Unrelieved Chronic Pain Research Articles

Transient Receptor Potential Channels and Botulinum Neurotoxins in Chronic Pain.

Pain afflicts more than 1.5 billion people worldwide, with hundreds of millions suffering from unrelieved chronic pain. Despite widespread recognition of the importance of developing better interventions for the relief of chronic pain, little is known about the mechanisms underlying this condition. However, transient receptor potential (TRP) ion channels in nociceptors have been shown to be essential players in the generation and progression of pain and have attracted the attention of several pharmaceutical companies as therapeutic targets. Unfortunately, TRP channel inhibitors have failed in clinical trials, at least in part due to their thermoregulatory function. Botulinum neurotoxins (BoNTs) have emerged as novel and safe pain therapeutics because of their regulation of exocytosis and pro-nociceptive neurotransmitters. However, it is becoming evident that BoNTs also regulate the expression and function of TRP channels, which may explain their analgesic effects. Here, we summarize the roles of TRP channels in pain, with a particular focus on TRPV1 and TRPA1, their regulation by BoNTs, and briefly discuss the use of BoNTs for the treatment of chronic pain.

Pain-Associated Clusters Among Nursing Home Residents

Chronic pain is common in older adults, particularly among nursing home residents (NHR). Internationally, the reported pain prevalence among NHR ranges from 3.7% to 79.5%. At least one in two German NHR are diagnosed with pain. Unrelieved chronic pain is associated with reduced physical functioning and psychological parameters. Given the high prevalence of pain among NHR, we hypothesized that there were likely pain-associated clusters in our target group. Clustering is an opportunity to identify differences in pain management and may enable better targeted health-service delivery for professionals. There are no available data regarding pain-associated clusters (sub-groups of NHR) based on different items measuring pain. This study was performed using baseline data, and was part of a cluster-randomized controlled trial conducted in 12 nursing homes in Berlin. We assessed pain using the German Brief Pain Inventory (BPI-NHR) among 137 NHR (mean age, 83.33 years) capable of self-report. We performed hierarchical agglomerative cluster analysis to generate three clusters (naming is based on the mean value of each BPI-NHR item in each cluster): pain-relieved (46.72 %), pain-restricted (22.63 %), and severe pain (30.66 %). Body-Mass-Index (F(2,129) = 4.274, P = 0.016), Barthel-Index (F(2,133) = 3.246, P = 0.042), and appropriateness of pain medication (F(2,119) = 12.007, P = 0.000) differed between clusters. Parameters associated with an increased or decreased risk of being in a pain-diagnosed cluster will be discussed. The observed need for clinical interventions aiming at shifting from pain-diagnosed clusters to pain-relieved status will be reflected.

Opioid Therapy for Chronic Noncancer Pain: Safe, Effective, Appropriate?

In determining the appropriate role of opioids, two public health crises must be balanced: the opioid abuse epidemic and the “silent” crisis of unrelieved chronic pain. Opioids can be used safely and effectively in selected patients; however, clinicians must be aware of their abuse liability and individual risk factors for opioid misuse. A number of opioids are approved for use in the United States, and although there are class effects, there can be great variability among patients with regard to opioid response. In addition to the medication, prescribers must also determine the most appropriate dose and route of administration. Considerations must be made for special population, such as the renally impaired, those with hepatic dysfunction, and pediatric and elderly patients. Another factor is abuse-deterrent properties. Of particular interest as an opioid agent is buprenorphine, which is available in various routes of administration and because of its unique pharmacokinetics may be administered to renally compromised and elderly patients without dosing restrictions. Buprenorphine is also associated with a lower abuse liability than other opioids. Patients suffering moderate to severe pain syndromes should not be denied access to effective pain control, which in some cases may appropriately include opioid therapy. Key words: Buprenorphine, Chronic Pain, Opioid, Opioid Abuse, Opioid Prescribing, Risk Factors for Opioid Abuse

Opioid Therapy for Chronic Noncancer Pain: Safe, Effective, Appropriate?

In determining the appropriate role of opioids, two public health crises must be balanced: the opioid abuse epidemic and the “silent” crisis of unrelieved chronic pain. Opioids can be used safely and effectively in selected patients; however, clinicians must be aware of their abuse liability and individual risk factors for opioid misuse. A number of opioids are approved for use in the United States, and although there are class effects, there can be great variability among patients with regard to opioid response. In addition to the medication, prescribers must also determine the most appropriate dose and route of administration. Considerations must be made for special population, such as the renally impaired, those with hepatic dysfunction, and pediatric and elderly patients. Another factor is abuse-deterrent properties. Of particular interest as an opioid agent is buprenorphine, which is available in various routes of administration and because of its unique pharmacokinetics may be administered to renally compromised and elderly patients without dosing restrictions. Buprenorphine is also associated with a lower abuse liability than other opioids. Patients suffering moderate to severe pain syndromes should not be denied access to effective pain control, which in some cases may appropriately include opioid therapy. Key words: Buprenorphine, Chronic Pain, Opioid, Opioid Abuse, Opioid Prescribing, Risk Factors for Opioid Abuse

Pain management and pain characteristics in obese and normal weight patients before joint replacement.

