Zsigeri fájdalom, nocebo-hatások, placebo-analgézia

Abstract

Összefoglaló. A belső szervek működési zavarai gyakran származnak viselkedési, lelki vagy pszichoszociális okokból, amelyeknek nem mindig vagyunk tudatában. Minthogy ebben a folyamatban egy bonyolult neuronális hálózat játssza a fő szerepet, ezeknek a zavaroknak a diagnózisa és terápiája számos tényező manipulálását igényli. A funkcionális gyomor-bélhuzam rendellenességek (FGID), például az irritábilisbél-szindróma (IBS), jellemző példái ennek: olyan működési zavarokról van szó, amelyek mögött jól detektálható szervi vagy biokémiai elváltozásokat nem találnak. Ilyenkor szükségesnek tűnik a komplex megközelítés, amely többféle szakember együttműködését kívánja meg. Szerepe lehet a pszichés vagy életmód terápiának, a gyógyszeres és fizikai kezelésnek is, és – ahogy ebben a cikkben megmutatjuk – a placebo-terápiának is. Summary. Functional disorders of the internal organs frequently are results of behavioral, mental or psycho-social dysfunctions, although we are usually not conscious about it. A typical example isirritable bowel syndrome (IBS), a characteristic functional gastro-intestinal disorder (FGID), which is regularly accompanied by abdominal pain and irregular intestinal motility and defecation. It has been shown that this disorder cannot be due to a single factor, nor is it a result of a local cause. Recently researchers have proven that malfunction of a complicated neuronal network, including several brain sites, may be responsible for IBS. It is believed now that IBS is the consequence of several nocebo-effects. IBS is a typical source of visceral pain or discomfort, a source that is frequently difficult to identify. Main factors are stimuli originating from the gastro-intestinal tract, passing through the spinal cord and reaching several brain structures, including cortical and sub-cortical sites. It has been shown that some structures become thicker while others thinner as a result of lasting visceral pain, resulting in altered top-down effects on the visceral organs. Several hormones accompany these processes resulting in a complicated network activity. Recent research has revealed that IBS requires a complex approach, optimally provided by a therapeutic team of physicians, psychologist/psychiatrist, associates, and even the patient himself/herself. They may apply or suggest medicines, physiotherapy, lifestyle modifications, alimentary changes etc. An important feature is that the nocebo-effect plays an important role in the generation of IBS, thus one may think the opposite phenomenon, placebo-effect could be used in the therapeutic process. And really, placebo-analgesia is a method frequently used in the therapy of IBS. Placebo-analgesia affects brain processes, including pain processing, release of hormones, including endogenous opioids, the primary pain-decreasing factors. A top-down pain-modification system exists which can be affected and activated by the placebo-analgesia thus counteracting the nocebo-effects and improving the condition of the individual. The placebo phenomenon is interesting in itself, too. By now, the major question is not the existence of the placebo-effect but the mechanisms behind it. Recently, as brain-mapping techniques have gained their role in research, a lot of new information proves that the placebo-effect (as well as the nocebo-effect) is a complex phenomenon that involves several different brain sites, including the brain cortex and the limbic system, respectively.P The placebo-effect is widely used in clinical practice, first of all as a reference treatment when new drugs or medicines are tested for their effectivity. There are numerous ethical problems in this area, recently, for example, when testing Covid-19 vaccines. The main problem is whether it is legal to keep a non-treated population, whether the placebo-group should be treated immediately after the trial ends, whether the members of the placebo-group should get adequate information.