The efficacy of high-intensity laser therapy in wound healing: a narrative review.

High-intensity laser therapy (HILT) has recently been incorporated into wound management therapeutic protocols (Mosca RC et al. (2019) Photobiomodulation Therapy for Wound Care: A Potent, Noninvasive, Photoceutical Approach. Adv Skin Wound Care 32(4):157-167. https://doi.org/10.1097/01.ASW.0000553600.97572.d2 ). Laser therapy is increasingly used as an adjunct to therapeutic interventions in clinical practice (Dundar U et al. (2015) Effect of high-intensity laser therapy in the management of myofascial pain syndrome of the trapezius: a double-blind, placebo-controlled study. Lasers Med Sci 30(1):325-332. https://doi.org/10.1007/s10103-014-1671-8 ). This study aimed to evaluate the efficacy of HILT and the potential benefits of incorporating co- interventions alongside HILT in wound management. The following databases were searched up to April 2023: Embase, MEDLINE, PubMed, and Cinahl, as well as manual searches. The search keywords included high- intensity laser therapy, high-power laser therapy, laser therapy, wound, ulcer, and wound healing. The primary measures were decreased wound surface area (WSA) and improved wound appearance (WA) or other objective wound assessment tools containing these two values. Six human studies investigating HILT in wound healing treatment and one animal study assessing the wound-healing effects of HILT in acute wounds of mice were selected (Thabet AAE, Mahran HG, Ebid AA, Alshehri MA. Effect of pulsed high intensity laser therapy on delayed caesarean section healing in diabetic women. J Phys Ther Sci.;30(4):570-575. doi:, Ebid AA, Thabet A, Helal O (2018) (2011) Efficacy of pulsed high intensity Nd: Yag Laser in Treatment of Chronic Diabetic Foot Ulcer. Energy for Health pp. 25-30); (Ebid AA, El-Kafy EM, Alayat MS (2013) Effect of pulsed Nd: YAG laser in the treatment of neuropathic foot ulcers in children with spina bifida: a randomized controlled study. Photomed Laser Surg 31(12):565-570. https://doi.org/10.1089/pho.2013.3533 ); (Hong SE et al. (2016) Effects of neodymium-yttrium-aluminum garnet (Nd: YAG) pulsed high-intensity laser therapy on full thickness wound healing in an experimental animal model. J Cosmet Laser Ther 18(8):432-437. https://doi.org/10.1080/14764172.2016.1202421 ); (Lu Q et al. (2021) Clinical effects of high-intensity laser therapy on patients with chronic refractory wounds: a randomised controlled trial. BMJ Open 11(7):e045866. https://doi.org/10.1136/bmjopen-2020-045866 ); (Pereira FLC et al. (2020) Use of a High-Power Laser for Wound Healing: A Case Report. J Lasers Med Sci 11(1):112-114. https://doi.org/10.15171/jlms.2020.19 ); (Thabet AAE et al. (2018) Effect of pulsed high intensity laser therapy on delayed caesarean section healing in diabetic women. J Phys Ther Sci 30(4):570-575. https://doi.org/10.1589/jpts.30.570 ); (Nussbaum EL, Baxter GD, Lilge L (2003) A Review of Laser Technology and Light-Tissue Interactions as a Background to Therapeutic Applications of Low Intensity Lasers and Other Light Sources. Phys Therapy Reviews 8(1):31-44. https://doi.org/10.1002/lsm.20769 ). This limited number of studies exhibited varying treatment parameters, blinding procedures, wound etiologies, irradiation protocols, and testing areas (Thabet AAE, Mahran HG, Ebid AA, Alshehri MA. Effect of pulsed high intensity laser therapy on delayed caesarean section healing in diabetic women. J Phys Ther Sci. ;30(4):570-575. doi:, Ebid