. The pain relief benefits had diminished by 3 years after surgery but remained significantly better than in the preoperative assessment. At the last evaluation, the proportion of patients achieving excellent relief of paroxysmal pain (66.7%) was double that for continuous pain (35.7%) (p < 0.001). New sensory phenomena were observed among 10 patients (52.6%), and 1 patient developed a motor deficit. DREZ lesioning is an effective and safe option for relieving BPA-associated pain, with good long-term outcomes and better benefits for paroxysmal pain than for the continuous pain component.

Tight adhesions after spinal cord stimulation observed during dorsal root entry zone lesioning for pain after spinal root avulsion: illustrative cases.

BACKGROUNDPatients often experience strong shooting pains after spinal root avulsion. The efficacy of spinal cord stimulation (SCS) for this type of pain is inconsistent; however, dorsal root entry zone (DREZ) lesioning (DREZ-lesion) has often proven to be an effective treatment modality. The authors report two cases in which DREZ-lesion was performed to treat pain after spinal root avulsion after implantation of SCS, but the operations were challenging due to strong adhesions.OBSERVATIONSThe authors present two cases of patients with pain after spinal root avulsion in whom SCS implantation was only temporarily effective. Patients complained of persistent and paroxysmal shooting pains in the upper extremities. SCS removal and DREZ-lesion were performed, but adhesions in the epidural and subdural space contacting the leads were strong, making it difficult to expose the DREZ.LESSONSAlthough adhesions around the spinal cord can be caused by trauma, the authors believe that in these cases, the adhesions could have been caused by the SCS leads. There are few previous reports confirming the efficacy of SCS in treating pain after spinal root avulsion; therefore, caution is required when considering SCS implantation.

Factors affecting long-term outcome in dorsal root entry zone lesioning for brachial plexus avulsion.

Dorsal root entry zone (DREZ) lesioning is a classical and effective treatment for brachial plexus avulsion (BPA). However, because of a limited number of cases reported in the literature, the factors affecting surgical outcomes are not known. Furthermore, whether this ablative procedure in the spinal level can change the status of phantom limb pain (PLP) and phantom limb sensation (PLS) is unknown. We retrospectively reviewed the patients with preganglionic BPA who underwent DREZ lesioning at a single center. Patients' baseline characteristics and long-term pain and complications were collected. Postoperative changes in PLP and PLS were recorded. Kaplan-Meier analysis was used to evaluate pain-free survival. Multivariate Cox regression analysis was performed to identify factors affecting pain outcomes. A total of 112 patients met the study inclusion criteria. With an average (range) follow-up of 47.4 (10-134) months, the long-term effectiveness and complication rate were 82.1% and 25.9%, respectively. Of 37 patients (33.0%) who developed PLS, 67.6% (25/37) experienced pain relief, whereas in 45.9% (17/37), PLS disappeared or changed after DREZ lesioning. Multivariate analysis showed that patients with shorter pain duration (≤5 years) and PLS had worse pain outcomes. This study revealed factors that predict the pain outcome of DREZ lesioning based on a large series of cases. The diverse postoperative changes in phantom limb indicate that the mechanisms underlying PLS and PLP at the spinal or supraspinal level may vary among patients with BPA. Future studies should investigate the contribution of maladaptive brain plasticity to the outcomes of patients undergoing DREZ lesioning.

Radiologic Findings of Dorsal Root Entry Zone Lesioning

Dorsal root entry zone lesioning is an intervention that may be performed in patients with brachial plexus avulsion injuries to reduce neuropathic pain. There is little description in the literature of the expected postoperative imaging findings following dorsal root entry zone ablation. We describe a case of a 36-year-old man who underwent MR imaging of the cervical spine 3 years following dorsal root entry zone lesioning. This article will also discuss the expected postoperative imaging findings following dorsal root entry zone lesioning as well as the imaging features of common complications of the procedure.

Dorsal Root Entry Zone Lesioning for Brachial Plexus Avulsion Injuries: Case Series and Literature Review.

