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RSD(reflex sympathetic dystrophy), CRPS(complex regional pain syndrome)
어떤 원인에 의한 교감신경의 과반응이 체신경을 자극하여 complex regional pain syndrome을 야기하는데 이 또한 무섭고도 어려운 통증중 하나이다.
원인은 미상(대개 중풍을 앓은 팔, 수술, 특이하게도 교통사고로 찾아오는 경우도 경험했음)
증상은 심한 통증, 피부의 감각과민, 부종 그리고 교감신경 증상으로 땀분비장애, 혈관수축과 이완장애
질병의 Natural history는 거의 통증 부종, 교감신경 증상이 악화되는 방향으로
아마도 reflex muslce contraction, arthrogenic muscle inhibition, sinuvertebral nerve의 미스테리 segmental pain, polysynaptic reflex arc, visceral reflex arc(autonomic reflex arc, sympathetic-somatic reflex) 등은 다 비슷비슷한 기전으로 통증과 염증을 악화시키는 것 같다.
여기에는 자극 -> nerve -> spinal cord의 interneuron -> to brain
-> muscle의 과수축, 과긴장 -> vicious cycle
문제는 어떻게 vicious cycle을 차단하느냐이다.
아마 reflex와 interneuron을 깊이 공부하다보면 어렵지만 최선의 해답을 찾을 수 있을지도 모른다.
panic bird........
What is Complex Regional Pain Syndrome?
Complex regional pain syndrome (CRPS) is a chronic pain condition. The key symptom of CRPS is continuous, intense pain out of proportion to the severity of the injury, which gets worse rather than better over time. CRPS most often affects one of the arms, legs, hands, or feet. Often the pain spreads to include the entire arm or leg. Typical features include dramatic changes in the color and temperature of the skin over the affected limb or body part, accompanied by intense burning pain, skin sensitivity, sweating, and swelling. Doctors aren’t sure what causes CRPS. In some cases the sympathetic nervous system plays an important role in sustaining the pain. Another theory is that CRPS is caused by a triggering of the immune response, which leads to the characteristic inflammatory symptoms of redness, warmth, and swelling in the affected area.
Because there is no cure for CRPS, treatment is aimed at relieving painful symptoms. Doctors may prescribe topical analgesics, antidepressants, corticosteroids, and opioids to relieve pain. However, no single drug or combination of drugs has produced consistent long-lasting improvement in symptoms. Other treatments may include physical therapy, sympathetic nerve block, spinal cord stimulation, and intrathecal drug pumps to deliver opioids and local anesthetic agents via the spinal cord.
The prognosis for CRPS varies from person to person. Spontaneous remission from symptoms occurs in certain individuals. Others can have unremitting pain and crippling, irreversible changes in spite of treatment.
The National Institute of Neurological Disorders and Stroke (NINDS) and other institutes of the National Institutes of Health (NIH) conduct research relating to CRPS in laboratories at the NIH and also support additional research through grants to major medical institutions across the country. NINDS-supported scientists are studying new approaches to treat CRPS and intervene more aggressively after traumatic injury to lower the chances of developing the disorder. Reflex sympathetic dystrophy, also known as RSD, is a condition of burning pain, stiffness, swelling, and discoloration of the hand. Reflex sympathetic dystrophy includes other medical diagnoses, such as causalgia, Sudeck's atrophy, and shoulder-hand syndrome. Reflex sympathetic dystrophy occurs from a problem in the sympathetic (unconscious) nervous system that controls the blood flow and sweat glands in the hand and arm. The nervous system becomes overactive. A burning pain, swelling, and warmth are felt in the affected arm. If not treated, reflex sympathetic dystrophy can cause stiffness and a loss of use of the affected part of the arm. In some cases, the cause of reflex sympathetic dystrophy is unknown. Often, an injury can cause reflex sympathetic dystrophy. The symptoms may appear after a surgery. Other causes include pressure on a nerve, infection, cancer, neck disorders, stroke, or heart attack. These conditions can cause pain, which sets off the sympathetic reflex, causing symptoms of reflex sympathetic dystrophy. Nerve injuries may change the way the nerve impulses are sent, causing a "short circuit." The pain associated with reflex sympathetic dystrophy is often described as burning in nature. Swelling can cause painful joints and stiffness. Reflex sympathetic dystrophy has three stages. Stage II can last three months to 12 months. Swelling is more constant. Skin wrinkles disappear. The temperature of the skin becomes cooler. Fingernails become brittle. Pain is more widespread, stiffness increases, and the affected area becomes sensitive to touch. Stage III occurs from one year on. The skin of the affected area is now pale, dry, tightly stretched, and shiny. The area is stiff, pain may decrease, and there is less hope of getting motion back. The diagnosis usually is made when at least three of the following symptoms are present:
