Recent advanceType I complex regional pain syndromeLe syndrome douloureux régional complexe de type I
Introduction
Complex regional pain syndrome (CRPS) is the current name for a syndrome first described by Ambroise Paré in the 17th century [1]. Various names have been used since then to describe it: causalgia, algodystrophy, reflex sympathetic dystrophy, shoulder-hand syndrome, and Sudeck syndrome [2]. Hand surgeons dread this all-too-common pathology, which is primarily characterized by chronic pain, autonomous nervous system involvement and motor and sensory problems [3]. Typically, only one limb is affected. The symptoms can appear in the absence of a known nerve injury, at which point the disease is called Type I complex regional pain syndrome [4], or following a peripheral nerve injury, which is then called Type II complex regional pain syndrome.
Chronic pain and stiffness are the main symptoms associated with this syndrome. The course is often drawn out and can result in permanent sequelae. The diagnosis of CRPS-I is solely based on clinical observations. Various paraclinical exams only help to guide the diagnosis when faced with an unusual presentation or to eliminate a potential differential diagnosis. In 2004, the International Association for the Study of Pain (IASP) published standardized diagnostic criteria for CRPS, which provide a nosological framework for a disease often misdiagnosed [1].
Although the pathophysiology is not fully understood, reviewing its history shows us how the medical community, by focusing solely on one theory, has made CRPS-I a disease mediated only by the sympathetic nervous system for the past half century [2]. Only since the mid-1990s, with the development of modern neurosciences and an animal model of CRPS-I, have the causes and mechanisms started to reveal themselves [1]. A better overall understanding of the pathology has led to the development of innovative therapies [1].
Early diagnosis and management are the most important components for treating this disabling pathology [5]. Some of the proposed treatments include NSAIDs, antidepressants and anticonvulsants. The latter, despite their good analgesic effects, do not cure CRPS-I. In selected cases, a surgical procedure aiming at removing a nociceptive stimulus can lead to spectacular improvements [6]. Overall, 80% of patients who are diagnosed and treated have had a positive outcome after one year. However, the prognosis of CRPS-I, when it complicates a distal radius fracture for example, is not as good. Stiffness of the metacarpophalangeal joints 12 weeks after the initial trauma is strongly correlated with development of chronic CRPS-I [1].
Section snippets
Historical perspective
Often in the art of medicine, knowing a disease's history helps us better understand and grasp more recent developments, which are generally quite distant from what we learned during our medical academic training. This is especially true for CRPS-I. This historical review aims to show how ideas about the pathophysiologic mechanisms of a disease, which are still largely a mystery for those researching and treating it, have evolved over time. If the reader wants an expanded historical perspective
Definition(s)
CRPS-I can be defined as an articular and periarticular pain syndrome associated with vasomotor deregulation triggered by various stresses with no relationship between the intensity of the initial injury and severity of the continuing pain. CRPS-I is a clinical condition without any specific markers. Diagnostic criteria set out by the IASP are shown in Table 1.
CRPS-I corresponds to the standard definition of algodystrophy and is defined by the presence of CRPS with no identifiable nerve injury,
Epidemiology
The incidence of CRPS-I is extremely difficult to evaluate because of the wide range of medical specialties involved. The few studies that have been performed estimate the incident to be between 5 and 25 per 100,000 people/year, with the frequency being higher with age (peak at 40–60 years) and in females (sex-ratio of about 4:1). Although any limb can be affected, upper limb is involved more often than the lower limb [18].
CRPS-I secondary to trauma is by far the most common. CRPS-I is a common
Clinical examination
History-taking often reveals a triggering injury or surgical procedure, which may actually have been a fairly minor event. It is important to have the patient describe the nature of the triggering injury and the treatments already performed, to help with diagnosis and also future disease management [1].
A full physical examination must be performed, looking not only for physical signs of CRPS-I, but also symptoms consistent with nerve injury, such as area of hypoesthesia, or motor problems. The
Standard X-rays
Standard X-ray assessment is used to look for osteopenia (reduced bone density), which is often present in patients with CRPS-I, but would only be seen on standard X-rays in advanced stages of the disease. The bone must have lost 30% of its mineral content for its effects to be visible on X-rays. Typical signs of subchondral atrophy are diffused involvement of the subcortical and subchondral areas of the affected limb [1].
Bone scan
Bone scans are often used to reinforce the CRPS-I diagnosis since they
Pathophysiologic mechanisms
As we touched on during the historical overview, the pathophysiologic mechanisms of CRPS-I are not fully understood, we have now moved beyond the concept of isolated deregulation of the sympathetic nervous system, which dominated the second half of the 20th century [2]. Greater research efforts focused on understanding CRPS-I during the last decade have led to important discoveries about pathophysiologic mechanisms, especially the likely multifactorial etiology of CRPS-I and central nervous
Treatments
Management of CRPS-I continues to be a therapeutic challenge. Several treatment protocols using various opioid analgesics, antipsychotics, antidepressants and anti-inflammatory agents have been carried out with the goal of treating CRPS-I [31], [32], [33]. However, most of these molecules were used because of their efficacy in treating non-CRPS neuropathic pain. Attempts at demonstrating efficacy in CRPS have been relatively disappointing. Some agents specifically targeting the hypothetical
Conclusion
Although the exact causes of CRPS-I have not yet been discovered, progress made over the past ten years in understanding the pathophysiologic mechanisms involved in both the initiation and maintenance of CRPS-I allows us to foresee new treatment options directed at the etiology. The increasing number of studies points to renewed interest in a disease that from now on might actually be curable. Preliminary results are promising since the control over pain has improved.