The objective was to compare the extent of pain interference and pain medication among persons who were classified as obese [body mass index (BMI)≥ 30 kg m(-2) ] and normal weighted (BMI ≤ 25 kg m(-2) ), before a hip or knee replacement surgery. Patients candidate for an orthopaedic surgery were successively enrolled, over a 6-month period, and classified in either the normal weight (BMI ≤ 25 kg m(-2) ) or the obese (BMI ≥ 30 kg m(-2) ) categories. Data were collected using self-administered questionnaires with items concerning pain characteristics, pain medication and pain interference. Two standardized questionnaires were associated: the Brief Pain Inventory (BPI) and the Hospital Anxiety and Depression scale (HAD). Fifty-two obese patients (candidates for 24 hip replacements and 28 knee replacements) and 51 non-obese (23 hip replacements and 28 knee replacements) were enrolled. Obese patients suffered from a higher rate of acute pain episodes than non-obese patients (65 versus 44%, P<0.05). Pain interference on walking distance, sleep and relations with others was higher in obese patients. HAD score showed no significant difference between groups. The use of strong opioids and of non-steroidal anti-inflammatory drugs (NSAIDs) was significantly more important in obese patients (13 versus 0% and 31 versus 14%). Obese patients suffer more significantly of unrelieved chronic pain, which lowers considerably their quality of life. Pain relief is more difficult to obtain, as it requires stronger pain medication and NSAIDs.

The outcomes and acceptability of tDCS in opioid-treated patients with unrelieved chronic pain

s / Brain Stimulation 7 (2014) e1ee16 e5 excitatory tDCS over the primary motor cortex and inhibitory tDCS over the dorsolateral prefrontal cortex on procedural memory acquisition and consolidation. Methods: Forty active duty military volunteers were randomly assigned to one of four groups (10 per group); anodal (excitatory) tDCS over motor cortex (M1), cathodal (inhibitory) tDCS over dorsolateral prefrontal cortex (DLPFC), both anodal tDCS over M1 and cathodal tDCS over DLPFC, or sham tDCS. Participants learned a set of procedures for identifying aircraft as friend or foe over four 5minute trials while receiving their tDCS condition. Twenty-four hours later, participants returned for retention testing consisting of 4 more trials. Results: The results showed significant main effects of stimulation type and trial on task performance during the training session and retention test (p<0.05). The three stimulation groups showed significantly better task performance when compared to the sham group in retention (p<0.05). The cathodal tDCS only group showed significantly better performance as compared to all groups in the retention test. Discussion: The results suggest that inhibition of the prefrontal cortex using cathodal tDCS leads to the greatest improvement in both procedural memory acquisition and retention. It is hypothesized that this is a result of a shift in dominance of the declarative memory system to the non-declarative procedural system, which improves acquisition and consolidation of the proceduralmemories gained during training. ** Volunteer Research Affiliate 11 The outcomes and acceptability of tDCS in opioid-treated patients with unrelieved chronic pain Ricardo A. Cruciani , Ethan P. Davoudzadeh *, Aaron Greenberg , Helena Knotkova a,b a Institute for Non-Invasive Brain Stimulation, Department of Pain Medicine and Palliative Care, Beth Israel Medical Center, New York, NY, USA Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, USA Department of Anesthesiology, Albert Einstein College of Medicine,

Evidence‐Based Interventional Pain Medicine According to Clinical Diagnoses

Unrelieved chronic pain is a worldwide epidemic. Chronic pain has been subject to multiple international initiatives through the World Health Organization. Interventional Pain Medicine, the use of minimally invasive techniques to relieve pain, is the best approach when simpler measures such as physical therapy or medications fail. However, these procedures can be associated with significant risk and expense. Establishing uniformity in diagnostic criteria and procedural performance can reduce both morbidity and unnecessary procedures, and hence healthcare expenditures. While other texts explain how to perform these procedures, little focus has been given to diagnostic considerations: if and when these procedures should be performed. Evidence-Based Interventional Pain Medicine focuses on a balance between effectiveness and safety of interventional management for specific diagnoses, across all areas of chronic pain including: Head, neck and shoulder pain. Lower back pain. Neuropathic pain syndromes. Complex Regional Pain Syndrome. Pain in patients with cancer. Vascular and visceral pain. Evidence-Based Interventional Pain Medicine provides essential knowledge for anyone who uses, or intends to use, interventional pain techniques.

