Effectiveness of Radiofrequency Ablation of the Genicular Nerves of the Knee for the Management of Intractable Pain from Knee Osteoarthritis.

BACKGROUND: The knee joint is one of the most common diseases in elderly individuals. This is a progressive and debilitating condition. The purpose of knee osteoarthritis treatment is to manage pain, increase mobility, and improve the quality of life. OBJECTIVES: This study evaluated the therapeutic effect of radiofrequency thermocoagulation (RFTC) on the genicular nerves in patients with intractable pain due to knee osteoarthritis, as well as its effects on pain severity and magnetic resonance imaging (MRI) findings. STUDY DESIGN: A prospective outcome study. SETTING: The outpatient clinic of a single academic medical center. METHODS: We conducted a prospective study. Fifty consecutive patients with intractable knee pain due to osteoarthritis were enrolled and underwent ultrasound (US)-guided RFTC of the genicular nerves (medial superior genicular nerve, medial inferior genicular nerve, and lateral superior genicular nerve). Pain severity was measured using the Numeric Rating Scale (NRS), and knee osteoarthritis-associated symptoms were evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at pretreatment and one, 3, and 6 months after RFTC treatment. We also analyzed the relationship between therapeutic outcomes and pain severity based on pre-treatment and knee MRI findings. RESULTS: No dropouts were observed. The most significant reduction in knee symptoms associated with knee osteoarthritis was observed after one month of treatment; however, at 3 and 6 months, there was a rebound effect, leading to a decrease in therapeutic efficacy. Nonetheless, there was still a noticeable decrease in symptoms due to knee osteoarthritis compared to those prior to RFTC treatment. The effect of RFTC treatment was better when pre-treatment pain was relatively less severe, knee effusion was not severe, there were no meniscal tears in the middle or posterior zones, no bone marrow edema in the middle and posterior zones of the femur and tibia, and no severe cartilage defects in the posterior femur and middle and posterior tibia. LIMITATIONS: We conducted our study without a control or a placebo group. CONCLUSION: RFTC of the genicular nerve is a good therapeutic option for controlling intractable pain following knee osteoarthritis. In addition, we found that a lower level of pain prior to treatment, along with the absence or lesser degree of knee joint effusion, as well as an absence or less severe middle or posterior knee pathologies associated with knee osteoarthritis, can predict a more favorable therapeutic outcome.

Targeted Nerve Root Stimulation Alleviates Intractable Chronic Limb Pain Associated with Complex Regional Pain Syndrome - A Prospective Multi-Center Feasibility Study.

BACKGROUND: There are limited therapeutic options to treat complex regional pain syndrome (CRPS). Spinal cord stimulation and dorsal root ganglion stimulation are proven therapies for treating chronic low limb pain in CRPS patients. There is limited evidence that stimulation of dorsal nerve roots can also provide relief of lower limb pain in these patients. OBJECTIVES: To demonstrate that electrical stimulation of dorsal nerve roots via epidural lead placement provides relief of chronic lower limb pain in patients suffering from CRPS. STUDY DESIGN: Prospective, open label, single arm, multi-center study. SETTING: The study was performed at the Center for Interventional Pain and Spine (Exton, PA), Millennium Pain Center (Bloomington, IL), and the Carolinas Pain Center (Huntersville, NC). It was approved by the Western Institutional Review Board-Copernicus Group Institutional Review Board and is registered at clinicaltrials.gov (NCT03954080). METHODS: Sixteen patients with intractable chronic severe lower limb pain associated with CRPS were enrolled in the study. A standard trial period to evaluate a patients' response to stimulation of the dorsal nerve roots was conducted over 3 to 10-days. Patients that obtained 50% or greater pain relief during the trial period underwent permanent implantation of a neurostimulation system. The primary outcome was the evaluated pain level after 3 months of device activation, based on NRS pain score relative to baseline. Patients were followed up for 6 months after activation of the permanently implanted system. RESULTS: At the primary endpoint, patients reported a significant (P = 0.0006) reduction in pain of 3.3 points, improvement in quality of life, improved neuropathic pain characteristics, improved satisfaction, and an overall perception of improvement with the therapy. Improvements were sustained throughout the duration of the study up to the final 6-month visit. LIMITATIONS: Due to the COVID-19 pandemic occurring during patient enrollment, only 16 patients were enrolled and trialed, with 12 being permanently implanted. Nine were able to complete the end of study evaluation at 6 months. CONCLUSIONS: The results of this short feasibility study confirm the functionality, effectiveness, and safety of intraspinal stimulation of dorsal nerve roots in patients with intractable chronic lower limb pain due to CRPS using commercially approved systems and conventional parameters.