AA, Thabet A, Helal O (2018) (2011) Efficacy of pulsed high intensity Nd: Yag Laser in Treatment of Chronic Diabetic Foot Ulcer. Energy for Health pp. 25-30); (Ebid AA, El-Kafy EM, Alayat MS (2013) Effect of pulsed Nd: YAG laser in the treatment of neuropathic foot ulcers in children with spina bifida: a randomized controlled study. Photomed Laser Surg 31(12):565-570. https://doi.org/10.1089/pho.2013.3533 ); (Hong SE et al. (2016) Effects of neodymium-yttrium-aluminum garnet (Nd: YAG) pulsed high-intensity laser therapy on full thickness wound healing in an experimental animal model. J Cosmet Laser Ther 18(8):432-437. https://doi.org/10.1080/14764172.2016.1202421 ); (Lu Q et al. (2021) Clinical effects of high-intensity laser therapy on patients with chronic refractory wounds: a randomised controlled trial. BMJ Open 11(7):e045866. https://doi.org/10.1136/bmjopen-2020-045866 ); (Pereira FLC et al. (2020) Use of a High-Power Laser for Wound Healing: A Case Report. J Lasers Med Sci 11(1):112-114. https://doi.org/10.15171/jlms.2020.19 ); (Thabet AAE et al. (2018) Effect of pulsed high intensity laser therapy on delayed caesarean section healing in diabetic women. J Phys Ther Sci 30(4):570-575. https://doi.org/10.1589/jpts.30.570 ); (Nussbaum EL, Baxter GD, Lilge L (2003) A Review of Laser Technology and Light-Tissue Interactions as a Background to Therapeutic Applications of Low Intensity Lasers and Other Light Sources. Phys Therapy Reviews 8(1):31-44. https://doi.org/10.1002/lsm.20769 ). All selected studies demonstrated favorable results in improving wound conditions (Thabet AAE, Mahran HG, Ebid AA, Alshehri MA. Effect of pulsed high intensity laser therapy on delayed caesarean section healing in diabetic women. J Phys Ther Sci. ;30(4):570-575. doi:, Ebid AA, Thabet A, Helal O (2018) (2011) Efficacy of pulsed high intensity Nd: Yag Laser in Treatment of Chronic Diabetic Foot Ulcer. Energy for Health pp. 25-30); (Ebid AA, El-Kafy EM, Alayat MS (2013) Effect of pulsed Nd: YAG laser in the treatment of neuropathic foot ulcers in children with spina bifida: a randomized controlled study. Photomed Laser Surg 31(12):565-570. https://doi.org/10.1089/pho.2013.3533 ); (Hong SE et al. (2016) Effects of neodymium-yttrium-aluminum garnet (Nd: YAG) pulsed high-intensity laser therapy on full thickness wound healing in an experimental animal model. J Cosmet Laser Ther 18(8):432-437. https://doi.org/10.1080/14764172.2016.1202421 ); (Lu Q et al. (2021) Clinical effects of high-intensity laser therapy on patients with chronic refractory wounds: a randomised controlled trial. BMJ Open 11(7):e045866. https://doi.org/10.1136/bmjopen-2020-045866 ); (Pereira FLC et al. (2020) Use of a High-Power Laser for Wound Healing: A Case Report. J Lasers Med Sci 11(1):112-114. https://doi.org/10.15171/jlms.2020.19 ); (Thabet AAE et al. (2018) Effect of pulsed high intensity laser therapy on delayed caesarean section healing in diabetic women. J Phys Ther Sci 30(4):570-575. https://doi.org/10.1589/jpts.30.570 ); (Nussbaum EL, Baxter GD, Lilge L (2003) A Review of Laser Technology and Light-Tissue Interactions as a Background to Therapeutic Applications of Low Intensity Lasers and Other Light Sources. Phys Therapy Reviews 8(1):31-44. https://doi.org/10.1002/lsm.20769 ). Although insufficient data support using HILT in wound management, the promising results encourage further research. HILT appears effective in wound healing, but more high-quality studies are needed to identify optimal laser protocols.