Introduction: Brachial plexus avulsion (BPA) injuries commonly occur secondary to motor vehicle collisions, usually in the young adult population. These injuries are associated with significant morbidity, and up to 90% of patients suffer from deafferentation pain. Neuromodulation procedures can be efficacious in the treatment of refractory neuropathic pain, although the treatment of pain due to BPA can be challenging. Dorsal root entry zone (DREZ) lesioning is a classical and effective neurosurgical technique which has become underutilized in treating refractory root avulsion pain.Methods: A systematic review of the different technical nuances, procedural efficacy, and complication profiles regarding DREZ lesioning for BPA injuries in the literature is included. We also present an institutional case series of 7 patients with BPA injuries who underwent DREZ lesioning.Results: In the literature, 692 patients were identified to have undergone DREZ lesioning for pain related to BPA. In 567 patients, the surgery was successful in reducing pain intensity by over 50% in comparison to baseline (81.9%). Complications included transient motor deficits (11%) and transient sensory deficits (11%). Other complications including permanent disability, cardiovascular complications, infections, or death were rare (<1.9%). In our case series, all but one patient achieved >50% reduction in pain intensity, with the mean pre-operative pain of 7.9 ± 0.63 (visual analog scale) reduced to 2.1 ± 0.99 at last follow-up (p < 0.01).Conclusion: Both the literature and the current case series demonstrate excellent pain severity reduction following DREZ ablation for deafferentation pain secondary to BPA.

Microscissor DREZotomy for post brachial plexus avulsion neuralgia: A single center experience

IntroductionBrachial neuralgia is a dreaded sequelae which substantially impairs the quality of life in patients with brachial plexus avulsion (BPA) injuries. Dorsal Root Entry Zone (DREZ) lesioning of the cervical spinal cord is the most utilized procedure for alleviating this painful condition. In this study, we share a single center experience of surgically managing post BPA neuropathic pain. The efficacy, results and complications of the modified technique of DREZ, called the Microscissor DREZotomy (MDZ) are discussed along with the review of relevant literature. MethodsThis retrospective analysis included all the patients undergoing MDZ for post BPA brachialgia over 5 years period (2012–2018) at our institution. The pain was quantified using the Numeric rating Scale (NRS) between 0 and 10 scale and was graded as ‘Excellent’ in patients with more than 75% pain relief, ‘Good’ with 50–75% relief, ‘Fair’ between 25% and 50% and ‘Poor’ if less than 25%. ResultsA total of 56 patients underwent MDZ and a mean follow up of 32 months (range 18–69 months) available for 47 patients. Thirty three patients (70.4%) judged pain relief as Excellent, Five (10.6%) as Good, 3 (7%) as Fair and 6 (12%) having poor pain relief. Overall, in 38 (81%) patients long term analgesic effect (> 50%) was noted and 3 (7%) patients had more than 25% pain relief, making up an overall 41 (87%) of patients with some relief from pain. ConclusionMDZ is a safe, efficacious technique with good long term pain relief and quality of life. This technique entails utilization of routine surgical instruments and can be performed with ease even in resource limited settings.

Dorsal Root Entry Zone Lesioning for Brachial Plexus Avulsion: A Comprehensive Literature Review.

Dorsal root entry zone (DREZ) lesioning is a neurosurgical procedure that aims to relieve severe neuropathic pain in patients with brachial plexus avulsion by selectively destroying nociceptive neural structures in the posterior cervical spinal cord. Since the introduction of the procedure over 4 decades ago, the DREZ lesioning technique has undergone numerous modifications, with a variety of center- and surgeon-dependent technical differences and patient outcomes. We have reviewed the literature to discuss reported methods of DREZ lesioning and outcomes.

Modified dorsal root entry zone lesioning for pain relief in cervical root avulsion injury.

Neuropathic pain in the upper extremity due to cervical root avulsion injury is refractory to medical treatments. Superficial layers in the posterior horn of spinal gray matter, including the substantia gelatinosa, are the main target of dorsal root entry zone (DREZ) lesioning, which has been the most effective surgical treatment for the relief of intractable pain; however, residual pain and a decrease in pain relief during the long-term follow-up period have been reported. Based on pain topography in the most recent basic studies, the conventional DREZ lesioning procedure was modified to improve clinical outcomes.The video can be found here: https://youtu.be/PyaAGmAE7Og

Microsurgical DREZ lesions for the control of cancer-related pain.

Pain in patients with cancer is a major problem, and sometimes it is necessary to surgically interrupt pain pathways to effectively control refractory pain. Surgical lesion of the dorsal root entry zone (DREZ) was first performed in 1972 for the treatment of pain related to a Pancoast-Tobias tumor. The rationale of DREZotomy is to preferentially interrupt the nociceptive inputs in the lateral part of the DREZ and the ventrolateral (excitatory) part of the dorsal horn. Microsurgical DREZotomy is one technique for DREZ lesioning that is suited for tailored control of pain in patients in good general condition who are experiencing pain in a well-defined territory.The video can be found here: https://youtu.be/JtLQDP7gYSQ

Dorsal root entry zone lesion: nuances of the technique and long-term results.

