Intrathecal methylprednisolone for intractable postherpetic neuralgia

Bone morphogenetic protein 4 derived from the cerebrospinal fluid in patients with postherpetic neuralgia induces allodynia via the crosstalk between microglia and astrocyte

INTRODUCTION

During postherpetic neuralgia (PHN), the cerebral spinal fluid (CSF) possesses the capability to trigger glial activation and inflammation, yet the specific changes in its composition remain unclear. Recent findings from our research indicate elevations of central bone morphogenetic protein 4 (BMP4) during neuropathic pain (NP), serving as an independent modulator of glial cells. Herein, the aim of the present study is to test the CSF-BMP4 expressions and its role in the glial modulation in the process of PHN.

METHODS

CSF samples were collected from both PHN patients and non-painful individuals (Control) to assess BMP4 and its antagonist Noggin levels. Besides, intrathecal administration of both CSF types was conducted in normal rats to evaluate the impact on pain behavior, glial activity, and inflammation.; Additionally, both Noggin and STAT3 antagonist-Stattic were employed to treat the PHN-CSF or exogenous BMP4 challenged cultured astrocytes to explore downstream signals. Finally, microglial depletion was performed prior to the PHN-CSF intervention so as to elucidate the microglia-astrocyte crosstalk.

RESULTS

BMP4 levels were significantly higher in PHN-CSF compared to Control-CSF (P < 0.001), with a positive correlation with pain duration (P < 0.05, r = 0.502). Comparing with the Control-CSF producing moderate paw withdrawal threshold (PWT) decline and microglial activation, PHN-CSF further exacerbated allodynia and triggered both microglial and astrocytic activation (P < 0.05). Moreover, PHN-CSF rather than Control-CSF evoked microglial proliferation and pro-inflammatory transformation, reinforced iron storage, and activated astrocytes possibly through both SMAD159 and STAT3 signaling, which were all mitigated by the Noggin application (P < 0.05). Next, both Noggin and Stattic effectively attenuated BMP4-induced GFAP and IL-6 upregulation, as well as SMAD159 and STAT3 phosphorylation in the cultured astrocytes (P < 0.05). Finally, microglial depletion diminished PHN-CSF induced astrogliosis, inflammation and endogenous BMP4 expression (P < 0.05).

CONCLUSION

Our study highlights the role of CSF-BMP4 elevation in glial activation and allodynia during PHN, suggesting a potential therapeutic avenue for future exploration.

Dexamethasone attenuates neuropathic pain through spinal microglial expression of dynorphin A via the cAMP/PKA/p38 MAPK/CREB signaling pathway

This study aimed to elucidate the opioid mechanisms underlying dexamethasone-induced pain antihypersensitive effects in neuropathic rats. Dexamethasone (subcutaneous and intrathecal) and membrane-impermeable Dex-BSA (intrathecal) administration dose-dependently inhibited mechanical allodynia and thermal hyperalgesia in neuropathic rats. Dexamethasone and Dex-BSA treatments increased expression of dynorphin A in the spinal cords and primary cultured microglia. Dexamethasone specifically enhanced dynorphin A expression in microglia but not astrocytes or neurons. Intrathecal injection of the microglial metabolic inhibitor minocycline blocked dexamethasone-stimulated spinal dynorphin A expression; intrathecal minocycline, the glucocorticoid receptor antagonist Dex-21-mesylate, dynorphin A antiserum, and κ-opioid receptor antagonist GNTI completely blocked dexamethasone-induced mechanical antiallodynia and thermal antihyperalgesia. Additionally, dexamethasone elevated spinal intracellular cAMP levels, leading to enhanced phosphorylation of PKA, p38 MAPK and CREB. The specific adenylate cyclase inhibitor DDA, PKA inhibitor H89, p38 MAPK inhibitor SB203580 and CREB inhibitor KG-501 completely blocked dexamethasone-induced anti-neuropathic pain and increased microglial dynorphin A exprression. In conclusion, this study reveal that dexamethasone mitigateds neuropathic pain through upregulation of dynorphin A in spinal microglia, likely involving the membrane glucocorticoid receptor/cAMP/PKA/p38 MAPK/CREB signaling pathway.

Therapeutic Strategies for Postherpetic Neuralgia: Mechanisms, Treatments, and Perspectives

PURPOSE OF REVIEW

Postherpetic neuralgia is an annoying pain that mainly affects older people. In order to give patients more options, this review summarizes the pharmacological and interventional treatments for postherpetic neuralgia and updates the research on the efficacy, thereby providing doctors with more treatment options. The adverse effects and effective doses of its various treatments are also presented so that the therapy can be prescribed according to their concrete physical conditions. In a word, this review is dedicated to providing a comprehensive overview of the treatment options for postherpetic neuralgia and offering patients more choices.

RECENT FINDINGS

Combinational therapy is more excellent than monotherapy. The local anesthesia and gabapentin comprised outstanding compatibility. In addition, two therapeutic tools for PHN patients, especially for the intractable ones, electroacupuncture (EA), and osteopathic manipulative treatment (OMT), show their efficacy and become potential options to alleviate pain. In terms of treatment, guidelines recommend patients use tricyclic antidepressants (TCAs), gabapentin, pregabalin, and 5% lidocaine patches as the first-line medications, and gabapentin is investigated most, especially the gabapentin enacarbil (GEn). And drug efficacy can be limited by adverse effects and tolerated doses. Interventional treatments, with their invasiveness and operational difficulty, are usually considered for intractable patients. Combinational therapies may be used when a single therapy cannot achieve the desired effect. Therapies such as OMT and EA have also been proposed to palliate pain in some cases, and future directions of treatment may be investigated in Chinese medicine and acupuncture.

The efficacy of intrathecal methyl-prednisolone for acute spinal cord injury: A pilot study

Study design

Randomized clinical trial.

Objectives

To evaluate the safety and effectiveness of intrathecal methyl-prednisolone compared to intravenous methyl-prednisolone in acute spinal cord injuries.

Setting

Imam Reza Hospital, Tabriz University of Medical Sciences.

Methods

Patients meeting our inclusion and exclusion criteria were enrolled in the study and divided randomly into two treatment arms: intrathecal and intravenous. Standard spinal cord injury care (including surgery) was given to each patient based on our institutional policy. Patients were then assessed for neurological status (based on ASIA scores, Frankel scores) and complications for six months and compared to baseline status after injury. To better understand the biological bases of methyl-prednisolone on spinal cord injuries, we measured two biomarkers for oxidative stress (serum malondialdehyde and total antioxidant capacity) in these patients at arrival and day three after injury.

Results

The present study showed no significant difference between the treatment arms in neurological status (sensory scores or motor scores) or complications. However, the within-group analysis showed improvement in neurological status in each treatment arm within six months. Serum malondialdehyde and total antioxidant capacity were analyzed, and no significant difference between the groups was seen.

Conclusion

This is the first known clinical trial investigating the effect of intrathecal MP in acute SCI patients. Our finding did not show any significant differences in complication rates and neurological outcomes between the two study arms. Further studies should be conducted to define the positive and negative effects of this somehow novel technique in different populations as well.

The Effectiveness of Various Types of Electrical Stimulation of the Spinal Cord for Chronic Pain in Patients with Postherpetic Neuralgia: A Literature Review

Introduction

Postherpetic neuralgia (PHN) is a severe condition that remains a challenge to treat. Spinal cord stimulation (SCS) is used in cases of insufficient efficacy of conservative treatment. However, in contrast to many other neuropathic pain syndromes, there is a huge problem in reaching long-term stable pain relief in patients with PHN using conventional tonic SCS. The objective of this article was to present a review of the current management strategies of PHN, their efficacy, and safety.