Risk factors for surgical site infection in advanced neuromodulation pain procedures: a retrospective study.

Aim: To assess the effects of diabetes mellitus (DM) and related variables on surgical site infection (SSI) risk in neuromodulation. Methods: This retrospective study followed patients who underwent neuromodulation procedures for at least 9 months to identify postoperative infections. Demographics, clinical characteristics and surgical outcomes were compared. Results: Of 195 cases included, 5 (2.6%) resulted in SSIs. Median HbA1c was significantly higher for the cases with SSIs (8.2 vs 5.6%; p = 0.0044). The rate of SSI was significantly higher among patients with DM (17.9 vs 0%; p = 0.0005), HbA1c≥7% (37.5 vs 0%; p = 0.0009), and perioperative glucose ≥200 mg/dl (40 vs 2.3%; p = 0.0101). Conclusion: DM, elevated HbA1c and perioperative hyperglycemia may all contribute to increased risk of SSIs with neuromodulation procedures.

Infections are feared complications of surgery. It is important to identify factors that increase the risk of infection to prevent these complications. This study looked at the effects of diabetes and high blood sugar on the risk of infection associated with pain procedures. The researchers followed patients who had these procedures and looked for any infections that occurred afterward. They found that patients with diabetes and high blood sugar levels before surgery were more likely to develop infections after these procedures. More research can help establish blood sugar targets so that physicians can better manage this risk for their patients.

Dorsal root ganglion stimulation for chemotherapy-induced peripheral neuropathy.

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a common consequence of cancer treatment that can be persistent and difficult to manage. Dorsal root ganglion stimulation (DRG-S) is a recently introduced but understudied treatment modality. This study explored the effect of DRG-S on pain and symptom burden associated with CIPN. METHODS: Patients with CIPN who underwent a DRG-S trial between January 2017 and August 2022 were identified through chart review after IRB approval was obtained. Demographic data, procedure details, pre-and postoperative scores, including the Numerical Rating Scale (NRS) and Edmonton Symptom Assessment System (ESAS), and duration of follow-up were recorded. Statistical analysis included descriptive statistics and paired t-tests to compare pre-and postoperative scores. RESULTS: Nine patients with an even mix of solid and hematologic malignancies underwent DRG-S trial and had a statistically significant decrease in NRS scores, with a mean reduction of 2.3 in their average pain (p = 0.014), 2.6 in worst pain (p = 0.023), and 2.1 in least pain (p = 0.018). Eight patients (88.9%) underwent permanent DRG-S implantation. Mean NRS scores remained lower than preoperative baselines through the first year of follow-up. Statistically significant reductions were noted at 3 months in average (2.1, p = 0.006) and least pain scores (1.9, p = 0.045), which further decreased after 6-12 months (average: 3.6, p = 0.049; least: 3.4, p = 0.023). Only the pain component of ESAS scores showed a significant reduction with DRG-S (2.0, p = 0.021). All patients endorsed improved sensation, 75% decreased their pain medication usage, and 37.5% reported complete pain relief by 2 years. CONCLUSION: Dorsal root ganglion stimulation can be an effective treatment for pain related to CIPN and deserves further investigation.

Peripheral Nerve Stimulation for Back Pain in Patients With Multiple Myeloma as Bridge Therapy to Radiation Treatment: A Case Series.

OBJECTIVES: Patients with spinal lesions or vertebral compression fractures from multiple myeloma often present with back pain that restricts their ability to lie flat and prevents them from undergoing cancer treatment. Temporary, percutaneous peripheral nerve stimulation (PNS) has been described for cancer pain secondary to oncologic surgery or neuropathy/radiculopathy from tumor invasion. The purpose of this case series is to show the use of PNS as an analgesic bridge therapy to treat myeloma-related back pain and allow patients to complete their course of radiation. MATERIALS AND METHODS: Temporary, percutaneous PNS was placed under fluoroscopic guidance for four patients with unremitting low back pain secondary to myelomatous spinal lesions. Before PNS, the patients had pain refractory to medical management and were unable to tolerate radiation mapping and treatment owing to low back pain while supine. Patients were followed with routine clinic visits to monitor pain and progression through cancer therapy. PNS was removed after approximately 60 days or after completion of radiation. RESULTS: This case series presents four successful cases of PNS to treat low back pain from myelomatous spinal lesions and associated vertebral compression fractures. PNS targeted the medial branch nerves to treat both nociceptive and neuropathic low back pain. All four patients successfully completed radiation therapy with PNS in place. CONCLUSIONS: PNS can effectively treat low back pain secondary to myeloma-related spinal lesions as a bridge therapy to radiation. The use of PNS is a promising option for back pain from other primary or metastatic tumors. Further research is needed into the use of PNS for cancer-related back pain.

Case report: use of high-intensity laser therapy for treatment of trigeminal neuralgia.

