Complex regional pain syndrome | |
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Other names | Algodystrophy, reflex neurovascular dystrophy |
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Leg of an individual (left) with complex regional pain syndrome following a tibial fracture | |
Specialty | Neurology, psychiatry, physiatry, anesthesiology |
Symptoms | Pain, hyperalgesia, allodynia, hypoesthesia or hyperesthesia, skin abnormalities, atrophy, stiffness, temperature asymmetry |
Types | CRPS-1 (previously, reflex sympathetic dystrophy [RSD]); CRPS-2 (previously, causalgia) |
Treatment | Physical therapy (more effective with early diagnosis); medications (e.g., anticonvulsants, opioids, & muscle relaxers); spinal cord stimulator implantation; peripheral nerve stimulator implantation; sympathetic nerve blockade; ketamine infusion; lidocaine infusion; implantable pharmaceuticals; amputation |
Medication | Anticonvulsants (e.g., gabapentin); muscle relaxers (e.g., baclofen), ketamine or lidocaine infusions[ citation needed ] |
Complex regional pain syndrome (CRPS type 1 and type 2), sometimes referred to by the hyponyms reflex sympathetic dystrophy (RSD) or reflex neurovascular dystrophy (RND), is a rare and severe form of neuroinflammatory and dysautonomic disorder causing chronic pain, neurovascular, and neuropathic symptoms. Although it can vary widely, the classic presentation occurs when severe pain from a physical trauma or neurotropic viral infection [1] outlasts the expected recovery time, and may subsequently spread to uninjured areas. The symptoms of types 1 and 2 are the same except type 2 is associated with nerve injury.
Usually starting in a single limb, CRPS often first manifests as pain, swelling, limited range of motion or partial paralysis, and/or changes to the skin and bones. It may initially affect one limb and then spread throughout the body; 35% of affected individuals report symptoms throughout the body. [2] Two types are thought to exist: CRPS type 1 (previously referred to as reflex sympathetic dystrophy) and CRPS type 2 (previously referred to as causalgia). It is possible to have both types. [3]
Amplified musculoskeletal pain syndrome, a condition that is similar to CRPS, primarily affects pediatric patients, falls under rheumatology and pediatrics, and is generally considered a subset of CRPS type I. [4]
The classification system in use by the International Association for the Study of Pain (IASP) divides CRPS into two types based on the presence or absence of measurable nerve pathophysiology. [5] [6]
Type | Clinical findings | Synonyms |
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Type I | CRPS without evidence of neuropathology in the affected limb. This accounts for about 90% of CRPS. | reflex sympathetic dystrophy, RSD, Sudeck's atrophy |
Type II | CRPS with evidence of neuropathology in the affected limb. | causalgia |
Clinical features of CRPS have been found to be inflammation resulting from the release of certain pro-inflammatory chemical signals from surrounding nerve cells; hypersensitization of pain receptors; dysfunction of local vasoconstriction and vasodilation; and maladaptive neuroplasticity. [7]
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. [8] Moving or touching the limb is disproportionately painful (allodynia). Other findings are aspects of disuse including swelling, stiffness (limited range of motion), and disuse related changes to the skin (temperature, color, sweating, texture) and bones (disuse osteoporosis). [9] [10]
A prior concept of CRPS having three stages is no longer in wide use. [11] The trend is now to consider distinct sub-types of CRPS. [11]
Complex regional pain syndrome is uncommon, and its cause is not clearly understood. CRPS typically develops after an injury, surgery, heart attack, or stroke. [8] [12] Investigators estimate that 2–5% of those with peripheral nerve injury, [13] and 13–70% of those with hemiplegia (paralysis of one side of the body) [14] will develop CRPS. In addition, some studies have indicated that cigarette smoking was strikingly present in patients and is statistically linked to CRPS. This may be involved in its pathology by enhancing sympathetic activity, vasoconstriction, or by some other unknown neurotransmitter-related mechanism. This hypothesis was based on a retrospective analysis of 53 patients with RSD, which showed that 68% of patients were smokers, compared to only 37% of the control population. The results are preliminary and are limited by their retrospective nature. [15] 7% of people who have CRPS in one limb later develop it in another limb. [16]
Inflammation and alteration of pain perception in the central nervous system are proposed to play important roles. The persistent pain and the perception of nonpainful stimuli as painful are thought to be caused by inflammatory molecules (IL-1, IL-2, TNF-alpha) and neuropeptides (substance P) released from peripheral nerves. This release may be caused by inappropriate cross-talk between sensory and motor fibers at the affected site. [17] CRPS is not a psychological illness, yet pain can cause psychological problems, such as anxiety and depression. Often, impaired social and occupational function occur. [18]
