Refractory Chronic Pain Research Articles

Spinal cord stimulation for chronic refractory pain: Long-term effectiveness and safety data from a multicentre registry.

Spinal cord stimulation (SCS) is an established therapy for refractory neuropathic pain. To ascertain the balance between treatment benefits and risks, the French National Authority for Health requested a post-market registry for real-world evaluation of the long-term effectiveness and safety of the therapy. A total of 402 patients undergoing implantation with a Medtronic SCS device as either a primo-implant (n=264) or replacement implant (n=138) were enrolled across 28 representative sites in France. Outcome measures at 2years included pain intensity, satisfaction with treatment, improvement of pain relief and daily life activity, willingness to undergo the treatment again and use of pain treatments. A patient was considered a responder if, compared to baseline, predominant pain reduction was ≥50%. At the 2-year follow-up visit, predominant pain intensity for primo-implant patients had decreased from baseline (p<0.001), with responder rates of 55%, 36% and 67% for the lower limbs, back and upper limbs, respectively. Most patients acknowledged an improvement in pain relief (89%) and daily life activity (82%) were satisfied with treatment (91%) and willing to undergo the treatment again (93%). A significant decrease (p<0.01) in the proportion of patients receiving pain treatment was observed for all drug and non-drug treatments. Reported adverse events were in line with the literature. Pain intensity at 2years was comparable for patients in the replacement group, supporting the long-term stability and effectiveness of SCS. Real-world evaluation of the use of spinal cord stimulation under the recommendations of the French Health Authority shows that two years after the first implantation of an SCS device close to 60% of the patients retain a significant pain reduction and 74% show improvement in pain scores [of at least 30%] with significant decreases in drug and non-drug pain treatments. This observational, prospective study in a real-life setting followed a large cohort of patients suffering from chronic pain and implanted with SCS devices in France. The study assessed the long-term effectiveness and safety of SCS therapy in a representative sample of implanting sites in France.

Dronabinol use in France between 2004 and 2017

ObjectivesTo investigate prescription practices for dronabinol, a pure extract of delta-9-tetrahydrocannabinol, prescribed for refractory chronic pain in France since 2004. DesignA descriptive study based on answers to a questionnaire sent to dronabinol prescribers throughout metropolitan France between June and July 2017. Main outcomes measuresWe assessed the type of prescribers including place of work (hospital, clinic or private practice) and their specialty. We also collected information about the patient profiles, diseases or symptoms initiating dronabinol prescription, its efficacy and side effects. ResultsWe received completed questionnaires from 26 prescribers in 17 different areas throughout 12 regions. This represented a total of 191 patients of the 377 indexed since 1st January 2006: the sex ratio was 1:1, with an average age of 51 years for men and of 45 for women. The reason for dronabinol prescription was: multiple sclerosis (49.7%); central neuropathic pain from other causes (36.6%); peripheral neuropathic pain (8%); Parkinson's disease (2.9%); and other causes (around 1%). The duration of dronabinol treatment ranged from 1 month to 6 years and the dose from 2.5mg to 30mg per day (in one or several intakes). 59% of the patients declared experiencing a 30 to 50% reduction in pain. ConclusionThis first investigation into dronabinol in France underlines the need to further investigate prescription practices and efficacy so as to define conditions of good use and the place of dronabinol in pain management.

Functional Ultrasound Imaging of Spinal Cord Hemodynamic Responses to Epidural Electrical Stimulation: A Feasibility Study.

