The characteristics of the clinical course in long term CRPS are not known. We report 12 cases of complex regional pain syndrome of over ten year's duration with particular attention to complications of the condition. CRPS is associated with a movement disorder, spread of allodynia, migraine, depression and urological symptoms. All of our cases developed a movement disorder. In 58% the movement disorder was disabling, 83% developed total body allodynia, 67% became depressed, 58% had bladder dysfunction and migraine occurred in 50%. We conclude that long term CRPS can have severe neurological complications.
The emotional or affective component of pain regulates mood; it occurs primarily in the brain's limbic system; and a negative impact on affect is required in order for stimulus to be accurately portrayed as “painful.” The integration of sensory and affective components of pain and the ensuing activation of higher brain centers involved in the perception of noxious stimuli is an emerging topic within the field of pain neurobiology. A relationship between pain and mood has been supported by numerous clinical studies indicating significant comorbidity of chronic pain and various types of depressive illnesses. Besides the assumption that pain is simply a form of stress, the physiological basis for the coexistence of pain and depression is still being investigated. Studies described in this review address some of the cellular and molecular events occurring within the hippocampus that may be common to both pain and stress, possibly reflecting underlying mechanisms of chronic pain-related depression.
Despite the availability of various treatment options, the satisfactory alleviation of painful peripheral neuropathic pain remains a challenge, due in part to the complex nature of this particular type of pain. Unlike nociceptive pain (caused by a painful stimulus in the presence of a normally functioning nervous system), neuropathic pain is typically produced in response to damage of, or pathological changes within, the peripheral and/or central nervous system. Many patients with neuropathic pain have comorbidities that result in the use of multiple pharmacotherapies, thereby causing a heightened risk of drug-drug interactions. Topically applied, peripherally acting analgesics provide a relatively safe treatment option due partly to low systemic absorption of the medication, thereby reducing the risk of drug interactions and systemic toxicity. The physiology of painful peripheral neuropathies is briefly presented along with a review of the evidence supporting the use of the lidocaine patch 5% as an effective pharmacotherapy option for the treatment of neuropathic pain.
Most neuropathic pain conditions are caused by damage to peripheral nociceptive neurons known as “small-fibers.” Examination of punch skin biopsies immunolabeled with pan-axonal markers has identified degeneration of distal nociceptive axons as a pathological hallmark of most neuralgias including numerous polyneuropathies, postherpetic neuralgia, and complex regional pain syndrome. Similar axonopathy is present in several rodent models of neuralgia (chronic constriction injury and spared nerve injury). Here we have measured the density of distal cutaneous small-fiber axons in rats with persistent mechanical allodynia caused by the sciatic inflammatory neuropathy (SIN), a model of painful neuritis. We have evaluated whether perineural immune activation sufficient to cause evoked-pain behaviors is also associated with loss of distal epidermal innervation.SIN was created in adult male Sprague-Dawley rats by perineural zymosan administration using established methods. Unoperated rats provided controls. Two weeks of sensory testing established the presence of static mechanical allodynia. Full-thickness punches were then collected from ipsilesional sural-innervated plantar hindpaw skin. These were immunolabeled against PGP9.5 using standard methods, and the density of epidermal neurites quantitated microscopically by a single examiner who was unaware of rats' experimental group. Neurite densities were similar in SIN and control samples (P = 0.96), suggesting that mechanical allodynia can occur from inflammation near a nerve, without distal small-fiber degeneration.
Angiogenesis is an important issue in cancer research and opioids are often used to treat pain in cancer patients. Therefore it is important to know if the use of opioids is associated with an aberrant stimulation of tumor growth triggered by the stimulation of angiogenesis in cancer patients. Some studies in the literature have suggested the presence of the μ3 opioid receptor, known as the receptor for many opioids, on endothelial cells, which are key players in the process of angiogenesis. In this study we used endothelial cells known to express the μ3 opioid receptor (MOR3), to evaluate the effects of morphine on angiogenesis. We first investigated the effect of morphine on the proliferation of endothelial cells. We showed that morphine is able to stimulate vascular endothelial cell proliferation in vitro. This effect of morphine is mediated by the mitogen-activated protein kinase (MAPK) pathway as pre-treatment with PD98059 inhibited this excessive proliferation. Because previous studies indicated nitric oxide (NO) as a downstream messenger we investigated the role of NO in the aberrant proliferation of endothelial cells. Our data could not confirm these findings using intracellular NO measurements and quantitative fluorescence microscopy. The potential use and pitfalls of opioids in cancer patients is discussed in light of these negative findings.
Animal models, using experimental peripheral nerve injury, have contributed greatly to the understanding of the spinal pathophysiology associated with neuropathic pain. Nerve injury provokes an initial, transient inflammatory response that involves release of cytokines and growth factors. These substances initiate a series of slowly-developing changes in the spinal cord and primary afferent neurons. These include increased excitability and altered Na+ channel expression in primary afferent fibers, attenuation of GAB Aergic inhibition and increased excitatory synaptic transmission within the dorsal horn. A better understanding of these processes will lead to rational development of novel therapies.
It is proposed that under certain circumstances peripheral nerve may exist in a poorly or nonfunctional reversible state [termed hibernating peripheral nerve (HPN)] after neural insult. Furthermore, it is speculated that certain high intraneural concentrations of lidocaine may conceivably facilitate a hypothetical state of hibernating peripheral nerve.
