Schwerpunktthema „Sympathikus und Schmerz”

Ohne Zusammenfassung     

Armut und Schmerz

Background

Poverty is an important problem in Germany. The health effects of poverty can lead to a higher risk of disease and the arising of chronic affections. On the other hand chronic illness may support the development and continuance of poverty. The context of chronic pain and poverty has not been analyzed so far.

Objectives

We investigated the correlation between chronic pain and poverty.

Materials and methods

In a prospective manner we interviewed 20 patients with pain syndromes during our consultation hour regarding their household income. Further, data from the German Federal Statistical Office were analyzed with respect to the correlation between the incidence of a chronic pain diagnosis and household income.

Results

At 1546?€, the average household income of the patients studied was below the poverty level. The analyzed data showed that women suffered from chronic pain more often than men did and also had a lower income. Another economic inequality was found between Eastern and Western Germany. There was a statistically significant correlation between income and the incidence of the diagnostic codes for chronic pain (R52.1, 2, 9) for men.

Conclusion

Our investigation showed the correlation between chronic pain and poverty. A commitment and cooperation of German medical associations and federal politics is necessary to overcome this sociopolitical issue.

     

Zytokinregulation und Schmerz

Cytokines are soluble peptides and proteins that are predominantly produced and secreted by immune cells. In numerous animal experiments the endogenous increase or application of exogenous pro-inflammatory cytokines is associated with pain behavior. In turn, cytokine inhibitors reduce such pain behavior in inflammatory and neuropathic pain models. Several clinical studies point out that cytokines are also important in different human pain states. Several chronic pain syndromes are associated with systemic pro-inflammatory cytokine profiles. In some pain syndromes these pro-inflammatory profiles are accompanied by a lack of analgesic anti-inflammatory cytokines. Numerous case reports and open clinical studies, but also some controlled trials show successful analgesic treatment using cytokine inhibitors. The following review article summarizes the main data of animal experiments and clinical trials concerning the role of cytokines in pain and the potential importance of cytokine modulation in pain treatment.     

Amalgam und Schmerz

Amalgam, which has long been used as a restorative material, has recently become the target of more and more criticism. An assessment of amalgam requires consideration of different aspects of toxicology, allergology, electrochemistry, psychology, and dentistry. Up to now, there is no scientific evidence that the physical properties of amalgam can lead to pain. Amalgam fillings with insufficiently formed chewing surfaces can cause myofacial pain, but the same can be said of restorations performed with any other material. Almost all preventive or therapeutic dental treatment can have adverse effects, and an attempt to eliminate all risks could well eliminate established methods in dentistry as well. This paper presents the ramifications of an amalgam ban, which is being called for by various groups, in some detail.     

Schlafentzug und Schmerz

It has now been established that sleep deprivation or fragmentation causes hyperalgesia which cannot be explained by a general change in somatosensory perception. However, it has not yet been clarified which of the sleep stages are most relevant for this effect. The seemingly paradoxical effects of sleep deprivation on pain-evoked brain potentials on the one hand and the subjective pain report on the other hand suggest complex changes in gating mechanisms. As the effects on pain and affect can be dissociated a common mechanism of action seems unlikely. Data from animal studies suggest that hyperalgesia due to sleep deprivation might be particularly strong under preexisting neuropathic conditions. Together with results from animal research the finding that endogenous pain modulation (CPM) is impaired by sleep deprivation suggests that the serotoninergic system mediates the effect of sleep deprivation on pain perception. However, other neurotransmitters and neuromodulators still have to be considered. The clinically relevant question arises why sleep deprivation induces hyperalgesia more easily in certain individuals than in others and why this effect then has a longer duration?     

Schmerz und Aufmerksamkeit

The primary symptom of fibromyalgia (FM) is chronic, widespread pain accompanied by diffuse tenderness to light palpation. However, many patients report a multitude of additional complaints and symptoms. Besides fatigue, exhaustibility and stiffness, a decrease in concentration and memory are further complaints that add significantly to the degree of suffering. This complaint, often termed “fibrofog”, is increasingly recognised as an independent symptom that has made its way into the medical literature under the term “dyscognition”. Nonetheless there are only a few studies that have specifically investigated neuropsychological deficits in FM patients in order to further specify clinical complaints. The studies performed so far have provided increasing evidence that FM patients have attention and working memory deficits, which are most prominent when patients have to cope with an additional source of distraction. With this review we intend to give an overview of the neuropsychological studies in FM performed so far and to assess possible implications for the underlying pathophysiology. In addition, we discuss potential clinical approaches to these symptoms. A systematic literature review up to June 2009 was carried out using the keywords (pairs) “fibromyalgia” and “cognition”, “fibromyalgia” and “dyscognition”, “fibromyalgia” and “cognitive deficits”.     