This study presents the first implementation of functional ultrasound (fUS) imaging of the spinal cord to monitor local hemodynamic response to epidural electrical spinal cord stimulation (SCS) on two small and large animal models. SCS has been successfully applied to control chronic refractory pain and recently was evolved to alleviate motor impairment in Parkinson's disease and after spinal cord injury. At present, however, the mechanisms underlying SCS remain unclear, and current methods for monitoring SCS are limited in their capacity to provide the required sensitivity and spatiotemporal resolutions to evaluate functional changes in response to SCS. fUS is an emerging technology that has recently shown promising results in monitoring a variety of neural activities associated with the brain. Here we demonstrated the feasibility of performing fUS on two animal models during SCS. We showed in vivo spinal cord hemodynamic responses measured by fUS evoked by different SCS parameters. We also demonstrated that fUS has a higher sensitivity in monitoring spinal cord response than electromyography. The high spatial and temporal resolutions of fUS were demonstrated by localized measurements of hemodynamic responses at different spinal cord segments, and by reliable tracking of spinal cord responses to patterned electrical stimulations, respectively. Finally, we proposed optimized fUS imaging and post-processing methods for spinal cord. These results support feasibility of fUS imaging of the spinal cord and could pave the way for future systematic studies to investigate spinal cord functional organization and the mechanisms of spinal cord neuromodulation in vivo.

Radiofrequency Thermoablation of the Gasserian Ganglion Versus the Peripheral Branches of the Trigeminal Nerve for Treatment of Trigeminal Neuralgia: A Randomized, Control Trial

Background: Trigeminal neuralgia is the most painful condition of facial pain leading to impairment of routine activities. Although radiofrequency thermoablation (RFT) of the Gasserian ganglion is widely used for the treatment of idiopathic trigeminal neuralgia in patients having ineffective pain relief with medical therapy, the incidence of complications like hypoesthesia, neuroparalytic keratitis, and masticatory muscles weakness is high. Recent case reports have shown the effectiveness of RFT of the peripheral branches of the trigeminal nerve for relief of refractory chronic facial pain conditions including trigeminal neuralgia. Objectives: This study was conducted to compare the efficacy and safety of RFT of the peripheral branches of the trigeminal nerve with RFT of the Gasserian ganglion for the management of idiopathic trigeminal neuralgia. Study Design: Prospective, randomized, observer-blinded, clinical trial. Setting: Tertiary care hospital and medical education and research institute. Methods: A total of 40 adult patients of idiopathic trigeminal neuralgia were randomly allocated into 2 groups. The control group received RFT of the Gasserian ganglion while the study group received RFT of the peripheral branches of trigeminal nerve. The procedures were performed in the operation room under all aseptic precautions with fluoroscopic guidance. Post-procedure, the patients were assessed for loss of sensation along the nerve distribution and the adequacy of pain relief on the Numerical Rating Scale (NRS). The patients were followed up for 3 month to assess the quality of pain relief by the NRS and the Barrow Neurological Institute (BNI) pain intensity scale. Improvement in pain was considered excellent if patients had complete pain relief without any medication, good if there was significant reduction in pain (&gt; 50%) with or without medication, and poor if there was less than 50% reduction in pain with medications. Patients were also assessed for numbness and any other side effects. Patients’ satisfaction with the procedure was recorded. Results: Nineteen patients in the control group and 18 in study group had effective pain relief of up to 3 months. Their pain scores were comparable at all time intervals, though the number of patients receiving supplementary medications was more in study group at 2 months (P = 0.015). The patients showed overall satisfaction score of 8.5 (8-9) and 8 (7-9) in control and study groups respectively. The average procedure duration was 30 (30-38) minutes in the control group and 28 (25-40) minutes in the study group. Most of the patients in both groups had mild numbness after the procedure. One patient in the control group had lower eyelid swelling and another had mild weakness of the masseter muscle, which resolved few days later. No major complication was reported in the study group except for 1 patient who reported local ecchymosis. Limitations: The main limitation of the study is that the patients and the investigator performing the procedure were not blinded, though the person who assessed the patient during follow-up was blinded to the group assignment. Another limitation is that we could not follow up with the patients after 3 months due to time constraints. Conclusion: We found that radiofrequency thermoablation of the peripheral branches of the trigeminal nerve is an effective and safe procedure for the management of idiopathic trigeminal neuralgia. Key words: Idiopathic trigeminal neuralgia, radiofrequency thermoablation, Gasserian ganglion, peripheral nerve branches, pain, trigeminal nerve

Quality of Life After Motor Cortex Stimulation: Clinical Results and Systematic Review of the Literature.