Radiofrequency regulation of the sphenopalatine ganglion in managing herpes zoster ophthalmicus neuralgia: A case series.

INTRODUCTION: Trigeminal herpes zoster, which comprises 10% to 20% of cases of herpes zoster, often leads to severe pain in the ophthalmic branches. Current treatments, including drug therapy and minimally invasive interventions, have limitations; accordingly, there is a need to explore alternative approaches. This study aimed to evaluate the efficacy and safety of computerized tomography (CT)-guided pulsed radiofrequency of the sphenopalatine ganglion in patients with intractable trigeminal herpetic pain. PATIENT CONCERNS: Three patients with intractable trigeminal ophthalmic zoster neuralgia were studied. All patients complained of bursts of headache, which occurred at least 10 times a day, usually in the periorbital and frontal regions. Conventional treatments, including oral medications and radiofrequency therapy targeting the trigeminal-semilunar ganglion and supraorbital nerve, could not sufficiently provide relief. DIAGNOSIS: Two patients were diagnosed with herpes zoster in the ocular branch of the trigeminal nerve with conjunctivitis, while one patient was diagnosed with postherpetic neuralgia in the ocular branch of the trigeminal nerve. INTERVENTIONS: This study employed a novel approach that involved CT-guided radiofrequency regulation of the pterygopalatine fossa sphenopalatine ganglion. OUTCOMES: In all three patients, pain relief was achieved within 1 to 3 days after treatment. During the follow-up, one patient had pain recurrence; however, its severity was ≈ 40% lower than the pretreatment pain severity. The second patient had sustained and effective pain relief. However, the pain of the third patient worsened again after 2 months. The average follow-up duration was 3 months. None of the enrolled patients showed treatment-related adverse reactions or complications. CONCLUSION: Our findings indicated that CT-guided radiofrequency regulation of the pterygopalatine fossa sphenopalatine ganglion was a safe and effective intervention for pain in patients with trigeminal ophthalmic zoster neuralgia, suggesting that it may be a therapeutic option if other treatments fail.

Effects of palliative intrathecal analgesia on patients with refractory cancer bone pain.

This study examined the effects of intrathecal analgesia (ITA) using an extracorporeal pump with a subcutaneous port system in cancer patients with bone metastasis. Among the patients who died of cancer with bone metastasis at the palliative care unit of our institution, 11 who received ITA were selected. Changes in pain, opioid doses, the palliative prognostic index (PPI), and Eastern Cooperative Oncology Group Performance Scale　after ITA were assessed. Pain, opioid doses, and PPI decreased after ITA (P = 0.002, 0.002, and 0.017). ITA for cancer patients with increased PPI due to refractory cancer bone pain decreased pain, opioid doses, and PPI.(100 words).

Demographics and PainDETECT as Predictors of 24-Month Outcomes for 10 kHz SCS in Nonsurgical Refractory Back Pain.

