Scandinavian Journal of Pain

Keeping an open mind: Achieving balance between too liberal and too restrictive prescription of opioids for chronic non-cancer pain: Using a two-edged sword

Harald Breivik, Torsten Gordh, Stephen Butler — 2012-01-01

In this issue of the Scandinavian Journal of Pain a highly respected, internationally known clinical pain researcher discusses his extensive experience with long-term opioid treatment of complex pain patients . Watson describes 10 patients illustrating that, in expert hands, relatively high doses of potent opioids can continue to be beneficial for selected patients for many years without developing tolerance, hyperalgesia, uncontrollable drug-seeking behaviour, or other serious adverse effects .

Chronic non-cancer pain and the long-term efficacy and safety of opioids: Some blind men and an elephant?

C. Peter N. Watson — 2012-01-01

Highlights: ► Chronic opioid therapy is useful for selected patients with chronic non-cancer pain (CNCP). ► This approach can be safe and effective for many years. ► For some patients high doses are required. ► Adverse effects (drowsiness and constipation) were not major problems due to either tolerance or selection. ► Careful screening regarding such issues as appropriate CNCP disorders and addiction risk, documentation and follow-up are critical.Abstract: Background: The use of opioids for chronic non-cancer pain (CNCP) remains very controversial. There are a number of randomized controlled trials (RCTs) showing efficacy and safety in the short-term, but long-term data are limited.Methods: This article contains 10 case reports (followed to 2011) that were selected from a survey of 84 patients with intractable CNCP treated with opioids and followed every 3 months now for a median of 10 years. The previous published survey of this group reported outcomes of pain severity, adverse effects, pain relief, satisfaction, mood, problematic opioid use, tolerance, physical dependency, functional status, health-related quality of life (HRQL), immune status and sexual function. The outcome measures for that study included a numerical rating scale (NRS) for pain, Hospital Anxiety and Depression Scale (HADS), the Brief Pain Inventory Interference Scale (BPI-I), the Pain Disability Index (PDI), and for Health Related Quality of Life (HRQL) the Short Form Health Survey 12 version 2 (SF12v2). These selected patient reports were chosen to illustrate some important aspects of the diagnostic categories of CNCP, the opioids and doses used, particular issues (concurrent addiction history, bipolar disorder, and combination therapy), disease-specific and other outcomes (pain severity and relief, adverse effects, mood, function) and duration of follow-up with complex pain problems.Results: Opioids were found to be safe and effective in the long-term for these particular patients, as well as in the larger group from which they originate. Most patients in the total sample reported 50% or greater relief and a moderate improvement in disability. Scores for functional status and HRQL were not severely affected (PDI and BPI-I ratings moderate or less and SF12v2 slightly below normative values for age). Problematic use, tolerance, and serious adverse effects including constipation were not major issues.Conclusion: These 10 reports of patients with intractable CNCP treated with opioids with some success over many years put a face on some of the participants in the larger survey of 84 suggesting that this approach is effective and safe for some patients over many years.Implications: These data may not be generalizable to a larger population of patients with CNCP because of the probable selection of patients who benefit and who do not have intolerable adverse effects.

National versions of fibromyalgia questionnaire: Translated protocols or validated instruments?

Seppo Soinila — 2012-01-01

Fibromyalgia remains a considerable challenge for both clinicians and researchers. In spite of established criteria , diagnostic accuracy of fibromyalgia seems to be far from satisfactory, there being both overdiagnosing and neglect of obvious cases. Perhaps even more significant, the assessment of fibromyalgia patients for the impact of the disease on physical and mental function, working capability, or quality of life includes large case-to-case variability. This may lead to biased judgement by treating physicians, consultants and decision-making authorities. Since the benefits offered by social security system are based on impaired function rather than the diagnosis itself, unequivocal and multi-dimensional description of the impact of fibromyalgia is crucial. Although careful informal description of the patient's status may include sufficient information, the ideal method would be based on standardized, validated assessment paradigm.