Motor cortex stimulation (MCS) is routinely used for the treatment of chronic neuropathic pain but its effect on quality of life remains uncertain. To systematically review the published literature on MCS and quality of life and report the effects of this therapy in a series of patients prospectively followed in our center. The systematic literature review was conducted using the search words "motor cortex stimulation and pain and neurosurgery" and "motor cortex stimulation and pain and quality of life." Quality of life in our clinical trial was investigated in a series of 10 patients with chronic neuropathic pain prospectively followed for 12 mo after MCS. Two hundred eighteen nonreplicated articles were pooled for analysis. Of these, 6 described measures of quality of life in the pre- and postoperative period. In these studies, 64 patients with different clinical conditions associated with neuropathic pain were followed for 6 to 84 mo after MCS surgery. Improvement in quality of life ranged from 35% to 85%. In our clinical series, visual analog scale (VAS), SF-12 physical (PhysCS), and mental scores (MenCS) recorded 12 mo after MCS were improved by 60±10% (P=.002), 50±13% (P=.002), and 22±6% (P=.01), respectively. No significant correlation was found between postoperative improvement in pain and either PhysCS (r=0.18; P=.6) or MenCS (r=-0.24; P=.5). MCS improves quality of life in patients with chronic refractory neuropathic pain. Additional factors other than a simple analgesic effect may contribute to these results.

Spinal Cord Stimulation for Refractary Neuropathic Pain and Its Action on the Neurovegetative Systems

BACKGROUND: Spinal Cord Stimulation (SCS) has been used for chronic refractory pain, however its effectivity on neurovegetative systems has not been evaluated to data. OBJECTIVES: The study was conducted to evaluate the effect of SCS in patients suffering from refractory neuropathic pain, related to analgesia, quality of life and neurovegetative actions on the digestive and urinary tracts. Fifteen patients acted as their own control related to all evaluations. P < 0.05 was considered significantly. RESULTS: 13 patients completed the study. The incidence of indication was 6% in our Center for Pain Treatment in the Teaching Hospital. The SCS improved quality of life, bowel transit and urinary function, as improved overall analgesia and decreased daily rescue analgesic (p < 0.001). CONCLUSIONS: In accordance with literature, the incidence of complications was 20%, and SCS improved analgesia and quality of life. In addition, patients also referred to improved bowel activity and urinary function.

Spinal cord stimulation modulates descending pain inhibition and temporal summation of pricking pain in patients with neuropathic pain

Spinal cord stimulation (SCS) is an established treatment option for patients with refractory chronic pain conditions. While effects of SCS on dorsal horn neuronal circuitries are intensively studied, current knowledge on the impact of SCS on descending pain pathways is scarce and relies on preclinical data. We aimed to address this topic and hypothesized a significant effect of SCS on descending pain modulation. In light of current efforts to determine the sensitivity of "static" versus "dynamic" somatosensory parameters to characterize pathophysiological pain conditions, all SCS patients were carefully investigated using both classes of somatosensory outcome parameters. Descending pain pathways were investigated by using a "Cold Pressor Test." This test enables to evaluate the efficacy of conditioned pain modulation (CPM) at the individual level. CPM efficacy was assessed in eight neuropathic pain patients (age 55.5±10.6) during the two conditions stimulator "ON" and "OFF." The impact of SCS on "static" and "dynamic" somatosensory parameters was explored by using a quantitative sensory testing (QST) battery. CPM efficacy on pressure pain sensitivity was nearly absent during "OFF" (- 1.2±5.6% facilitation), but increased significantly to 16.3±3.4% inhibition during "ON" (p = 0.03). While most "static" nociceptive QST parameters, represented by mechanical/thermal pain thresholds, exhibited only small effects of SCS (p > 0.05), the wind-up ratio was strongly reduced to within the normal range during "ON" (p = 0.04; Cohen's d = 1.0). Dynamic mechanical allodynia was abolished in six of seven patients. Our study provides first human evidence for an impact of SCS on descending pain pathways in the dorsolateral funiculus and emphasizes the significance of "dynamic" pain measures like "CPM"-efficacy and "temporal summation" to evaluate SCS treatment effects. Future prospective studies may use these measures of nociceptive processing to predict SCS therapy response.