Materials and Methods

We searched for articles containing the keywords "spinal cord stimulation AND postherpetic neuralgia," "high-frequency stimulation AND postherpetic neuralgia," "burst stimulation AND postherpetic neuralgia" and "dorsal root ganglion stimulation AND postherpetic neuralgia" in Pubmed, Web of Science, and Scopus databases. The search was limited to human studies published in the English language. There were no publication period limitations. Bibliographies and references of selected publications on neurostimulation for PHN were further manually screened. The full text of each article was studied once the abstract was analyzed by the searching reviewer and found appropriate. The initial search yielded 115 articles. Initial screening based on abstract and title allowed us to exclude 29 articles (letters, editorials, and conference abstracts). The full-text analysis allowed us to exclude another 74 articles (fundamental research articles, research utilizing animal subjects, and systemic and nonsystemic reviews) and results of PHN treatment presented with other conditions, leaving 12 articles for the final bibliography.

Results

12 articles reporting on the treatment of 134 patients with PHN were analyzed, with a disproportionally large amount of traditional SCS treatment than that to alternative SCS: DRGS (13 patients), burst SCS (1 patient), and high-frequency SCS (2 patients). Long-term pain relief was achieved in 91 patients (67.9%). The mean VAS score improvement was 61.4% with a mean follow-up time of 12.85 months. Although the number of patients in alternative SCS studies was very limited, almost all of them showed good responses to therapy with more than 50% VAS improvement and reduction of analgesic dosage. The article contains a review analysis of 12 articles concerning the current methods of treatment for postherpetic neuralgia including conservative treatment, spinal cord stimulation, and novel neuromodulation strategies. Available information on the pathophysiology of PHN and the effect or stimulation on its course, together with a number of technical nuances concerning various types of neurostimulation are also elucidated in this article. A number of alternative invasive treatments of PHN are also discussed.

Conclusions

Spinal cord stimulation is an established treatment option for patients with pharmacologically resistant PHN. High-frequency stimulation, burst stimulation, and dorsal root ganglion stimulation are promising options in the management of PHN due to the absence of paresthesias which can be painful for patients with PHN. But more research is still required to recommend the widespread use of these new methods.

Efficacy and Safety of Botulinum Toxin A and Pulsed Radiofrequency on Postherpetic Neuralgia: A Randomized Clinical Trial

This study evaluated the effectiveness and safety of botulinum toxin type A (BoNT-A) and pulsed radiofrequency (RF) in the clinical treatment of postherpetic neuralgia (PHN). A total of 100 patients with PHN were randomly divided into two groups (n = 50 per group): RF group and BoNT-A group. Based on conventional drug treatment, patients were treated with either a single nerve root pulsed radiofrequency therapy or a single local subcutaneous injection of BoNT-A in the lesion area. All the patients were followed up for 24 weeks on pain scores, sleep quality, anxiety, and depression scores, etc. In the last follow-up at the end of 24 weeks postoperation, the pain scores of patients in both groups were significantly lower than those before the operation (P < 0.05), indicating that both treatments were effective against PHN; however, there was no significant difference between these two groups (P > 0.05). It is noteworthy that the subcutaneous injection of BoNT-A is relatively easy to administer and less expensive compared to RF. Therefore, we believe that the subcutaneous injection of BoNT-A is an effective and safe method for the treatment of PHN.

The effect of subcutaneous injection of methylprednisolone acetate and lidocaine for refractory postherpetic neuralgia: a prospective, observational study

BACKGROUND

Postherpetic neuralgia (PHN) is the most common and bearable complication of herpes zoster (HZ). This pain may have negative impact on the patient's all aspects of daily life and health-related quality of life (HRQOL). Despite numerous advances in treatment, many patients remain resistant to the current therapy options. It is the first time subcutaneous injection of methylprednisolone acetate and lidocaine has been used to treat refractory PHN. We report the results of this treatment evaluating pain relief and HRQOL improvement in this disorder.

METHODS

A total of 43 patients with refractory PHN was enrolled in the observational study. All patients received daily subcutaneous injection of methylprednisolone acetate and lidocaine for 10 consecutive days. The severity of pain was assessed by using Visual Analog Scale (VAS), and 36-Item Short Form Survey (SF-36) was applied to evaluate HRQOL. Assessment of the pain and HRQOL was carried out at baseline and posttreatment at 4 weeks as well as 6 and 12 months.

RESULTS

At baseline, all patients experienced severe PHN with average VAS scores of 8.44 ± 0.85 (minimum 7; maximum 10). At 4 weeks, 6 months, and 12 months after treatment, the pain had significantly decreased (P < .001), and all subjects showed significant improvement in all eight domains of HRQOL. No major adverse events associated with the subcutaneous injection were observed.

CONCLUSIONS

Our results indicate that subcutaneous injection of methylprednisolone acetate and lidocaine can be an effective and safe treatment for PHN.

Differential expression of cerebrospinal fluid neuroinflammatory mediators depending on osteoarthritis pain phenotype

Supplemental Digital Content is Available in the Text.

Distinct cerebrospinal fluid neuroinflammatory profiles may be associated with different objective characteristics of persistent pain in osteoarthritis patients undergoing total hip arthroplasty.

Neuroinflammation is implicated in the development and maintenance of persistent pain states, but there are limited data linking cerebrospinal fluid (CSF) inflammatory mediators with neurophysiological pain processes in humans. In a prospective observational study, CSF inflammatory mediators were compared between patients with osteoarthritis (OA) who were undergoing total hip arthroplasty due to disabling pain symptoms (n = 52) and pain-free comparison controls (n = 30). In OA patients only, detailed clinical examination and quantitative sensory testing were completed. Cerebrospinal fluid samples were analyzed for 10 proinflammatory mediators using Meso Scale Discovery platform. Compared to controls, OA patients had higher CSF levels of interleukin 8 (IL-8) (P = 0.002), intercellular adhesion molecule 1 (P = 0.007), and vascular cell adhesion molecule 1 (P = 0.006). Osteoarthritis patients with central sensitization possibly indicated by arm pressure pain detection threshold <250 kPa showed significantly higher CSF levels of Fms-related tyrosine kinase 1 (Flt-1) (P = 0.044) and interferon gamma-induced protein 10 (IP-10) (P = 0.024), as compared to subjects with PPDT above that threshold. In patients reporting pain numerical rating scale score ≥3/10 during peripheral venous cannulation, Flt-1 was elevated (P = 0.025), and in patients with punctate stimulus wind-up ratio ≥2, CSF monocyte chemoattractant protein 1 was higher (P = 0.011). Multiple logistic regression models showed that increased Flt-1 was associated with central sensitization, assessed by remote-site PPDT and peripheral venous cannulation pain, and monocyte chemoattractant protein-1 with temporal summation in the area of maximum pain. Multiple proinflammatory mediators measured in CSF are associated with persistent hip OA-related pain. Pain phenotype may be influenced by specific CSF neuroinflammatory profiles.

Prospective Randomized Control Trial Comparing Effect of Dexamethasone Versus Fentanyl as Adjuvants to Intrathecal Bupivacaine for Orthopedic Surgery

Introduction

Spinal anesthesia is the most consistent block for lower limb orthopedic surgeries. We conducted this randomized prospective study to evaluate comparative efficacy of intrathecal dexamethasone with fentanyl and normal saline as adjuvants to hyperbaric bupivacaine in spinal anesthesia administered to patients scheduled for lower limb orthopedic surgery.

Materials and methods

105 patients scheduled for lower limb orthopedic surgeries under spinal anesthesia were included in this clinical trial. After randomization, patients received an intrathecal injection of hyperbaric bupivacaine (12.5 mg) with 4 mg of dexamethasone in group I, hyperbaric bupivacaine (12.5 mg) with 25 ug fentanyl with 0.5 ml of normal saline in group II and hyperbaric bupivacaine (12.5 mg) with normal saline (1 ml) in group III, so as to make volume of drug equal in all three groups. The observer evaluated the sensory and motor blocks and other parameters like time to self-void, stay in post-anesthesia care unit (PACU) and complications.