The treatment of deafferentation pain is a primary goal of a referral center for peripheral nerve surgery. DREZ is an important asset in the neurosurgeon’s armamentarium. The surgical technique and long-term results are analyzed in two series, with or without intraoperative monitoring (IOM). DREZotomy is highly effective in lumbar root avulsive injuries but is ineffective in resolving pain due to spinal cord injuries. Cervical DREZotomy for cancer pain is not superior to intrathecal morphine. In brachial plexus avulsive injuries, the largest series shows a 74% success rate, but the efficacy of the procedure is lost over time. No relevant difference has been observed since the introduction of IOM.The video can be found here: https://youtu.be/uG_kkQj5m1U

Central Neuropathic Pain and Complex Regional Pain Syndrome Following Brachial Plexus Injury Treated Successfully With Dorsal Root Entry Zone Lesioning

Abstract INTRODUCTION Central neuropathic pain (CNP) and complex regional pain syndrome (CRPS) present as chronic, unrelenting, and disabling pain resulting from central and peripheral nervous system injuries. For patients who have failed conservative management, dorsal root entry zone (DREZ) lesioning may serve as an alternative for the management of intractable pain. METHODS A 36-yr-old male presented with complete right brachial plexus injury and avulsion of nerve roots following a motorcycle accident. He developed disabling type I CRPS of the right upper extremity. After failing medical therapy, he underwent a trial of conventional SCS using 2 percutaneous leads in the upper cervical spine but did not get topographical coverage. He underwent a second SCS trial with the placement of a paddle lead using burst therapy, but his initial partial pain relief subsided after 3 d. Subsequently, he underwent SCS removal, C2 to T1 right DREZ lesioning, and C4 to T1 laminoplasty. The patient gained a significant pain relief and became more functional. Five months postoperatively, he experienced an improvement in his pain and narcotic consumption. RESULTS Using an insulated neurotomy electrode, 2-mm-deep lesions were made at 75°C for 15 s. A total of 83 lesions were made from T2 to C3. Each lesion was spaced 1 mm apart. The impedance was less than 1000 ohms, which was consistent within an area of injury. Somatosensory and motor-evoked potentials were at baseline during the case without significant changes. CONCLUSION When SCS fails, lesioning of the dorsal root entry zone is a useful tool in the armamentarium for the management of refractory brachial plexus neuropathic pain.

The Neurosurgeons' Armamentarium for the Management of Refractory Post-Herpetic Neuralgia

Abstract INTRODUCTION Post-herpetic neuralgia (PHN) can be refractory to medical treatment. Its complex pathophysiology explains the numerous neurosurgical procedures available. The present study summarizes all available neurosurgical strategies for the management of resistant PHN and evaluates respective safety and efficacy. METHODS A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The PubMed and Cochrane Library databases were searched up to October 2018. RESULTS A total of 38 studies comprising 811 patients with refractory PHN were included. Ten studies with 243 patients reported use of spinal cord stimulation. The mean visual analog scale (VAS) score was 7.6 and 2.7 before and after the procedure. Dorsal root entry zone (DREZ) lesioning was performed in 85 patients. The mean VAS score before and after the procedure was 8.6 and 3.7. During the postoperative period, 42.3% of patients developed motor deficits. Five studies investigated intrathecal (IT) injections or pump insertions. The combined IT injections demonstrated a strong analgesic effect 87% of patients reported pain reduction &gt;50%. Spinal trigeminal nucleotomy was reported in 4 studies with a total of 60 patients with 78.3% of patients pain-free during long-term follow-up. However, motor and sensory deficits occurred in 75% to 100%. DRG pulsed radiofrequency lesioning was reported by 2 studies (69 patients) with mean VAS before and after was 6.9 and 2.7, respectively. Peripheral nerve simulation was reported by 3 studies comprising 10 patients in total. This strategy was among the safest and most effective, demonstrating a VAS pain reduction from 8.6 to 2 without any complications. CONCLUSION Neurosurgical approaches for recalcitrant PHN include neuromodulatory and ablative procedures. Patients with resistant PHN should undergo minimally invasive procedures first, including SCS, PNS, or DRG radiofrequency lesioning. More invasive procedures should be reserved for refractory cases. Comparative studies are needed in order to construct a PHN neurosurgical management algorithm.