Validation of a Finnish version of the Fibromyalgia Impact Questionnaire (Finn-FIQ)

2012-01-01

Highlights: ► The Fibromyalgia Impact Questionnaire (FIQ) is the most widely used instrument to evaluate fibromyalgia patient's functioning. ► The Finnish version of the FIQ (Finn-FIQ) is a valid instrument to mirror the functioning of FM patients. ► The Finn-FIQ covers the main components of the International Classification of Functioning, Disability and Health (ICF) framework hence reflecting the whole spectrum of functioning.Abstract: Background and purpose: Fibromyalgia (FM) is a chronic pain syndrome, which affects up to 5% of the general population. The aetiology of FM is unclear. The lack of specific diagnostic laboratory tests or imaging options combined with the severe burden on both patients and society caused by the FM syndrome demands the development of valid instruments able to measure the current health status of the FM patients. The Fibromyalgia Impact Questionnaire (FIQ) is the most widely used of these instruments. Our objective was to translate the Fibromyalgia Impact Questionnaire (FIQ) into Finnish and evaluate its validity in Finnish speaking FM patients.Methods: FIQ was translated by two bilingual researchers into the Finnish version (Finn-FIQ) and linked to the categories of International Classification of Functioning, Disability and Health (ICF). Finn-FIQ was administered to 162 patients who had prior fibromyalgia diagnoses M79.0 according to ICD-10 year 2006 version. They also filled in the Health Assessment Questionnaire (HAQ), the Rand 36-item Health Survey (RAND-36), the Beck Depression Inventory IA (BDI IA), the Chronic Pain Acceptance Questionnaire (CPAQ), the International Physical Activity Questionnaire Short Form (IPAQ), and they assessed their general well-being on a 0–100mm visual analogue scale while attending a clinical check-up visit. Internal consistency was estimated according to Cronbach's alpha internal consistency. An exploratory factor analysis was performed to identify related items and to show construct validity. Correlation coefficients were calculated by the Spearman method.Results: From the 162 participants 153 were female and 9 male, 119 (73%) had an active job or were students, 21 (13%) were unemployed, 16 (10%) were retired and 6 (4%) were on sick leave.The mean age was 47 years. The internal consistency value (95% CI) was 0.90 for the overall Finn-FIQ. The factor analysis performed for construct analysis showed that Finn-FIQ was loaded on 4 factors. These factors were loaded on components of ICF and explained 69% of total variance. Significant correlations were obtained between patients own assessments of general well-being and Finn-FIQ total score (r=0.64 [95% CI 0.53–0.73]) and also between Finn-FIQ total score and HAQ total score (r=0.56 [95% CI 0.44–0.66]). Finn-FIQ questions had significant correlations with RAND-36 domains.Conclusion: Finn-FIQ is a valid and feasible instrument to mirror the functioning of FM patients according to its internal consistency, correlation to general well-being, convergent validity and response rate. It covers the main components of the ICF framework hence reflecting the whole spectrum of functioning.Implications: In our study Finn-FIQ was proven as a valid instrument with Finnish speaking FM patients. Original FIQ and other validated translations have already confirmed their place in fibromyalgia research. After this study Finnish fibromyalgia research can be included in those using the best-known instrument in validated form and native language. Current study showed also Finn-FIQ's ability to measure functioning of the FM patients, and it had good applicability among Finnish speaking patients. Therefore it can be recommended also for monitoring individual FM patients and their functioning for example during different treatment trials.

The impact of chronic pain—European patients’ perspective over 12 months

Stephen Butler — 2012-01-01

The authors of the one-year observational study of chronic pain patients are to be commended on two counts. The first is to organize a multinational investigation to gain more perspective on the effects of chronic pain and its treatment in a short longitudinal study. The second is to use qualitative as well as quantitative methods since qualitative methods give richer information through narrative than can be obtained through the usual patient reported outcome (PRO) questionnaires. It is hoped that analysis of the qualitative data can be done to flesh out the dry statistical information from the PROs.