 Results

The total duration of sensory blockade was found to be 311.43, 197.86 and 115.29 minutes and motor blockade of 223.43, 163.86 and 83.0 minutes in groups I, II and III respectively. The PACU stay was 233.14, 173.86 and 93.00 minutes in groups I, II and III, respectively. The average time to self-void was 400.00, 315.29 and 203.00 in three groups, respectively.

Conclusion

Intrathecal dexamethasone seemed to be an effective adjuvant to spinal bupivacaine as it prolongs the duration of analgesia, stable hemodynamic profile with minimal side effects. Further studies are required to evaluate the optimum dose and long-term safety of intrathecal dexamethasone.

Updated Review: The Steroid Controversy for Management of Spinal Cord Injury

BACKGROUND

Acute spinal cord injury (ASCI) is a devastating event that can have a profound impact on the lives of patients and their families. While no definitive medical treatment exists, the role of methylprednisolone (MP) in the management of ASCI and other spinal cord pathologies has been investigated in depth; however, its use remains contentious. While MP initially showed promise in the efficacy of ASCI treatment, more recent studies have questioned its use citing numerous systemic adverse effects. Pharmacologic treatments in this area are poorly understood due to the scarcity of knowledge surrounding the pathophysiology and heterogeneity of patients presenting with these conditions. Despite these shortcomings and due to the lack of alternative treatment options, MP is still widely used by physicians.

METHODS

We review prior and current literature on the use of MP treatment for ASCI patients with a discussion of novel drug delivery systems that have demonstrated the potential to improve MP's bioavailability at the site of injury while minimizing systemic side effects. In addition, current views on the role of MP and dexamethasone in metastatic spinal cord compression and postoperative infection are reviewed.

RESULTS

While some data support benefits in the use of steroids on spinal cord pathology, extensive research suggests at best limited effects and an unresolvable risk/benefit problem.

CONCLUSIONS

At present, evidence regarding use of dexamethasone for MSCC is contentious, especially regarding dose regiments. Ultimately, further investigation into the use of steroids is required to determine its utility in treating patients with spinal cord pathology.

Post herpetic neuralgia: A retrospective study to evaluate response to modified Jaipur block with increased concentration of dexamethasone

Background:

Postherpetic neuralgia (PHN) is a complication of herpes zoster characterized by persistent dermatomal pain. It has a negative impact on the quality of life. There is no gold standard therapy for PHN, and various local and systemic treatments have been tried. There are studies reporting the use of combination of steroids and local anesthetics but there is no standardized method.

Aim:

To evaluate the response of modified Jaipur block with increased concentration of dexamethasone.

Methods:

We conducted a retrospective study in patients who were given Jaipur block. The patients age, sex, duration of PHN, type and severity of pain were observed. A combination of 2% lignocaine and 0.5% bupivacaine and dexamethasone was injected subcutaneously. The pain was scored using visual analogue scale at the baseline, and 1 month after 1^st, 2^nd, and 3^rd session of block and follow up after 6 months and 1 year.

Results:

The mean age of our patient was 63.33 ± 9.5 years. The males outnumbered females. Thoracic dermatomes were more commonly involved. The mean duration of PHN was 11.58 ± 12.76 months; stimulus evoked PHN was the commonest type of pain seen. The mean visual analogue score (VAS) decreased progressively after each session of the block. Maximum patients (50%) had excellent response, whereas 1.9% did not respond to the block. Relapse of pain was seen in 5.6% of the patients. There was no significant side effect noted.

Limitations:

There was no objective method used to assess pain.

Conclusion:

PHN is chronic neuropathic pain. Response to modified Jaipur block is good, but if the duration of PHN is more, the recurrence rate is higher. Modified Jaipur block is an effective and safe treatment for PHN

Addition of corticosteroids to local anaesthetics for chronic non-cancer pain injections: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Despite common use, the benefit of adding steroids to local anaesthetics (SLA) for chronic non-cancer pain (CNCP) injections is uncertain. We performed a systematic review and meta-analysis of English-language RCTs to assess the benefit and safety of adding steroids to local anaesthetics (LA) for CNCP.

METHODS

We searched MEDLINE, EMBASE, and CENTRAL databases from inception to May 2019. Trial selection and data extraction were performed in duplicate. Outcomes were guided by the Initiative in Methods, Measurements, and Pain Assessment in Clinical Trials (IMMPACT) statement with pain improvement as the primary outcome and pooled using random effects model and reported as relative risks (RR) or mean differences (MD) with 95% confidence intervals (CIs).

RESULTS

Among 5097 abstracts, 73 trials were eligible. Although SLA increased the rate of success (42 trials, 3592 patients; RR=1.14; 95% CI, 1.03-1.25; number needed to treat [NNT], 13), the effect size decreased by nearly 50% (NNT, 22) with the removal of two intrathecal injection studies. The differences in pain scores with SLA were not clinically meaningful (54 trials, 4416 patients, MD=0.44 units; 95% CI, 0.24-0.65). No differences were observed in other outcomes or adverse events. No subgroup effects were detected based on clinical categories. Meta-regression showed no significant association with steroid dose or length of follow-up and pain relief.

CONCLUSIONS

Addition of cortico steroids to local anaesthetic has only small benefits and a potential for harm. Injection of local anaesthetic alone could be therapeutic, beyond being diagnostic. A shared decision based on patient preferences should be considered. If used, one must avoid high doses and series of steroid injections.

CLINICAL TRIAL REGISTRATION

PROSPERO #: CRD42015020614.

Post-herpetic Neuralgia: A Systematic Review of Current Interventional Pain Management Strategies

Background:

Post-herpetic neuralgia (PHN) is usually a constant or intermittent burning, stabbing, or sharp shooting pain with hyperalgesia or allodynia, persisting beyond the healing of herpetic skin lesions. This review was carried out in concordance to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We used PICOS (Population, Intervention, Control, and Outcome Study) design for inclusion of potential studies into this review. Online literature available in PubMed, Cochrane, and Embase was searched for studies from January 1995 till March 2020, which evaluated interventional treatments in PHN by an independent reviewer, using the relevant medical subject heading (MeSH) terms. We analyzed the following outcome parameters with regard to each intervention—pain status at predefined fixed intervals after the intervention, quality of sleep using any of the reported questionnaires, analgesic consumption, functional evaluation, and quality of life assessment after the intervention.

Conclusion:

Interventional pain management options provide effective and long-lasting pain relief to patients not responding to medical management. The choice of intervention will depend on the region involved, cost, and invasiveness. Simple procedures such as intercostal nerve blocks/neurolysis, stellate ganglion blocks, paravertebral neurolysis, epidural steroid injections, and dorsal root ganglion–radiofrequency ablation are effective interventions, and if they fail, spinal cord stimulators could be effective in the hands of experienced pain physicians.