Occurrence and Characteristics of Chronic Pain in a Community-Based Cohort of Indigent Adults Living With HIV Infection

Pain is common among people living with HIV/AIDS (PLWHA), but little is known about chronic pain in socioeconomically disadvantaged HIV-infected populations with high rates of substance abuse in the postantiretroviral era. This cross-sectional study describes the occurrence and characteristics of pain in a community-based cohort of 296 indigent PLWHA. Participants completed questionnaires about sociodemographics, substance use, depression, and pain. Cut-point analysis was used to generate categories of pain severity. Of the 270 participants who reported pain or the use of a pain medication in the past week, 8.2% had mild pain, 38.1% had moderate pain, and 53.7% had severe pain. Female sex and less education were associated with more severe pain. Depression was more common among participants with severe pain than among those with mild pain. Increasing pain severity was associated with daily pain and with chronic pain. Over half of the participants reported having a prescription for an opioid analgesic. Findings from this study suggest that chronic pain is a significant problem in this high risk, socioeconomically disadvantaged group of patients with HIV disease and high rates of previous or concurrent use of illicit drugs. Perspective This article presents epidemiological data showing that unrelieved chronic pain is a significant problem for indigent people living with HIV. Participants reported pain severity similar to those with metastatic cancer. Despite high rates of substance use disorders, approximately half received prescriptions for opioid analgesics, although few for long-acting agents.

Racial Variation in Response to Music in a Sample of African-American and Caucasian Chronic Pain Patients

The incidence of chronic pain is similar in African-American and Caucasian populations; however, depression and disability secondary to unrelieved chronic pain is higher in African-American populations. In light of this difference, it is important to understand racial variations in response to chronic pain treatments, including complementary therapies such as music. The purpose of this study was to examine racial variation in response to music in an adult population with chronic pain, and specifically to determine if post treatment pain scores differed by race. Secondary analysis from a previously reported randomized controlled trial (n = 60) was used to answer the research questions. Music interventions consisted of listening to music for 1 hour a day for 7 consecutive days. Pain was measured with the McGill Pain Questionnaire short form and a 100-mm visual analog scale. Univariate and multivariate analysis was used to examine differences between groups. Music groups regardless of race experienced a decrease in pain and depression at posttest compared with the control group. However, this difference was only statistically significant for the Caucasian music group. Although our findings demonstrate that music may be an effective intervention for individuals with chronic nonmalignant pain; individuals from different racial backgrounds may respond differently. Further studies are needed to understand these differences in response to music.

Characterization of a Clinical Cohort of 87 Women with Interstitial Cystitis/Painful Bladder Syndrome

To provide a characterization of a cohort of women with interstitial cystitis/painful bladder syndrome (IC/PBS) by describing their historical and clinical characteristics. This was reported with the National Institutes of Health chronic prostatitis cohort, but a literature review did not reveal a similar study for women with IC/PBS. A total of 87 women with IC/PBS were referred to the Beaumont Women's Initiative for Pelvic Pain and Sexual Health program. A certified nurse practitioner took a comprehensive history and performed a pelvic exam for each. Data were analyzed using descriptive statistics to describe this cohort. Most women experienced constant pain for 5 or more years (mean Visual Analog Scale = 5 out of 10). A total of 94.2% had levator pain. More than 50% had vulvar pain with exam. More than half reported a history of abuse, often in more than one life stage. A total of 28% had cesarean births and 76% had a history of miscarriage, stillbirth, or abortion. Women averaged 4 lifetime pelvic surgeries, and 48% had hysterectomies, two-thirds of which were done before IC/PBS diagnosis. Premenstrual women reported pain throughout the menstrual cycle. As many as 12% had chlamydia previously, which was higher than the national average. Common comorbidities were pelvic pain (93%), allergies (86%), and sexual dysfunction (72%). This population of women with unrelieved chronic pain, frequency, and urgency is in desperate need of care. Researchers should continue to search for the etiology, prevention, and treatment interventions that are effective in dealing with IC/PBS. It may be most therapeutic to develop a multimodal plan of care that includes physical therapy, oral and intravesical therapies, neuromodulation, and cognitive-behavioral therapies.

INTERVENTIONAL PAIN MANAGEMENT: Appropriate When Less Invasive Therapies Fail to Provide Adequate Analgesia

Unrelieved chronic pain is costly to patients and society. Noninvasive and less costly therapies should be used before more invasive and more costly therapies. Therapies for pain control should be used according to a pain treatment continuum. Nerve-blocking techniques, neurolytic techniques, and implantable neuromodulatory technologies, such as SCC and spinal delivery of analgesics, are cost-effective when less invasive therapies fail to provide adequate analgesia.