Volume 3, Issue 4

Background The prevalence of chronic non-malignant pain in developed countries is high, ranging from 14% to 50%. Patients with chronic pain are active users of health-care services and they report impaired health-related quality of life (HRQoL) when compared with the general population. Psychological distress has been identified as one of the risk factors for pain chronicity. Depression, anxiety and negative beliefs are associated with pain interference and perceived disability. Multidisciplinary pain management (MPM) aims to rehabilitating chronic pain patients by addressing both physical, psychological, social and occupational factors related to the pain problem. MPM programmes have been shown to be effective in reducing pain and improving function in patients with diverse chronic pain states. However, MPM programmes are often heterogeneous and predicting MPM treatment results in different patients groups may be difficult. Methods The present study examined changes in HRQoL after MPM in 439 patients treated at a multidisciplinary pain clinic using the 15D HRQoL questionnaire. The characteristics of the 100 patients with the greatest improvement and the 100 patients with the largest decrease in HRQoL were examined more closely (demographics, characteristics of pain, pain interference, psychiatric comorbidity, employment status, details of MPM) after answering a follow-up 15D questionnaire at three years after their MPM had ended. Result During MPM, HRQoL was significantly improved in 45.6% of the 439 patients, decreased in 30.7% of the patients and did not change in 23.7% of the patients. Patient-related factors that predicted a better HRQoL among the 100 patients with good MPM outcome compared with the 100 patients with poor MPM outcome were higher education and better employment status. Age, gender, marital status, duration of pain, number of pain sites, pain intensity or pain interference at baseline did not differ between the patient groups. Patient expectations regarding MPM were similar. A tendency towards more psychiatric comorbidity in the non-responder group was seen. The duration of MPM in the two patient groups was similar, as well as the number of medications started, the variety of specialists seen and psychiatric counselling with supportive therapy included. More non-responder than responder patients had died during the three-year follow-up period, some of the deaths were related to substance abuse. Conclusions and Implications HRQoL in chronic pain patients was significantly improved during MPM compared with the baseline. Pain duration of several years, multiple pain sites and neuropathic pain were not discerning factors between the responders and non-responders of the present study, implying that a positive change in HRQoL may be achieved by MPM even in these pain patients. In agreement with previous studies, factors predicting poor treatment outcome in the non-responder group of chronic pain patients were not treatment related. To further improve MPM outcome even in pain patients with risk factors for less benefit of treatment such as low education and poor general health, more individualized MPM approaches with emphasis on analysis and treatment of psychological symptoms and patient beliefs is essential.

Introduction Chronic musculoskeletal pain represents a significant health problem among adults in Norway. The prevalence of chronic pain can be up to 50% in both genders. However, the prevalence of chronic widespread pain is significantly higher in females than in males. Chronic widespread pain is seen as the end of a continuum of pain. There is rather sparse knowledge about the incidence of pain in initially pain free individuals and the course of self-reported pain over time. Moreover, little is known about risk factors for incidence of chronic pain or prognostic factors for the course of self-reported pain. We believe that such knowledge may contribute to develop strategies for treatment at an early stadium of the pain condition and thereby reduce the prevalence of chronic pain included chronic widespread pain. Aims of the study The aims of this study were threefold: (1) to calculate the incidence of self-reported musculoskeletal pain in a female cohort, (2) to describe the course of pain and (3) to investigate whether or not health complaints and sleep problems are predictive factors for onset of pain or prognostic factors for the course of pain. Methods This is a prospective population-based study of all women between 20 and 50 years who were registered in Arendal, Norway, in 1989 ( N = 2498 individuals). A questionnaire about chronic pain (pain >3 months duration in muscles, joints, back or the whole body), modulating factors for pain, sleep problems and seven non-specific health complaints was mailed to all traceable women, in 1990 ( N =2498), 1995 ( n = 2435) and 2007 ( n = 2261). Of these, 1338 responded on all three occasions. Outcome measures were presence and extent of chronic pain. Results The prevalence of chronic pain was 57% in 1990 and 61% in 2007. From 1990 to 2007, 53% of the subjects changed pain category. The incidence of chronic pain in initially pain free individuals during follow-up was 44%, whereas the recovery rate was 25%. Impaired sleep quality predicted onset of chronic pain. There was a linear association between the number of health complaints and the incidence of chronic pain in initially pain free individuals. Equivalent results were found for persistence of pain and worsening of pain. Conclusion The prevalence of chronic pain was rather stable throughout the follow-up period, but the prevalence of chronic widespread pain increased. Individual changes in pain extent occurred frequently. The presence of sleep disturbances and number of health complaints predicted onset, persistence and worsening of pain. Implications Sleep problems must be thoroughly addressed as a possible risk factor for onset or worsening of pain. Elimination of sleep problems in an early phase is an interesting approach in treating chronic pain. More research is needed to illuminate the possible pathogenetic relations between pain, non-specific health complaints, sleep problems and also depression.

