Complex regional pain syndrome (CRPS) is any of several painful conditions that are characterized by a continuing (spontaneous and/or evoked) regional pain that is seemingly disproportionate in time or degree to the usual course of any known trauma or other lesion. Usually starting in a limb, it manifests as extreme pain, swelling, limited range of motion, and changes to the skin and bones. It may initially affect one limb and then spread throughout the body; 35% of affected people report symptoms throughout their whole bodies. Two types exist: reflex sympathetic dystrophy (RSD) and causalgia. Having both types is possible. Classification
The classification system in use by the International Association for the Study of Pain (IASP) divides CRPS into two types. It is recognised that people may exhibit both types of CRPS. Signs and symptoms
Clinical features of CRPS have been found to be inflammation resulting from the release of certain proinflammatory chemical signals from the nerves, sensitized nerve receptors that send pain signals to the brain, dysfunction of the local blood vessels ability to constrict and dilate appropriately, and maladaptive neuroplasticity.The signs and symptoms of CRPS usually manifest near the injury site. The most common symptoms are extreme pain, including burning, stabbing, grinding, and throbbing. The pain is out of proportion to the severity of the initial injury. Moving or touching the limb is often intolerable. With diagnosis of either CRPS types I or II, patients may develop burning pain and allodynia.
Subacromial bursitis is a condition caused by inflammation of the bursa that separates the superior surface of the supraspinatus tendon (one of the four tendons of the rotator cuff) from the overlying coraco-acromial ligament, acromion, and coracoid (the acromial arch) and from the deep surface of the deltoid muscle. The subacromial bursa helps the motion of the supraspinatus tendon of the rotator cuff in activities such as overhead work. Musculoskeletal complaints are one of the most common reasons for primary care office visits, and rotator cuff disorders are the most common source of shoulder pain.Primary inflammation of the subacromial bursa is relatively rare and may arise from autoimmune inflammatory conditions such as rheumatoid arthritis, crystal deposition disorders such as gout or pseudogout, calcific loose bodies, and infection. More commonly, subacromial bursitis arises as a result of complex factors, thought to cause shoulder impingement symptoms. These factors are broadly classified as intrinsic (intratendinous) or extrinsic (extratendinous). They are further divided into primary or secondary causes of impingement. Secondary causes are thought to be part of another process such as shoulder instability or nerve injury.In 1983 Neer described three stages of impingement syndrome. He noted that "the symptoms and physical signs in all three stages of impingement are almost identical, including the impingement sign..., arc of pain, crepitus, and varying weakness". The Neer classification did not distinguish between partial-thickness and full-thickness rotator cuff tears in stage III.