The complexity of this syndrome, the involvement of many (para) medical disciplines in the treatment and the functional outcome regarding psycho-social functioning, it was necessary to develop a guideline which was based on literature, expert views and intensive discussion within the experts. In this case it would be possible to give every patient in the Netherlands the same treatment based on the evidence based developed guidelines.The aim of the development of the guideline was to come forward with recommendations to guide paramedics and medical doctors in their daily practice. The guideline had to have as a basis the evidence coming from international literature. The guideline had to give advices regarding diagnostics, treatment, aftercare, follow up and information and support of children and adults with CRPS-I.The implementation of the guideline is taken in account throughout the entire development process. The recommendations in the guidelines are based on the best available scientific evidence and further considerations, such as costs, side effects, patient perspectives, organisational aspects.
The diagnostic criteria of complex regional pain syndrome remain controversial. Continuing efforts to refine diagnostic criteria by optimizing sensitivity and specify for clinical and research purposes are ongoing.
Aim: To characterize the impact of neuropathic pain (NeP) related to cervical radiculopathy (CR) on health and employment status and outpatient healthcare utilization, we conducted a cross-sectional survey of 81 patients with CR-related NeP in general practice in six European countries.Methods: Patients and physicians completed a one-time survey. Physicians recorded demographic and treatment information. Patients provided information on CR-related NeP, health impact and utilization.Results: Mean age was 57.0 ñ13.3 years. The mean Pain Severity Index was 5.2 ñ 1.8, and 89% reported moderate or severe pain. Patients reported moderate levels of pain-related interference with health domains (mean 4.7 ñ 2.0) despite 94% of patients receiving prescription medications for NeP. Prescriptions were predominantly for standard analgesics (79%), and multiple physician visits for NeP was common. Disruption in employment occurred in 62% of patients. Increasing pain severity was associated with reduced health valuation (P < 0.001) and increased functional interference (P < 0.001).Conclusions: NeP in CR is associated with substantial patient burden. Improved management strategies and physician education may reduce this burden. Additional research is needed to better understand this pain condition.
Some minor nerve injuries may rarely lead to devasting painful consequences resembling a complex regional pain syndrome like picture in both preclinical and clinical arenas.
ABSTRACTCRPS-1 in childhood may be less severe than in adulthood. The long-term prognosis in childhood needs further evaluation.KEYWORDS: CRPSRSDpediatric
Functional restoration has historically and empirically been considered a critical component of interdisciplinary pain management of CRPS. The evidence for suggesting the significance of functional restoration and reanimation remain modest but credible, and the need for further studies is to be encouraged.
ABSTRACTChronic pain disability is a challenging condition in which biological, psychological, and social factors dynamically interact with each other. Especially the treatment and rehabilitation of patients with CRPS put demands on techniques as well as on the rehabilitation framework. The general recommendation is a multidisciplinary team approach for CRPS patients. The psychological contribution should comprise a thorough assessment, followed by a psychological pain management component including relaxation/biofeedback training, cognitive interventions, behavioral interventions and extended cognitive-behavioral therapy.Approximately one-half to two-third of all patients diagnosed with chronic pain manifest various levels of psychological distress. Still, there is insufficient research-based information about the role of psychological factors in the etiology, prognosis and clinical picture of CRPS.Studies reveal that patients for whom CRPS-1 developed after radial forearm fracture seem to have neither a unique psychological pattern nor display more symptoms of depression than those who fully recover. In fact, CRPS patients seem to have common psychological features and show the same amount of anxiety and depression as patients with Fibromyalgia and Repetitive Strain Injury. Physical therapy in combination with autogenic relaxation training seems to lead to a significant improvement in limb temperature compared to physical therapy alone.Further research is needed to improve theory about psychological factors in CRPS. At present, there seems to be no published study specifically evaluating psychological factors in the etiology, clinical picture or prognosis of CRPS. Comparative controlled studies should be made to create practical clinical treatment methods for the patients. Probable psychological topics of importance in understanding CRPS are, among other distress factors: affect regulation and particularly alexithymia, fear-avoidance and catastrophising.KEYWORDS: CRPSpsychological factorsmultidisciplinary approach
Evidence-based pharmacotherapy for CRPS, as well as assorted symptoms faced in chronic CRPS are discussed.
There is a growing appreciation of the significant number of patients with complex regional pain syndrome suffer from movement disorders.
In patients with CRPS-I there are varying manifestations in the development and progression of the syndrome. It may lead to minimal impairment (i.e., loss of strength or pain with exposure to cold) or it may lead to major impairment, resulting in chronic invalidism. In extreme cases CRPS-I may even lead to amputation. There is a lack of knowledge in the efficacy of most treatments, time dependent symptoms of CRPS-I, natural course, prognostic factors and psychological and psychosomatic aspects of CRPS-I. In general the scientific background for therapy and for paramedical treatment particular is lacking. It may appear strange that without much evidence rehabilitation has such an important emphasis in these guidelines. The fact of the matter is that there are essentially no evidence-based therapies, and to not treat patients until ‘hard science’ is available is nihilistic. The rehabilitation method, especially physical and occupational therapies (PT and OT), provide a varied and balanced empirical approach, which at the present moment is the only way to proceed. In this paper a review of all published PT and OT papers are discussed.