Background and purpose Postherpetic neuralgia (PHN) is a complication of acute herpes zoster (HZ). The evidence base for management of PHN has increased by recent publications. Therefore, we reviewed incidence of HZ, prevalence, risk factors, and mechanism of PHN pain, prevention and treatment of PHN with special interest in studies on adult vaccination and topical application of lidocaine and concentrated capsaicin patch. Methods We searched databases with an English language restriction: MEDLINE 1944–2011, EMBASE 1988–2011, PubMed, and the Cochrane Controlled Trial Register and Cochrane Library (2011). From retrieved publications, we selected studies focusing on our main goals, prevention and treatment of PHN in particular. The review was therefore systematic, but with a pragmatic approach to which studies to select for closer review. Results From the large number of abstracts retrieved we selected 65 papers for closer review and as evidence base for our conclusions and recommendations for prevention and treatment of HZ and PHN. The incidence of HZ and risks of having PHN after HZ increases markedly with age above 60–70. Severity of symptoms and their impact on quality of life is a major health problem of persons above 70 years of age. Adult vaccination with the reinforced varicella virus vaccine reduces the incidence of HZ and PHN by about 50%. This is an important health and quality of life gain for the elderly. Antiviral drugs given early in an episode of HZ reduce pain and duration of HZ and decrease the risk of PHN. Pharmacological management of PHN are with nortriptyline (or amitriptyline in the younger patients), and or a gabapentinoid as first line drugs. Early treatment also is with topical lidocaine for immediate but short-lasting relief of burning hyperalgesia, and topical capsaicin relieving hypersensitivity for up to 12 weeks. A number of second and third line drugs have less evidence-base for effect, and often more adverse effects than the first line drugs: serotonin and noradrenaline uptake inhibitors (venlafaxin, duloxetin), antiepileptics (valproate), and opioid analgesics. Opioids are indicated for bridging in patients with severe PHN-symptoms while waiting for the more specific first line drugs to take effect. In these elderly patients, systemic pharmacological treatments are always a difficult balance between effects and adverse effects. It is important with close supervision of the patients, especially during start-up of systemically administered drugs, in order to prevent tragic complications from falls in sedated, dizzy, and confused elderly patients. Topical treatment with lidocaine and capsaicin patches does not have these problems. Conclusions Prevention of this significant health problem of the increasing elderly population is now possible through adult vaccination against varicella zoster virus (VZV) reactivation, as well as vigorous and early antiviral treatment during acute HZ. The evidence -base supports the oral use of tricyclic antidepressants, gabapentinoids, and opioids for bridging till the first line drugs take effect. Topical therapy with lidocaine and capsaicin patches is effective and well supported by evidence. A number of second and third line drugs and treatments are available, but have less evidence-base. All drug treatments, except topical lidocaine and capsaicin, have adverse effects that are often problematic and can be dangerous in the elderly patients. Close supervision of the patients is mandatory. Implications Recent advances in prevention and management of this serious health problem should be better known and implicated: Adult vaccination for prevention of varicella zoster virus reactivation, antiviral drugs and combinations of drugs can reduce the suffering from acute HZ and chronic PHN. Topical lidocaine and capsaicin are now evidence-based therapies that reduce suffering from hypersensitivity and hyperalgesia in patients with PHN. When properly applied, they have few complications.