The impact of chronic pain—European patients’ perspective over 12 months

Tony O’Brien, Harald Breivik — 2012-01-01

Highlights: ► Patients with moderate-severe chronic non-cancer pain were followed-upfor 1 year. ► 2/5 had more, 2/5 had less pain, all had major negative impacts on quality of their life. ► Still, 50% believed that everything possible had been done to manage their pain. ► Healthcare providers need education to manage better the huge burden of chronic pain. ► Patients need access to a pain service when standard measures in primary care fail.Abstract: Background and methods: Pain Study Tracking Ongoing Responses for a Year (PainSTORY) is a longitudinal study generating some quantitative and limited qualitative data concerning the experiences of individual patients with non-malignant chronic pain. Research was conducted across 13 European countries and a total of 294 patients completed the full evaluation process over 12 months. Adult patients (>18 years old) scoring >4 on an 11-point numeric pain rating scale (NRS-11) for most days during an average week were eligible. Four waves of interviews (W1–W4) were conducted over 12 months and information was recorded regarding pain levels, the impact of pain, pain treatment and treatment-associated side effects.Results: At 3 months, 95% of respondents rated their worst pain level over the past week as ≥4. Most respondents had felt this pain level for ≥1 year, with 47% of patients reporting NRS-11 scores of 8–10 for >2 years. At 12 months, 93% of respondents still rated their worst pain level over the past week as ≥4. The overall net percentage of respondents with ≥4 pain intensity did not change substantially over 12 months of follow up. However, 40% (119/294) of patients felt their current pain level increased and 41% (121/294) felt their current pain level decreased during this time, with just 18% (53/294) of respondents reporting no change (1% of respondents not stated). At 3 months, 30% of respondents reported being managed by a pain specialist within the last 3 months, decreasing to 13% 9–12 months later. Patients were typically taking a combination of prescribed and non-prescribed medications; approximately 10% at W1 and 14% at 12 months were prescribed a strong opioid. Among those whose current pain level decreased over the year, a slightly lower proportion of patients were taking prescription medication (78%) at 12 months than in either the group with no change to their current pain level (85%), or the group whose pain level increased over the 12 month period (87%). Pain negatively affected quality of life, with respondents reporting difficulties with daily activities, including sleeping, walking, family and social interaction. Approximately half of respondents taking prescription medication reported suffering from ‘constipation and associated symptoms’. In spite of no change in pain intensity, 51% of patients were happy with their pain management at W4.Conclusions: The heavy individual and societal burden of uncontrolled chronic pain is demonstrated in this study. This silent epidemic has not attracted the focus of attention that it deserves. Despite the significant negative impact on individual quality of life, patients evolve to a position where they believe that chronic pain is inevitable and untreatable.Implications: It is clear that there is a real need for a coordinated response by healthcare providers and planners across European countries. Minimum standards of care should be developed and implemented at national level. Healthcare professionals and students of these disciplines must be educated to recognise, assess and manage pain within a reasonable timeframe. Patients who are not responding to standard measures must have rapid and easy access to a comprehensive, inter-disciplinary pain service.

Pressure pain algometry – A call for standardisation of methods

Audun Stubhaug — 2012-01-01

Algometry has been used in both experimental pain research and in clinical research for many years. It has been shown to be useful for the study of regional analgesia . Pressure algometry has been shown to be sensitive for the analgesic effect of opioids , corticosteroids , and paracetamol in healthy volunteers.

Experimental pressure-pain assessments: Test–retest reliability, convergence and dimensionality

Tamara E. Lacourt, Jan H. Houtveen, Lorenz J.P. van Doornen — 2012-01-01

Highlights: ► Methodological issues in measuring pressure-pain responsiveness were addressed. ► Pain threshold and pain ratings are distinct aspects of pain responsiveness. ► In measuring pain threshold, one practice trial per body point is recommended. ► Pain thresholds should be mean-aggregated over multiple body points. ► Bilateral combinations of pain-threshold points are recommended.Abstract: Introduction: Experimental pain studies can provide unique insight into the dimensions of pain and into individual differences in pain responsiveness by controlling different aspects of pain-eliciting stimuli and pain measures. In experimental pain studies, pain responsiveness can be assessed as pain threshold, pain tolerance or pain ratings. The test-theoretical qualities of these different measures, however, have not yet been completely documented. In the current study, several of these qualities were investigated in a pain experiment applying different algometric techniques. The objective of the study was to investigate the reliability (test–retest) and the convergent validity (correspondence) of the different methods found in the literature of measuring pressure-pain threshold, and the interrelationship between pressure-pain threshold, pressure-pain tolerance, and pressure-pain ratings.Methods: Sixty-six healthy female subjects were enrolled in the study. All pressure stimuli were applied by a trained investigator, using a digital algometer with a 1cm2 rubber tip. Pressure-pain thresholds were assessed repeatedly on six different body points (i.e. left and right calf one third of total calf muscle length below the popliteal space), the lower back (5cm left and right from the L3), and left and right forearm (thickest part of brachioradialis muscle). Next, pressure-pain tolerance was measured on the thumbnail of the non-dominant hand, followed by rating affective and sensory components (on visual analogue scales) of a stimulus at tolerance level. Last, affective and sensory ratings were obtained for two pressure intensities.Results: With intraclass correlations above .75 for pain responses per body point, test–retest reliability was found to be good. However, values obtained from all first measurements were significantly higher as compared with the two succeeding ones. Convergent validity of pain thresholds across different body points was found to be high for all combinations assessed (Cronbach's alpha values >.80), but the highest for bilateral similar body parts (>.89). Finally, principal components analysis including measures of threshold, tolerance and pain ratings yielded a three-factor solution that explained 81.9% of the variance: Moderate-level stimulus appraisal & pain tolerance; Pain threshold; Tolerance-level stimulus appraisal.Conclusion and implications: Findings of the current study were used to formulate recommendations for future algometric pain studies. Concerning pressure-pain threshold, it is recommended to exclude first measurements for every body point from further analyses, as these measurements were found to be consistently higher compared with the following measurements. Further, no more than two consecutive measurements (after the first measurement) are needed for a reliable mean threshold value per body point. When combining threshold values of several body points into one mean-aggregated threshold value, we suggest to combine bilateral similar points, as convergent validity values were highest for these combinations. The three-factor solution that was found with principal components analyses indicates that pressure-pain threshold, subjective ratings of moderate intensity stimuli, and subjective ratings of the maximum (tolerance) intensity are distinct aspects of pain responsiveness. It is therefore recommended to include a measure of each of these three dimensions of pain when assessing pressure pain responsiveness. Some limitations of our study are discussed.