Pharmacological and non-pharmacological treatments for neuropathic pain: Systematic review and French recommendations

Neuropathic pain remains a significant unmet medical need. Several recommendations have recently been proposed concerning pharmacotherapy, neurostimulation techniques and interventional management, but no comprehensive guideline encompassing all these treatments has yet been issued. We performed a systematic review of pharmacotherapy, neurostimulation, surgery, psychotherapies and other types of therapy for peripheral or central neuropathic pain, based on studies published in peer-reviewed journals before January 2018. The main inclusion criteria were chronic neuropathic pain for at least three months, a randomized controlled methodology, at least three weeks of follow-up, at least 10 patients per group, and a double-blind design for drug therapy. Based on the GRADE system, we provide weak-to-strong recommendations for use and proposal as a first-line treatment for SNRIs (duloxetine and venlafaxine), gabapentin and tricyclic antidepressants and, for topical lidocaine and transcutaneous electrical nerve stimulation specifically for peripheral neuropathic pain; a weak recommendation for use and proposal as a second-line treatment for pregabalin, tramadol, combination therapy (antidepressant combined with gabapentinoids), and for high-concentration capsaicin patches and botulinum toxin A specifically for peripheral neuropathic pain; a weak recommendation for use and proposal as a third-line treatment for high-frequency rTMS of the motor cortex, spinal cord stimulation (failed back surgery syndrome and painful diabetic polyneuropathy) and strong opioids (in the absence of an alternative). Psychotherapy (cognitive behavioral therapy and mindfulness) is recommended as a second-line therapy, as an add-on to other therapies. An algorithm encompassing all the recommended treatments is proposed.

Efficacy of intermittent epidural dexamethasone bolus for zoster-associated pain beyond the acute phase

Herpes zoster develops when latent varicella zoster virus is reactivated in the trigeminal or dorsal root ganglions. Zoster-associated pain (ZAP) is neuropathic pain caused by the herpes zoster virus. Histological studies of postherpetic neuralgia patients suggest that inflammation is involved in ZAP. The effectiveness of local anesthetic and steroid epidural injections in ZAP patients has been reported. However, most studies included patients with acute herpes zoster, and the safety and therapeutic effects of different doses of epidural steroids in ZAP patients remain elusive. In this study, we randomly assigned 42 patients with severe ZAP beyond the acute phase, as determined by a numeric rating scale (NRS) score ≥7, to receive continuous epidural infusion of local anesthetics with either a one-time 5-mg dose or intermittent repeated doses (15 mg total) of dexamethasone. We found that intermittent repeated epidural dexamethasone bolus resulted in reduced NRS scores and an increased likelihood of complete remission in ZAP patients without any adverse effects. Thus, our results suggest that intermittent repeated epidural dexamethasone administration is safe and effective for treatment of ZAP beyond the acute phase.

A Breast Cancer Survivor's Self-Controlled Case Report: Methylprednisolone Acetate Provided a Week Longer Analgesia Than Dexamethasone Sodium Phosphate via Thoracic Paravertebral Blockade

Proper perioperative pain control with opioid-sparing techniques that extend into post-discharge arena is desirable yet hard to accomplish in breast cancer patients. We here reported a case where we took advantage of long-acting local anesthetics in conjunction with glucocorticoids of different hydrophilic/lipophilic properties and achieved prolonged analgesia for days after single administration thoracic paravertebral blockade. Further exploration into the potential effects of long-acting glucocorticoids in breast cancer patients through peripheral nerve blockage is warranted.

Electrophysiological responsiveness and clinical outcomes of local corticosteroid injection in the treatment of carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is the most common mononeuropathy caused by entrapment of the median nerve at the wrist. Common treatment options for CTS include oral analgesics, splinting, hand therapy, local injections with steroids or surgery. OBJECTIVE The aim of the present study was to assess the short-term clinical and electrophysiological outcomes of local corticosteroid injection (LCI) in patients with symptomatic CTS. METHODS Electrophysiological parameters were evaluated before and three months after LCI. Moreover, the Numeric Rating Scale (NRS), the Boston Symptom Severity Scale (SSS) and the Functional Status Scale (FSS) were administered before and after the injection. A mixture of 1 mL (40 mg) of methylprednisolone and 1 mL of 0.5% bupivacaine were injected blindly on the volar side of the forearm between the tendons of the radial carpal flexor muscle and long palmar muscle. RESULTS A total of 25 patients (45 hands) were enrolled in the study. Twenty women and five men with a mean age of 49.28 ± 11.37 years were included. A statistically significant difference was noted for improvement of sensory conduction velocities, sensory peak latency, and motor distal latency (p = 0.001) after LCI. A significant difference was recorded between pre- and post-injection for NRS, SSS and FSS scores (p = 0.000). CONCLUSION Local corticosteroid injection for CTS provides a short-term improvement in neurophysiological and clinical outcomes such as pain intensity, symptom severity and functional ability.

Parameters associated with efficacy of epidural steroid injections in the management of postherpetic neuralgia: the Mayo Clinic experience

Purpose: Thirty percent of patients with postherpetic neuralgia (PHN) receiving conservative treatment report unsatisfactory pain relief. Epidural steroid injections (ESIs) are commonly used as a therapeutic intervention in these patients. In this study, we aimed to determine if there are variables that predict the efficacy of ESI in patients with PHN.

Patients and methods: We retrospectively identified patients seen at Mayo Clinic who had PHN and received ESI. From their medical records, we abstracted the demographic variables, concurrent medication use, anatomic approach and medication for ESI, and degree of pain relief at 2 and 12 weeks' postintervention.

Results: None of the studied variables were significantly associated with efficacy of ESI in patients with PHN. PHN that began <11 months before treatment was predictive of a response to ESI at 12 weeks postintervention (positive predictive value, 55%). Patients who reported poor ESI efficacy 2 weeks after the intervention had a 94% chance of still having pain at 12 weeks.

Conclusion: For this cohort of patients with PHN being treated with ESI, no demographic characteristics, concurrently used medications, or type of ESI were associated with ESI treatment efficacy at 2 or 12 weeks after the intervention.

Epidural levobupivacaine versus a combination of levobupivacaine and dexamethasone in patients receiving epidural analgesia

Background and Aims

The use of dexamethasone as an adjuvant to local anesthetic rarely has been described. Some studies have demonstrated the analgesic effect of local spinal and systemic corticosteroids in combination with bupivacaine. It works by decreasing inflammation and blocking transmission of nociceptive C-fibers and by stopping the ectopic discharge of the nerve. The aim of this randomized controlled trial was to compare the efficacy of epidural levobupivacaine alone versus a combination of levobupivacaine with dexamethasone for labor analgesia.

Material and Methods

This prospective double-blind trial included the 60 primigravidas during vaginal delivery with a cervical dilatation ≥4 cm and 50% effacement randomly assigned to one of two groups - Group A (n=30): epidural levobupivacaine 0.125% in normal saline in a total volume of 15 mL and Group B (n=30): epidural levobupivacaine 0.125% in normal saline combined with dexamethasone 4 mg in a total volume of 15 mL. At first request of analgesia, 10 mL of 0.125% levobupivacaine was administrated through epidural catheter. Further analgesia was provided with 8 mL of 0.125% levobupivacaine hourly. Primary outcome measure was the duration of epidural analgesia. Secondary outcome measures include pain score by Visual Analog Scale score before the block and 15 min following it, the total amount of levobupivacaine used, Apgar score and umbilical vein blood gas analysis, maternal satisfaction, and side effects recorded.

Results and Conclusion

The duration of epidural analgesia was significantly longer (P < 0.05) upon adding dexamethasone to levobupivacaine. Total epidural levobupivacaine consumption was significantly lower (P = 0.05) in Group B. There were no statistical differences between the two groups regarding hemodynamics, pain score, neonatal outcome, and complications. Epidural dexamethasone plus levobupivacaine prolongs the duration of epidural analgesia during management of labor pain with hemodynamic stability and limited maternal and neonatal adverse effects.

Intrathecal betamethasone for cancer pain: A study of its analgesic efficacy and safety

BACKGROUND

A preliminary study has shown effective cancer pain relief by intrathecal betamethasone (ITB). However, further evidence is needed to support this new approach.

