miércoles, 21 de septiembre de 2016

EFIC Symposium: Myths and facts about joint pain

A lot of incorrect assumptions about joint pain are in circulation. “The sometimes overly pessimistic misconceptions can prevent patients from getting into therapy even though it could improve their condition and reduce their pain,” pain expert Serge Perrot criticized. Perrot, a professor from Descartes University and Cochin Hospital, Paris, France, made these remarks at a symposium focusing on severe and chronic joint pain being staged in Dubrovnik by the European Pain Federation EFIC. The expert talked about some of the most common myths concerning joint pain.

Myth #1: The more extensive the joint damage, the more severe the pain.
The misconception that the intensity of pain correlates with the extent of anatomical joint damage is especially persistent. Prof Perrot: “This statement is true at most in connection with very severe lesions.” Data shows that half of the individuals with radiologically verifiable joint damage live free of pain whereas, conversely, one in every two patients with knee pain has an intact joint. Prof Perrot: “So the question has to be this: Are there joint changes that induce pain?” Various cohort studies (MOST, Framingham) prove, for example, that a constriction of the intra-articular space is more likely to result in knee pain than osteophytes are, i.e. degenerative, structural changes in the bone. According to MRT studies (Torres, Osteoarthritis Cartilage 2006), intense pain is strongly correlated with synovialitis (inflammation of the synovial membrane) or bone marrow injuries but not with osteophytes, changes in cartilage, bone cysts, subluxations of the meniscus or lacerated ligaments.
Myth #2: Joint pain is synonymous with inflammation.
Anyone who automatically assumes that inflammation is the reason for joint pain is equally off track. Prof Perrot provided more precise information: “Inflammations play a role mainly in acute pain but not in chronic and mechanical pain.” Viewed pathophysiologically, joint pain is both, namely, an inflammation of the synovial membrane and bone pain caused by a constriction of the intra-articular space that increases the local pressure. According to one study (Laslett, EULAR 2011, London), treatment with a 5mg IV of zoldedronic acid can reduce bone pain by 15 points on the 100-point VAS scale. Injuries to bone marrow are reduced by 37 percent. For pain caused by an inflammation of the synovial membrane, treatment with non-steroidal anti-inflammatory drugs (NSAIDs) can help. Treatment of bone marrow oedemas also helps mitigate the pain.

Myth #3: Joint pain emanates from the joint.
The assumption that joint pain has to emanate from the joint would seem obvious but is in fact incorrect. Prof Perrot: “Joint pain is a complex experience in which social factors, pain behaviour, feelings, thoughts, the perception of pain and damage to nociceptive tissue come into play.” He cited arthritis as an example that demonstrates just how much a matter of the mind pain ultimately is: Spontaneous arthritic pain is exhibited in the brain in the medial prefrontal cortex and affects the person’s emotional state. Pain induced by a stimulus exhibits itself in brain regions that process somatosensorily nociceptive processes. In the central nervous system, joint pain sensitizes the brain, thereby creating excess local sensitivity.

Myth #4: Joint pain comes with age.
Prof Perrot: “80 percent of arthritis patients are 50 or older but age alone does not determine whether a person suffers from joint pain and how severe that pain is.” Besides age, two other cofactors for the intensity of arthritis pain are obesity and local injuries. People with the genotype Ile585Val TRPV1 are less sensitive to pain in the lower part of their body and therefore have a significantly lower risk of suffering from painful arthritis in their knees. With inflammatory joint diseases, gender can determine the level of pain: Women suffer more from these diseases than men do. Hormones can also be involved in joint pain: A blockage of oestrogen, for instance in connection with breast cancer treatment, can quickly result in inflammatory changes to wrists and ankles.

Myth #5: Joint pain is not treatable.
Even if freedom from pain is not a realistic goal of therapy in some cases: Joint pain does not have to be accepted without any hope of relief. Even intense pain is not synonymous with serious damage to the joint. “Joint pain is highly heterogeneous. The pain phenotypes therefore have to be precisely analysed to be able to initiate a suitable treatment,” the expert emphasised. He recommended that pain management should in any case consist of a combination of pharmacological and non-drug therapies.
EFIC has declared 2016 to be the European Year against Joint Pain. The goal of this information campaign is to focus on a health problem from which more than half of the worldwide population over age 50 suffers. Against this background, experts attending the symposium in Dubrovnik are discussing the many current trends for understanding and treating joint pain.