Complex regional pain syndrome 1--the Swiss cohort study

BACKGROUND

Little is known about the course of Complex Regional Pain Syndrome 1 and potential factors influencing the course of this disorder over time. The goal of this study is a) to set up a database with patients suffering from suspected CRPS 1 in an initial stadium, b) to perform investigations on epidemiology, diagnosis, prognosis, and socioeconomics within the database and c) to develop a prognostic risk assessment tool for patients with CRPS 1 taking into account symptomatology and specific therapies.

METHODS/DESIGN

Prospective cohort study. Patients suffering from a painful swelling of the hand or foot which appeared within 8 weeks after a trauma or a surgery and which cannot be explained by conditions that would otherwise account for the degree of pain and dysfunction will be included. In accordance with the recommendations of International Classification of Functioning, Disability and Health (ICF model), standardised and validated questionnaires will be used. Patients will be monitored over a period of 2 years at 6 scheduled visits (0 and 6 weeks, 3, 6, 12, and 24 months). Each visit involves a physical examination, registration of therapeutic interventions, and completion of the various study questionnaires. Outcomes involve changes in health status, quality of life and costs/utility.

DISCUSSION

This paper describes the rationale and design of patients with CRPS 1. Ideally, potential risk factors may be identified at an early stage in order to initiate an early and adequate treatment in patients with increased risk for delayed recovery.

[News in diagnostic and treatment of complex regional pain syndrome]

The complex regional pain syndrome (previously called algodystrophy) remains difficult to diagnose and to treat. New diagnostic criteria, easy to apply, based on patient's reports and clinical examination, have recently been proposed and deserve a large diffusion. On a therapeutic level, physiopathological data suggesting a disruption of sensory-motor integration have inspired interesting approaches. In particular, a rehabilitation program combining laterality recognition, mental imagery and mobilisation in front of a mirror showed a significant improvement of pain and functional capacities in a randomised, controlled, single blind study. This treatment is noninvasive, cheap, has no severe complications and favors patients autonomy.

Squamous cell carcinoma occurring within incision of recently implanted spinal cord stimulator

Spinal Cord Stimulation (SCS) is a treatment option for chronic pain patients. Spinal cord stimulation has been employed in the treatment of chronic pain for more than 30 years. The most common indication for SCS is the failed back syndrome with leg pain. Its indications have expanded beyond back and lower extremities pain to include axial low back pain, CRPS, mesenteric ischemia, peripheral neuropathy, limb ischemia, and refractory angina pectoris. The SCS has become a more versatile form of analgesia. The number of wound complications will surely rise in conjunction with the increasing number of devices being implanted. We describe a case of a well-differentiated squamous cell carcinoma occurring within the incision site of a recently implanted spinal cord stimulator early in the postoperative period. The patient developed a rapidly growing mass within the leads incision. The mass was confirmed to be squamous cell carcinoma by biopsy. The mass was excised under local anesthesia with appropriate margins. It was determined that the carcinoma did not extend below the dermis, and that there was no involvement of the underlying fascia. The device was tested for proper functioning, and the leads were thus left in place. While the development of skin malignancies in surgical wounds has been described in the literature, to our knowledge there have been no reports of a cutaneous neoplasm developing early in the postoperative period after spinal cord stimulator implantation.

Successful intravenous regional block with low-dose tumor necrosis factor-alpha antibody infliximab for treatment of complex regional pain syndrome 1

Cytokines, particularly tumor necrosis factor-alpha, may play an important role in the mediation of mechanical hyperalgesia and autonomic signs in complex regional pain syndrome 1. We performed an IV regional block with low-dose administration of the tumor necrosis factor-alpha antibody, infliximab, in a patient with typical clinical signs of complex regional pain syndrome 1 (moderate pain, edema, hyperhidrosis, elevated skin temperature compared with the contralateral side). A significant improvement of clinical variables was observed 24 h after infliximab treatment. Almost complete remission was reached within 8 wk, but sensory signs improved only after 6 mo. No adverse events were observed.