Trigeminal neuralgia represents a form of chronic facial pain that is characterized by its incapacitating nature. The current therapeutic approaches encompass pharmacological agents with carbamazepine or non-pharmacologic options including utilization of percutaneous rhizotomy, Gamma knife radiosurgery or microvascular decompression may be indicated in certain cases. While the interventions may be effective, medications have negative side effects and procedures are invasive which can pose challenges for patients with various comorbidities. High-intensity laser therapy (HILT) has demonstrated safety and efficacy for many types of chronic pain such as musculoskeletal, autoimmune and neuropathic. Herein, we demonstrate the benefits of HILT therapy in the management of trigeminal neuralgia in a 72 year-old patient with a complex history of facial surgery and radiation who had failed pharmacological treatments and denied any invasive procedures.

Trigeminal neuralgia causes severe facial pain, often requiring medications or invasive procedures. High-intensity laser therapy (HILT), known for treating many chronic pains, was explored for a 72 year-old patient with a complex medical history. Previous treatments had failed, and alternatives carried risks. HILT, a safe approach improving blood flow, was given for 3 days, targeting the painful area in the face. The patient experienced improved tissue oxygen supply and pain relief. The follow-up visit at 4 weeks showed sustained relief, enhanced jaw movement and no side effects. Although promising, further research is needed to confirm HILT's effectiveness for trigeminal neuralgia on a larger scale.

Genicular nerve neurolysis with phenol for chronic knee pain: A case series.

Chronic knee pain continues to be a common complaint amongst patients and continues to grow as the elderly population lives longer. New ways to treat chronic pain conditions, including chronic knee pain, are necessary as increased co-morbidities prevent patients from being surgical candidates. Recently, the genicular nerves have received more attention due to their role in innervating the anterior knee joint capsule as well as the intraarticular and extraarticular knee ligaments. Initial interest in the genicular nerve included radiofrequency ablation. RFA while effective, also brings with it increased procedure and equipment costs with a non-response rate of around 25%. Alcohol neurolysis of the genicular nerve is being seen as a potential alternative, low-cost, effective option for relieving chronic knee pain in patients. Previous case reports have focused on the use of alcohol, we report the use of phenol for genicular neurolysis. Of the four genicular nerve branches, only three are targeted due to the proximity of the inferolateral genicular nerve to the common peroneal nerve. The purpose of this case report is to show the effectiveness of phenol for neurolysis of the genicular nerves in relieving chronic knee pain in patients in which surgery is not an option.

Clinical practice guidelines for the management of patients with complex regional pain syndrome: a systematic appraisal using the AGREE II instrument.

Aim: Complex regional pain syndrome (CRPS) is a debilitating, painful condition of limbs that often arises after an injury and is associated with significant morbidity. Materials & methods: The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument, used to assess the quality of clinical practice guidelines (CPGs), was used to evaluate seven CRPS management guideline. Results: Out of the seven CPGs evaluated using the AGREE II instrument, only one from Royal College of Physicians was found to have high-quality consensus guidelines for diagnosis and management of CRPS. Conclusion: Future CPGs should be backed by systematic literature searches, focus on guidelines clinical translation into clinical practice and applicability to the desired patient population.

Ultrasound-guided superficial cervical plexus block for cancer-related clavicle pain.

Pain is one of the most feared conditions a cancer patient may face. Bone is a common site of metastasis in many malignancies, including breast, prostate, kidney, and lung cancer. Conventional therapy for tumor-related bone pain involves the use of opioids, non-steroidal anti-inflammatory drugs, and bisphosphonates. Palliative radiation therapy may be incorporated for refractory bone pain. We describe an innovative case of cancer-related clavicle pain successfully managed with a superficial cervical plexus block in an opioid-intolerant patient. Considering the lack of guidelines for pain interventions in this setting, such peripheral nerve blocks may be a useful adjunctive tool in refractory cancer pain management.

Normal Saline Trigger Point Injections vs Conventional Active Drug Mix for Myofascial Pain Syndromes.