Complex regional pain syndrome is a multifactorial disorder with clinical features of neurogenic inflammation (inflammation mediated by nerve cells), nociceptive sensitisation (which causes extreme sensitivity or allodynia), vasomotor dysfunction (blood flow problems which cause swelling and discolouration) and maladaptive neuroplasticity (where the brain changes and adapts with constant pain signals); CRPS is the result of an "aberrant [inappropriate] response to tissue injury". [7] The "underlying neuronal matrix" of CRPS is seen to involve cognitive and motor as well as nociceptive processing; pinprick stimulation of a CRPS affected limb was painful (mechanical hyperalgesia) and showed a "significantly increased activation" of not just the S1 cortex (contralateral), S2 (bilateral) areas, and insula (bilateral) but also the associative-somatosensory cortices (contralateral), frontal cortices, and parts of the anterior cingulate cortex. [19] In contrast to previous thoughts reflected in the name RSD, it appears that there is reduced sympathetic nervous system outflow, at least in the affected region (although there may be sympatho-afferent coupling). [20] Wind-up (the increased sensation of pain with time) [21] and central nervous system (CNS) sensitization are key neurologic processes that appear to be involved in the induction and maintenance of CRPS. [22]
Compelling evidence shows that the N-methyl-D-aspartate (NMDA) receptor has significant involvement in the CNS sensitization process. [23] It is also hypothesized that elevated CNS glutamate levels promote wind-up and CNS sensitization. [22] In addition, there exists experimental evidence demonstrating the presence of NMDA receptors in peripheral nerves. [24] Because immunological functions can modulate CNS physiology, a variety of immune processes have also been hypothesized to contribute to the initial development and maintenance of peripheral and central sensitization. [25] [26] Furthermore, trauma-related cytokine release, exaggerated neurogenic inflammation, sympathetic afferent coupling, adrenoreceptor pathology, glial cell activation, cortical reorganisation, [27] and oxidative damage (e.g., by free radicals) are all factors which have been implicated in the pathophysiology of CRPS. [28] In addition, autoantibodies are present in a wide number of CRPS patients and IgG has been recognized as one of the causes of hypersensitivity that stimulates A and C nociceptors, attributing to the inflammation. [29]
The mechanisms leading to reduced bone mineral density (up to overt osteoporosis) are still unknown. Potential explanations include a dysbalance of the activities of sympathetic and parasympathetic autonomic nervous system [30] [31] [32] and mild secondary hyperparathyroidism. [33] However, the trigger of secondary hyperparathyroidism has not yet been identified.[ citation needed ]
In summary, the pathophysiology of complex regional pain syndrome has not yet been defined; CRPS, with its variable manifestations, could be the result of multiple pathophysiological processes. [20]
Diagnosis is primarily based on clinical findings. The original diagnostic criteria for CRPS adopted by the International Association for the Study of Pain (IASP) in 1994 have now been superseded in both clinical practice and research by the "Budapest Criteria" which were created in 2003 and have been found to be more sensitive and specific. [34] They have since been adopted by the IASP. The criteria require there to be pain as well as a history and clinical evidence of sensory, vasomotor, sudomotor, and motor or trophic changes. It is also stated that it is a diagnosis of exclusion. [35]
To make a clinical diagnosis all four of the following criteria must be met: [36]
No specific test is available for CRPS, which is diagnosed primarily through observation of the symptoms. However, thermography, sweat testing, X-rays, electrodiagnostics, and sympathetic blocks can be used to build up a picture of the disorder. Diagnosis is complicated by the fact that some patients improve without treatment. A delay in diagnosis and/or treatment for this syndrome can result in severe physical and psychological problems. Early recognition and prompt treatment provide the greatest opportunity for recovery.[ citation needed ]
Presently, established empirical evidence suggests against thermography's efficacy as a reliable tool for diagnosing CRPS. Although CRPS may, in some cases, lead to measurably altered blood flow throughout an affected region, many other factors can also contribute to an altered thermographic reading, including the patient's smoking habits, use of certain skin lotions, recent physical activity, and prior history of trauma to the region. Also, not all patients diagnosed with CRPS demonstrate such "vasomotor instability"—particularly those in the later stages of the disease. [37] Thus, thermography alone cannot be used as conclusive evidence for—or against—a diagnosis of CRPS and must be interpreted in light of the patient's larger medical history and prior diagnostic studies. [38]