Complex regional pain syndrome with special emphasis on the knee

Complex regional pain syndrome is characterised by an exaggerated response to injury in a limb with intense prolonged pain, vasomotor disturbance, delayed functional recovery and trophic changes. This review describes the current knowledge of the condition and outlines the methods of treatment available with particular emphasis on the knee.

Regional pain syndrome: clinical characteristics, mechanisms and management

Regional soft-tissue complaints are commonplace, and they usually relate to a disease process, such as strain, inflammation or degeneration of a muscle, tendon or related muscle-tendon unit. The clinical features and investigations of the causative processes of these complaints are characteristic, and outcomes to treatments are usually predictable and satisfactory. Regional pain syndromes are different: these syndromes present with regional pain and tenderness, and other sensory symptoms unaccounted for by a simple musculoskeletal mechanistic explanation. Approved classification criteria for regional pain syndromes are lacking, and these syndromes are poorly understood and frequently misdiagnosed. Regional pain syndromes often occur after injury and overlap extensively with other musculoskeletal pain syndromes, in terms of clinical signs and symptoms. The clinician and patient are often confused about the nature of the problem and routine treatments directed to putative tissue damage will fail. Review of the epidemiology of regional pain syndromes combined with knowledge of other similar pain syndromes has enabled an evolving understanding of the condition. The musculoskeletal and central nervous systems both contribute to regional pain syndromes, through spine-related pain mechanisms and central sensitization, respectively. The patient's emotional state, particularly the effect on pain modulation, links these two systems.

Quadriparesis and spinal cord stimulation: case report

STUDY DESIGN

Case report.

OBJECTIVE

To report the occurrence of a rare complication following revision of a spinal cord stimulator.

SUMMARY OF BACKGROUND DATA

Puncture of the dura with placement of an electrode within the spinal cord has not been reported as a complication of spinal cord stimulation.

METHODS

A patient presented with upper and lower extremity weakness following inadvertent placement of an electrode into the spinal cord. The clinical case is presented as well as review of the literature.

RESULTS

The patient had the electrode successfully removed; however, her neurologic status deteriorated.

CONCLUSION

Revision of spinal cord stimulators is usually a safe procedure. However, placement of an electrode within the spinal cord during the revision process is a potential complication resulting in severe neurologic injury.

Pediatric complex regional pain syndrome

Complex regional pain syndrome (CRPS) is a relatively new diagnostic entity in pediatrics. There is debate as to what constitutes the most effective treatment for pediatric CRPS. This study presents the patient characteristics, clinical course, and treatment outcome of 20 children diagnosed with CRPS at a major children's hospital during a 4-year period. The results showed that pediatric CRPS occurs predominantly in girls (90%) in later childhood and adolescence (mean age, 11.8 [range, 8-16 years]). It affects mainly the lower limbs (85%), with a predilection for the foot (75% of all cases), and was frequently initiated by minor trauma (80%). In many cases, there was a lengthy time to diagnosis (mean, 13.6 weeks) that delayed the institution of treatment, which consisted of intensive physiotherapy and psychological therapy. Most children (70%) required adjuvant medications (amitriptyline and/or gabapentin) for analgesia and to enable them to participate in physiotherapy. A high percentage of children had complete resolution of symptoms using this treatment regime (mean, 15.4 weeks [range, 3 days to 64 weeks]), but 40% required treatment as a hospital inpatient and 20% had a relapse episode. In conclusion, pediatric CRPS is under-recognized by clinicians, resulting in diagnostic delays, but has a favorable outcome to noninvasive treatment in that complete resolution of symptoms and signs occur in most patients. However, the lengthy period to achieve symptom resolution in some children and a high relapse rate support the need for further research into other treatment modalities.

Treatment of CRPS with ECT

BACKGROUND

Electroconvulsive therapy (ECT) is a well-established treatment method for medically refractory depression. ECT has also been used in the treatment of pain for over 50 years. The mechanism of action of ECT is still unknown, although several observations have been made regarding the effect of ECT on pain processes. It has been reported that several patients with medically refractory depression and Complex Regional Pain Syndrome who were treated with ECT for their depression were also cured of their CRPS symptoms.

