Maarten van Kleef

Spinal Cord Stimulation for Complex Regional Pain Syndrome Type I: A Prospective Cohort Study With Long‐Term Follow‐Up

Spinal cord stimulation (SCS) is an effective treatment for intractable complex regional pain syndrome type I pain. Long‐term data are scarce on effectiveness, degree of pain relief, predictors, and complications.

Predictors of Pain Relieving Response to Sympathetic Blockade in Complex Regional Pain Syndrome Type 1

Background: Sympathetic blockade with local anesthetics is used frequently in the management of complex regional pain syndrome type 1(CRPS-1), with variable degrees of success in pain relief. The current study investigated which signs or symptoms of CRPS-1 could be predictive of outcome. The incidence of side effects and complications of sympathetic blockade also were determined prospectively. Methods: A prospective observational study was done of 49 patients with CRPS-1 in one extremity only and for less than 1-yr duration who had severe pain and persistent functional impairment with no response to standard treatment with medication and physical therapy. Results: Fifteen (31%) patients had good or moderate response. The response rate was not different in patient groups with cold or warm type CRPS-1 or in those with more or less than 1.5°C differential increase in skin temperature after sympathetic blockade. Allodynia and hypoesthesia were negative predictors for treatment success in CRPS-1. There were no symptoms or signs of CRPS-1 that positively predicted treatment success. A majority of patients (84%) experienced transient side effects such as headache, dysphagia, increased pain, backache, nausea, blurred vision, groin pain, hoarseness, and hematoma at the puncture site. No major complications were reported. Conclusions: The presence of allodynia and hypoesthesia are negative predictors for treatment success. The selection of sympathetic blockade as treatment for CRPS-1 should be balanced carefully between potential success and side effect ratio. The procedure is as likely to cause a transient increase in pain as a decrease in pain. Patients should be informed accordingly.

Radiofrequency Treatment of Facet-related Pain: Evidence and Controversies

Pain originating from the lumbar facet joints is estimated to represent about 15% of all low back pain complaints. The diagnostic block is considered to be a valuable tool for confirming facetogenic pain. It was demonstrated that a block of the ramus medialis of the ramus dorsalis is preferred over an intra-articular injection. The outcome of the consequent radiofrequency treatment is not different in patients reporting over 80% pain relief after the diagnostic block than in those who have between 50% and 79% pain relief. There is one well-conducted comparative trial assessing the value of one or two controlled diagnostic blocks to none. The results of the seven randomized trials on the use of radiofrequency treatment of facet joint pain demonstrate that good patient selection is imperative for good clinical outcome. Therefore, we suggest one block of the ramus medialis of the ramus dorsalis before radiofrequency treatment.

Reduced Incidence of Chronic Postsurgical Pain after Epidural Analgesia for Abdominal Surgery

Chronic postsurgical pain (CPSP) is a common complication of surgery with high impact on quality of life. Peripheral and central sensitization caused by enhanced and prolonged afferent nociceptive input are considered important mechanisms for the development of CPSP. This case–control study investigated whether epidural analgesia is associated with a reduced incidence of CPSP after open abdominal surgery.

Health-related quality of life in 975 patients with complex regional pain syndrome type 1.