In order to minimise the confounding influence of external factors, patients undergoing infrared thermographic testing must conform to special restrictions regarding the use of certain vasoconstrictors (namely, nicotine and caffeine), skin lotions, physical therapy, and other diagnostic procedures in the days prior to testing. Patients may also be required to discontinue certain pain medications and sympathetic blockers. After a patient arrives at a thermographic laboratory, he or she is allowed to reach thermal equilibrium in a 16–20 °C, draft-free, steady-state room wearing a loose fitting cotton hospital gown for approximately twenty minutes. A technician then takes infrared images of both the patient's affected and unaffected limbs, as well as reference images of other parts of the patient's body, including his or her face, upper back, and lower back. After capturing a set of baseline images, some labs further require the patient to undergo cold-water autonomic-functional-stress-testing to evaluate the function of their autonomic nervous system's peripheral vasoconstrictor reflex. This is performed by placing a patient's unaffected limb in a cold water bath (approximately 20 °C) for five minutes while collecting images. In a normal, intact, functioning autonomic nervous system, a patient's affected extremity will become colder. Conversely, warming of an affected extremity may indicate a disruption of the body's normal thermoregulatory vasoconstrictor function, which may sometimes indicate underlying CRPS. [39]
Scintigraphy, plain radiographs, and magnetic resonance imaging may all be useful diagnostically. Patchy osteoporosis (post-traumatic osteoporosis), which may be due to disuse of the affected extremity, can be detected through X-ray imagery as early as two weeks after the onset of CRPS. A bone scan of the affected limb may detect these changes even sooner and can almost confirm the disease. Bone densitometry can also be used to detect changes in bone mineral density. It can also be used to monitor the results of treatment since bone densitometry parameters improve with treatment.[ citation needed ]
Ultrasound-based osteodensitometry (ultrasonometry) may be potential future radiation-free technique to identify reduced bone mineral density in CRPS. [33] Additionally, this method promises to quantify the bone architecture in the periphery of affected limbs. [33] This method is still under experimental development.[ citation needed ]
Electromyography (EMG) and nerve conduction studies (NCS) are important ancillary tests in CRPS because they are among the most reliable methods of detecting nerve injury. They can be used as one of the primary methods to distinguish between CRPS types I and II, which differ based on evidence of actual nerve damage. EMG and NCS are also among the best tests for ruling in or out alternative diagnoses. CRPS is a "diagnosis of exclusion", which requires that no other diagnosis can explain the patient's symptoms. This is very important to emphasise because patients otherwise can be given a wrong diagnosis of CRPS when they actually have a treatable condition that better accounts for their symptoms. An example is severe carpal tunnel syndrome (CTS), which can often present in a very similar way to CRPS. Unlike CRPS, CTS can often be corrected with surgery to alleviate the pain and avoid permanent nerve damage and malformation. [40]
Both EMG and NCS involve some measure of discomfort. EMG involves the use of a tiny needle inserted into specific muscles to test the associated muscle and nerve function. Both EMG and NCS involve very mild shocks that in normal patients are comparable to a rubber band snapping on the skin. Although these tests can be very useful in CRPS, thorough informed consent must be obtained prior to the procedure, particularly in patients experiencing severe allodynia. In spite of the utility of the test, these patients may wish to decline the procedure to avoid discomfort.[ citation needed ]
Patients are frequently classified into two groups based upon temperature: "warm" or "hot" CRPS in one group and "cold" CRPS in the other group. The majority of patients (about 70%) have the "hot" type, which is said to be an acute form of CRPS. [41] Cold CRPS is said to be indicative of a more chronic CRPS and is associated with poorer McGill Pain Questionnaire scores, increased central nervous system reorganisation, and a higher prevalence of dystonia. [41] Prognosis is not favourable for cold CRPS patients; longitudinal studies suggest these patients have "poorer clinical pain outcomes and show persistent signs of central sensitisation correlating with disease progression". [42]
Vitamin C supplementation may be useful in prevention of the syndrome following fracture of the forearm, foot, or ankle. [43]
Treatment of CRPS often involves a number of modalities. [44]
Physical and occupational therapy have low-quality evidence to support their use. [45] Physical therapy interventions may include transcutaneous electrical nerve stimulation, progressive weight bearing, graded tactile desensitization, massage, and contrast bath therapy. In a retrospective cohort (unblinded, non-randomised and with intention-to-treat) of fifty patients diagnosed with CRPS, the subjective pain and body perception scores of patients decreased after engagement with a two-week multidisciplinary rehabilitation programme. The authors call for randomised controlled trials to probe the true value of multidisciplinary programs for CRPS patients. [46]