High prevalence of posttraumatic stress disorder (PTSD) and pain sensitization in two Scandinavian samples of patients referred for pain rehabilitation

Troels Staehelin Jensen — 2012-01-01

In the study by Andersen et al. published in the present issue of the Scandinavian Journal of Pain the authors report on posttraumatic distress disorder (PTSD) as seen in two pain rehabilitation units in Scandinavia and show a rather high proportion of patients having PTSD in these pain clinics. PTSD is a syndrome characterized by the presence of a specific traumatic event – physical or psychological – together with a series of different symptoms. These symptoms are related to the re-experience of symptoms during the traumatic event, avoidance and hypervigilance. The criteria have now been emphasized in the DSM IV criteria for PTSD. According to the DSM IV classification of PTSD, serious illness and traffic accident now qualify for one of the A criteria of PTSD. Given the fact that events such as traffic accidents now represent a qualifying condition for PTSD, it is not surprising that PTSD is seen in pain clinics and pain centers in high numbers. For example, pain in the neck and head following forced flexion–extension injury to the neck after traffic accidents as part of the so-called whiplash syndrome is a well known pain disorders referred to pain clinics for rehabilitation. In the present study by Andersen et al., pain was assessed indirectly and retrospectively by the referral of patients to a pain clinic so the exact contribution of pain per se cannot be determined. Further studies are necessary to determine more precisely the role of, for example, pain intensity and the role of pain among possible causes of the PTSD syndrome.

The traumatised chronic pain patient—Prevalence of posttraumatic stress disorder - PTSD and pain sensitisation in two Scandinavian samples referred for pain rehabilitation

Tonny Elmose Andersen, Per Grünwald Andersen, Merja Annika Vakkala, Ask Elklit — 2012-01-01

Highlights: ► PTSD was examined in patients referred consecutively to multidisciplinary pain rehabilitation. ► A high prevalence of PTSD (23%) was found in multidisciplinary pain rehabilitation. ► No particular pain diagnosis was significantly related to PTSD. ► Altered sensory processing was significantly associated with PTSD. ► It is important to screen chronic pain patients for PTSD at admission for rehabilitation.Abstract: Introduction: Correctly identifying chronic pain patients with posttraumatic stress disorder (PTSD) is important because the comorbidity of a chronic pain condition and PTSD is found to compromise treatment success. In addition, the existence of PTSD is associated with pain sensitisation, elevated levels of pain, and disability. Furthermore, the diagnostic criteria for PTSD has changed dramatically in the last two decades which has had a profound impact on the reported prevalence rates of PTSD in chronic pain samples. To our knowledge, no study has employed the DSM-IV criteria for estimating the prevalence of PTSD in chronic pain patients referred consecutively for multidisciplinary pain rehabilitation.Aim: The aim of the present study was to assess the prevalence of significant traumatic stressors and PTSD in chronic pain patients referred consecutively to multidisciplinary pain rehabilitation. We wanted to investigate whether specific pain diagnoses were more related to PTSD than others. Moreover, we investigated the possible association of altered sensory processing (hypersensitivity or hyposensitivity) and PTSD.Methods: Data were collected from two Scandinavian multidisciplinary pain centres (Denmark and Finland). All patients referred consecutively were assessed for PTSD and sensitisation at admission. A total of 432 patients were assessed, of which 304 (DK, N=220, female n=144; FIN, N=84, female n=44) were admitted and consented to participate. All patients had to be diagnosed with a non-malign chronic pain condition lasting for at least 6 months (median=6.0 years). The Harvard Trauma Questionnaire was employed to measure PTSD symptoms, using the DSM-IV criteria. To measure altered sensory processing, anaesthetists performed quantitative sensory testing on admission. Patients were asked to report if cold, brush, and pinprick mechanical stimulation resulted in decreased or increased sensation or pain.Results: A high prevalence of PTSD was found in both consecutive samples. Using the DSM-IV criteria, 23% fulfilled the criteria for a possible PTSD diagnosis. There were no gender differences in PTSD. The three most reported traumatic events: traffic accidents, serious illness personally or in the family, and the actual loss of someone, were reported as the primary traumatic events by almost 50% of those with PTSD. No particular pain diagnosis was significantly related to PTSD. However, hypersensitivity to cold and hyposensitivity to brush were significantly associated with PTSD.Discussion: The prevalence of PTSD in the present study was 23%. Earlier studies finding a lower prevalence rate of PTSD may reflect the use of older diagnostic criteria for PTSD or other estimates, for instance PTSD symptom cut-off scores.Conclusion: The study emphasised the importance of screening all chronic pain patients for PTSD at admission for pain rehabilitation, using up to date diagnostic tools.Implications: Untreated PTSD may exacerbate or maintain the pain condition and negatively affect outcome of pain rehabilitation.

