ON Chiropractic Spring 2015 | Page 11

ON Chiropractic Segmental Inflammation: Beyond MSK C -Sens can also induce a response called neurogenic inflammation. In other words, if a spinal segment is centrally sensitized, the muscles and organs connected to that segment can also become inflamed. A research review from RRS Education describes this process: “This neurogenically mediated inflammation refers to the discharge of inflammatory mediators and neuropeptides (such as substance P or calcitonin gene-related peptide) from the peripheral terminals of nociceptors in tissues (both visceral and somatic) that are neurologically linked to a primary pathology.b“ The review continues, “Neurogenic inflammation has also been linked to other non-musculoskeletal pathologies (e.g., irritable bowel syndrome, cystitis and changes in both uterine and bladder contractility).b” Dr. Srbely refers to a 2007 rat study wherein distension of the colon led to an inflammatory response in the bladder.Q The colon and bladder are neurologically linked and this study is an example of neurogenic inflammation spreading between organs. Given that the dorsal horn of the spinal cord is the location where somatic and visceral pathways converge, it is hypothesized that C-Sens is a key mechanism linking disrupted musculoskeletal and organ health. “You could have a simple disc herniation,” Dr. Srbely says, “and if we allow the sensitization to remain, the neurogenic inflammatory response will kick in. It will augment the inflammation locally at the disc but then it will begin to spread to other tissues that are segmentally linked.” So, not only might the perceived pain of an MSK issue become amplified and sustained once it triggers C-Sens, this sensitization may send altered signals to muscles and glands in the same segment “where they may initiate abnormal physiologic responses and, potentially, pathogenic processes if allowed to persist.”: injury would. If you continue applying pressure to this area, the clinician feels a relaxation response in that muscle and the patient actually desires more pressure. Initially it might be sore but if the pressure is maintained, patients describe it as a ‘feel-good pain’.” This “You could have a simple disc herniation,” Dr. Srbely says, “and if we allow the sensitization to remain, the neurogenic inflammatory response will kick in. It will augment the inflammation locally at the disc but then it will begin to spread to other tissues that are segmentally linked.” Dr. John Srbely Myofascial Pain Syndrome and Trigger Points C -Sens may lead to myofascial pain syndrome, a condition commonly encountered by chiropractors. Dr. Srbely’s neurogenic hypothesis suggests that neurogenic inflammation is a primary mechanism underlying the pathophysiology of myofascial trigger points and myofascial pain syndrome., Rather than being caused by local overuse or chronic injuries, emerging evidence suggests that trigger points may be a result of a central mechanism. “Any clinician will tell you that one of the key clinical differences between a local injury and a myofascial trigger point is the nature of tenderness,” Dr. Srbely says. “When a clinician presses on a myofascial trigger point, it does not induce a withdrawal reflex like a local was one of the first observations which suggested to Dr. Srbely that trigger points may be the result of an underlying neurogenic phenomenon rather than a local injury. In a 2010 journal article, Dr. Srbely covers several more indications of the neurogenic nature of myofascial trigger points including: ∞∞ “Referred pain” which suggests a centrally mediated network of sensitized trigger point circuits, ∞∞ The way trigger point formation follows segmental patterns, and ∞∞ The previously mentioned “soothing ache” of trigger point pain which is differentiated from the sharp pain and withdrawal reflex of local injuries. OCA members may also be interested in reading RRS Education’s review of Dr. Srbely’s article on this topic.b www.chiropractic.on.ca 11