Mirror box therapy uses a mirror box, or a stand-alone mirror, to create a reflection of the normal limb such that the patient thinks they are looking at the affected limb. Movement of this reflected normal limb is then performed so that it looks to the patient as though they are performing movement with the affected limb. Mirror box therapy appears to be beneficial at least in early CRPS. [47] However, beneficial effects of mirror therapy in the long term is still unproven. [48]
Graded motor imagery appears to be useful for people with CRPS-1. [49] Graded motor imagery is a sequential process that consists of (a) laterality reconstruction, (b) motor imagery, and (c) mirror therapy. [44] [50]
Transcutaneous Electrical Nerve Stimulation (TENS)
Transcutaneous Electrical Nerve Stimulation (TENS) is a therapy that uses low-voltage electrical signals to provide pain relief through electrodes that are placed on the surface of the skin. Evidence supports its use in treating pain and edema associated with CRPS, but it does not seem to increase functional ability in CRPS patients. [51]
Tentative evidence supports the use of bisphosphonates, calcitonin, and ketamine. [45] [52] Nerve blocks with guanethidine appear to be harmful. [45] Evidence for sympathetic nerve blocks generally is insufficient to support their use. [53] Intramuscular botulinum injections may benefit people with symptoms localized to one extremity. [54]
Ketamine, a dissociative anesthetic, appears promising as a treatment for CRPS. [55] It may be used in low doses if other treatments have not worked. [56] [57] No benefit on either function or depression, however, has been seen. [57]
As of 2013, high-quality evidence supports the use of bisphosphonates (either orally or via IV infusion) in the treatment of CRPS. [52] Bisphosphonates inhibit osteoclasts: cells involved in the resorption of bone. Bone remodeling (via osteoclast activity in resorption of bone) is thought to sometimes be hyperactive in CRPS. It is hypothesized that bone resorption causes acidification of the intercellular milieu which, in turn, activates nerves involved in nociception that densely innervate bone and causes pain. [52] Therefore, inhibiting bone resorption and remodeling is thought to help with regard to CRPS pain. [52] CRPS involving high levels of bone resorption, as seen on bone scan, is more likely to respond to bisphosphonate therapy. [52]
Opioids such as oxycodone, morphine, hydrocodone, and fentanyl have a controversial place in treatment of CRPS. These drugs must be prescribed and monitored under close supervision of a physician as they can quickly lead to physical dependence and addiction. [58] To date so far, no long-term studies of oral opioid use in treating neuropathic pain, including CRPS, have been performed. The consensus among experts is that opioids should not be a first-line therapy and should be considered only after all other modalities (e.g., non-opioid medications, physical therapy, and procedures) have been trialed. [59]
Spinal cord stimulation appears to be an effective therapy in the management of patients with CRPS type I (level A evidence) and type II (level D evidence). [60] Although they improve patient pain and quality of life, evidence is unclear regarding effects on mental health and general functioning. [61]
Dorsal root ganglion stimulation is a type of neurostimulation that is effective in the management of focal neuropathic pain. The FDA approved its use in February 2016. The ACCURATE Study demonstrated superiority of dorsal root ganglion stimulation over spinal (dorsal column) stimulation in the management of CRPS and causalgia. [62]
Surgical, chemical, or radiofrequency sympathectomy—interruption of the affected portion of the sympathetic nervous system—can be used as a last resort in patients with impending tissue loss, edema, recurrent infection, or ischemic necrosis. [63] However, little evidence supports these permanent interventions to alter the pain symptoms of the affected patients, and in addition to the normal risks of surgery, such as bleeding and infection, sympathectomy has several specific risks, such as adverse changes in how nerves function.[ citation needed ]
No randomized study in medical literature has studied the response with amputation of patients who have failed the above-mentioned therapies and who continue to be in pain. Nonetheless, on average, about half of the patients will have resolution of their pain, while half will develop phantom limb pain and/or pain at the amputation site. As in any other chronic pain syndrome, the brain likely becomes chronically stimulated with pain, and late amputation may not work as well as it might be expected. In a survey of 15 patients with CRPS type 1, 11 responded that their lives were better after amputation. [64]
Cannabidiol (CBD), despite evidence of very low quality, is proposed to relieve pain. [65]