Local infiltration analgesia (LIA) and repeated bolus or continuous infusion peripheral nerve blocks for acute postoperative pain: Be ware of local anaesthetic toxicity, especially in elderly patients with cardiac co-morbidities!

Harald Breivik, Axel Sauter — 2012-01-01

Peripheral nerve blocks for postoperative pain, repeated bolus injections or continuous infusion through catheters placed near a plexus or peripheral nerves is an effective way of relieving localized acute pain after surgery, e.g. femoral nerve block after total knee replacement . Electrical nerve stimulation and ultrasound guided localization of peripheral nerves make this technique more effective . Local infiltration of a large dose of a local anaesthetic drug during major joint surgery and subsequent bolus injection through a catheter left in situ is a recently popularized technique. Total knee replacement is the operation in which such local infiltration analgesia (LIA) is documented to be effective . LIA is less effective for pain after hip arthroplasty . In addition to the local anaesthetic, adrenaline and an NSAID are added in the LIA technique. Adrenaline is usually not added for intermittent or continuous femoral nerve block .

A randomized study comparing plasma concentration of ropivacaine after local infiltration analgesia and femoral block in primary total knee arthroplasty

2012-01-01

Highlights: ► High dose ropivacaine is used in local infiltration analgesia (LIA) in knee arthroplasty. ► Some patients reach potentially toxic ropivacaine plasma concentrations after LIA. ► Maximal ropivacaine plasma levels were detected 4–6h after release of tourniquet of LIA. ► Toxicity monitoring with ECG in risk patients should cover this period of maximal plasma levels. ► Ketorolac is still present in plasma 24h after local injection of 30mg as part of the LIA.Abstract: Pain after total knee arthroplasty (TKA) is difficult to control. A recently developed and increasingly popular method for postoperative analgesia following knee and hip arthroplasty is Local Infiltration Analgesia (LIA) with ropivacaine, ketorolac and epinephrine. This method is considered to have certain advantages, which include administration at the site of traumatized tissue, minimal systemic side effects, faster postoperative mobilization, earlier postoperative discharge from hospital and less opioid consumption. One limitation, which may prevent the widespread use of LIA is the lack of information regarding plasma concentrations of ropivacaine and ketorolac.The aim of this academically initiated study was to detect any toxic or near-toxic plasma concentrations of ropivacaine and ketorolac following LIA after TKA.Methods: Forty patients scheduled for primary total knee arthroplasty under spinal anaesthesia, were randomized to receive either local infiltration analgesia with a mixture of ropivacaine 300mg, ketorolac 30mg and epinephrine or repeated femoral nerve block with ropivacaine in combination with three doses of 10mg intravenous ketorolac according to clinical routine. Plasma concentration of ropivacaine and ketorolac were quantified by liquid chromatography–mass spectrometry (LC–MS).Results: The maximal detected ropivacaine plasma level in the LIA group was not statistically higher than in the femoral block group using the Mann–Whitney U-test (p=0.08). However, the median concentration in the LIA group was significantly higher than in the femoral block group (p<0.0001; Mann–Whitney U-test).The maximal plasma concentrations of ketorolac following administration of 30mg according to the LIA protocol were detected 1h or 2h after release of the tourniquet in the LIA group: 152–958ng/ml (95% CI: 303–512ng/ml; n=20). The range of the plasma concentration of ketorolac 2–3h after injection of a single dose of 10mg was 57–1216ng/ml (95% CI: 162–420ng/ml; n=20).Conclusion: During the first 24h plasma concentration of ropivacaine seems to be lower after repeated femoral block than after LIA. Since the maximal ropivacaine level following LIA is detected around 4–6h after release of the tourniquet, cardiac monitoring should cover this interval. Regarding ketorolac, our preliminary data indicate that the risk for concentration dependent side effects may be highest during the first hours after release of the tourniquet.Implication: Femoral block may be the preferred method for postoperative analgesia in patients with increased risk for cardiac side effects from ropivacaine. Administration of a booster dose of ketorolac shortly after termination of the surgical procedure if LIA was used may result in an increased risk for toxicity.

