Validation of the Danish Version of the Fibromyalgia Impact Questionnaire Revised.

Purpose: Increasing recognition of chronic pain diseases, including Fibromyalgia, warrants the need for tools to monitor the impact of the disease as well as the efficacy of interventions. The Revised Fibromyalgia Impact Questionnaire (FIQR) has previously proved to be a valuable tool in both clinical and research settings. The study objective was to translate and validate the FIQR in Danish.

Naltrexone 6 mg once daily versus placebo in women with fibromyalgia: a randomised, double-blind, placebo-controlled trial.

Background: Low-dose naltrexone is used to treat fibromyalgia despite minimal evidence for its efficacy. This trial aimed to investigate whether 12-week treatment with 6 mg low-dose naltrexone was superior to placebo for reducing pain in women with fibromyalgia.

Methods: We did a single-centre, randomised, double-blind, placebo-controlled trial in Denmark.

The Danish Pain Research Biobank (DANPAIN-Biobank): a collection of blood, cerebrospinal fluid, and clinical data for the study of neuroimmune and glia-related biomarkers of chronic pain.

Background: Chronic pain is a major health problem worldwide but the limited knowledge of its underlying pathophysiology impairs the opportunities for diagnostics and treatment. Biomarkers of chronic pain are greatly needed to understand the disease and develop new targets for interventions and drug treatments, and potentially introduce more precise diagnostic procedures. Much evidence points to a neuroimmune pathology for many chronic pain conditions and that important neuroimmune biomarkers exist in the cerebrospinal fluid (CSF) of patients with chronic pain.

Comparison of Spinal Cord Stimulation Outcomes Between Preoperative Opioid Users and Nonusers: A Cohort Study of 467 Patients.

Objectives: Spinal cord stimulation (SCS) is a surgical treatment modality reserved for a subset of patients with neuropathic pain in which conventional pharmacologic treatment has proven insufficient. Previous studies have suggested a possible negative relationship between opioid use at referral and subsequent success of SCS therapy. The aim of this cohort study was to investigate whether preoperative opioid use was associated with inferior SCS outcomes.

Low-dose naltrexone for the treatment of fibromyalgia: protocol for a double-blind, randomized, placebo-controlled trial.

Background: Low-dose naltrexone (LDN) is used widely as an off-label treatment for pain despite limited evidence for its effectiveness. A few small trials with a high risk of bias have investigated the effect of LDN on pain associated with fibromyalgia in women, but larger and more methodologically robust studies are needed. The primary aim of this randomized controlled trial is to investigate if 12 weeks of LDN treatment is superior to placebo in reducing the average pain intensity during the last 7 days in women with fibromyalgia.

Performance of the 2016 diagnostic criteria for fibromyalgia in a tertiary care pain rehabilitation setting: a diagnostic accuracy study.

Objectives: With the International Classification of Diseases 11th revision (classifying fibromyalgia as a primary pain disorder) soon to be implemented, the importance of pain physicians being able to identify patients with fibromyalgia is emphasized. The diagnostic criteria proposed in 2016 are based on self-reported pain distribution and symptom severity. The study aimed to evaluate the diagnostic accuracy of the 2016 diagnostic criteria for fibromyalgia applied in a population of patients with high impact chronic pain referred for pain rehabilitation.

Spinal cord stimulation in severe cases of complex regional pain syndrome: A retrospective cohort study with long-term follow-up.

Background: Complex regional pain syndrome (CRPS) is a debilitating pain condition often resistant to standard treatment modalities. In these cases, spinal cord stimulation (SCS) can be an option, but the effect on CRPS remains disputed. We aimed to assess the long-term effect of SCS on CRPS.

The effect of pre-analytical handling on the stability of fractalkine, monocyte chemoattractant protein 1 (MCP1), interleukin 6 and interleukin 8 in samples of human cerebrospinal fluid.