OBJECTIVE

We report a case of CRPS in a patient who also suffered from medically refractory depression. She was treated with ECT for her depression and subsequently was relieved of all her CRPS symptoms.

CASE REPORT

A 42 year-old female patient underwent a series of 12 standard bitemporal electroconvulsive therapy treatments for medically refractory depression. Physical examination and Quantitative Sensory Testing was done before and after the patient's treatment with ECT. This standard treatment procedure for refractory depression completely resolved the patient's depressive symptoms. In addition, the patient's CRPS symptoms were also reversed. Physical examination as well as Quantitative Sensory Testing done before and after the ECT treatment correlated with her CRPS symptom improvement.

CONCLUSION

ECT was effective in the treatment of severe refractory CRPS in this patient.

Ten consecutive cases of complex regional pain syndrome of less than 12 months duration in active duty United States military personnel treated with spinal cord stimulation

Complex regional pain syndrome describes a constellation of symptoms that may involve the sympathetic nervous system. Emerging consensus recommends early intervention with spinal cord stimulation to facilitate physical therapy. Isolated case reports suggest this may be an effective treatment. Ten consecutive active duty United States military personnel with newly diagnosed complex regional pain syndrome underwent early intervention with spinal cord stimulation with favorable results, including decreased pain scores and decreased opioid intake. Six received injuries directly as a result of service in Iraq or Afghanistan. These patients also had posttraumatic stress disorder, but it did not interfere with successful pain control. Additionally, 6 of 10 patients continued on active duty.

[Iatrogenic peripheral nerve injury; mechanism and therapy]

The pain remaining after a needle stick is categorized as neuropathic pain. CRPS (Complex Regional Pain Syndrome) is a typical disease in this category. Neuropathic pain is extremely intractable when it becomes chronic pain, inducing psychological and physical pain in patients over a long period of time. Neuropathic pain is a complex system caused by various factors, and its mechanism remains unclear. For prevention, medical practioners should carefully select centesis, and apply necessary measures corresponding to the situation. There is no established treatment for neuropathic pain. We usually treat the disease with nerve block and drug therapy. Nerve block is useful for pain relief. We typically use a sympathetic nerve block (SGB; stellate ganglion block, IRSB; intravenous regional sympathetic block et. al.) as the initial treatment. In the stage of chronic pain, it is very important to improve patients' ADL (activity of daily living) and QOL (quality of life). If neuropathic pain is suspected, it is crucial to treat at an early stage. Therefore, it should be emphasized that when pain persists after a needle stick, the patient should immediately consult a pain clinician or an orthopedist.

Pain syndromes after missile-caused peripheral nerve lesions: part 2--treatment

OBJECTIVE

To analyze treatment procedures and treatment outcomes of painful missile-caused nerve injuries and factors influencing the outcome.

METHODS

The study included 326 patients with clinically significant pain syndromes, including complex regional pain syndrome Type II, deafferentation pain, reinnervation pain, and neuralgic pain. Treatment modalities included drug therapy, nerve surgery, sympatholysis, and dorsal root entry zone operation. Pain intensity was assessed before and after the treatment using a visual analog scale, and treatment outcome was defined as successful (pain relief >70%), fair (pain relief between 50 and 69%), or poor (pain relief <50%). The outcome was compared between different pain syndromes and different treatment modalities.

RESULTS

A successful outcome was achieved in 28.6% of patients with deafferentation pain, in 76.9% of patients with complex regional pain syndrome Type II, and in 87.9 to 100% of patients with other pain syndromes (P = 0.002). Each type of pain syndrome required a specific treatment algorithm, but average pain relief was similar for all definitive treatment modalities (range, 81-88%; P > 0.05). Ten factors were found to significantly influence the treatment outcome, but only three factors were independent predictors of a successful outcome: type of pain syndrome (P < 0.001), severity of nerve injury (P < 0.001), and absence of pain paroxysms (P = 0.03).