Computer work can cause deep tissue hyperalgesia: Implications for prevention and treatment

Harald Breivik — 2012-01-01

In this issue of the Scandinavian Journal of Pain Vegard Strøm and his co-workers publish a study of neck and shoulder pain induced by computer-work under stressful conditions . Persons with chronic neck and shoulder pain were compared with healthy persons without chronic pain. The subjects did computer work with keyboard and mouse for 90min with a stress load from time pressure and high precision demands. With a pressure algometer they measured pressure pain thresholds (PPTs) before, 15, and 30min after the computer work period. They measured PPT on the sternum and bilaterally on shoulder and forearm (upper trapezius and extensor carpi lateralis muscles). After the 90min of stressful computer work, lower thresholds for pain provoked by pressure on the muscles was observed in chronic pain persons as well as pain free persons. This occurred in the upper shoulder muscles on the active side (handling the computer mouse) and the inactive side, as well as the forearm of the active side, in both groups. However, in the persons with chronic neck and shoulder pain, the pressure pain threshold was lowered also in the forearm of the inactive side, i.e. in the resting forearm not taking part in the computer work.

Deep tissue hyperalgesia after computer work

Vegard Strøm, Cecilie Røe, Dagfinn Matre, Stein Knardahl — 2012-01-01

Highlights: ► Time- and precision-requirements during computer office-work cause pain in active muscles. ► Chronic neck and shoulder pain sensitizes muscles for pain during/after computer office-work. ► Chronic neck and shoulder pain increase risk of pain also in inactive muscles.Abstract: Background and purpose: A growing number of people are using computers. Shoulder and neck pain occur commonly during computer work. Peripheral and central sensitization may play a major role in establishing and maintaining several chronic pain conditions. We have previously reported that a 90min simulated computer office-work induced substantial pain in the shoulders and neck. We hypothesized that the development of pain during the computer work may be related to sensitization. The aim of the present study was to examine if the 90min computer work induced deep tissue muscle hyperalgesia manifested as altered pressure pain thresholds (PPTs).Methods: Twenty-two subjects with chronic shoulder and neck pain (pain group) and 26 healthy and pain free subjects (reference group) performed a standardized computer office-work task with use of a computer-mouse and with time pressure and high precision demands continuously for 90min. The pressure pain threshold was measured with a pressure algometer in shoulder and forearm muscles (bilaterally in upper trapezius and extensor carpi radialis), and at sternum, before and 15min and 30min after the computer work task.Results: The PPTs before starting the computer work were not different between the groups at any of the five locations. In both groups, the PPTs in the active and inactive side of the upper trapezius as well as in the extensor carpi radialis of the forearm operating the computer mouse were significantly reduced after the 90min computer work compared with the pre-work levels. In the pain group, also the PPT in the inactive resting forearm was significantly reduced. The changes seen in PPTs from pre- to post-work were not significantly different between the groups, except for the inactive resting forearm where the groups exhibited different time course.Conclusion: A decrease in pressure pain thresholds of involved muscles suggests that computer office-work can induce deep tissue hyperalgesia within 90min. The development of pain during the computer work indicates peripheral sensitization as the predominant mechanism. Decreased pressure pain thresholds also in sites distant from pain areas may indicate a contribution from central sensitization in the subjects with chronic shoulder and neck pain.Implications: The lasting pain after work and the reduced PPTs both in involved and distant musculature may indicate need for frequent pauses during computer work, especially when performed with time pressure and high precision demands, in order to avoid pain to increase and sustain after work, and thus to prevent the possibility of pain to become chronic.