Summary Quality‐of‐life in patients with complex regional pain syndrome is not dependent on gender or the type of limb affected; instead, quality‐of‐life scores differ according to the diagnostic criteria used. ABSTRACT There are limited data available on health‐related quality of life (QoL) in patients with complex regional pain syndrome (CRPS). In the present study we examined QoL in 975 CRPS patients attending 6 different clinics in the Netherlands. QoL was assessed using the MOS 36‐Item Short‐Form Health Survey (SF‐36) with the Mental Health Summary Score (MHS) and the Physical Health Summary Score (PHS) as dependent variables. The influences of gender, type of affected limb, disease duration, pain scores, CRPS severity and set of diagnostic criteria used were investigated. We found the lowest scores of QoL in the physical domains of the SF‐36, with lower‐limb CRPS patients reporting poorer results than patients with an affected upper limb. Influence of gender on QoL was not observed, and correlations of QoL with disease duration and the CRPS severity score were weak. Pain correlated moderately with QoL. In addition, patients fulfilling stricter diagnostic criteria (ie, the Budapest criteria) had lower QoL scores than patients fulfilling less strict criteria (ie, the Orlando criteria). We conclude that loss of QoL in CRPS patients is due mainly to reduced physical health. A comparison with data available from the literature shows that CRPS patients generally report poorer QoL than patients with other chronic pain conditions, particularly in the physical domains. Pain correlated moderately with QoL and therefore deserves ongoing attention by physicians. Finally, patients meeting the diagnostic Budapest criteria have lower QoL scores than patients meeting the Orlando criteria, highlighting the impact of different sets of criteria on population characteristics.

Neonatal repetitive needle pricking: Plasticity of the spinal nociceptive circuit and extended postoperative pain in later life

Repetitive exposure of neonates to noxious events is inherent to their health status monitoring in neonatal intensive care units (NICU). Altered basal nociception in the absence of an injury in later life has been demonstrated in ex‐NICU children, but the impact on pain hypersensitivity following an injury in later life is unknown. Also, underlying mechanisms for such long‐term changes are relatively unknown. The objective of this study is to investigate acute and long‐term effects of neonatal repetitive painful skin‐breaking procedures on nociception and to investigate plasticity of the nociceptive circuit. The repetitive needle prick animal model was used in which neonatal rats received four needle pricks into the left hind paw per day during the first postnatal week and control animals received nonpainful tactile stimuli. Repetitive needle pricking during the first week of life induced acute hypersensitivity to mechanical stimuli. At the age of 8 weeks, increased duration of postoperative hypersensitivity to mechanical stimuli after ipsilateral hind paw incision was shown in needle prick animals. Basal nociception from 3 to 8 weeks of age was unaffected by neonatal repetitive needle pricking. Increased calcitonin gene‐related peptide expression was observed in the ipsilateral and contralateral lumbar spinal cord but not in the hind paw of needle prick animals at the age of 8 weeks. Innervation of tactile Aβ‐fibers in the spinal cord was not affected. Ourresults indicate both acute and long‐term effects of repetitive neonatal skin breaking procedures on nociception and long‐term plasticity of spinal but not peripheral innervation of nociceptive afferents.

Pulsed Radiofrequency for Chronic Intractable Lumbosacral Radicular Pain: A Six-Month Cohort Study

BACKGROUND AND OBJECTIVESnThere is little evidence concerning the medical management of lumbosacral radicular pain. The prognosis for patients suffering pain for more than 3 months is poor. Pulsed radiofrequency (PRF) treatment of the dorsal root ganglion (DRG) has been suggested as a minimally invasive treatment. We studied the effect on pain and quality of life of PRF treatment of the DRG in patients with chronic, severe lumbosacral radicular pain.nnnMETHODSnPatients with lumbosacral radicular pain were screened to select a homogeneous population. PRF treatment of the DRG was performed at L5 or S1. Evaluation was carried out at 6 weeks, 3 months, and 6 months. Pain reduction and fully recovered or much improvement, in terms of the global perceived effect, were the primary outcomes. Quality of life (RAND-36), disability (Oswestry Disability Index), and the neuropathic pain scales leeds assessment of neuropathic symptoms and signs (LANSS) and DN4 were registered at each time point. Medication use was scored with the Medication Quantification Scale.nnnRESULTSnOut of 461 screened patients, 65 were included. According to the intention to treat analysis, clinical success was achieved in 56.9%, 52.3%, and 55.4% of the patients at respectively 6 weeks, 3 months, and 6 months. DN4, Oswestry Disability Index and physical component for the RAND-36 quality of life improved significantly while the mental component remained unchanged. The number of patients on opioids was reduced.nnnCONCLUSIONSnPRF treatment of the DRG may be considered for patients with chronic, severe lumbosacral radicular pain refractory to conventional medical management.