Complex Regional Pain Syndromes
Definition Epidemiology Symptoms Causes Current treatments Conservative treatment Psychotherapy: Psychological counselling and antidepressant drug therapy may be required to treat the depression that is often associated with CRPS. Such therapies have been shown to improve quality of life and to help develop pain-coping skills and cognitive-behavioural psychotherapy. Psychotherapy can also facilitate progress in the other treatment modalities. Pharmacological management and regional anaesthesia techniques Interventional pain management Minimally interventional: Sympathetic nerve blocks involve injecting anaesthetic into different nerves. These include stellate ganglion nerve blocks, lumbar sympathetic nerve blocks and More interventional: If patients fail to progress through the rehabilitative pathway, or have inadequate or only partial pain relief, more interventional procedures are used. Epidural and plexus catheter blocks may be considered if the patient had a partial response to sympathetic Neurostimulation: This therapy is increasingly replacing ablative pain surgery procedures. Neurostimulation can be administered as either spinal cord stimulation (SCS) or peripheral This new evidence, in combination with the cost-effectiveness of neurostimulation, suggests that this therapy is currently being underused. Intrathecal drug delivery: Intrathecal drug delivery can be used to treat CRPS patients who have Surgery - sympathectomy Interdisciplinary clinical pathway CRPS patients generally respond to conservative treatment including pharmacological management, whilst some patients may experience short-term pain relief with nerve blocks. Treatment pathway for CRPS
[Source: Stanton-Hicks at al. Pain Practice, 2002; 2(1): 1-16]
Early intervention is paramount, and ideally each step in the algorithm should be accomplished with 2-3 weeks Rehabilitation is the mainstay of CRPS treatment. The concurrent implementation of physiotherapy with pain management and psychological therapies is meant to facilitate a sequential progression through the steps of the rehabilitation pathway. The focus of psychological treatment for CRPS is on improving quality of life, developing pain coping skills, cognitive-behavioural psychotherapy and facilitating progress in the other treatment modalities. It is recommended that patients experiencing significant CRPS symptoms for more than 6-8 weeks should undergo clinical psychological assessment. (Stanton-Hicks, 2002) Management of pain must be dynamic and flexible, corresponding to the disease progression, Kemler MA et al, Mekhail NA et al, Reg Anesth Pain Med 1999 Segal R et al, Neurol Res 1998 Further reading
References:
- Allen G, et al. Epidemiology of complex regional pain syndrome: a retrospective chart review of 134 patients. Stage I Acute
Stage II Dystrophic
Stage III Atrophic
The term 'complex regional pain syndrome' or 'CRPS' was introduced in 1993 by the International Association for the Study of Pain (IASP) to more accurately describe the pain syndromes reflex sympathetic dystrophy (type I), in which injury occurs to the skin, bones, joints or tissue; and causalgia (type II), in which injury occurs to major nerves. However, the clinical definition and scientific understanding of this complex condition are still evolving. 'Regional' refers to the fact
that the pain is located in one region of the body (typically the hand or foot); however, the condition can spread to additional areas.
The actual incidence of CRPS is unknown. It is thought to be rare but is often misdiagnosed.
The aetiology of CRPS is typically an injury: 16% after a fracture; 10-29% after a strain or sprain;
3-24% post-surgery; 8% after contusion or crush injury; 6% spontaneous; and 2%-17% due to other causes or of an unknown aetiology (Harden, 1999; Allen, 1999). One report has estimated that CRPS develops in 1%-5% of patients who have sustained peripheral nerve injury (type II) (Bonica, 1990). Despite treatment, many patients are left with varying degrees of chronic pain
and disability. There are currently significant unmet medical needs for patients suffering from CRPS.
Because CRPS affects the sympathetic nervous system, and this in turn affects all tissue
levels (skin, bone, etc.), many symptoms may occur. The overriding symptom is extreme
pain, either neuropathic or nociceptive, characterized as aching, burning, pricking or shooting.