Key takeaways
CRPS-I is a clinical diagnosis that can be made with high sensitivity using the IASP criteria.
CRPS-I is a seemingly multifactorial pathology where the central nervous system is involved in the onset and/or maintenance of the symptoms.
Multidisciplinary management of the disease must be initiated early on to have a chance of quickly resolving the condition.
Calcitonin must not be used anymore to treat CRPS-I.
Disclosure of interest
The authors declare that they have no conflicts of interest concerning this article.
References (44)
- et al.
Proprioceptive feedback enhancement induced by vibratory stimulation in complex regional pain syndrome type I: an open comparative pilot study in 11 patients
Joint Bone Spine
(2007) Complex regional pain syndrome: what's in a name?
J Pain
(2011)- et al.
Traumatic neuralgias: complex regional pain syndromes (reflex sympathetic dystrophy and causalgia): clinical characteristics, pathophysiological mechanisms and therapy
Neurol Clin
(1998) - et al.
[The prognosis of algodystrophic syndrome of the hand. Late results in 47 patients]
Ann Chir Main Memb Super
(1995) - et al.
Features of algodystrophy ten years after Colles’ fracture
J Hand Surg Br
(1992) - et al.
Diagnosis and management of complex regional pain syndrome complicating upper extremity recovery
J Hand Ther
(2005) - et al.
Meta-analysis of imaging techniques for the diagnosis of complex regional pain syndrome type I
J Hand Surg
(2012) - et al.
Motor cortex dysfunction in complex regional pain syndrome
Clin Neurophysiol
(2010) - et al.
Neuropeptides, neurogenic inflammation and complex regional pain syndrome (CRPS)
Neurosci Lett
(2008) Reflex sympathetic dystrophy, sympathetically maintained pain, and complex regional pain syndrome: diagnoses of inclusion, exclusion, or confusion?
J Hand Ther
(2000)
Peripheral sympathetic function as a predictor of complex regional pain syndrome type I (CRPS I) in patients with radial fracture
Auton Neurosci
Brain processing during mechanical hyperalgesia in complex regional pain syndrome: a functional MRI study
Pain
Adjuvant analgesics
Med Clin North Am
Effect of vitamin C on frequency of reflex sympathetic dystrophy in wrist fractures: a randomised trial
Lancet
Current management of reflex sympathetic dystrophy syndrome (complex regional pain syndrome type I)
Joint Bone Spine
Effect of vitamin C on prevention of complex regional pain syndrome type I in foot and ankle surgery
Foot Ankle Surg
Adjuvant physical therapy versus occupational therapy in patients with reflex sympathetic dystrophy/complex regional pain syndrome type I
Arch Phys Med Rehabil
Pain and reduced mobility in complex regional pain syndrome I: outcome of a prospective randomised controlled clinical trial of adjuvant physical therapy versus occupational therapy
Pain
Clinical expression profiles of complex regional pain syndrome, fibromyalgia and a-specific repetitive strain injury: more common denominators than pain?
Disabil Rehabil
Evidence based guidelines for complex regional pain syndrome type 1
BMC Neurol
Derangement of body representation in complex regional pain syndrome: report of a case treated with mirror and prisms
Exp Brain Res
Algodystrophie de la main. Étude clinique et thérapeutique
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2022, Integrative Medicine ResearchCitation Excerpt :The analgesic effect of BAA provides a good basis for improving the efficacy of routine RT on post-stroke SHS. Previous studies have confirmed that RT, including OT and PT, not only can reduce pain and improve active mobility in CRPS type-I patients within 1 year but also can improve the symptoms of stage I patients with post-stroke SHS.33-34 However, there are some disadvantages of routine RT for post-stroke SHS patients, such as high treatment cost, long treatment duration, more manpower input, and high requirements for patients' active cooperation ability.
Complex Region Pain Syndrome Following Shoulder Surgery
2021, Arthroscopy, Sports Medicine, and RehabilitationCitation Excerpt :Inability to form a full fist and grip weakness were the most disabling residual symptoms at the last follow-up visit. The incidence of CRPS is difficult to estimate, as multiple diagnostic criteria have been used in the past for the CRPS and may have led to overdiagnosis.1,8 In 2010, a European task force solidified a new International Association for the Study of Pain or Budapest Criteria to be used for diagnosis of CRPS, which will make comparing of prior studies and reporting of new studies more meaningful.9,10
Physical therapy under hypnosis for the treatment of patients with type 1 complex regional pain syndrome of the hand and wrist: Retrospective study of 20 cases
2017, Hand Surgery and RehabilitationCitation Excerpt :Various treatments have been used to treat CRPS-1: NSAIDs, anticonvulsants, antidepressants, sodium-channel blockers, vasodilators. The efficacy of these treatments varies, although none has been able to quickly and effectively cure CRPS-1 [1–3]. These treatments are used in combination with pain-relieving physical therapy modalities and contrast baths; however, no physical therapy modality has been demonstrated to be effective.
Complex pain regional syndrome after distal radius fractures
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2016, Hand Surgery and RehabilitationCitation Excerpt :Complex regional pain syndrome (CRPS) is condition that often leaves the practitioner feeling helpless or in an awkward position. A complex, disabling disease [1–3], it leaves the patient dependent on others for activities of daily living (ADLs) [4–6]. Collaboration between surgeons, physiatrists and rehabilitation professionals (physical therapists and occupational therapists) [7] is vital.