Sunday, May 5, 2013
The Origins of RSD
What is RSD? Injuries happen all the time – we bang a toe, thump a knee, or twist an ankle – but we try not to let it phase us and keep going. While the initial pain may be gripping, it usually goes away after a short time. For the unfortunate few, this isn't always the case. The pain remains, and it gets worse over time, to the point where it can be excruciating and really impact the quality of life of the individual. These exceptional injuries and the consequent chronic pain are the indicator of a disease called complex regional pain syndrome. Reflex Sympathetic Dystrophy, commonly referred to as RSD, was first identified by Dr. S. Weir Mitchell, a Philadelphia physician. He detected and first discussed the ailment in "Injuries of Nerves and Their Consequences," a paper he published in 1872. Dr. Mitchell was popular for his research into the human nervous system. He was a surgeon and treated wounded soldiers from the Union Army. He found a reoccurring condition amongst those who had been injured but whose wounds had healed, namely that they experienced ongoing pain that appeared to travel through the body. Common discomforts included a burning pain, sensitivity to touch and temperature fluctuations in the affected limbs. In 1946, a doctor in Boston – James Evans – introduced the term reflex sympathetic dystrophy in explaining a similar issue he documented in patients who had no visible nerve afflicition. The International Association for the Study of Pain, in 1994, renamed the disease and gave it further definition. It was reclassified as complex regional pain syndrome, or CRPS, and was characterized by two types: CRPS Types 1 and 2. CRPS Type 1 occurs when there is no known nerve injury while Type 2 does involve injury to a nerve in the nervous system. A 2002 report issued by the World Institute of Pain state that "excruciating pain is the hallmark of the disease." Up until the 1980s, scientists asserted that pain impulses uniformly affected the body. Over the past 30 years, studies have now shown that the nervous system exhibits a more dynamic response to various classes of pain. The nervous system is composed of millions of nerve endings called neurons. Usually, these individual neurons form connections with other neurons, called synapses. These links create multiple pathways between the spinal cord, the central component of the nervous system, and the brain. The path taken by an individual impulse distinguishes the type of pain we feel, such as a throbbing pain, burning sensation or a dull aching pain. However, if a nerve sustains damage, changes in how that damaged nerve and surrounding nerves communicate pain can occur. This unintended modification is a disease, and pain in both the symptom and disease. Affected nerves can begin to release proteins that cause swelling, redness, and edema (temperature fluctuations) in surrounding tissue. This pathology is what makes identifying RSD so difficult.