Other symptoms vary, but can include sensory changes (allodynia, hyperalgesia), oedema, abnormalities of temperature, sudomotor activity and a change in skin colour. The symptoms usually occur after an identified precipitating event or trauma. Diagnosis depends on both
clinical findings and a detailed history. A confirmatory test is unavailable, although a plain radiograph or a three-phase bone scan have been shown to be useful. In addition, CRPS
has associated psychological sequelae. Because of continuous pain and associated
disability, patients with CRPS may develop depression, anxiety and hypochondria.
The pathophysiology of CRPS is poorly understood. The theory that CRPS is caused by dysfunction of the sympathetic nervous system remains the subject of much controversy.
A peripheral inflammatory component is also thought to play a role. The condition can be initiated by trauma, often involving the hands or feet. CRPS has also occurred as an iatrogenic complication after surgical procedures such as arthroscopy and carpal tunnel release. In addition, the syndrome has been reported after nerve injury caused by intra-muscular injection or routine venipuncture, and as an adverse reaction to subcutaneous allergy injections. CRPS has also been associated with medical conditions such as diabetic
neuropathy, multiple sclerosis, myocardial infarction and cancerous infiltration of a nerve plexus.
Current guidelines recommend interdisciplinary management for CRPS, emphasizing three
core treatment elements: pain management, rehabilitation and psychological therapy. However, increasing evidence suggests that some cases are refractory to conservative measures and instead require earlier intervention with neurostimulation.
Rehabilitation: Rehabilitation is the cornerstone and first-line treatment for CRPS. Mild cases
can respond to occupational therapy, physiotherapy and physical modalities. These progress
from activation and isometric movement, to resisted range of motion (ROM) and stress loading,
to ergonomics. A recent report of 103 children meeting IASP criteria showed that 92% of patients experienced resolution or reduction of pain after undergoing exercise therapy (Sherry, 1999).
In those cases that are mild to moderate, and in which rehabilitation is only partially successful, adjuvant treatment with drugs such as anti-inflammatories, corticosteroids, antidepressants, anticonvulsants, calcitonin or opioids can be administered. Patients often take several different drugs simultaneously to maximise their pain relief. However, no single drug or combination of drugs has been shown to produce long-lasting symptom relief.
In those patients that develop refractory chronic pain, a multidisciplinary approach is required
that includes other pain interventions in addition to conservative treatments. Other pain relieving measures include sympathetic/somatic blockade, neurostimulation and intrathecal drug delivery. Increasingly, neurosurgical methods are becoming an indispensable part of the therapeutic armamentarium for treatment of CRPS.
Bier blocks. However, there is little clinical evidence to suggest that sympathetic nerve blocks
are effective. Other minimally invasive block techniques include intravenous (IV) regional blocks and somatic nerve blocks. These treatments have been shown to provide immediate pain relief
for CRPS sufferers, but in many cases the effects are not long-lasting. Furthermore, there is a
lack of prospective studies evaluating the clinical efficacy of these treatments.
or somatic nerve blocks, although there is a lack of clinical evidence to support their use.
The next step in the pain management pathway is neurostimulation.
nerve stimulation (PNS), although SCS is the standard practice. In one study (Kumar, 1997), neurostimulation showed effective pain relief that was superior to ablative surgery. Another
recent study showed that neurostimulation resulted in sustained pain control in severe CRPS
type 1 sufferers with a probable reduction in narcotics (Kemler, 2000). This study also showed
that neurostimulation provided significantly better long-term pain relief compared with physiotherapy alone. A recent review suggests that SCS may produce substantial and long-lasting pain relief in 60-70% of patients (Meyerson, 2001). In addition, neurostimulation has also been found to be less costly than standard treatment. A cost analysis model of patients with CRPS
type I found that although at 12 months the mean cost of neurostimulation per patient (?9,352)
was more expensive than physical therapy (?6,735), this difference was reversed over a lifetime analysis, resulting in a cost saving with neurostimulation (?58,471). Given that SCS is both more effective and less costly than conventional treatment, the authors concluded that 'there is compelling evidence for its adoption and appropriate utilization'.
a significant component of dystonia, who have failed neurostimulation, who have longstanding disease, who have multi-limb involvement or who need palliative care. Patient selection appears
to be critical to success with intrathecal drug delivery for pain, and suitable candidates can be easily established through a screening test. This method of delivery reduces the opioid dose
that must be administered compared with systemic methods, with the consequence that there
are fewer side effects. Two recent studies demonstrated the effectiveness of intrathecal baclofen
in the treatment of CRPS-associated dystonia (van Hilten, 2000; Zuniga, 2002).