BACKGROUND: Nonsurgical refractory back pain (NSRBP) is broadly defined as chronic refractory back pain in patients who have not had previous spine surgery and, because they are deemed inappropriate candidates for surgery, are reliant on conventional medical management (CMM), which often provides poor long-term outcomes. High-frequency spinal cord stimulation (10kHz SCS) has demonstrated high rates of pain relief and improvements in functioning in patients with NSRBP. However, despite the use of temporary trial stimulation to select patients who will respond to therapy, some patients fail to achieve long-term therapy response with permanent implants. Prediction analysis founded on patients' baseline characteristics may enrich the appropriate selection of patients for permanent implantation. OBJECTIVES: To examine baseline patient characteristics to predict long-term pain and functional responses to treatment with 10 kHz SCS for NSRBP. STUDY DESIGN: A retrospective analysis of baseline patient characteristics as predictors of 24-month pain and functional outcomes from a previous multicenter randomized controlled trial of 10 kHz SCS in patients with NSRBP. PATIENTS: Patients diagnosed with chronic, neuropathic, axial, low back pain refractory to CMM who had had no previous spine surgery, were deemed unsuitable candidates for it according to a spine surgeon, were implanted with 10kHz SCS and continued with CMM for up to 24 months. METHODS: The baseline characteristics of and 24-month outcomes in the 125 implanted patients who participated in the NSRBP randomized controlled trial (RCT) were included in this analysis. The baseline characteristics included demographics, baseline pain on the visual analog scale (VAS), baseline function based on the Oswestry Disability Index (ODI), mental health according to the patient health questionnaire-9 (PHQ-9), neuropathic pain as measured by PainDETECT, and each patient's temporary trial response. Patient response at 24 months was defined as absolute change from the baseline on the VAS and ODI, and each patient was also classified as a pain responder (achieving at least a 50% decrease in VAS pain score from the baseline) and a function responder (at least a 10-point decrease in ODI or a 24-month score of no more than 20 points). Multivariate prediction models based on regression and classification and regression tree (CART) techniques were developed using the response variables discussed above as the dependent variables and the baseline characteristics as the independent variables. RESULTS: Different factors contributed to pain and functional outcomes. Patients presenting with neuropathic pain (PainDETECT >= 19) and female gender had higher odds of being pain responders to 10 kHz SCS therapy than did males and those without neuropathic pain. Both higher age and depression score (PHQ-9) independently reduced the odds that a patient would be an ODI responder. Years since diagnosis, the reason the patient was deemed unsuitable for spine surgery, and pain etiology were not predictive of pain or functional outcomes. LIMITATIONS: A retrospective sub-analysis of a single pragmatic randomized controlled trial. CONCLUSIONS: There may be an opportunity to increase pain relief and functional improvement if additional patient screening accompanies the temporary lead trial. The presence of neuropathic pain, female gender, age, and depression had some predictive value, but this analysis demonstrates the treatment efficacy of 10 kHz SCS across a wide range of patients with NSRBP.

Intrathecal morphine delivery at prepontine cistern to control refractory cancer-related pain: a case report of extensive metastatic and refractory cancer pain.

BACKGROUND: Extensive metastatic and refractory cancer pain is common, and exhibits a dissatisfactory response to the conventional intrathecal infusion of opioid analgesics. CASE PRESENTATION: The present study reports a case of an extensive metastatic esophageal cancer patient with severe intractable pain, who underwent translumbar subarachnoid puncture with intrathecal catheterization to the prepontine cistern. After continuous infusion of low-dose morphine, the pain was well-controlled with a decrease in the numeric rating scale (NRS) of pain score from 9 to 0, and the few adverse reactions to the treatment disappeared at a low dose of morphine. CONCLUSIONS: The patient achieved a good quality of life during the one-month follow-up period.

Diagnostic and therapeutic value of intracellular biomarker testing in chronic pain.

Aim: Micronutrient and metabolic compound supplementation as a method of treating chronic pain is not well understood. Case: A 58 year-old woman presented with refractory painful neuropathy. She did not respond to conservative treatment and was seeking spinal cord stimulator implantation. She underwent a biomarker panel that revealed low intracellular levels of multiple compounds. As she supplemented her deficiencies, her symptoms fully resolved, and the implant was no longer indicated. Discussion: Micronutrient and metabolic compound testing could potentially expand non-invasive treatment options for patients with refractory chronic pain. Caution should be exercised given limited regulatory oversight in the supplement industry and actively ongoing nutritional research. Conclusion: Biomarker testing panels may be a useful adjunct in the management of refractory neuropathic pain.

Implantable Subdural Cortical Stimulation for Chronic Intractable Pain Treatment-The Mayo Experience and Review of Literature.

OBJECTIVES: Motor cortex stimulation (MCS) is an effective technique in treating chronic intractable pain for some patients. However, most studies are small case series (n < 20). Heterogeneity in technique and patient selection makes it difficult to draw consistent conclusions. In this study, we present one of the largest case series of subdural MCS. MATERIALS AND METHODS: Medical records of patients who underwent MCS at our institute between 2007 and 2020 were reviewed. Studies with at least 15 patients were summarized for comparison. RESULTS: The study included 46 patients. Mean age was 56.2 ± 12.5 years (SD). Mean follow-up was 57.2 ± 41.9 months. Male-to-female ratio was 13:33. Of the 46 patients, 29 had neuropathic pain in trigeminal nerve territory/anesthesia dolorosa; nine had postsurgical/posttraumatic pain; three had phantom limb pain; two had postherpetic pain, and the rest had pain secondary to stroke, chronic regional pain syndrome, and tumor. The baseline numeric rating pain scale (NRS) was 8.2 ± 1.8 of 10, and the latest follow-up score was 3.5 ± 2.9 (mean improvement of 57.3%). Responders comprised 67% (31/46)(NRS ≥ 40% improvement). Analysis showed no correlation between percentage of improvement and age (p = 0.352) but favored male patients (75.3% vs 48.7%, p = 0.006). Seizures occurred in 47.8% of patients (22/46) at some point but were all self-limiting, with no lasting sequelae. Other complications included subdural/epidural hematoma requiring evacuation (3/46), infection (5/46), and cerebrospinal fluid leak (1/46). These complications resolved with no long-term sequelae after further interventions. CONCLUSION: Our study further supports the use of MCS as an effective treatment modality for several chronic intractable pain conditions and provides a benchmark to the current literature.

