https://www.practicalpainmanagement.com/pain/spine/arachnoiditis-diagnosis-treatment I have been exploring the potential role of the sacrum and pelvis in the causation and promotion of Fibromyalgia and Chronic Fatigue Syndrome for nearly 20 years. For me, this long nightmare of fatigue, pain, and multiple neurological symptoms began with an injury to my sacrum, pelvis, and most likely lower spinal cord and cauda equina. The spinal cord normally tapers and ends in the lumbar area at about L-1. Below this point the spinal cord essentially branches into many nerves known as the cauda equina, the 'horse's tail.' These nerves enervate the lower abdomen, bladder, bowel, pelvis, and all parts below. It is important to appreciate that all of these nerves must pass though the dura-meningeal lining of the central nervous system. There are 3 layers in this eloquent system : dura mater ( outer most layer, very tough), arachnoid mater ( in the middle), and the pia mater ( innermost layer). Once the sacral nerve bundles pass through this lining of the CNS, they travel through the holes/foramina in the sacrum ( 5 pairs of holes total) to the various organs of the lower abdomen, pelvis, and legs. Thus, the stability and integrity of the sacrum is critical to proper nerve transmission and health. Imagine if scoliosis, or a serious fall on the tailbone, or some other injury, causes the sacrum to twist or drop on one side, as happened to me. There is the potential for direct nerve trauma and also tension on the cauda equina nerve bundles. Women may be especially prone to injury due to our wider, inherently more unstable sacrums, and pregnancy and childbirth. An expert, Dr. Forest Tennant, MD ( link above) also comments that viruses and toxicity, and epidurals and spinal anesthesia can cause inflammation in the cauda equina nerves/surrounding neuro tissues. The glial cells in the nerve roots of the caudal equina produce neuroinflammatory chemicals, which can cause adhesions and scars and can result in the nerve roots sticking together or adhering to the arachnoid part of the dura meningeal system. Dr. Tennant details possible symptoms : constant pain, pain and weakness when standing too long, jerking/tremors in legs, difficulty initiating urination/ defecation. intense episodes heating/sweating ( dysautonomia anyone ??), burning feet, episodic blurred vision !!!!, headache, odd skin sensations - bugs crawling, water dropping, pins sticking. Also, mental impairment, memory, abstract thinking, even reading/writing impairment. He mentions that adhesive arachnoiditis may predispose to autoimmune conditions ( like Hashimoto's thyroiditis). Please read the entire article by Dr. Tennant for more details on this condition called (adhesive) arachnoiditis. My comments: Many researchers are now looking carefully at the brain, at the mitochondria, at the gut, at every minute chemical reaction in the human body. But are these diligent and careful searches missing something very important ? Something capable of causing disturbance and dysfunction from the brain to the feet ? Something that can cause altered spinal fluid flow and pressures, something that can cause a chronic neuro-inflammatory state ? Something that explains why women are the overwhelming majority of sufferers of autoimmune conditions, of Fibromyalgia, of Chronic Fatigue Syndrome ? I think I am remembering correctly from years ago when I read that Ida Rolf said that the sacrum is the 'seat of the soul.' ?? Just maybe the sacrum/pelvis complex holds the secret to unlocking a great mystery, and can help us find the answers we have so desperately sought for so many years?? Blessings to All.