The prognosis of CRPS is improved with early and aggressive treatment, with the risk of chronic, debilitating pain being reduced with the early treatment. [66] If treatment is delayed, however, the disorder can quickly spread to the entire limb, and changes in bone, nerve, and muscle may become irreversible. The prognosis worsens with the chronic "cold" form of CRPS and CRPS affecting the upper extremities. [66] Inactivity of the limb following an injury, whether due to pain or recovery or, in some instances, psychological distress after the injury, can lead to deconditioning. The absence of movement contributes to muscle atrophy, swelling, joint stiffness and pain, and reduced circulation, among other processes. This sequence of physiological changes not only intensifies the symptoms of CRPS but is also associated with a less favorable prognosis. [66] Some cases of CRPS may resolve spontaneously, with 74% of patients in a Minnesota study experiencing complete symptom resolution, while others may have chronic or relapsing-and-remitting disease. [66] Once one is diagnosed with CRPS, should it go into remission, the likelihood of it resurfacing after remission is considerable. Taking precautions and seeking immediate treatment upon any injury is important. [67]
CRPS can occur at any age, with the average age at diagnosis being 42. [13] It affects both men and women; however, CRPS is three times more frequent in females than males. [13]
CRPS affects both adults and children, and the number of reported CRPS cases among adolescents and young adults has been increasing, [68] with a recent observational study finding an incidence of 1.16/100,000 among children in Scotland. [69]
The condition currently known as CRPS was originally described by Ambroise Paré, who treated a severe and persistent pain syndrome suffered by Charles IX of France after a limb phlebotomy. [70] Silas Weir Mitchell is sometimes credited with inventing the name "causalgia" during the American Civil War. [71] However, the term was actually coined by Mitchell's friend Robley Dunglison from the Greek words for heat and pain. [72] Causalgia, linked to neurological lesions, is significantly influenced by vasomotor and sudomotor symptoms. In the 1940s, the term "reflex sympathetic dystrophy" was introduced, highlighting the role of sympathetic hyperactivity in its pathophysiology. [73] In 1959, Noordenbos observed in causalgia patients that "the damage of the nerve is always partial." [74] Misuse of the terms, as well as doubts about the underlying pathophysiology, led to calls for better nomenclature. In 1993, a special consensus workshop held in Orlando, Florida, provided the umbrella term "complex regional pain syndrome", with causalgia and reflex sympathetic dystrophy as subtypes. [75]
The National Institute of Neurological Disorders and Stroke (NINDS), a part of the National Institutes of Health, supports and conducts research on the brain and central nervous system, including research relevant to RSDS, through grants to major medical institutions across the country. NINDS-supported scientists are working to develop effective treatments for neurological conditions and ultimately, to find ways of preventing them. Investigators are studying new approaches to treat CRPS and intervene more aggressively after traumatic injury to lower the patient's chances of developing the disorder. In addition, NINDS-supported scientists are studying how signals of the sympathetic nervous system cause pain in CRPS patients. Using a technique called microneurography, these investigators are able to record and measure neural activity in single nerve fibers of affected patients. By testing various hypotheses, these researchers hope to discover the unique mechanism that causes the spontaneous pain of CRPS, and that discovery may lead to new ways of blocking pain. Other studies to overcome chronic pain syndromes are discussed in the pamphlet "Chronic Pain: Hope Through Research", published by the NINDS.[ citation needed ]
Research into treating the condition with mirror visual feedback is being undertaken at the Royal National Hospital for Rheumatic Disease in Bath. Patients are taught how to desensitize in the most effective way, then progress to using mirrors to rewrite the faulty signals in the brain that appear responsible for this condition. [76] However, while CRPS can go into remission, the chance of it reoccurring is significant.[ citation needed ]
The Netherlands has the most comprehensive program of research into CRPS, as part of a multimillion-Euro initiative called TREND. [77] German and Australian research teams are also pursuing better understanding and treatments for CRPS.[ citation needed ] [78]
CRPS has also been described in non-human animals, such as cattle. [79]
Bell's palsy is a type of facial paralysis that results in a temporary inability to control the facial muscles on the affected side of the face. In most cases, the weakness is temporary and significantly improves over weeks. Symptoms can vary from mild to severe. They may include muscle twitching, weakness, or total loss of the ability to move one or, in rare cases, both sides of the face. Other symptoms include drooping of the eyebrow, a change in taste, and pain around the ear. Typically symptoms come on over 48 hours. Bell's palsy can trigger an increased sensitivity to sound known as hyperacusis.