METHODS

Cancer patients with opioid-resistant pain received lumbar intrathecal administration of betamethasone 2 or 3 mg once a week for 28 days. Immediate and short-term analgesia (using a percentage pain reduction scale and a numerical rating scale, NRS) and long-term analgesia (using NRS) were assessed. Patients were classified into two groups according to the most painful site of metastasis: vertebral column and/or surrounding nerve plexus metastases (group A) and other metastases distal from the vertebral column (group B).

RESULTS

A total of 104 patients received ITB. Pain relief was observed not only in the lower half but also in the upper half of the body. The proportion of group A patients who experienced immediate analgesia was 81% (47/58), which was significantly greater than that of group B (P < 0.001). A decrease in NRS scores 1 day after ITB administration was observed in significantly more patients in group A than in group B (P < 0.001). Long-term analgesia was also recorded in a greater proportion of patients in group A than in group B in the 7-day (59%, 38/64 vs 6%, 2/33) and 28-day periods (71%, 40/56 vs 31%, 8/26) (P < 0.001). No adverse effects related to neurotoxicity were recorded.

CONCLUSION

Intrathecal injection of betamethasone produced analgesia for opioid-resistant cancer pain, and may be a potent therapeutic option for intolerable pain from vertebral column and/or surrounding nerve plexus metastases.

Adhesive arachnoiditis following lumbar epidural steroid injections: a report of two cases and review of the literature

Lumbar epidural steroid injections (LESIs) are commonly used for managing lower back pain (LBP) and radicular pain. LESIs are generally considered safe with only rare serious complication. One very rare complication that is frequently cited in the literature is adhesive arachnoiditis. However, a literature search failed to detect even one published manuscript, clearly documenting LESI induced arachnoiditis. This article presents two patients who received a transforaminal L5–S1 and two L3–L4 interlaminar LESIs. Although the presented patients developed clear radiological (MRI) findings of arachnoiditis, they were not accompanied by any improvement or deterioration in their clinical condition. The article also reviews the literature on the prevalence, pathogenesis, diagnosis, and clinical features of adhesive arachnoiditis. Literature suggests that adhesive arachnoiditis following LESIs is a rare entity, which – as seen in our patients – has clear radiological characteristics but uncertain pathogenesis. It has a large spectrum of clinical presentation, ranging from an incidental finding to a serious neurological sequela. In at least some patients with adhesive arachnoiditis following LESI, the radiological and clinical findings may fail to correlate with each other. In light of the fact that LESI is one of the most commonly performed procedures for managing LBP, clinicians should be aware of this rare yet existing entity.

The Effect of Interventional Pain Management on Treating Postherpetic Neuralgia

Background:

Herpes zoster (HZ) is identified to induce postherpetic neuralgia (PHN) which is difficult to cure. PHN-related pain brings patients not only physical discomfort but also mental depression and anxiety. Currently, the main purpose of PHN treatment is to reduce patients’ pain. Now treatment combining some international pain management and drug therapy has come up.

Aims and Objective:

This study aims to evaluate the effect of interventional management through meta-analysis.

Materials and Methods:

Interventional pain management was defined as a direct strategy on nerve through physical or chemical method. Drug therapy was always regarded as control. Potentially relevant articles were searched in PubMed, EMBASE, and the Cochrane Library through key words by consensus. Pain severity was evaluated by a validated visual analog scale (VAS). Moreover, the weighted mean difference was used to calculate pain intensity. Some trails recorded the efficiency rate and odds ratio was used to calculate the effectiveness. Statistical heterogeneity was measured by the value of I², and when statistical I² > 50%, subgroup analysis was used to seek for the source of heterogeneity.

Results:

Pulsed radiofrequency (PRF) combined with medication reduced the VAS scores at 1, 2, 4, and 8 weeks after treatment. The nerve block combined with medication reduced VAS scores at 8 weeks after treatment, but there is no difference between the results of medication alone at 1, 2, and 4 weeks after treatment.

Conclusion:

The interventional mean of PRF combined with medication has a good effect on PHN. The effect of nerve block combined with medication on PHN seems to be the same as that of medication alone. Besides, a long period with high-quality randomized controlled trial should be done to verify the results.

Rethinking the causes of pain in herpes zoster and postherpetic neuralgia: the ectopic pacemaker hypothesis

INTRODUCTION

Pain in herpes zoster (HZ) and postherpetic neuralgia (PHN) is traditionally explained in terms of 2 processes: irritable nociceptors in the rash-inflamed skin and, later, deafferentation due to destruction of sensory neurons in one virally infected dorsal root ganglion.

OBJECTIVES AND METHODS

Consideration of the evidence supporting this explanation in light of contemporary understanding of the pain system finds it wanting. An alternative hypothesis is proposed as a replacement.

RESULTS

This model, the ectopic pacemaker hypothesis of HZ and PHN, proposes that pain in both conditions is driven by hyperexcitable ectopic pacemaker sites at various locations in primary sensory neurons affected by the causative varicella zoster virus infection. This peripheral input is exacerbated by central sensitization induced and maintained by the ectopic activity.

CONCLUSIONS

The shift in perspective regarding the pain mechanism in HZ/PHN has specific implications for clinical management.

The analgesic effect of intravenous methylprednisolone on acute neuropathic pain with allodynia due to central cord syndrome: a retrospective study

Background

Central cord syndrome (CCS) may be associated with severe neuropathic pain that often resists to conventional pain therapy regimens and affects the patients’ quality of life (QoL) seriously. Current treatments for CCS-associated neuropathic pain have limited evidence of efficacy. This retrospective study was performed to present the effects of early treatment with methylprednisolone (MP) on acute neuropathic pain relief and the QoL in CCS patients.

Patients and methods

Data were collected from the medical records of CCS patients who suffered from acute neuropathic pain with allodynia. All the patients received intravenous MP treatment for up to 1 week. Patients were evaluated with standard measures of efficacy: neuropathic pain intensity, the area of allodynia, and the QoL at baseline, daily treatment, and at 1 and 3 months after the end of MP treatment.

Results

Thirty-four eligible patients were enrolled in our study. By the end of MP treatment, the proportion of patients who gained total or major (visual analog scale [VAS] score decreased by 50% or more) allodynia relief from the treatment was 91.18%, and a decrease in spontaneous pain was also observed. Moreover, this study showed MP could significantly improve the QoL of patients based on McGill Pain Questionnaire Short Form and EuroQol Five Dimensions Questionnaire. Four patients (11.76%) during MP treatment experienced mild or moderate side effects. None of the patients manifested CCS-associated neuropathic pain recurrence and MP-associated side effects at follow-up.

Conclusion

The current results suggested that MP offered an effective therapeutic alternative for relieving CCS-associated acute neuropathic pain with allodynia. Given the encouraging results of this study, it would be worthwhile to confirm these results in randomized placebo-controlled clinical trials.

Neuropathic Pain

PURPOSE OF REVIEW

Neuropathic pain is a frequently encountered condition that is often resistant to treatment and is associated with poor patient satisfaction of their treatment. Several medications have been shown to be effective in treating neuropathic pain associated with diabetic neuropathy and postherpetic neuralgia, and these medications are often used to treat neuropathic pain associated with other conditions as well. This article summarizes the diagnosis and assessment of patients with neuropathic pain as well as available pharmacologic and interventional treatment options.

RECENT FINDINGS

Evidence-based recommendations for the treatment of neuropathic pain have been published, and first-line medications include antidepressants, anticonvulsants, topical agents, as well as opioid analgesics. Interventional options include anesthetic and steroid injections, nerve blocks, and spinal cord stimulation. Essential to the treatment algorithm of neuropathic pain is the assessment and treatment of psychosocial comorbidities and the utilization of a multidisciplinary team approach, including cognitive-behavioral and rehabilitative therapies. Questions remain about the comparative effectiveness of various medications and combination therapies. Increasing interest also exists in the optimization and personalization of pharmacotherapy based upon the underlying mechanism(s) of neuropathic pain according to the quality of the patient's symptoms.

