Volume 5, Issue 1

Background There are several studies about the relationship between depression and chronic non-malignant pain. These studies have shown that up to 50% of chronic pain patients are suffering from depression. It is, therefore, reasonable to expect that pain patients would also have an increased risk of suicidal behaviour. This problem is not well studied. Since 1990 the Centre for Suicide Research, Odense, Denmark has registered all suicide attempts in patients residing in the Region of Funen, Denmark. The Pain Clinic, Odense University Hospital receives patients with chronic pain from the entire Region of Southern Denmark. Purpose The purpose of the study has been: To investigate, whether patients treated in the Pain Clinic during the period from 1 January 2004 to 31 December 2009 had an increased risk of suicide attempts compared with the background population. Materials and methods The Register for Suicide Attempts (RSA) is a product of the WHO research programme WHO/EURO Multicentre Study on Para suicide. The RSA is a longitudinal person-based register. It contains information about people who have been in contact with the health care system in the County of Funen as a result of a suicide attempt. The Pain Clinic, Odense University Hospital receives patients with non-malignant chronic pain from the Region of Southern Denmark with 1,194,659 inhabitants. Data about age, sex, and time of treatment for patients treated in the Pain Clinic during the period were registered. Time and method of the suicide attempts were registered in the RSA. By registry linkages between the patient registers it was possible to calculate any excess risk of suicide attempts in chronic pain patients in the study period. We used a cohort design and calculated incidence rates (IR) and incidence rate ratios (IRRs) for suicide attempts, based on data from RSA. Poisson Regression analyses were used for calculation of IR and IRR for suicide attempts. Results In the study period from 1 January 2004 to 31 December 2009 1871 patients residing in the Region of Funen in Denmark were referred to The Pain Clinic. In the patient group 258 suicide attempts in 110 persons were registered. In all 6% of the patient group had attempted suicide. An increased risk of suicide attempts was found in the pain population as the incidence rate ratio (IRR) was 3.76 95% CI (3.22; 4.40). No statistical significant differences between men and women were found. Conclusion In a chronic non-malignant pain population, referred to a pain clinic, the risk of suicide attempts was increased. Implications It is important to be aware of risk factors for suicidal behaviour, i.e. pain history, depression, anxiety, abuse problems, and social problems when caring for patients with chronic pain. More knowledge and training of the staff caring for chronic pain patients are needed to decrease the risk of suicidal behaviour.

Background and aims Provoked vestibulodynia (PVD) is the most common cause of dyspareunia among young women. The aetiology is largely unknown and treatment is often extensive and longstanding with varying outcomes. Patients display general pain hypersensitivity and there are correlations with other chronic pain syndromes such as fibromyalgia later in life. The A118G polymorphism in the μ-opioid receptor ( OPRM1 ) gene influences endogenous pain regulation and pain sensitivity, but has not been studied in this patient group before. We aimed to investigate a possible association between A118G polymorphism and PVD, with correlation to plasma levels of β-endorphin, and to explore relationships between this polymorphism and pain sensitivity among women with PVD and healthy controls. Methods This case-control study included 98 women with PVD and 103 controls. Participants filled out study-specific questionnaires and underwent quantitative sensory testing of pressure pain thresholds on the arm, leg and in the vestibular area. Levels of β-endorphin were analyzed by radioimmunoassay using the EURIA-beta-endorphin kit, and the A118G single-nucleotide polymorphism (SNP; rs1799971) in the OPRM1 gene was analyzed using the TaqMan SNP genotyping assay. Results The 118G allele was more common in controls (44%) than in patients (30%) ( p = 0.042). The odds ratio of having PVD was 1.8 in participants carrying the 118A allele compared to participants hetero- or homozygous for the 118G allele (OR = 1.846, CI: 1.03-3.31, p = 0.039). Pressure pain thresholds on the leg were higher for participants carrying the 118G allele (mean 480 kPa, SD 167.5) than for those carrying the 118A allele (mean 419, SD 150.4, p = 0.008). Levels of β-endorphin were higher in patients (mean 17.9 fmol/ml, SD 4.71) than in controls (mean 15.8 fmol/ml, SD 4.03) ( p < 0.001). Conclusion We found an association between the A118G polymorphism in the OPRM1 gene and an increased risk of PVD and increased pain sensitivity among participants carrying the 118A allele. PVD patients were more sensitive to pressure pain and had higher levels of plasma β-endorphin than controls. The results indicate that differences in endogenous pain modulation involving the opioid system could contribute to the pathophysiology of PVD and the general pain hypersensitivity seen in these women. Implications The data support the conceptualization of PVD as part of a general pain disorder with a possible genetic predisposition. The age of onset of PVD is usually between 18 and 25 years and already at this age general pain hypersensitivity is present but rarely causing disability. We believe that early recognition and treatment, with the risk of further development of chronic pain taken into consideration, might prevent future aggravated pain problems in this patient group.