Ketamine subcutaneous continuous infusion for non-cancer neuropathic pain at home: a case report.

OBJECTIVE: Ketamine is a drug that can effectively treat neuropathic pain by blocking the N-methyl-D-aspartate receptor. It has been studied as a supplement to opioids for cancer pain, but its effectiveness for non-cancer pain is still limited. However, despite its usefulness in managing refractory pain, ketamine is not commonly used for home-based palliative care. METHODS: A case report of a patient with severe central neuropathic pain who was treated with a subcutaneous continuous infusion of morphine and ketamine at home. RESULTS: The introduction of ketamine in the patient's treatment plan effectively controlled pain. Only one possible ketamine side effect was observed and easily treated with pharmacological and non-pharmacological measures. CONCLUSIONS: We have found success in using subcutaneous continuous infusion of morphine and ketamine to alleviate severe neuropathic pain in a home setting. We also observed a positive impact on the patient's family members' personal, emotional and relational well-being after ketamine was introduced.

Topical Diclofenac to Manage Opioid-Refractory Pain in a Rare Pancreatic Fibrosarcoma.

Pancreatic cancer is often diagnosed at an advanced stage and is frequently associated with severe pain. Traditional pain management in this condition may be improved with the use of topical diclofenac. A 39-year-old man with advanced pancreatic fibrosarcoma metastatic to the thoracic spine presented to the hospital with severe abdominal pain refractory to escalating doses of opioids. A celiac plexus block produced significant, yet inadequate, pain reduction. Satisfactory pain control and opioid de-escalation were ultimately achieved with the application of topical diclofenac gel to an area of bony metastasis. This case illustrates the potential for pain control using topical diclofenac in patients with pancreatic soft tissue tumors and vertebral metastases. Topical diclofenac may exert antitumoral effects and targeted application may improve absorption, leading to improved pain control. The use of topical diclofenac for pain management in metastatic pancreatic cancer presents an interesting tool that should be considered in similar cases.

Oral ketamine for neuropathic cancer pain.

Optimal pain management in patients with advanced cancer often requires multiple pharmacological interventions and multimodal approach. Ketamine is an anaesthetic agent with increasing evidence supporting its use for pain. Due to its N-methyl-D-aspartate antagonism and its activity at opioid receptors, it is an adjuvant to traditional analgesics. Ketamine has a safety profile with limited experience of oral prolonged use in patients with cancer. We report a case of a 40-year-old man with refractory neuropathic cancer-related pain. Opioid rotation to methadone was previously performed, coanalgesics were added, the patient was reluctant to invasive anaesthetic techniques and his pain was poorly controlled. Ketamine was added to attenuate pain keeping functionality. This is a report of a patient with refractory cancer pain treated with methadone and ketamine orally during months, without reported side effects. Ketamine's use to treat pain is increasing along with its evidence of efficacy for long-term oral use.

1. Lumbosacral radicular pain.

INTRODUCTION: Patients suffering lumbosacral radicular pain report radiating pain in one or more lumbar or sacral dermatomes. In the general population, low back pain with leg pain extending below the knee has an annual prevalence that varies from 9.9% to 25%. METHODS: The literature on the diagnosis and treatment of lumbosacral radicular pain was reviewed and summarized. RESULTS: Although a patient's history, the pain distribution pattern, and clinical examination may yield a presumptive diagnosis of lumbosacral radicular pain, additional clinical tests may be required. Medical imaging studies can demonstrate or exclude specific underlying pathologies and identify nerve root irritation, while selective diagnostic nerve root blocks can be used to confirm the affected level(s). In subacute lumbosacral radicular pain, transforaminal corticosteroid administration provides short-term pain relief and improves mobility. In chronic lumbosacral radicular pain, pulsed radiofrequency (PRF) treatment adjacent to the spinal ganglion (DRG) can provide pain relief for a longer period in well-selected patients. In cases of refractory pain, epidural adhesiolysis and spinal cord stimulation can be considered in experienced centers. CONCLUSIONS: The diagnosis of lumbosacral radicular pain is based on a combination of history, clinical examination, and additional investigations. Epidural steroids can be considered for subacute lumbosacral radicular pain. In chronic lumbosacral radicular pain, PRF adjacent to the DRG is recommended. SCS and epidural adhesiolysis can be considered for cases of refractory pain in specialized centers.