Background and purpose ‘Central sensitization’ (CS) may play a major role in maintaining several chronic pain conditions. CS has been proposed to play a significant role in a range of musculoskeletal pain conditions, such as trapezius myalgia, fibromyalgia, temporomandibular disorders, and low back pain. Whether CS varies over time within an individual is not known. This study evaluated (1) whether there is an intraindividual association between clinical pain and signs of CS, and (2) whether there is an inter-individual association between clinical pain and signs of CS. Methods Twenty-seven sedentary workers (19 women, 8 men) with varying neck/shoulder pain participated in a pre-test and in two test sessions. On one of the test sessions the subjects had weak (or no) clinical pain ( weak-pain day ). On the other test session the subjects had stronger clinical pain ( strong-pain day ). As an indicator of ‘central sensitization’, we assessed the area of secondary pinprick hyperalgesia (tested by 84.4 g/mm 2 Von Frey hairs) in response to a first-degree burn to the volar fore-arm (contact heat, 46°C, 5 min). While in the lab, the subjects’ current clinical pain intensity (0–10 cm VAS) and distribution was assessed (PINT lab and PDIST lab ). The subjects also rated their pain intensity and distribution retrospectively from the past 30 days (PINT 30 d and PDIST 30 d ). Results PINT lab was lower on the weak-pain day (1.7 ± 1.5 cm) than on the strong-pain day (4.3 ± 1.6 cm). This was also the case for the other clinical pain measures (PDIST lab , PINT 30 d and PDIST 30 d ) and indicated that the participants were successfully recruited at days that differed in clinical pain severity. Despite a significant intra-individual difference in clinical pain between days, the area of secondary hyperalgesia did not differ between weak -and strong-pain days (50.3 ± 13.5 cm 2 vs. 51.2 ± 12.6 cm 2 ). Testing the inter-individual association between clinical pain and secondary hyperalgesia, we found a positive correlation between PINT lab and secondary hyperalgesia on the weak-pain day (rho = 0.6), but not on the strong-pain day (rho = 0.1). Given the stable secondary hyperalgesia across weak-and strong-pain days, this implies that subjects with a small secondary hyperalgesic area exhibited a relatively large variation in clinical pain between days, whereas subjects with a large secondary hyperalgesic area exhibited relatively small variation in clinical pain. Conclusions When subjects are observed across days, ‘central sensitization’, measured as the area of secondary hyperalgesia after a first-degree burn, does not seem to be important for clinical pain intensity per se, but may be important for clinical pain variation. Subjects with indication of low ‘central sensitization’ seem to exhibit larger variation in pain between “good” and “bad” days than subjects with indication of high ‘central sensitization’. The study indicates that ‘central sensitization’ does not explain intra-individual variations in clinical pain. Implications This study raises the question of the role of ‘central sensitization’ in clinical musculoskeletal pain disorders. Furthermore, a precise definition of the ‘central sensitization’ concept is called for.

Introduction Patients exposed to whiplash trauma are at risk of developing pain and dysfunction of the neck and shoulder. Although rarely discussed in the literature, some patients also develop autonomic dysfunction. Case presentation A previously healthy 41-year-old woman was involved in a “head-on” car crash. During the following 3 years she developed severe and complex post-traumatic pain syndrome, which consisted of neck pain, lumbar pain, sensory-motor dysfunction, and myoclonic muscular contractions. Despite pharmacotherapy, physiotherapy, and rehabilitation, her condition worsened, resulting in severe disability. Fourteen years after the car crash, an interventional pain therapy program was started, which consisted of sympathetic ganglion impar block and medial branch blocks of facet joints at different levels. These treatment strategies ultimately normalized her sensory-motor dysfunction, reduced her autonomic dysfunction, and stopped the myoclonic muscular contractions. Conclusion This case highlights a possible interaction between the pain-generating facet joints, the somatosensory nervous system, and the autonomic/sympathetic nervous systems. The case also highlights the importance of identifying autonomic dysfunction in patients with persisting pain syndromes. Implications This complex case shows that many clinical phenomena cannot be explained using our present knowledge of pain mechanisms. We hope that readers who have observed similar cases can learn from our case, and are encouraged to publish their observations.