BACKGROUND: Myofascial pain syndrome (MPS) originates in the muscle and fascia. MPS presents with referred pain specific for each muscle and a trigger point that reproduces the symptoms. Trigger-point-injection (TPI) is an effective approach to treating MPS. Some TPI agents, however, are associated with systemic and local side effects. OBJECTIVE: The aim of this study was to evaluate the effectiveness of TPI with a conventional active drug mixture (CADM) vs. that with normal saline solution (NS) alone in patients with MPS presenting to the emergency department (ED). METHODS: Adults with MPS diagnosed in the ED, participants were randomly assigned to receive TPI with NS or with CADM. Pain intensity was scored using a 0-10 numeric rating scale prior to and after TPI, before discharge and 2 weeks after TPI. RESULTS: Among 48 patients analyzed, 23 received TPI with NS. The mean pain scores were as follows: immediately before TPI, 7.59 (NS) and 7.44 (CADM); immediately after TPI, 2.22 (NS) and 1.76 (CADM); prior to discharge, 1.52 (NS) and 1.76 (CADM). At 2-week follow up, the mean pain scores were 4.29 (NS) and 4.14 (CADM). Pain was significantly reduced after TPI in both groups. At 2 weeks, the mean pain scores were similar between the groups. No adverse events were reported. CONCLUSION: In cases of MPS in the ED, pain can be controlled with TPI independent of the injectate. TPI with NS may be preferred over CADM because of its lower cost and more favorable side effect profile.

Sacroiliac joint pain following iliac-bone marrow aspiration and biopsy: a cohort study.

Background: Sacroiliac joint (SIJ) pain is a common source of lower back pain; the factors associated have not been studied in cancer patients. Observing patients with bone marrow aspiration and biopsy (BMAB) who subsequently developed SIJ-pain led to this investigation. Aim: To investigate this possible relationship. Methods: A cohort study of cancer patients diagnosed with SIJ pain. The association of BMAB with SIJ pain was evaluated, as were variables that differed between the groups. Results: The prevalence of SIJ pain was 4.95% (231/4669). Among 231 patients with SIJ pain, 34% (78/231) did not have prior history of lower back pain and had undergone BMAB prior to their diagnosis of SIJ pain. A statistically significant association between BMAB-SIJ-pain was found (p < 0.01). Conclusion: We found linear correlation between BMAB and subsequent SIJ pain.

Can oliceridine (TRV130), an ideal novel µ receptor G protein pathway selective (µ-GPS) modulator, provide analgesia without opioid-related adverse reactions?

All drugs have both favorable therapeutic and untoward adverse effects. Conventional opioid analgesics possess both analgesia and adverse reactions, such as nausea, vomiting, and respiratory depression. The opioid ligand binds to µ opioid receptor and non-selectively activates two intracellular signaling pathways: the G protein pathway induce analgesia, while the ß-arrestin pathway is responsible for the opioid-related adverse reactions. An ideal opioid should activate the G protein pathway while deactivating the ß-arrestin pathway. Oliceridine (TRV130) has a novel characteristic mechanism on the action of the µ receptor G protein pathway selective (µ-GPS) modulation. Even though adverse reactions (ADRs) are significantly attenuated, while the analgesic effect is augmented, the some residual ADRs persist. Consequently, a G protein biased µ opioid ligand, oliceridine, improves the therapeutic index owing to increased analgesia with decreased adverse events. This review article provides a brief history, mechanism of action, pharmacokinetics, pharmacodynamics, and ADRs of oliceridine.

Iliocostalis Thoracis-Lumborum Myofascial Pain: Reviewing a Subgroup of a Prospective, Randomized, Blinded Trial. A Challenging Diagnosis with Clinical Implications.