The Use of Ketamine for Malignant and Nonmalignant Chronic Pain in Children: A Review of Current Evidence.

Chronic pain in children continues to pose significant challenges. The pharmacological approach most often revolves around trials and errors, expert opinions, and extrapolation of adult study findings. Ketamine is one of the agents used for chronic pain, especially with a neuropathic component. This article aims to provide an overview of its properties and highlight the current evidence for its use in malignant and nonmalignant chronic pain management. A search on the use of ketamine for chronic pain in children up to 18 years of age covering the period from January 1, 2000, to December 14, 2022, was performed through PubMed, Cochrane Library, EBSCO, EBM Review, Wiley, BMJ, Web of Science, Google Scholar, and the Saudi Digital Library. 218 articles were found and 42 underwent full review. Currently, the evidence about ketamine efficacity and safety for chronic pain management is at best of moderate to low quality. The heterogeinity of ketamine infusion protocols and frequent concomitant use of other analgesics make it difficult to draw robust conclusions. The long-term effect of prolonged usage also remains a concern. Nevertheless, with careful monitoring, the drug may be a reasonable choice for malignant and nonmalignant pain management in selected cases, especially for refractory pain not responding to conventional approaches.

Effectiveness of CT-guided percutaneous cordotomy in intractable cancer pain: Experience in 14 patients.

BACKGROUND: Severe and treatment-resistant pain is a major issue for patients with cancer. Cordotomy is an effective approach for addressing severe cancer-related pain. It is based on blocking the transmission of pain by damaging the lateral spinothalamic tract. METHODS: Computed tomography guided cordotomy was performed on 14 patients who did not respond to medical and interventional pain management methods. RESULTS: Fourteen patients with cancer pain underwent CT-guided percutaneous cordotomy. Pain relief was reported in 86% of the patients. The visual analog scale values before and after cordotomy were compared and a significant difference was found (p = 0.0001). The improvement in the Karnofsky Performance Scale score of the patients was found to be statistically significant (p = 0.0001). CONCLUSION: We believe that CT-guided cordotomy, performed by experienced hands in a team of experienced individuals and applied to the right patients, is an effective treatment. However, it is crucial to exercise extreme caution regarding potential side effects and serious complications during the cordotomy procedure.

Retrograde thoracic spinal cord stimulation paddle placement for complex persistent spinal pain syndrome type 2.

BACKGROUND: Spinal cord stimulation (SCS) is a cost-effective option for treating refractory persistent spinal pain syndrome type-2 (PSPS-2). For patients with extensive spine instrumentation including the thoraco-lumbar junction, percutaneous placement of SCS leads is usually not an option being paddle leads typically implanted anterograde. Paddle lead placement will be particularly challenging in more complex cases when the instrumentation covers the targeted level. To overcome this barrier, we studied using a retrograde approach to reach the sweet spot, facilitate the placement, and reduce associated risks. OBJECTIVES: To study the use of retrograde SCS paddle as a placement method to optimize the spinal cord target and reduce the risks of conventional placement in complex cases. STUDY DESIGN: Case series and technical note. METHODS: We present three cases of thoracic retrograde SCS paddle lead placement cases, detailing patient selection, operative technique, and outcome. All the cases had extensive instrumentation to the thoraco-lumbar spine, and one had additional spinal canal stenosis. The surgical procedure entailed a retrograde midthoracic inter-laminar approach, flavectomy, and caudal placement of the paddle lead with intraoperative neurophysiologic monitoring (IONM) guidance for functional midline determination. RESULTS: All the cases had a successful lead placement over the sweet spot without complications. The same approach was used to decompress a focal spinal stenosis in one case. One case had significantly improved pain and hence underwent a pulse generator implant. The other cases had non-satisfactory pain control and were explanted. LIMITATIONS: These case description could guide technical procedural steps, however, a larger number of such cases would be needed to describe further technical nuances. CONCLUSIONS: We demonstrated that placing SCS paddle leads via retrograde midthoracic approach with IONM guidance is safe. This procedure should be an option for SCS paddle implants in patients with posterior spinal fusion encompassing the intended targeted spinal stimulation level.