CONCLUSION

The treatment outcome of painful nerve injury depends on several factors, including the type of pain syndrome, severance of nerve injury, and absence of pain paroxysms. Drug therapy (carbamazepine, amitriptyline, or gabapentin) should be recommended, at least as a part of treatment, for patients with reinnervation pain, deafferentation pain, and complex regional pain syndrome Type II. Nerve surgery should be recommended for patients with posttraumatic neuralgia, either as the first treatment choice (acute nerve compression or intraneural foreign particles) or after unsuccessful pharmacological treatment (other causes of neuralgic pain).

Monoparesis with complex regional pain syndrome-like symptoms due to brachial plexopathy caused by the varicella zoster virus: a case report

Viral invasion of the motoneurons and the subsequent inflammation in the anterior horn cells by the varicella zoster virus results in a weakness in the area of the cutaneous eruption. The exact mechanism of zoster paresis is uncertain. The occurrence of symptoms resembling complex regional pain syndrome (CRPS) is common in subjects where the herpes zoster (HZ) outbreak affects an extremity, particularly if it is the distal extremity that is involved. We report the case of a 54-year-old man with monoparesis, hyperalgesia, allodynia, edema, and both color and skin-temperature changes in his left arm after a skin eruption. Electrophysiologic examination revealed the partial degeneration of the superior, middle, and inferior truncus in the brachial plexus, with evidence of HZ infection. Magnetic resonance imaging of the cervical spine and brachial plexus showed degenerative changes without any evidence of nerve root compression. Brachial plexopathy may be the direct cause of the reversible upper-limb paresis resulting from HZ with CRPS-like symptoms.

Prism adaptation to optical deviation alleviates pathologic pain

BACKGROUND

The human visual and somatosensory systems are interdependent. Using a visual subjective body-midline (SM) judgment task, we previously confirmed that pathologic pain and deafferentation can modify visuospatial perception, indicating that altered somatosensory experience can modify visual perception. Conversely, in the present study we investigated whether a change in visual experience can modify perception of pathologic pain.

METHODS

We used prism adaptation (PA) to modify subjects' visual experience. Five patients with complex regional pain syndrome (CRPS) adapted to wedge prisms, producing a 20-degree visual displacement toward the unaffected side. Further, we used several types of prisms in a longitudinal single-case study. Wearing prismatic goggles, the subjects performed a target-pointing task once a day for 2 weeks. We evaluated pain intensity and visual SM judgment to measure the adaptive aftereffects at three time points: before PA (pre-test), immediately after the first PA exposure (IA-test), and after a 14-day sequence of PA exposure (post-test).

RESULTS

PA toward the unaffected side alleviated pathologic pain and other CRPS pathologic features, when measured at post-test. None of the IA-test results showed an analgesic effect. In the longitudinal study, sham PA and 5-degree PA did not produce any effects, and PA toward the affected side actually exacerbated the subjective pain.

CONCLUSIONS

Our findings suggest that vision can influence pathologic pain, and preliminarily suggest that prism adaptation has a direction-specific and reproducible effect on not only pathologic pain but also other CRPS pathologic features. Thus, prism adaptation may be a viable cognitive treatment for CRPS.

[Perioperative analgesia with continuous peripheral nerve blocks in children]

Recently, regional anaesthesia in children has generated increasing interest. But single injection techniques have a limited duration of postoperative analgesia. Then, continuous peripheral nerve blocks have taken an important position in the anaesthetic arsenal, allowing an effective, safe and prolonged postoperative pain management. As adults, indications for continuous peripheral nerve blocks depend on the analysis of individual benefits/risks ratio. Main indications are intense postoperative pain surgical procedures, with or without postoperative rehabilitation, and complex regional pain syndrome. Contraindications to these procedures are rather similar to those in adults, plus parental and/or children refusal. Continuous peripheral nerve blocks are usually performed under general anaesthesia or sedation in children, and require appropriate equipment in order to decrease the risk of nerve injury. New techniques, such as transcutaneous nerve stimulation or ultrasound guidance, appeared to facilitate nerve and plexus approach identification in paediatric patients. Nevertheless, continuous peripheral nerve block may theoretically mask a compartment syndrome after trauma surgical procedures. Finally, ropivacaine appears to be the most appropriate drug for continuous peripheral nerve blocks in children, requiring low flow rates and concentrations of local anaesthetic. These techniques may facilitate early ambulation by an improved pain management or even postoperative analgesia at home with disposable pumps. One might infer from the current review that excellent pain relief coupled with a reduction of side effects would contribute to improve the quality of life and to decrease the frequency of disabling behavioural modifications in children, sometimes psychologically injured by hospital stay and postoperative pain.