BACKGROUND: Pain of myofascial origin is a well-recognized pathology characterized by the presence of two components: referred pain; which is often distant from its source and specific to each muscle, and the trigger point, a localized hyperirritable band present in the affected muscle and able to reproduce the referred pain when stimulated. Myofascial pain (MP) commonly coexists in patients with acute or chronic pain of other etiologies. The uniqueness of the clinical presentation of some MPs and the lack of training of most specialties represent a clinical challenge. Thus, many patients with MPS receive less than optimal management of this condition. OBJECTIVE: Pain at the anterior torso, originating at the posterior torso, can mimic common pathologies that correlate with the same anatomical area such as cardiac and intra-abdominal conditions. These clinical characteristics could be caused by MP of the iliocostalis thoracis-lumborum (ITL) muscle. However, this entity has not been well addressed in the medical literature. In this report we characterize the manifestations, diagnosis, and clinical implications of ITL MP. STUDY DESIGN: Observational assessment. SETTING: Two university-based academic emergency medicine departments (ED) in an urban setting in the United States. METHODS: A convenience sample of 43 patients who presented to the ED with pain at the anterior aspect of the torso (chest, abdomen, or pelvis) and clinical evidence of MP originated in the ITL muscle.Of a clinical trial of patients with MP, we describe a subgroup of patients with MP of the ITL which was clinically evident by the presence of a trigger point (TP) in its ability to reproduce the referred pain present at the anterior aspect of the torso. Patients received a TP injection. In this trial we intend to demonstrate that TP injections using particulate steroids mixed with a local are no more effective than saline alone to treat MP. The primary outcome was pain control (decrease in intensity of 50% or more below baseline numeric pain rating). A follow-up telephone interview was performed by third-party abstractors. RESULTS: Forty-three patients presented with pain of the anterior torso and ipsilateral back, both correlating with the level of the TP of the ITL muscle. The pain had been present from 2 days to 7 years. The most common locations of pain were the right-lower quadrant and the left side of the chest. In many of them a pattern of missed diagnosis was evident despite extensive workups and consultations. Only 17 patients were able to identify the precipitating event; the most common was coughing. Two weeks after TP injection, all patients still had satisfactory pain control. After treatment, no missed pathology or returns to the ED were reported. LIMITATIONS: This descriptive portion of the ongoing study does not affect the integrity of the trial itself but could be subject to the introduction of subject selection and selective reporting bias. Similarly, this convenience sample does not establish the incidence of this pathology and challenges the external validity to other clinical settings. CONCLUSIONS: Anterior torso pain often resulted in extensive workups before ITL myofascial pain was diagnosed. TP injections were diagnostic and therapeutic of ITL myofascial pain.

Peripheral Nerve Stimulation for the Treatment of Chronic Intractable Headaches: Long-term Efficacy and Safety Study.

BACKGROUND: Despite the various modalities available for treating headaches, typical therapy does not provide adequate pain relief for some patients. OBJECTIVES: This study explored the efficacy and safety of long-term peripheral nerve stimulation (PNS) for intractable chronic headaches. STUDY DESIGN: Retrospective study of refractory headache patients at academic pain center. METHODS: The medical records of all patients (N = 46) permanently implanted with PNS between January 2005 and January 2012 were reviewed retrospectively. Patient records and phone interviews were used to quantify the levels of pain intensity, headache days per month, and overall patient satisfaction with treatment. The correlation between headache duration and effectiveness of PNS was also assessed. RESULTS: Pain intensity on the 11-point Numeric Rating Scale decreased from 7.60 ± 1.73 before implantation to 3.78 ± 2.41, 3.32 ± 2.67, 3.42 ± 2.74, and 2.04 ± 2.27 at one, 6, 12, and > 12 (19-98) months after implantation, respectively (P < .001). The mean number of headache days per month decreased by about 14 days from the base line. No correlation (r = -.33) was found between the number of years the patients had suffered from headaches and the efficacy of treatment. LIMITATIONS: Due to the limitation of a retrospective study, the data collected via chart reviews and phone interviews are susceptible to selection and information biases. CONCLUSIONS: PNS is an effective modality in the long-term management of intractable chronic headaches. Despite long histories of chronic headaches, the majority of patients had significant reductions in pain scores and the number of headache days per month. The outcomes were not dependent on the number of years the patients had suffered from headaches before PNS treatment.

The effect of clonidine pretreatment on epidural resiniferatoxin in a neuropathic pain rat model.

Resiniferatoxin (RTX) is an ultrapotent synthetic TRPV1 (transient receptor potential vanilloid subtype 1) agonist with significant initial transient hyperalgesia followed by a prolonged analgesic effect in response to thermal stimulus. Using a rat model of neuropathic pain, we evaluated the effect of pretreatment with clonidine-which has been shown to relieve intradermal capsaicin-induced hyperalgesia-on the initial hyperalgesic response and the thermal analgesic property of RTX. Thirty-six male rats were divided into 6 treatment groups (n=6 each):RTX 500 ng, RTX 1 µg, clonidine 20 µg (Cl), Cl＋RTX 500 ng, Cl＋RTX 1 µg, or normal saline 20 µL (control). We evaluated the short-term (180 min) and long-term (20 days) analgesic effects of RTX after thermal stimulation and mechanical stimulation. RTX had significant initial transient hyperalgesia followed by a prolonged analgesic effect in response to the thermal stimulus, but the RTX 500 ng and RTX 1 µg groups showed no initial short-term thermal hyperalgesic responses when pretreated with clonidine. The Cl＋RTX 1 µg rats' behavior scores indicated that they were more calm and comfortable compared to the RTX 1 µg rats. Even though we cannot precisely confirm that pretreatment with clonidine potentiates or adds to the analgesic effect of RTX, clonidine pretreatment with epidural RTX eliminated the initial RTX-associated hyperalgesic response and systemic toxicity in this neuropathic pain rat model.