Evaluation of Safety and Efficacy of Radiofrequency Lesioning of Thoracic Dorsal Root Ganglion in Chest Cancer Pain Patients

Background: since cancer-associated pain is a common occurrence in malignancies involving the chest. In these cases, pain is complex and may have visceral, somatic or neuropathic components. It has been noticed that the number of cancer patients with refractory chest pain is increasing with more cancer prevalence, also with the advances in therapy and prolonged life expectancy. The demand for interventional procedures to control pain for these patients also increases. Interventional pain procedures are indicated for refractory pain when analgesic drugs are ineffective or associated with intolerable side effects. In controlling cancer pain it is commonly inadequately managed for these patients leading to suffer form of physical disabilities, psychological disturbance and avoiding treatment. Aim of the work: this study was designed to test both the efficacy and safety of thermo-coagulative ablation of the thoracic dorsal root ganglia for pain control in cancer patients that have refractory chest pain. Methodology: this prospective randomized study was conducted in the National Cancer Institute, Cairo University and Aswan University after board approval from October 2016 to March 2018. Sixty-five patients with Refractory Chronic Chest Cancer Pain were selected randomly and prospectively from the pain clinic of both the National Cancer Institute of Cairo University and Aswan University, after taken an informed written consent from the patient. The complete duration of the follow up lasted 3 months post-interventional with assessments after 1 week, 1 month and 3 months. At each follow up each patient was re-assessed with the following assessments; VAS, ECOG Performance Status. Results: we found that with effective pain relief there was a significant reduction in the mean VAS values; which means that there was functional improvement, in all the postinterventional follow ups. Also, there was an improvement in the functional state of the patients throughout the follow-up post-intervention with regards to the ECOG performance status from the results.Conclusion: we concluded that thermal radiofrequency ablation is considered an alternative for treating refractory chronic chest cancer pain of several types and causes. This is because of its efficacy, safety and ease of use. It also requires a minimal hospital stay or can even be performed on an outpatient basis.

Evaluation of Safety and Efficacy of Radiofrequency Lesioning of Thoracic Dorsal Root Ganglion in Chest Cancer Pain Patients Daily Activities and their Quality of Life

Background: in controlling cancer pain it is commonly inadequately managed for these patients leading to suffer in the form of physical disabilities, psychological disturbance, avoiding treatment. Therefore pain that is caused by cancer may directly affect the patient's quality of life; by having an effect on his/her daily activity, physical state and also psychological and emotional status. Thus, making pain relief and control the patient's right; right for a new life "pain free" or at least tolerable non-disabling pain. Aim of the work: this study aimed to test both the efficacy and safety of thermo-coagulative ablation of the thoracic dorsal root ganglia for pain control in cancer patients that have refractory chest pain And the impact on quality of life for patients. Patients and Methods: our prospective study was done on sixty-five patients selected from pain clinics of both the National Institute of Cancer, Cairo University and Aswan University with refractory chronic chest cancer pain according to the inclusion and exclusion criteria. The complete duration of the follow up lasted 3 months postinterventional; with assessments after 1 week, 1 month and 3 months. At each follow up each patient was reassessed with the following assessments; VAS, ECOG performance status, QOLS, drug consumption, side-effects (complications) and patient satisfaction. Results: we found that with effective pain relief there was a significant reduction in the mean VAS values which means that there was functional improvement, in all the postinterventional follow ups. Also, there was an improvement in the functional state of the patients throughout the follow-up post-intervention with regardsto the ECOG performance statusfrom the results. In addition to the ECOG improvement there was also a significant improvement in the QOL (Quality of Life) results, which was due to the pain relief. Regarding drug consumption, it was recorded that all three drugs; pregabalin, oxycodone and amitryptline, should maximum reduction after 1 month following the intervention, with a slight increase 3 months post-interventional, which matched the degree of pain reduction based on the pain scaling scores. Only 11% of our patients were found with numbness and neuritis, which were the only two complications reported. With regards to our patients, 30.6% certainly would repeat the procedure, 54.8% probably would, and 12.9 % probably would not while, only 1.6% certainly would not repeat it. With25.8% certainly would recommend the same procedure, 56.5% probably would, 14.5% probably would not and only 3.2% certainly would not recommend it. Conclusion: we concluded that thermal radiofrequency ablation is considered an alternative for treating refractory chronic chest cancer pain of several types and causes. This is because of its efficacy, safety and ease of use, patient’s quality of life of was largely affected.