Background and aims Female genital pain is a debilitating problem that negatively affects several aspects of the life of women. Several studies present figures of prevalence indicating that the problem affects nearly 20% of young women. However, many women fail to consult health care and the estimated prevalence therefore remains insecure. Historically, genital pain was commonly viewed as either physiological or psychosexual. Although the current field of research and clinical expertise in general agree upon a biopsychosocial conceptualization, less is known about the manifestation of the problem in everyday life and the experience of seeking health care among afflicted women. The objectives of the present study was to examine genital pain in a general female population living in Sweden cross-sectionally in terms of prevalence, sexual function, sexual satisfaction and help seeking, and to identify possible predictors of genital pain among women. Methods The study was a population-based study using a postal questionnaire administered to 4052 women (age 18--35). Of these 944 (response rate: 23%) took part in the study. Results Genital pain of six months duration was reported by 16.1% of the women. Women with pain more commonly reported fungal infections, other pain problems, sexual dysfunctions and symptoms of anxiety than pain-free women and in addition lower sexual satisfaction. There were no differences in sexual frequency. Pain was most commonly reported during sexual intercourse, but many women also experienced pain during non-sexual activities, with pain durations of several hours after the pain eliciting activity was interrupted. Of those reporting pain, 50% had sought care for their pain. The most common was to counsel a doctor and to receive topical treatment. However, the experienced effects of the treatments were on average low. In the explanatory model, fungal infections, and sexual dysfunctions were associated with genital pain. Conclusions The study had a low response rate, but still indicates that genital pain is common and negatively affects several aspects of women’ life, not just sexual activities. Although many women report pro-longed pain experiences, many fail to consult health care and among those who seek care the effects of treatment are on average poor. There are strong associations between sexual dysfunctions (lack of sexual arousal, vaginal muscle tension hindering intercourse) and genital pain that, based on previous findings in this field of research, might be viewed in terms of circular maintaining processes. Implications Female genital pain is not just limited to the sexual context, but often negatively affects several situations in women’ life. The size of the problem calls for immediate development of preventive interventions and treatment programs that focus on sexual education and to encourage a healthy sexuality among women and their partners. There is a need to identify methods in order to assemble evidence based interventions of female genital pain. Such methods are currently lacking, resulting in poor treatment options for women with pain.

Background and aim The Norwegian version of the Neck Disability Index (NDI) has been widely used in previous studies. To our knowledge, the test–retest reliability and responsiveness of the NDI have not been investigated. Thus, the aim of the present study was to investigate the test–retest reliability and responsiveness of the Norwegian version of the NDI in neck pain patients seen in a specialized outpatient clinic. Methods This study included patients referred to the neck and back outpatient clinic at Oslo University Hospital. A total of 255 patients were included in the study, of which 42 participated in the test–retest portion of the study. The intraclass correlation coefficient (ICC) was used to assess test-retest reliability. A total of 113 patients participated in the responsiveness analyses. Based on their responses on the Global Rating Scale of Change (GRS), patients were categorized into the following groups: worsened ( n = 24), unchanged ( n = 7) and improved ( n = 62). The minimal detectable change (MDC) for the NDI was calculated. Responsiveness was assessed by constructing a Receiver Operating Characteristic curve (ROC curve) to distinguish patients who had improved or worsened from those who remained unchanged. The minimum clinically important difference (MCID) was estimated. Results The test–retest reliability between the baseline scores and the retest NDI scores was very good (ICC = 0.84; 95% CI 0.72–0.91). The ability of the NDI to discriminate between improved and unchanged patients (responsiveness) over time was acceptable based on the ROC curve analysis (AUC = 0.70; 95% CI 0.58–0.82). The estimated MDC for the Norwegian version of the NDI is 12.3%, and the MCID is 16.6%. Conclusion The Norwegian version of the NDI proved to be an instrument with good test–retest reliability and acceptable responsiveness for assessing neck pain-related disability among neck pain patients in a specialized outpatient clinic