Acute rhabdomyolysis in a patient with long-term exposure to intrathecal ziconotide: a case report.

INTRODUCTION: Ziconotide is an intrathecally administered nonopioid analgesic for the treatment of severe chronic pain. Previous reports have noted rhabdomyolysis in patients receiving ziconotide during the initial single-shot trial or due to concurrent medical problems. We present a case of an acute rhabdomyolysis following an intrathecal bolus injection of ziconotide on a patient who had long-term exposure to the drug. CASE REPORT: The patient suffered from chronic neuropathic pain with diagnosis of failed back surgery syndrome and received intrathecal ziconotide for 2 years. Moderate side effects resulting from dose escalation led to a discontinuation of the drug. The pump medication was changed to morphine, which failed to provide adequate analgesia even with dose titration. A single intrathecal bolus of ziconotide, as an adjunctive therapy, resulted in good pain control. Two months later, the patient received a second ziconotide injection. Sixteen hours after the injection, she presented to local emergency center with nausea, vomiting, diarrhea, and myalgia. She had significantly increased CK levels and was admitted for intravenous hydration and close observation. Her serum CK level peaked at 4940 IU/L. The patient was discharged on hospital day 3 with a CK level of 808 IU/L. Her symptoms resolved without renal impairment. DISCUSSION: The clinical scenario described is a case of acute rhabdomyolysis from an intrathecal bolus injection of ziconotide in a patient with prior long-term exposure to the drug. The decrease in CK levels coincided well with the average half-life of ziconotide; however, the rhabdomyolysis may have been potentiated by hypokalemia.

Utilization of spinal cord stimulation in patients with failed back surgery syndrome.

STUDY DESIGN: Retrospective analysis of a population-based insurance claims data set. OBJECTIVE: To evaluate the use of spinal cord stimulation (SCS) and lumbar reoperation for the treatment of failed back surgery syndrome (FBSS), and examine their associated complications and health care costs. SUMMARY OF BACKGROUND DATA: FBSS is a major source of chronic neuropathic pain and affects up to 40% of patients who undergo lumbosacral spine surgery for back pain. Thus far, few economic analyses have been performed comparing the various treatments for FBSS, with these studies involving small sample sizes. In addition, the nationwide practices in the use of SCS for FBSS are unknown. METHODS: The MarketScan data set was used to analyze patients with FBSS who underwent SCS or spinal reoperation between 2000 and 2009. Propensity score methods were used to match patients who underwent SCS with those who underwent lumbar reoperation to examine health care resource utilization. Postoperative complications were analyzed with multivariate logistic regression. Health care use was analyzed using negative binomial and general linear models. RESULTS: The study cohort included 16,455 patients with FBSS, with 395 undergoing SCS implantation (2.4%). Complication rates at 90 days were significantly lower for SCS than spinal reoperation (P < 0.0001). Also in the matched cohort, hospital stay (P < 0.0001) and associated charges (P = 0.016) were lower for patients with SCS. However outpatient, emergency room, and medication charges were similar between the 2 groups. Overall cost totaling $82,586 at 2 years was slightly higher in the lumbar reoperation group than in the SCS group with total cost of $80,669 (P = 0.88). CONCLUSION: Although previous studies have demonstrated superior efficacy for the treatment of FBSS, SCS remains underused. Despite no significant decreases in overall health care cost with SCS implantation, because it is associated with decreased complications and improved outcomes, this technology warrants closer consideration for the management of chronic pain in patients with FBSS.

Insurance disparities in the outcomes of spinal cord stimulation surgery.