Evaluation of Safety and Efficacy of Radiofrequency Lesioning of Thoracic Dorsal Root Ganglion in Chest Cancer Pain Patients

Background: since cancer-associated pain is a common occurrence in malignancies involving the chest. In these cases, pain is complex and may have visceral, somatic or neuropathic components. It has been noticed that the number of cancer patients with refractory chest pain is increasing with more cancer prevalence, also with the advances in therapy and prolonged life expectancy. The demand for interventional procedures to control pain for these patients also increases. Interventional pain procedures are indicated for refractory pain when analgesic drugs are ineffective or associated with intolerable side effects. In controlling cancer pain it is commonly inadequately managed for these patients leading to suffer form of physical disabilities, psychological disturbance and avoiding treatment. Aim of the work: this study was designed to test both the efficacy and safety of thermo-coagulative ablation of the thoracic dorsal root ganglia for pain control in cancer patients that have refractory chest pain. Methodology: this prospective randomized study was conducted in the National Cancer Institute, Cairo University and Aswan University after board approval from October 2016 to March 2018. Sixty-five patients with Refractory Chronic Chest Cancer Pain were selected randomly and prospectively from the pain clinic of both the National Cancer Institute of Cairo University and Aswan University, after taken an informed written consent from the patient. The complete duration of the follow up lasted 3 months post-interventional with assessments after 1 week, 1 month and 3 months. At each follow up each patient was re-assessed with the following assessments; VAS, ECOG Performance Status. Results: we found that with effective pain relief there was a significant reduction in the mean VAS values; which means that there was functional improvement, in all the postinterventional follow ups. Also, there was an improvement in the functional state of the patients throughout the follow-up post-intervention with regards to the ECOG performance status from the results.Conclusion: we concluded that thermal radiofrequency ablation is considered an alternative for treating refractory chronic chest cancer pain of several types and causes. This is because of its efficacy, safety and ease of use. It also requires a minimal hospital stay or can even be performed on an outpatient basis.

Cannabinoids and spinal cord stimulation for the treatment of failed back surgery syndrome refractory pain.

ObjectiveThis study aimed to evaluate pain and its symptoms in patients with failed back surgery syndrome (FBSS) refractory to other therapies, treated with a combination of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), in association with spinal cord stimulation (SCS).SettingsOutpatients referred at Pain Unit of San Vincenzo Hospital in Taormina (Italy), between September 2014 and January 2016.SubjectsEleven FBSS patients diagnosed with neuropathic pain using the Douleur Neuropathique 4 questionnaire and suffering from moderate to severe chronic refractory pain, and undergoing treatment with SCS and a combination of THC/CBD for 12 consecutive months.Materials and methodsAll the included patients discontinued previous unsuccessful therapy at least 2 months before the beginning of the cannabinoid therapy, with the exception of the SCS that was continued. Patients received a fixed dosage of cannabinoid agonists (THC/CBD) that could be increased subjective to pain control response. A Brief Pain Inventory questionnaire was administered to measure pain and its interference with characteristic dimensions of feelings and functions. The duration of treatment with SCS and THC/CBD combination was 12 months.ResultsEffective pain management as compared to baseline result was achieved in all the cases studied. The positive effect of cannabinoid agonists on refractory pain was maintained during the entire duration of treatment with minimal dosage titration. Pain perception, evaluated through numeric rating scale, decreased from a baseline mean value of 8.18±1.07–4.72±0.9 by the end of the study duration (12 months) (P<0.001).ConclusionThe results indicate that cannabinoid agonists (THC/CBD) can have remarkable analgesic capabilities, as adjuvant of SCS, for the treatment of chronic refractory pain of FBSS patients.