Background and purpose Modic changes (MC) are bone marrow and vertebral endplate lesions seen in magnetic resonance imaging (MRI) which have been found to be associated with low back pain (LBP), but the association between MC and health-related quality of life (HRQoL) is poorly understood. The aim of this study was to assess the relationship between MC and HRQoL among patients referred to spine surgery. Methods The study population consisted of 181 patients referred to lumbar spine surgery in Northern and Eastern Finland between June 2007 and January 2011. HRQoL was assessed using RAND-36 health survey. Lumbar MC were evaluated and classified into ‘No MC’, ‘Type I’ (Type I or I/II), and ‘Type II’ (Type II, II/III or III). Results In total, 84 patients (46%) had MC. Of these, 37% had ‘Type I’ and 63% ‘Type II’. Patients with MC were older, more likely females, had longer duration of LBP and a higher degree of disc degeneration than patients without MC. The total physical component or physical dimensions did not differ significantly between the groups. The total mental component of RAND-36 ( P = 0.010), and dimensions of energy ( P = 0.023), emotional well-being ( P = 0.012) and emotional role functioning ( P = 0.016) differed significantly between the groups after adjustments for age and gender. In the mental dimension scores, a statistically significant difference was found between ‘No MC’ and ‘Type II’. Conclusions Among patients referred to spine surgery, MC were not associated with physical dimensions of HRQoL including dimension of pain. However, ‘Type II’ MC were associated with lower mental status of HRQoL. Implications Our study would suggest that Type II MC were associated with a worse mental status. This may affect the outcome of surgery as it is well recognized that patients with depression, for instance, have smaller improvements in HRQoL and disability. Thus the value of operative treatment for these patients should be recognized and taken into consideration in treatment. Our study shows that MC may affect outcome and thus clinicians and researchers should be cognizant of this and take this into account when comparing outcomes of surgical treatment in the future. A longitudinal study would be needed to properly address the relationship of MC with surgical outcome.

Background and purpose Local infiltration anaesthesia is frequently painful due to low pH of the used anaesthetics, such as lidocaine. Usually pH of the solution is near 4.0, which causes tissue irritation and excitation of the pain mediating nerve endings. Warming and buffering the local anaesthetic solution have been shown to reduce the patient’s experience of pain and unpleasantness during infiltration. Buffering reduces the dissociation of the local anaesthetic molecule and may enhance the anaesthetic’s entrance into nerve cells. In this randomized placebo-controlled trial warmed and buffered lidocaine with adrenaline was compared to room temperature unbuffered lidocaine with adrenaline infiltrated before bone marrow aspiration and/or biopsy (BMAB). The aim was to find out to what extent warming and buffering would diminish pain during infiltration and whether this would be reflected in less pain also during subsequent steps of the BMAB procedure. Methods One hundred patients scheduled to undergo BMAB were interviewed regarding subjective experiences from previous medical procedures, current chronic and temporary medications, and their present state of anxiety before the BMAB procedure. They received local anaesthetic infiltration of lidocaine prior to BMAB. The solution used was either warmed lidocaine 20 mg/ml with adrenaline buffered with sodium bicarbonate 75 mg/ml (warmed and buffered group, 50 patients, pH approximately 7.3, 32°C) or unbuffered lidocaine 20 mg/ml with adrenaline mixed with NaCl 0.9% solution (control group, 50 patients, pH approximately 3.7, room temperature). The lidocaine concentration was similar in both groups. The bone marrow sampling needle was inserted 2 min after local anaesthetic infiltration. The grade of preprocedural anxiety, and pain sensations during the BMAB, both rated on NRS (numeral rating scale, 0–10) were compared between the groups. Results In comparison with the use of an unbuffered solution at room temperature warmed and buffered lidocaine with adrenaline caused less pain during infiltration (median NRS 4.0 vs. 2.0, P < 0.002) but it did not make performing the other phases of BMAB any less painful. As expected, painful experiences from previous medical, other than BMAB, or dental procedures and anxiety were associated with local anaesthetic infiltration pain during BMAB. Patients’ own pain or anxiolytic medication did not lessen pain during BMAB. Conclusions By warming and buffering the lidocaine solution containing adrenaline it is possible to make the pain during infiltration less intense. Unfortunately, such benefit was not detected during the following steps of BMAB, initiated 2 min later. Preprocedural anxiety made procedural pain more intense including that of the local anaesthetic infiltration. Implications Warming and buffering the local anaesthetic prior to its administration is an effective and simple way of diminishing pain during infiltration. This benefit seems to be underutilized in the BMAB procedure. However, warming and buffering are not sufficient enough to diminish pain during bone marrow sampling and thus additional pain alleviating methods should be used, particularly in patients showing preprocedural anxiety.