SUMMARY

The management of chronic neuropathic pain is challenging and is best achieved with the use of a multidisciplinary team. Pain is a subjective experience, and it is important to validate a patient's pain, address psychosocial comorbidities, and set realistic treatment goals. Evidence-based guidelines are available to guide treatment, but frequently, high-quality evidence-based recommendations are lacking.

Increased Central Nervous System Interleukin-8 in a Majority Postlaminectomy Syndrome Chronic Pain Population

Background and Objectives

Multiple processes have been identified as potential contributors to chronic pain, with increasing evidence illustrating an association with aberrant levels of neuroimmune mediators. The primary objectives of the present study were to examine central nervous system cytokines, chemokines, and growth factors present in a chronic pain population and to explore patterns of the same mediator molecules over time. Secondary objectives explored the relationship of central and peripheral neuroimmune mediators while examining the levels of anxiety, depression, sleep quality, and perception of pain associated with the chronic pain patient experience.

Methods

Cerebrospinal fluid (CSF) from a population of majority postlaminectomy syndrome patients (N = 8) was compared with control CSF samples (N = 30) to assess for significant differences in 10 cytokines, chemokines, and growth factors. The patient population was then followed over time, analyzing CSF, plasma, and psychobehavioral measures.

Results

The present observational study is the first to demonstrate increased mean CSF levels of interleukin-8 (IL-8; P < 0.001) in a small population of majority postlaminectomy syndrome patients, as compared with a control population. Over time in pain patients, CSF levels of IL-8 increased significantly (P < 0.001).

Conclusions

These data indicate that IL-8 should be further investigated and psychobehavioral components considered in the overall chronic pain paradigm. Future studies examining the interactions between these factors and IL-8 may identify novel targets for treatment of persistent pain states.

Using dexamethasone as an adjuvant to levobupivacaine in epidural anesthesia to change the pain intensity and duration in painless labor

Background and Objective

This is a randomized controlled trial aiming at comparing the effectiveness of levobupivacaine alone versus a levobupivacaine with dexamethasone in the epidural injection for painless labor.

Patients and Methods

This is a comparative randomized controlled double-blinded clinical trial with 49 patients were included in this study, all of them were primigravidas and were during vaginal delivery with a cervical dilatation ≥4 cm. Patients were included randomly in one of two groups either Group C (26 cases) with epidural levobupivacaine 0.125% in normal saline or Group D (23 cases) with epidural levobupivacaine 0.125% in normal saline combined with dexamethasone 8 mg. The duration of a second dose request, total dose given, neonatal outcome and adverse effects of epidural were recorded.

Results

Group D showed a longer duration of analgesia than Group C (80.5 ± 12.39 min in Group D vs. 61.75 ± 10.74 min in Group C) with a P < 0.05 (0.001). Furthermore, the patients in Group D received smaller dose of levobupivacaine than those in Group C with a statistically significant difference (90.87 ± 33.42 vs. 127.21 ± 40.68 mg with P = 0.002). There were no statistical differences between the two groups regarding hemodynamics, pain score, neonatal outcome, and complications.

Conclusion

Dexamethasone in epidural analgesia for painless labor has a prolonged duration of analgesia with no complications for both the mother and the infant.

Comparison of efficacy of continuous epidural block and pulsed radiofrequency to the dorsal root ganglion for management of pain persisting beyond the acute phase of herpes zoster

Background

There is little evidence regarding the effectiveness of intervention methods in the treatment of zoster-related pain (ZAP) after the acute phase of zoster. Generally, if ZAP remains after more than 180 days from its onset, the likelihood of pain reduction is very low; this condition is considered as a “well established” post-herpetic neuralgia (PHN). Although the clinical efficacy of intrathecal steroid injection and spinal cord stimulation (SCS) for ZAP management has been reported, these interventions are not widely used due to inherent disadvantages. Continuous epidural block is widely used in clinical practice, and the effectiveness of pulsed radiofrequency (PRF) to the dorsal root ganglion (DRG) in the treatment of ZAP already has been reported.

Objectives

The purpose of this study was to compare the clinical efficacy of continuous epidural block and DRG PRF beyond acute phase of zoster, bur before PHN was well established (from 30 days to180 days after zoster onset).

Study design

Retrospective comparative study.

Methods

A total of 42 medical records were analyzed. Patients were divided into two groups according to the type of procedure utilized: continuous epidural block (continuous epidural group) and DRG PRF (PRF group). The clinical efficacy of the procedure was evaluated using a numeric rating scale (NRS) and the medication dose before and 1 to 6 months after the procedure.

Results

There was a significant decrease in the NRS value with time in both groups. However, this decrease was more significant in the PRF group than in the continuous epidural group. The medication doses decreased significantly in the PRF group over time, but not in the continuous epidural group. The rate of clinically meaningful PHN (NRS≥3) was also lower in the PRF group than in the continuous epidural group.

Conclusions

This study revealed that DRG PRF was more effective than a continuous epidural block in treating ZAP after the acute phase of zoster. A neuromodulation method such as DRG PRF may be a useful option for reducing the progression of neuropathic changes caused by the persistent transmission of a pain signal after the acute phase of zoster.

Effect of Repetitive Intracutaneous Injections with Local Anesthetics and Steroids for Acute Thoracic Herpes Zoster and Incidence of Postherpetic Neuralgia

Background

Treatment of established postherpetic neuralgia (PHN) is difficult and often disappointing. In this study, we assessed the efficacy of repetitive intracutaneous injections with local anesthetics and steroids in acute thoracic herpes zoster (HZ) pain, herpetic eruption, and incidence of PHN.

Methods

Ninety-three patients with acute thoracic HZ were randomly assigned to receive a standard treatment of antiviral medication with p.o. analgesics or the standard treatment with the addition of repetitive intracutaneous injections of a local anesthetic and steroid mixture. Patients were permitted to take tramadol when the visual analog scale (VAS) ≥ 4. Pain assessment using VAS was conducted at the initial visit, as well as 1, 2, 4, 12, and 24 weeks after the end of the treatments.

Results

In comparison with the standard treatment group, the VAS scores of the intracutaneous injection group were significantly lower during the study. The intracutaneous injection group also reported shorter duration of pain and skin eruption than the control group ( P  = 0.005 vs P  < 0.001, respectively). At 1 month post-therapy, 12.8% patients in the intracutaneous injection group reported zoster-associated pain, compared with 47.8% in the standard treatment group ( P  < 0.001). At 3 and 6 months post-therapy, the incidence of PHN was still significantly lower in the intracutaneous injection group than the standard treatment group. EuroQol VAS scores were significantly higher in the intracutaneous injection group vs standard treatment group (P < 0.001).

Conclusion

Repetitive intracutaneous injections with local anesthetics and steroids along with standard treatment significantly reduce the duration of pain and herpetic eruption and incidence of PHN.

Intrathecal dexamethasone vs. meperidine for prevention of shivering during transurethral prostatectomy: a randomized controlled trial

BACKGROUND

Shivering is a common complication after spinal anesthesia. Also, during transurethral prostatectomy a large amount of irrigating fluids is used which may cause hypothermia and shivering. We hypothesized that intrathecal dexamethasone could effectively attenuate post-spinal shivering following transurethral prostatectomy as intrathecal meperidine.

METHODS

Ninety male patients, ASA II-III, 50-75 years old were included in this prospective and randomized double-blind study. Patients were divided into three equal groups; Group D received 8 mg dexamethasone, Group M received 0.2 mg/kg meperidine, and Group C received 2 ml of normal saline, each in addition to intrathecal hyperbaric bupivacaine 0.5%. Shivering incidence, intensity and recurrence, dose of IV meperidine required to treat shivering, and adverse events were recorded for 150 min after the start of spinal anesthesia.