Effect of Pulsed Radiofrequency Therapy on Chronic Refractory Atlanto-Occipital Joint Pain

Despite several methods of conservative management, many patients with atlanto-occipital (AO) joint pain complain of persistent pain. In the current study, the authors investigated the clinical efficacy of intra-articular pulsed radiofrequency (PRF) therapy for the management of refractory chronic AO joint pain. Twenty patients with refractory AO joint pain were recruited, and each received intra-articular AO joint PRF stimulation. Pain reduction after PRF therapy was measured using a numerical rating scale (NRS) before and at 1 and 3 months after treatment. Successful pain relief was defined as ≥50% reduction in the NRS score compared with the pretreatment score. At 3 months after treatment, patient satisfaction levels were also examined. Patients reporting very good (score= 7) or good (score= 6) results were considered to be satisfied with the procedure. The NRS scores changed significantly over time. At 1 and 3 months after PRF therapy, the NRS scores were significantly reduced compared with pretreatment scores. Sixteen of the 20 (80%) patients reported pain relief and were satisfied with treatment results 3 months after PRF. No adverse effects were reported. Intra-articular PRF therapy is a beneficial treatment tool for managing refractory chronic AO joint pain.

Kétamine et douleur chronique : une revue narrative de son efficacité et sécurité

Ketamine is frequently used in the management of refractory chronic pain. To date, the level of proof in the literature on ketamine in this type of indication is generally poor and physicians have no consensus or recommendation to support their practice. This narrative review is an update on literature data assessing the efficacy and safety of ketamine in chronic pain. The electronic search of the Medline, PubMed, Google Scholar and Cochrane databases identified a total of 61 articles including randomized and non-randomized trials and 14 international reviews. In view of these data, it is difficult to conclude on the effectiveness of ketamine in this type of indication and on its safety due to the heterogeneity of practice in terms of doses, routes, duration and frequency of administration and especially a lack of clinical trials with a high level of evidence.

Long-term, prolonged-release oral tapentadol for the treatment of refractory chronic low back pain: a single-center, observational study.

Chronic back pain is a leading cause of disability worldwide and it is still inadequately treated. Tapentadol is a dual-acting analgesic drug μ-opioid receptor (MOR) agonist/norepinephrine reuptake inhibitor, carrying a lower risk for opioid withdrawal symptoms and opioid-related adverse effects in comparison to potent opioid drugs. This study investigates the effectiveness, safety and tolerability of the prolonged release oral formulation of tapentadol (tapentadol PR) in 27 patients affected by refractory chronic low back pain during a long-term follow-up (up to 51 months). This is an observational study conducted at the Pain Therapy and Palliative Care Unit of University Hospital of Cagliari, Italy. We enrolled 27 patients affected by chronic low back pain refractory to other pharmacological treatments according to the inclusion criteria. We prospectively evaluated oral tapentadol PR therapy during a long-term follow-up (up to 51 months) according to the following outcomes: pain intensity during the previous 72 hours (Numeric Rating Scale 3), quality of life (Short Form-12 Health Survey), self-reported treatment effectiveness (Patient Global Impression of Change scale), physician evaluation of treatment effectiveness (Clinician Global Impression of Change scale), treatment-related adverse effects, reason for tapentadol therapy interruption and tapentadol dosage. All the patients reported a significant improvement of pain intensity and quality of life at the last follow-up. These results show the long-term effectiveness, safety and tolerability of oral tapentadol PR for the treatment of refractory chronic low back pain in a real-life clinical setting.