Carpal tunnel syndrome (CTS) is a nerve compression syndrome associated with the collected signs and symptoms of compression of the median nerve at the carpal tunnel in the wrist. Carpal tunnel syndrome usually has no known cause, but there are environmental and medical risk factors associated with the condition. CTS can affect both wrists.
Tetraplegia, also known as quadriplegia, is defined as the dysfunction or loss of motor and/or sensory function in the cervical area of the spinal cord. A loss of motor function can present as either weakness or paralysis leading to partial or total loss of function in the arms, legs, trunk, and pelvis. The paralysis may be flaccid or spastic. A loss of sensory function can present as an impairment or complete inability to sense light touch, pressure, heat, pinprick/pain, and proprioception. In these types of spinal cord injury, it is common to have a loss of both sensation and motor control.
Compartment syndrome is a serious condition. Increased pressure in a body compartment can harm blood flow and tissue function. If not treated quickly, it may cause permanent damage. There are two types: acute and chronic. Acute compartment syndrome can lead to a loss of the affected limb due to tissue death.
Fibromyalgia is a medical syndrome that causes chronic widespread pain, accompanied by fatigue, awakening unrefreshed, and cognitive symptoms. Other symptoms can include headaches, lower abdominal pain or cramps, and depression. People with fibromyalgia can also experience insomnia and general hypersensitivity. The cause of fibromyalgia is unknown, but is believed to involve a combination of genetic and environmental factors. Environmental factors may include psychological stress, trauma, and some infections. Since the pain appears to result from processes in the central nervous system, the condition is referred to as a "central sensitization syndrome". Although a protocol using an algometer (algesiometer) for determining central sensitization has been proposed as an objective diagnostic test, fibromyalgia continues to be primarily diagnosed by exclusion despite the high possibility of misdiagnosis.
Ankylosing spondylitis (AS) is a type of arthritis from the disease spectrum of axial spondyloarthritis. It is characterized by long-term inflammation of the joints of the spine, typically where the spine joins the pelvis. With AS, eye and bowel problems—as well as back pain—may occur. Joint mobility in the affected areas sometimes worsens over time. Ankylosing spondylitis is believed to involve a combination of genetic and environmental factors. More than 90% of people affected in the UK have a specific human leukocyte antigen known as the HLA-B27 antigen. The underlying mechanism is believed to be autoimmune or autoinflammatory. Diagnosis is based on symptoms with support from medical imaging and blood tests. AS is a type of seronegative spondyloarthropathy, meaning that tests show no presence of rheumatoid factor (RF) antibodies.
Raynaud syndrome, also known as Raynaud's phenomenon, is a medical condition in which the spasm of small arteries causes episodes of reduced blood flow to end arterioles. Typically the fingers, and, less commonly, the toes, are involved. Rarely, the nose, ears, nipples, or lips are affected. The episodes classically result in the affected part turning white and then blue. Often, numbness or pain occurs. As blood flow returns, the area turns red and burns. The episodes typically last minutes but can last several hours. The condition is named after the physician Auguste Gabriel Maurice Raynaud, who first described it in his doctoral thesis in 1862.
Erythromelalgia, or Mitchell's disease, is a rare vascular peripheral pain disorder in which blood vessels, usually in the lower extremities or hands, are episodically blocked, then become hyperemic and inflamed. There is severe burning pain and skin redness. The attacks are periodic and are commonly triggered by heat, pressure, mild activity, exertion, insomnia or stress. Erythromelalgia may occur either as a primary or secondary disorder. Secondary erythromelalgia can result from small fiber peripheral neuropathy of any cause, polycythemia vera, essential thrombocythemia, hypercholesterolemia, mushroom or mercury poisoning, and some autoimmune disorders. Primary erythromelalgia is caused by mutation of the voltage-gated sodium channel α-subunit gene SCN9A.
Piriformis syndrome is a condition which is believed to result from nerve compression at the sciatic nerve by the piriformis muscle. It is a specific case of deep gluteal syndrome.