RESULTS

The number of patients with shivering was higher in Group C (13) than in Group D (2) and Group M (3) with no differences between Group D and M; P = 0.001. Intensity and recurrence of shivering and dose of IV meperidine used to treat shivering were higher in Group C compared to Group D and Group M; P = 0.01, P = 0.064, and P = 0.004, respectively. Adverse events were not different between groups except sedation and pruritus which occurred only in Group M compared to Group D and Group C; P = 0.005 and P = 0.001, respectively.

CONCLUSION

Intrathecal dexamethasone was as effective as intrathecal meperidine in attenuation of shivering compared to placebo in patients scheduled for prostate surgery under spinal anesthesia with less adverse events.

The Proteomics of Intrathecal Analgesic agents for Chronic Pain

Chronic pain remains a challenging clinical problem with a growing socio-economic burden for the state. Its prevalence is high and many of the patients are of work age. Our knowledge regarding the pathophysiology of chronic pain is poor. The consensus view is that the central nervous system plays a key role in the persistence of pain after an initiating event has long ceased. However the specifics of this biological response to an initiating event remains unclear. There is a growing body of evidence to support the concept that a central neuroimmune response is initiated and a number of small peptides have been implicated in this process following cerebrospinal fluid analysis in patients with chronic pain. This central biosynthetic peptide response leads to a process called central sensitization. Therapy is aimed at modulating and even inhibiting this response. However current pharmacological therapeutic options are limited in efficacy with significant deleterious side effect profiles. Proteomic studies extend single molecule analysis by identifying the components of biological networks and pathways and defining their interactions. This tool offers the potential to provide a molecular overview of the biological processes involved in chronic pain. It will also facilitate examination of gene-drug interactions. This technique offers a mechanism of defining the central biological responses that result in chronic pain and this information may facilitate the development of better therapies.

Effect of intrathecal glucocorticoids on the central glucocorticoid receptor in a rat nerve ligation model

BACKGROUND AND AIMS

Despite widespread use, the efficacy of neuraxial glucocorticoids for neuropathic pain is subject to debate. Since most glucocorticoid actions are mediated through its receptor, we explored the effects of intrathecal methylprednisolone acetate (MPA) on total glucocorticoid receptor (tGR) levels and activation of the glucocorticoid receptor (phosphorylated state=pGR) within the spinal dorsal horn (SDH) and dorsal root ganglion (DRG) in a spinal nerve ligation (SNL) model in rats.

METHODS

Rats received unilateral ligation of the L5/L6 spinal nerves and were treated with two intrathecal doses of either 400μg MPA or 0.9% saline with a 72-h interval. Plantar tactile thresholds were measured over time. Seven days after drug treatment, DRG and SDH were harvested to assess tGR and pGR levels using immunohistochemistry and qPCR.

RESULTS

Allodynia, defined by lowered tactile withdrawal thresholds after SNL, was unaltered by intrathecal MPA. In saline controls, mRNA levels of tGR did not change after SNL in the DRGs or SDH. tGR and pGR protein levels in the SDH however, significantly increased on the ipsilateral side of SNL compared to the contralateral side and to naïve tissue. When treating rats with MPA, tGR mRNA levels were significantly reduced in the SDH compared to saline controls. tGR and pGR protein levels, however were not significantly lower compared to saline controls.

CONCLUSIONS

In intrathecal MPA treated rats, tGR mRNA levels decreased after SNL. However this did not result in lower tGR and pGR protein levels compared to saline controls, and did not decrease ligation-induced mechanical hypersensitivity.

IMPLICATIONS

Intrathecal MPA treatment after SNL did not result in lower tGR and pGR levels within the SDH and DRG compared to saline controls. In present study we did not differentiate between the various isoforms of the GR which might clarify this finding.

The Treatment of Longstanding Complex Regional Pain Syndrome with Oral Steroids

OBJECTIVE

Evaluate the effectiveness of oral steroids in relieving pain in patients with Complex Regional Pain Syndrome (CRPS) of more than 3 months duration.

DESIGN

Service evaluation/Open label uncontrolled trial.

SETTING

Two pain outpatient clinics specialized in CRPS diagnosis and treatment in the period 2009-2012.

SUBJECTS

Thirty-one patients diagnosed with CRPS with the Budapest criteria in two specialized centers, with a disease duration of more than 3 months and not responsive to standard treatment were included.

METHODS

Patients were treated with oral prednisolone in both centers [100 mg daily tapered by 25 mg every 4 days to zero (Σ1g) at center 1 (C1) and 60 mg daily for 2 weeks lowered 20 mg every 4 days to zero (Σ1.06g) at center 2 (C2)]. The average pain intensity was recorded by patients using a numeric rating scale before the treatment start, and 6 weeks after treatment onset (treatment duration was respectively 16 days and 22 days at the two centers).

RESULTS

Overall the authors observed no significant reduction in the average pain intensity (P = 0.059), but 2 patients had a consistent reduction in pain intensity with return to baseline pain levels 9 weeks after treatment onset, and 1 patient had ongoing stable pain relief of >50%.

CONCLUSIONS

This study provides indications that the efficacy of oral corticosteroids is limited in treating CRPS of more than 3 months duration who did not respond to previous treatment. Randomized controlled studies (with enriched designs), or single subject designs would be required to identify the possible existence of a patient subgroup with a specific disease profile that may benefit from a steroid treatment.

The effect of addition of dexamethasone to levobupivacaine in parturients receiving combined spinal-epidural for analgesia for vaginal delivery

Background and Aims:

Regional analgesia is commonly used for the relief of labour pain, Prolongation of analgesia can be achieved by adjuvant medications. The aim of this randomised controlled trial was to evaluate the efficacy of intrathecal levobupivacaine with dexamethasone for labour analgesia.

Methods:

A total of 80 females were included in this study, all were primigravidas undergoing vaginal delivery with cervical dilatation ≥4 cm and 50% or more effacement. Forty females were included randomly in either Group L (received intrathecal levobupivacaine 0.25% in 2 mL) or Group LD (received intrathecal levobupivacaine 0.25% combined with dexamethasone 4 mg in 2 mL). The primary outcome was the duration of spinal analgesia. Secondary outcomes included the total dose of epidural local anaesthetic given, time to delivery, neonatal outcome and adverse effects.

Results:

The duration of spinal analgesia was significantly longer in the LD group compared with L group (80.5 ± 12.4 min vs. 57.1 ± 11.5 min, respectively; P < 0.001). In Group LD compared with Group L, time from spinal analgesia to delivery was significantly lower (317.4 ± 98.9 min vs. 372.4 ± 118.8 min, respectively; P = 0.027), and total epidural levobupivacaine consumption was significantly lower (102.4 ± 34.8 mg vs. 120.1 ± 41.9 mg, respectively; P = 0.027). The two groups were comparable with respect to characteristics of sensory and motor block, haemodynamic parameters, pain scores, neonatal outcome and frequency of adverse effects.

Conclusion:

Intrathecal dexamethasone plus levobupivacaine prolongs the duration of spinal analgesia during combined spinal-epidural CSE for labour analgesia.

One-time intrathecal triamcinolone acetonide application alters the redox potential in cerebrospinal fluid of progressive multiple sclerosis patients: a pilot study

INTRODUCTION

Cerebrospinal fluid analysis may provide insight into the interplay between chronic inflammation and response to treatment.

OBJECTIVES

To demonstrate the impact of one intrathecal triamcinolone injection on the redox potential and on ascorbyl radical appearance in the cerebrospinal fluid of chronic progressive multiple sclerosis patients.