This highly controversial treatment involves the destruction of nerves using surgery or chemicals, and is indicated only for profoundly disabled patients who have responded positively to sympathetic blockade and have no other treatment options. Evidence to support the use of sympathectomy is limited, and as such its use is not widely recommended. Some retrospective studies of surgical sympothectomy have shown long-term success (Schwartzman, 1997; Kim, 2002; Brandyk, 2002). However, these successful outcomes should be balanced with reports
of the negative impact of surgical sympathectomy (Furlan, 2001).
The goal of treatment is to improve function, relieve pain and achieve remission using an interdisciplinary approach with simultaneous application of rehabilitation, pain management
and psychological treatments. These modalities should be applied in a timely manner, with advanced treatments applied according to the patient's clinical response. Failure to progress
in the rehabilitation pathway requires more advanced pain management and psychological approaches. The importance of criteria to define appropriate patient selection in CPRS has
been recently highlighted.
When patients are refractory to conservative measures, flexible use of neurostimulation (SCS) should be considered, based on each patient's clinical progress. In addition, the interdisciplinary clinical pathway suggests that SCS should be used earlier in CRPS patients who do not respond to an acceptable level of treatment within 12 weeks (Stanton-Hicks, 2002). This may be particularly beneficial for younger patients.
to provide the patient pain relief and enhance their ability to optimise function. Less invasive techniques are pharmacological management and regional anaesthesia techniques.
When these prove less efficacious, then it becomes important to consider more invasive techniques. (Stanton-Hicks, 2002)
Neurology 2002
Kemler MA et al,
New Eng J Med 2000
Oakley JC et al,
Neuromodulation
1999
Click here to access key paper summaries on the use of Neurostimulation and Intrathecal Drug Delivery for the treatment of CRPS and related conditions
Pain 1999;80:539-44.
- Bonica JJ. The management of pain. 2nd edition. Philadelphia: Lea & Febiger, 1990;221-2, 231.
- Brandyk DF, et al. Surgical sympathectomy for reflex sympathetic dystrophy syndromes.
J Vasc Surg 2002;35(2):269-77.
- Furlan AD, et al. Are we paying too high a price for surgical sympathectomy?
A systematic literature review of late complications. J Pain 2000;1:245-57.
- Harden RN, et al. Complex regional pain syndrome: are the IASP diagnostic criteria valid and sufficiently
comprehensive? Pain 1999;83:211-9.
- Kemler MA, et al. Spinal cord stimulation in patients with chronic reflex sympathetic dystrophy.
N Engl J Med 2000;343:618-24.
- Kemler MA, et al. Economic evaluation of spinal cord stimulation for chronic reflex sympathetic dystrophy.
Neurology 2002;59:1203-9.
- Kim KD, et al. Sympathectomy: Open and thoracoscopic. In: Burchiel KJ (ed): Surgical Management of Pain.
New York: Thieme Medical Publishers; 2002:688-700.
- Kumar K, et al. Spinal cord stimulation is effective in the management of reflex sympathetic dystrophy.
Neurosurgery 1997;40:503-9.
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- Schwartzman RJ, et al. Long-term outcome following sympathectomy for complex regional pain syndrome
type I (RSD). J Neurol Sci 1997;150:149-52.
- Sherry D, et al. Short- and long-term outcomes of children with complex regional pain syndrome type I
treated with exercise therapy. Clin J Pain 1999;15:218-23.
- Stanton-Hicks, et al. An updated Interdisciplinary Clinical Pathway for CRPS: Report of an Expert Panel.
Pain Practice 2002;2(1):1-16.
- van Hilten BJ, et al. Intrathecal baclofen for the treatment of dystonia in patients with reflex sympathetic
dystrophy. N Engl J Med 2000;343:625-30.
- Zuniga RE, et al. Intrathecal baclofen: a useful agent in the treatment of well-established complex regional
pain syndrome. Reg Anest Pain Med 2002;27(1):90-3.