Persistent pain and its predictors after starting anti-tumour necrosis factor therapy in psoriatic arthritis: what is the role of inflammation control?

OBJECTIVE: While considerable focus has been placed on pain due to inflammation in psoriatic arthritis (PsA), less is reported on pain despite inflammation control. Here, we aimed to investigate the occurrence/predictors of persistent pain, including non-inflammatory components, after starting anti-tumour necrosis factor (anti-TNF) therapy. METHOD: Bionaïve PsA patients starting a first anti-TNF therapy 2004-2010 were identified (South Swedish Arthritis Treatment Group register; N = 351). Outcomes included unacceptable pain [visual analogue scale (VAS) pain > 40 mm], and unacceptable pain despite inflammation control (refractory pain; VAS pain > 40 mm + C-reactive protein < 10 mg/L + ≤ 1 swollen joint of 28), assessed at 0, 3, 6, and 12 months. Baseline predictors were estimated by logistic regression. RESULTS: Upon starting anti-TNF therapy, 85% of patients reported unacceptable pain, falling to 43% at 3 months and then remaining stable. After 12 months, refractory pain constituted 63% of all unacceptable pain. Higher baseline VAS pain/global, worse physical function and lower health-related quality-of-life were associated with a higher risk of unacceptable/refractory pain at 12 months. More swollen joints and higher evaluator's global assessment were associated with a lower risk of 12-month refractory pain. CONCLUSIONS: A substantial proportion of PsA patients reported unacceptable pain throughout the first anti-TNF treatment year. At 12 months, refractory pain constituted about two-thirds of this remaining pain load. More objective signs of inflammation at anti-TNF initiation were associated with less future refractory pain. This highlights insufficient effect of biologics in patients with inflammation-independent pain, warranting alternative treatments.

Optimization of Radiofrequency Needle Placement in Percutaneous Cordotomy Using Electromyography in the Deeply Sedated Patient.

BACKGROUND AND OBJECTIVES: Cordotomy, the selective disconnection of the nociceptive fibers in the spinothalamic tract, is used to provide pain palliation to oncological patients suffering from intractable cancer-related pain. Cordotomies are commonly performed using a cervical (C1-2) percutaneous approach under imaging guidance and require patients' cooperation to functionally localize the spinothalamic tract. This can be challenging in patients suffering from extreme pain. It has recently been demonstrated that intraoperative neurophysiology monitoring by electromyography may aid in safe lesion positioning. The aim of this study was to evaluate the role of compound muscle action potential (CMAP) in deeply sedated patients undergoing percutaneous cervical cordotomy (PCC). METHODS: A retrospective analysis was conducted of all patients who underwent percutaneous cordotomy while deeply sedated between January 2019 and November 2022 in 2 academic centers. The operative report, neuromonitoring logs, and clinical medical records were evaluated. RESULTS: Eleven patients underwent PCC under deep sedation. In all patients, the final motor assessment prior to ablation was done using the electrophysiological criterion alone. The median threshold for evoking CMAP activity at the lesion site was 0.9 V ranging between 0.5 and 1.5 V (average 1 V ± 0.34 V SD). An immediate, substantial decrease in pain was observed in 9 patients. The median pain scores (Numeric Rating Scale) decreased from 10 preoperatively (range 8-10) to a median 0 (range 0-10) immediately after surgery. None of our patients developed motor deficits. CONCLUSION: CMAP-guided PCC may be feasible in deeply sedated patients without added risk to postoperative motor function. This technique should be considered in a group of patients who are not able to undergo awake PCC.

Palliative Radiofrequency Ablation Therapy for Intractable Cancer-Related Pain Due to Malignant Psoas Syndrome: Case Report.

Uncontrollable cancer pain is a highly feared and debilitating symptom. The effectiveness of radiofrequency ablation (RFA) for osseous metastases with intractable cancer-related pain refractory to pharmacological therapy has been reported previously. This case report is the first to demonstrate the use of RFA to achieve pain relief in a patient suffering severe pain caused by para-aortic lymph node metastasis. A 55-year-old male complained of intractable pain in the left groin and perineum due to malignant psoas syndrome caused by metastatic para-aortic lymph nodes. The pain was refractory to medications including opioids and nerve blocks. Considering the dermatome indicating referred pain and the imaging findings, RFA of the area of invasion was performed at the L3 level. The severe pain was relieved within 24 hours without any complications. Opioids were tapered at each postoperative outpatient visit. We discuss the use of RFA for control of intractable cancer-related pain refractory to medication, including opioids.