METHODS

A total of 16 patients received 40 mg triamcinolone. Electron-spin resonance spectroscopy measured the oxidation range after copper ion [Cu (II)] addition and ascorbyl-radical bioavailability.

RESULTS

There was an increase of Cu (II) ion absorption, which reflects an augmented content of reduced proteins. Ascorbyl radicals were present in contrast to healthy controls according to the literature.

CONCLUSION

Intrathecal steroid application alters the redox potential in cerebrospinal fluid. Our findings support the beneficial role of steroids on oxidative stress generally demonstrated by ascorbyl radical appearance. Reactive oxygen species decline is necessary for an upregulated production of reduced proteins.

Analgesic properties of intrathecal glucocorticoids in three well established preclinical pain models

BACKGROUND AND AIMS

Glucocorticoids, a group of anti-inflammatory agents, are frequently administered in pain medicine. Of interest is the reported activity after intrathecal delivery in patients with neuropathic pain syndromes such as postherpetic neuralgia, though its efficacy is controversial. After the publication of two randomized clinical trials in postherpetic neuralgia patients treated with similar intrathecal methylprednisolone acetate (MPA) dosing regimes with conflicting results; one showing significant pain reduction (Kotani N, Kushikata T, Hashimoto H, Kimura F, Muraoka M, Yodono M, Asai M, Matsuki A: Intrathecal methylprednisolone for intractable postherpetic neuralgia. N Engl J Med 2000;23: 1514-9), the other increased pain sensations (Rijsdijk M, van Wijck AJ, Meulenhoff PC, Kavelaars A, van der Tweel I, Kalkman CJ: No beneficial effect of intrathecal methylprednisolone acetate in postherpetic neuralgia patients. Eur J Pain 2013;38: 175-200), we decided additional research was warranted. Present study sought to determine effects of intrathecally delivered methylprednisolone on pain-like behaviour and pain-associated markers in three well established rodent pain models: (1) intraplantar carrageenan, (2) intraplantar formalin, and (3) ligation of L5/L6 spinal nerves (SNL model).

METHODS

Male rats with intrathecal catheters were examined for (1) tactile allodynia after unilateral hindpaw intraplantar carrageenan injection (2%), (2) flinching and subsequent long term tactile allodynia after unilateral hindpaw intraplantar formalin injection (2.5%) or (3) tactile allodynia after unilateral ligation of the L5 and L6 spinal nerves. Rats were treated with the maximum tolerable intrathecal dose of the soluble methylprednisolone sodium succinate (MP) or the particulate methylprednisolone acetate (MPA). Dorsal root ganglia and spinal cords were harvested for immunohistochemistry to assess markers of neuronal damage (ATF3) and glial activation (GFAP, Iba1).

RESULTS

During dose finding, severe generalized allodynia was observed with high intrathecal doses of both MPA and MP in naive rats. MPA had no effect upon tactile allodynia after carrageenan. MP and MPA did not reverse tactile allodynia in the SNL model, and did not reduce flinching in the formalin model. MP and MPA prevented the delayed (7-day) tactile allodynia otherwise observed in the formalin-injected paw. Systemic MP or perineural MP or MPA did not reduce pain-like behaviour in the SNL model. No reduction of neuronal injury (ATF3) in the dorsal root ganglion or astrocyte activation (GFAP) in the spinal dorsal horn with intrathecal MP or MPA was observed. There was a decrease in microglial activation (Iba1) in the spinal dorsal horn with MPA after SNL.

CONCLUSION

Severe generalized allodynia was observed after high intrathecal doses of MP and MPA in naive rats. No acute analgesic effects with intrathecal glucocorticoids were observed in three well established pain models. Only a late antiallodynic effect was present in the formalin model, 7 days after formalin injection and drug treatment.

IMPLICATIONS

Our results do not support use of intrathecal methylprednisolone in the treatment of pain.

Neurological complications associated with epidural steroid injections

Multiple case reports of neurological complications resulting from intraarterial injection of corticosteroids have led the Food and Drug Administration (FDA) to issue a warning, requiring label changes, warning of serious neurological events, some resulting in death. The FDA has identified 131 cases of neurological adverse events, including 41 cases of arachnoiditis. A review of the literature reveals an overwhelming proportion of the complications are related to transforaminal epidural injections, of which cervical transforaminal epidural injections constituted the majority of neurological complications. Utilization data of epidural injections in the Medicare population revealed that cervical transforaminal epidural injections constitute only 2.4 % of total epidural injections and <5 % of all transforaminal epidural injections. Multiple theories have been proposed as the cause of neurological injury including particulate steroid, arterial intimal flaps, arterial dissection, dislodgement of plaque causing embolism, arterial muscle spasm, and embolism of a fresh thrombus following disruption of the intima.

Perioperative pain in patients with trigeminal neuralgia undergoing radiofrequency thermocoagulation of the Gasserian ganglion

Trigeminal neuralgia is the worst pain that human beings have ever experienced. Few researches have illustrated perioperative pain in patients with trigeminal neuralgia undergoing radiofrequency thermocoagulation (RFT) of the gasserian ganglion under local anesthesia. Because there are some undeniable drawbacks of using intravenous short-term anesthesia during the intervention repeatedly, some physicians keep patients awake throughout the puncture procedure, using local anesthesia. The purpose of this investigation was to examine perioperative pain in patients with trigeminal neuralgia undergoing RFT of the gasserian ganglion. Participants were 104 patients with classic trigeminal neuralgia. Worst pain intensity, mean pain intensity, quality of sleep, and analgesia satisfaction were evaluated for 24 hours before admission, 24 hours before operation, and 24 hours after operation. Intraoperative worst pain intensity was determined. Preoperative pain was serious, and preoperative sleep quality significantly and positively correlated with preoperative mean pain (r = 0.52; P = 0.00) and worst pain (r = 0.49; P = 0.00). Few patients (1.9%) responded to preoperative treatment, and the preoperative treatment obtained low analgesia satisfaction scores (3.9 [1.3]). Most patients experienced severe pain during cannulation under local anesthesia. No patients complained of pain during radiofrequency lesioning. The RFT of the gasserian ganglion alleviated pain obviously. Most patients (94.2%) responded to the operation, and the operation got high analgesia satisfaction scores (8.9 [0.7]). The results demonstrate that preoperative pain in patients with trigeminal neuralgia undergoing RFT of the gasserian ganglion is prevalent and undertreated and that intraoperative pain is severe under local anesthesia during cannulation.

Herpes Zoster and Postherpetic Neuralgia: Practical Consideration for Prevention and Treatment

Herpes zoster (HZ) is a transient disease caused by the reactivation of latent varicella zoster virus (VZV) in spinal or cranial sensory ganglia. It is characterized by a painful rash in the affected dermatome. Postherpetic neuralgia (PHN) is the most troublesome side effect associated with HZ. However, PHN is often resistant to current analgesic treatments such as antidepressants, anticonvulsants, opioids, and topical agents including lidocaine patches and capsaicin cream and can persist for several years. The risk factors for reactivation of HZ include advanced age and compromised cell-mediated immunity (CMI). Early diagnosis and treatment with antiviral agents plus intervention treatments is believed to shorten the duration and severity of acute HZ and reduce the risk of PHN. Prophylactic vaccination against VZV can be the best option to prevent or reduce the incidence of HZ and PHN. This review focuses on the pathophysiology, clinical features, and management of HZ and PHN, as well as the efficacy of the HZ vaccine.

Three common neuralgias

The pain experienced by patients with trigeminal, occipital, or postherpetic neuralgia is often severe, chronic, and difficult to treat. In this article, Drs Ashkenazi and Levin outline the pathologic mechanisms of pain in these common neuralgias and discuss individually tailored pharmacologic and surgical approaches to their treatment.