Pulsed Radiofrequency: A Review of the Basic Science as Applied to the Pathophysiology of Radicular Pain A Call for Clinical Translation

Abstract Radicular pain is an important health care problem, with only limited evidence-based treatments available. Treatment selection should ideally target documented pathophysiological pathways. In herniated discs, a sequence in the inflammatory cascade can be observed that initiates and maintains increased nociceptive signal input. Inflammatory mediators including tumor necrosis factor &agr; are released from the nucleus pulposus and the degenerating peripheral nerve, which, in turn, induces production of neurotrophins like nerve growth factor and brain-derived neurotrophic factor. Neurotrophins interfere not only with the generation of ectopic firing of nociceptive neurons in the dorsal root ganglion but also with the excitability and sensitization of neuronal transmission in the dorsal spinal horn. Radicular pain is further characterized by the electrophysiological spreading of the afferent nociceptive input over different spinal nerve roots. Both the complex pathophysiological pathways involved and the spreading of the nociceptive signal make radicular pain difficult to treat. Pulsed radiofrequency (PRF) is considered an option in treatment of radicular pain. To understand and increase the efficiency of PRF interventional treatments in radicular pain, both in vitro and in vivo studies aiming at elucidating part of the mechanism of action of PRF are described. Potential factors that may improve the efficacy of PRF treatment in radicular pain are discussed.

Feasibility of a mobile and web-based intervention to support self-management in outpatients with cancer pain

PURPOSEnCancer pain is a prevalent and distressing symptom. To enhance self-management in outpatients, a multi-component intervention was developed, integrating patient self-management and professional care through healthcare technology. This article describes feasibility of the intervention in everyday practice.nnnMETHODnPatients with moderate to severe cancer pain (nxa0=xa011) and registered nurses specialized in pain and palliative care (nxa0=xa03) participated in a four-week study. The intervention involved daily monitoring, graphical feedback, education, and advice by means of a mobile application for patients and a web application for nurses. Learnability, usability and desirability were measured in patients with a 20-item questionnaire (1-5 scale), higher scores indicating better feasibility. Patients adherence was based on completion rates from server logs. Single semi-structured interviews with patients and a focus group interview with nurses provided insight into experiences.nnnRESULTSnQuestionnaire findings confirmed learnability (4.8), usability (4.8) and desirability (4.6) of the application for patients. Average completion rates were 76.8% for pain monitoring, 50.4% for medication monitoring and 100% for education sessions. Interviews revealed that patients were pleased with the simplicity of the mobile application and appreciated different components. Nurses agreed upon the added value and were mostly positive about the possibilities of the web application. Patients and nurses provided ideas for improvements relating to the content and technical performance of the intervention.nnnCONCLUSIONSnStudy results demonstrate feasibility of the intervention in everyday practice. Provided that content-related and technical adjustments are made, the intervention enables patients with cancer pain to practice self-management and nurses to remotely support these patients.

Sustained Treatment Effect of Spinal Cord Stimulation in Painful Diabetic Peripheral Neuropathy: 24-Month Follow-up of a Prospective Two-Center Randomized Controlled Trial

Spinal cord stimulation (SCS) has been demonstrated to serve as a successful second-line treatment modality for painful diabetic peripheral neuropathy (PDPN), as documented in two randomized clinical trials (RCTs) (1,2). Besides the fact that these two RCTs demonstrate a pain-relieving effect for a period of 6 months after the start of SCS treatment, only small observational studies suggest a long-term sustained effect in PDPN (3–5). In this article, we present the 24-month follow-up data of our recently published RCT in Diabetes Care (1).nnThirty-six patients were enrolled in this study, and after randomization, 22 patients with PDPN in the lower limbs (15 male, mean age 57.1 years [SD 12.4], years of PDPN 6.0 [SD 5.1]) were assigned to the SCS group. A 2-week trial stimulation was performed to evaluate sufficient pain relief. After 6 …