Cytokine networks in cerebrospinal fluid (CSF) are important to our understanding of several neuroinflammatory diseases. Knowledge about optimal handling of samples is limited but important to minimize bias and reduce costs in CSF biomarker studies. The aim of this study was to examine the effect of storage temperature and time delay from CSF sample collection until freezing on the concentration of 11 different cytokines thought to be associated with chronic pain.

Pain Catastrophizing Does Not Predict Spinal Cord Stimulation Outcomes: A Cohort Study of 259 Patients With Long-Term Follow-Up.

Objective: Spinal cord stimulation (SCS) is an important treatment modality used to treat chronic neuropathic pain. However, reported success rates of 26%-70% entail an increased focus on patient selection. An area of core interest is psychological evaluation, often using scales such as the Pain Catastrophizing Scale (PCS).

Complications and Effects of Dorsal Root Ganglion Stimulation in the Treatment of Chronic Neuropathic Pain: A Nationwide Cohort Study in Denmark.

Objectives: Dorsal root ganglion (DRG) stimulation is a novel treatment of chronic neuropathic pain and has been shown to be efficacious across several case reports and randomized trials. However, long-term follow-up is limited, as are reports of complication rates. This study presents efficacy and complications for patients treated with DRG stimulation.

Low-Dose Naltrexone for the Treatment of Fibromyalgia: Investigation of Dose-Response Relationships.

Objective: This study explores dose-response relationships when treating fibromyalgia with low-dose naltrexone.

Design: A single-blinded clinical trial was carried out using the "up-and-down" method.

Subjects: Subjects included women with a diagnosis of fibromyalgia aged 18-60 years who had been referred to treatment at a public pain clinic at a Danish university hospital.

From acute to chronic pain after thoracic surgery: the significance of different components of the acute pain response.

Purpose: Acute postoperative pain is a strong predictor for postthoracotomy pain syndrome (PTPS), but the mechanism is unknown. Even though thoracic pain is usually considered the dominating acute pain after thoracic surgery, up to 45% of patients consider shoulder pain to be dominating pain and often this shoulder pain is referred visceral pain. This study aims to examine which components of the acute pain response after thoracic surgery were associated with PTPS and if any signs of a generalized central hypersensitivity could be identified in patients with PTPS.

From acute to chronic postsurgical pain: the significance of the acute pain response.

The thesis comprises an overview and four papers, all published or submitted for publication in international peer-reviewed scientific journals.
 
Chronic pain after surgery is a common and debilitating complication after many types of surgery. The cause and pathology behind is still mainly uncovered, though several risk factors have been proposed.

[Treating post-operative pain].

Post-operative pain is a problem for many patients and affects recovery, risk of post-operative complications and quality of life. A thorough preoperative evaluation, careful perioperative planning, identification, and individualized treatment of high-risk patients can reduce post-operative pain. Multimodal treatment combines different analgesic techniques in order to utilize synergistic and additive effects of different treatments and has the potential to optimize effects and reduce side effects.

The importance of phrenic nerve preservation and its effect on long-term postoperative lung function after pneumonectomy.

Objectives: The importance of phrenic nerve preservation during pneumonectomy remains controversial. We previously demonstrated that preservation of the phrenic nerve in the immediate postoperative period preserved lung function by 3-5% but little is known about its long-term effects. We, therefore, decided to investigate the effect of temporary ipsilateral cervical phrenic nerve block on dynamic lung volumes in mid- to long-term pneumonectomy patients.

Early visceral pain predicts chronic pain after laparoscopic cholecystectomy.

Chronic pain after laparoscopic cholecystectomy is related to postoperative pain during the first postoperative week, but it is unknown which components of the early pain response is important. In this prospective study, 100 consecutive patients were examined preoperatively, 1 week postoperatively, and 3, 6, and 12 months postoperatively for pain, psychological factors, and signs of hypersensitivity. Overall pain, incisional pain (somatic pain component), deep abdominal pain (visceral pain component), and shoulder pain (referred pain component) were registered on a 100-mm visual analogue scale during the first postoperative week.