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Electrotherapy is the use of electrical energy as a medical treatment. In medicine, the term electrotherapy can apply to a variety of treatments, including the use of electrical devices such as deep brain stimulators for neurological disease. Electrotherapy is a part of neurotherapy aimed at changing the neuronal activity. The term has also been applied specifically to the use of electric current to speed up wound healing. The use of electromagnetic stimulation or EMS is also very wide for dealing with muscular pain. Additionally, the term "electrotherapy" or "electromagnetic therapy" has also been applied to a range of alternative medical devices and treatments. Evidence supporting the effectiveness of electrotherapy is limited.
Neurofibromatosis type I (NF-1), or von Recklinghausen syndrome, is a complex multi-system human disorder caused by the mutation of neurofibromin 1 (NF-1). NF-1 is a gene on chromosome 17 that is responsible for production of a protein (neurofibromin) which is needed for normal function in many human cell types. NF-1 causes tumors along the nervous system that can grow anywhere on the body. NF-1 is one of the most common genetic disorders and is not limited to any person's race or sex. NF-1 is an autosomal dominant disorder, which means that mutation or deletion of one copy of the NF-1 gene is sufficient for the development of NF-1, although presentation varies widely and is often different even between relatives affected by NF-1.
Mirror therapy (MT) or mirror visual feedback (MVF) is a therapy for pain or disability that affects one side of the patient more than the other side. It was invented by Vilayanur S. Ramachandran to treat post-amputation patients who had phantom limb pain (PLP). Ramachandran created a visual illusion of two intact limbs by putting the patient's affected limb into a "mirror box," with a mirror down the center.
The stellate ganglion is a sympathetic ganglion formed by the fusion of the inferior cervical ganglion and the first thoracic ganglion, which is present in 80% of individuals. Sometimes, the second and the third thoracic ganglia are included in this fusion.
Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired autoimmune disease of the peripheral nervous system characterized by progressive weakness and impaired sensory function in the legs and arms. The disorder is sometimes called chronic relapsing polyneuropathy (CRP) or chronic inflammatory demyelinating polyradiculoneuropathy. CIDP is closely related to Guillain–Barré syndrome and it is considered the chronic counterpart of that acute disease. Its symptoms are also similar to progressive inflammatory neuropathy. It is one of several types of neuropathy.
Pelvic pain is pain in the area of the pelvis. Acute pain is more common than chronic pain. If the pain lasts for more than six months, it is deemed to be chronic pelvic pain. It can affect both the male and female pelvis.
Radiculopathy, also commonly referred to as pinched nerve, refers to a set of conditions in which one or more nerves are affected and do not work properly. Radiculopathy can result in pain, weakness, altered sensation (paresthesia) or difficulty controlling specific muscles. Pinched nerves arise when surrounding bone or tissue, such as cartilage, muscles or tendons, put pressure on the nerve and disrupt its function.
Spinal stenosis is an abnormal narrowing of the spinal canal or neural foramen that results in pressure on the spinal cord or nerve roots. Symptoms may include pain, numbness, or weakness in the arms or legs. Symptoms are typically gradual in onset and improve with leaning forward. Severe symptoms may include loss of bladder control, loss of bowel control, or sexual dysfunction.
Hard flaccid syndrome (HFS), also known as hard flaccid (HF), is a rare acquired dysautonomic condition characterized by a flaccid penis that remains in a firm, semi-rigid state in the absence of sexual arousal. Patients often describe their flaccid penis as firm to the touch, rubbery, shrunken, and retracted, frequently accompanied by pain, discomfort, and various other symptoms. While the condition is not fully understood, current research indicates that HFS results from excessive sympathetic nervous system activity in the smooth muscle tissue of the penis, triggered by a pathological activation of a proposed pelvic/pudendal-hypogastric reflex. Among other causes, injuries to the erect penis, blunt trauma to the pelvis or perineum, and damage to the cauda equina are thought to induce this reflex. Although unproven, it is possible that axon sprouting in sympathetic ganglia following a peripheral nerve injury is the true explanation for HFS. The majority of patients are in their 20s and 30s, with symptoms severely affecting their quality of life. Treatment typically involves a combination of alpha blockers and PDE5 inhibitors, although there is limited evidence supporting their efficacy. Due to the lack of comprehensive understanding and awareness within the scientific and medical communities, there is currently no definitive treatment for HFS.
Amplified musculoskeletal pain syndrome (AMPS) is an illness characterized by notable pain intensity without an identifiable physical cause.