OBJECTIVES: The Affordable Care Act aims to expand health insurance and to help narrow existing health care disparities. Medicaid patients have previously been noted to be at an increased risk for impaired access to health care, delayed medical treatment, and the receipt of substandard care. Conversely, those with commercial insurance may be subject to overtreatment. The goal of this study was to evaluate how Medicaid versus commercial insurance status affects outcomes following spinal cord stimulation (SCS) surgery. MATERIALS AND METHODS: A retrospective cohort study of 13,774 patients underwent either percutaneous or paddle permanent SCS implantation, selected from the Thomson Reuter's MarketScan database between 2000 and 2009. Patients were characterized by age at initial procedure, gender, baseline comorbidity burden, procedure-associated diagnosis code, follow-up, and type of insurance (Medicaid vs. commercial insurance). Outcome measures included probability of reoperation, timing and type of reoperation, presence of postoperative complications (immediate, 30 days, and 90 days), and overall utilization of health resources postoperatively. Multivariate analysis was performed comparing the relative effect of insurance status on outcomes following initial surgery. RESULTS: Medicaid patients had greater healthcare resource utilization as measured by medications prescribed, emergency department visits, and length of stay; however, commercially insured patients had significantly higher overall costs ($110,908 vs. $64,644, p < 0.0001). Commercial and Medicaid patients did not significantly differ in their complication rates during the index hospitalization or at 30 days or 90 days postoperatively. The group were also not significantly different in their two-year reoperation rates (7.32% vs. 5.06%, p = 0.0513). CONCLUSIONS: There are substantial insurance disparities that affect healthcare utilization and overall cost following SCS. Efforts for national healthcare reform should examine system factors that will reduce socioeconomic disparities in outcomes following SCS.

Peripheral nerve stimulation for the treatment of primary headache.

A headache is a common neurological disorder, and large numbers of patients suffer from intractable headaches including migraine, tension headache and cluster headache, etc., with no clear therapeutic options. Despite the advances made in the treatment of headaches over the last few decades, subsets of patients either do not achieve adequate pain relief or cannot tolerate the side effects of typical migraine medications. An electrical stimulation of the peripheral nerves via an implantable pulse generator appears to be good alternative option for patients with treatment-refractory headaches. A number of clinical trials show considerable evidence supporting the use of peripheral nerve stimulator (PNS) for headaches not responding to conservative therapies. However, the mechanism by which PNS improves headaches or predicts who will benefit from PNS remains uncertain. The decision to use PNS should be individualized based on patient suffering and disability. Hence, further work is imperative. Here, we discuss the mechanism, indication, efficacy, implant technique, and complications of PNS.

The effect of epidural resiniferatoxin in the neuropathic pain rat model.

BACKGROUND: Resiniferatoxin (RTX) is a potent synthetic agonist for transient receptor potential vanilloid subtype 1 (TRPV1), which has a selectivity for antinociception. The analgesic effect of epidural RTX in a rat model of neuropathic pain has not yet been studied. OBJECTIVES: The purpose of this study was to evaluate the analgesic effect of epidural RTX on neuropathic pain in a rat model to mechanical and thermal stimulation. The dose-related behavior changes and side effects were also studied. STUDY DESIGN: A randomized, experimental trial. SETTING: Department of Anesthesiology and Pain Medicine, Korea University Guro Hospital METHODS: A spinal nerve ligation model was prepared using male Sprague-Dawley rats (7 weeks old, weight 230-250 g). An epidural catheter was placed at the L4-L5 level. Each study group (n = 6) received a different dose of RTX: 100 ng, 500 ng, 1 µg, 2 µg, 4 µg and 10 µg. All substances were administered in 20 µL volume doses. The control group (n = 6) received 20 µL of normal saline. We evaluated the response to mechanical and thermal stimuli as well as the sedation score at both short-term (3 hours) and long-term (20 days) after the epidural RTX injection. RESULTS: Prolonged analgesia to thermal stimulation was preceded by a transient dose-dependent hyperalgesia (500 ng, 1 µg) or sedation (>/= 2 µg) during the initial 60 minutes after RTX administration. Marked sedation and hyperventilation were noted at higher doses (>/= 2 µg), while 2 out of 6 rats died with a 10 µg dose. ED50 for epidural RTX was 265 ng (95% confidence interval 216.1-324.9 ng). The increased latency to thermal stimulation continued for 20 days at RTX >/=1 µg. But the threshold to mechanical stimulation increased only in the acute period and returned to the baseline after 3-5 days, regardless of the administered dose. LIMITATIONS: A histological examination by electron-microscopic staining was not performed. The observation period was not very long (20 days). CONCLUSION: RTX has potential to be used in an epidural route for neuropathic pain in a rat model with a relatively small amount, which produces transitory improvement of mechanical hypersensitivity and prolonged thermal analgesic response.