Schmerz und Bewusstsein

Six articles are presented which illustrate the activities at the summer workshop “Pain and awareness” held 27–28 May 2005 in Marienfeld by the German Interdisciplinary Collaboration for Pain Therapy (DIVS). One article on pain constructs in the mind explains the advantages of functional imaging methods: these enable characterization of partial aspects of pain processing in the brain and the mechanisms that lead to chronic states of pain syndromes. A further overview explains the influence of different drugs on pain perception and various conscious states. How back pain patients experience their illness was analyzed in a study using an explanatory model interview: somatic aspects were dominant, but in three-fourths of the patients psychological illness attributions also played a role. A summary from the perspective of religious history and theology explores how pain is interpreted and accepted in various religious communities. Another article addresses hypnosis as a complementary technique to anesthesia procedures in surgical medicine, for treating chronic pain and experimental acute pain. The last contribution deals with how people in different cultures experience pain: ethnocentric bias can lead to difficulties in communication and misjudgments when treating foreign-born patients. All in all the workshop highlighted important formative factors in pain processing in a condensed form and offered stimulating perspectives for this area of pain research and future treatment options.     

Schmerz und Politik

Ohne Zusammenfassung     

Schmerz und Schmerzlosigkeit

Voltage-gated sodium channels (Navs) are crucial for the generation and propagation of action potentials in all excitable cells, and therefore for the function of sensory neurons as well. Preclinical research over the past 20 years identified three Nav-isoforms in sensory neurons, namely Nav1.7, Nav1.8 and Nav1.9. A specific role for the function of nociceptive neurons was postulated for each. Whereas no selective sodium channel inhibitors have been established in the clinic so far, the relevance of all three isoforms regarding the pain sensitivity in humans is currently undergoing a remarkable verification through the translation of preclinical data into clinically manifest pictures. For the last ten years, Nav1.7 has been the main focus of clinical interest, as a large number of hereditary mutants were identified. The so-called “gain-of-function” mutations of Nav1.7 cause the pain syndromes hereditary erythromelalgia and paroxysmal extreme pain disorder. In addition, several Nav1.7 mutants were shown to be associated with small-fiber neuropathies. On the contrary, “loss-of-function” Nav1.7 mutants lead to a congenital insensitivity to pain. Recently, several gain-of-function mutations in Nav1.8 and Nav1.9 have been identified in patients suffering from painful peripheral neuropathies. However, another gain-of-function Nav1.9 mutation is associated with congenital insensitivity to pain. This review offers an overview of published work on painful Nav mutations with clinical relevance, and proposes possible consequences for the therapy of different pain symptoms resulting from these findings.     

Chronischer Schmerz und Psyche

Ohne Zusammenfassung     

Kortikale Reorganisation und Schmerz

The neuroscientific research of the past years has shown that extensive plastic change occurs in the adult human brain. The functional reorganization of the somatosensory and motor maps related to phantom limb pain is described. Subsequent to deafferentation amputees with phantom limb pain show a shift of neighbouring representation zones into the deafferented zone of the somatosensory and motor cortex that can be detected with noninvasive neuroimaging methods. This reorganization of the sensory and motor maps is not found in painfree amputees and persons with congenital loss of a limb. We discuss a model of the development of phantom limb pain that incorporates both peripheral and central factors and assigns an important role to chronic pain before the amputation. The modulation of plasticity and phantom limb pain by anesthesiological interventions is described and the results of preemptive analgesia for the prevention of phantom limb pain are discussed. Opioid treatment and behaviorally relevant stimulation are effective means to eliminate phantom limb pain and cortical somatosensory pain memories.     

Schmerz und Bewegungsangst im Alter

According to evidence-based guidelines a physically activating therapy approach in older chronic pain patients is necessary for the preservation of autonomy. Often the elderly are not easy to motivate for this because of inappropriate attitudes, low self-efficacy, fear of pain and fear of falling. The latter might be more important for self-induced restriction of activity in older pain patients than fear avoidance beliefs known from pain research. The fear of caregivers concerning pain and falls can also lead to physical restrictions in the elderly. The underlying diseases and drug effects have to be borne in mind in exercise-oriented therapy. It seems necessary to design special therapy elements for all national care sectors using age-specific motivation strategies and to assure an interdisciplinary cooperation.