Activity and Exercise Intolerance After Concussion: Identification and Management of Postural Orthostatic Tachycardia Syndrome.

Postural orthostatic tachycardia syndrome (POTS) is increasingly recognized as a complication affecting recovery from concussion. Individuals with POTS demonstrate refractory dizziness, lightheadedness, cognitive dysfunction, fatigue, headache, chronic pain, nausea and gastrointestinal dysmotility, activity and exercise intolerance, syncope, and tachycardia. Subtypes of POTS may include hypovolemia, hyperadrenergic states, autonomic neuropathy, and underlying autoimmunity, which may variably impact response to rehabilitation in varying ways. The subtle presentation of POTS postconcussion is often mistaken for underlying anxiety, conversion disorder, or lack of motivation for recovery. This article will present clinical features of POTS that may arise after concussion, and propose a role for physical therapists in the diagnosis and management of POTS during concussion recovery. Data recorded and entered into a database during clinic visits from a large pediatric institution indicate that 11.4% of individuals diagnosed with POTS report onset of symptoms within 3 months of sustaining a concussion. Activation of the sympathetic nervous system can result in lightheadedness, shortness of breath, chest pain, tachycardia, palpitations on standing or with exertion, and activity and exercise intolerance. Identified comorbidities in people with POTS such as joint hypermobility and autoimmune disorders can further influence recovery. Physical therapists may identify signs and symptoms of POTS in a subset of individuals who remain refractory to typical interventions and who exhibit symptom exacerbation with orthostatic activity. Incorporation of an individualized POTS exercise program into current established concussion interventions may be useful, with emphasis on initial recumbent exercises and ongoing physical therapy assessment of exercise tolerance for dosing of activity intensity and duration.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A211).

Validated chromatographic method for the simultaneous determination of eight drugs (morphine, ropivacaine, bupivacaine, baclofen, clonidine, sufentanil, fentanyl and ziconotide) for intrathecal analgesia

Intrathecal analgesia has increased over the past two decades in various indications: chronic refractory pain from cancerous or non-cancerous origins, spasticity. These different indications involve the use of different molecules alone or in combination such as morphine, ropivacaine, bupivacaine, fentanyl, sufentanil, clonidine, baclofen and ziconotide. Pump refills are prepared at the pharmacy under a laminar flow hood. An analytical control should be carried out before release of the preparation. A new method of analytical control by chromatography has been developed and validated according to the International Conference on Harmonization guideline in order to secure the production process.

Existential Meaning of Patients with Chronic Facial Pain.

Coping strategies are necessary to deal with pain, one of the most disabling conditions. Treatments are often refractory, and the elaboration of existential meaning is necessary to live with residual pain. The objective of this study was to discuss the relevance of the meaning of life in coping with refractory chronic neuropathic facial pain according to singular cases. Each patient is unique and needs a singular approach to understand and treat the pain phenomenon. Self-transcendence, existential issues and philosophical values are central concepts to assess chronic conditions and should be highlighted in medical practice these days.

(239) - Chronic abdominal pain due to anterior cutaneous nerve entrapment syndrome, a diagnosis almost missed

Chronic abdominal wall pain due to anterior cutaneous nerve entrapment syndrome is frequently confused with visceral pain which often leads to extensive testing before the correct diagnosis. In this condition, the cutaneous branches of lower thoraco abdominal intercostals nerves are entrapped at the lateral border of rectus abdominis muscle resulting in severe, often refractory chronic pain. This syndrome is often under diagnosed and under treated. It is very well illustrated by case of 16-year-old male who was seen at our Pain clinic for long standing localized right sided upper abdominal pain which was brought on by activity. He had extensive work up performed by Gastroenterologist and Sports Medicine involving multiple Xrays, CT abdomen, endoscopy, colonoscopy, HIDA scan and performance evaluations without a conclusive diagnosis for over a year. Based on the presentation we suspected anterior cutaneous nerve entrapment syndrome and hence right rectus abdominus trigger point injections were attempted. Point of maximal pain was elicited by active jogging on treadmill and ultrasound visualization to inject in and around the muscle belly. It provided significant improvement in his symptoms but was relatively short lived. Plan was then made for cryoablation with which patient was able to achieve more prolonged relief. Hence, significant pain relief after trigger point injection is considered to establish the diagnosis. The current treatment options include ultrasound guided injections, radiofrequency ablation, cryoablation, anterior neurectomy which can provide adequate relief for the patient. To summarize, the diagnostic challenge posed by this condition can be addressed by having higher degree of suspicion on the part of physicians. An early diagnosis can prevent central sensitization, avoid plethora of investigations and successful intervention can be therefore be made.

Small Fiber Polyneuropathy Is Prevalent in Patients Experiencing Complex Chronic Pelvic Pain.

To demonstrate the prevalence of small fiber polyneuropathy (SFPN) in patients with refractory chronic pelvic pain (CPP). Retrospective study of prospective database. Participants were complex CPP patients recruited from subspecity referral clinics defined as those who were refractory to initial treatment and/or exhibited comorbid pain syndromes at initial presentation. Comprehensive treatment history for CPP was obtained, and participants referred as above; 3-mm punch biopsies were obtained of the lower extremity and sent to diagnostic reference labs to evaluate for SFPN. The reported lab sensitivity and specificity for SFPN are 78-92% and 65-90%, respectively. Twenty-five of 39 patients (64%) were positive for SFPN. Comorbid conditions noted in our population included gastroesophageal reflux disease (46%), migraine (38%), irritable bowel syndrome (33%), lower back pain (33%), fibromyalgia (38%), endometriosis (15%), interstitial cystitis (18%), vulvodynia (5%), and other chronic pain syndromes (36%). The prevalence of SFPN in our specialty referral patients with complex CPP is remarkably high vs published general population prevalence data (53/100,000). Identification of SFPN in this complex population shifts the focus from undefined syndromes to symptom complexes with linked potentially treatable mechanisms (e.g., SFPN, central sensitization). Most CPP patients with SFPN are undiagnosed. Considering the diagnosis may expand treatment options beyond conventional or so-called adjuvant analgesics. Treatment may expand to therapies such as IV lidocaine, IVIG, or other immunomodulatory options. In addition, the value to the patient of receiving a diagnosis for a multisystem or refractory pain syndrome, often attributed to negative psychologic factors, cannot be underestimated. Identifying SFPN should be contemplated in CPP patients who present with multisystem pain or who have not responded to initial evaluation and management.

Low-dose intrathecal naloxone to enhance intrathecal morphine analgesia: A case report

Ultra low doses of opioid antagonists such as naloxone block excitatory opioid receptor pathways may paradoxically enhance morphine analgesia. This case study reports safety and efficacy of ultra low-dose intrathecal (IT) naloxone added to IT morphine for the treatment of severe refractory chronic low back pain. A 56-year-old man with a history of severe chronic low back pain (post-laminectomy syndrome) was evaluated. Extensive multidisciplinary therapies had all failed. Initial treatment at our clinic was a lumbar IT trial of morphine (unsuccessful) up to 50 mg/day. We administered an IT bolus of morphine 2 mg combined with IT naloxone of 20 ng with the patient's consent and approval. The onset of pain relief was within 20 minutes and peaked at 1 hour with a 50 percent reduction in VAS pain score. There were no signs of adverse drug toxicity or hemodynamic compromise. An IT infusion of daily morphine 5 mg and naloxone 50 ng was started. Throughout the 3-year follow-up period, the patient maintained pain reduction of 60 to 80 percent, with a return to daily activities and no further hospitalizations.