[Complex regional pain syndromes: new aspects on pathophysiology and therapy]

Complex-regional pain syndromes (CRPS), formerly known as Sudeck's dystrophy and causalgia, belong to the neuropathic pain syndromes. CRPS may develop following fractures, limb trauma or lesions of the peripheral or central (CNS) nervous system. Occasionally, CRPS may also develop spontaneously. The clinical picture comprises a characteristic clinical triade of symptoms including autonomic (disturbances of skin temperature, colour, presence of sweating abnormalities), sensory (pain and hyperalgesia) and motor (paresis, tremor, dystonia) disturbances. Diagnosis is mainly based on clinical signs. However, additional laboratory, neurophysiological and radiological examinations may help to corroborate correct diagnosis. Several pathophysiological concepts have been proposed to explain the complex symptoms of CRPS: 1, facilitated neurogenic inflammation; 2, pathological sympatho-afferent coupling; 3, neuroplastic changes within the CNS. Furthermore, there is accumulating evidence that genetic factors may predispose for CRPS. Therapy is based on a multidisciplinary approach. Non-pharmacological approaches include physiotherapy and occupational therapy. Pharmacotherapy is based on individual symptoms and includes steroids, free radical scavengers, treatment of neuropathic pain, and finally agents interfering with bone metabolism (calcitonin, biphosphonates). Sympathetic blocks are useful for the treatment of sympathetically maintained pain. Invasive therapeutic concepts include implantation of spinal cord stimulators. This review covers new aspects of pathophysiology and therapy of CRPS.

Advances in treatment of complex regional pain syndrome: recent insights on a perplexing disease

PURPOSE OF REVIEW

The paper is a critical appraisal of recent advances in the treatment of complex regional pain syndrome. Rapidly changing concepts related to the pathophysiology of this disease has transformed its current management and necessitates an updated review of the literature.

RECENT FINDINGS

Chronic regional pain syndrome is a perplexing disease that continues to challenge researchers with respect to its cause and treatment. Recent modification to diagnostic criteria has enabled clinicians to diagnose this disease in a more consistent fashion. Emerging data indicate a possible role of inflammation in the overall pathophysiology and have led to treatment trials with newer anti-inflammatory medications. Certain 'conventional' interventional techniques have been recently scrutinized. A few novel therapeutic options like graded imagery are also outlined.

SUMMARY

Enhanced insight into the pathophysiology of chronic regional pain syndrome has modified current clinical practice and the focus of research. Certain 'standard' therapeutic options for chronic regional pain syndrome have failed the test of time while others have prevailed. New options have recently been evaluated and have shown promising early results. Knowledge of recent advances in chronic regional pain syndrome will help pain physicians provide optimal care to these patients.

Psychological and behavioral aspects of complex regional pain syndrome management

Psychological and behavioral factors can exacerbate the pain and dysfunction associated with complex regional pain syndrome (CRPS) and could help maintain the condition in some patients. Effective management of CRPS requires that these psychosocial and behavioral aspects be addressed as part of an integrated multidisciplinary treatment approach. Well-controlled studies to guide the development of a psychological approach to CRPS management are not currently available. A sequenced protocol for psychological care in CRPS is therefore proposed based on available data and clinical experience. Regardless of the duration of the condition, all CRPS patients and their families should receive education about the negative effects of disuse, the pathophysiology of the syndrome, and possible interactions with psychological/behavioral factors. Patients with acute CRPS (<6-8 weeks) may not need additional psychological care. All patients with chronic CRPS should receive a thorough psychological evaluation, followed by cognitive-behavioral pain management treatment, including relaxation training with biofeedback. Patients making insufficient overall treatment progress or in whom comorbid psychiatric disorders/major ongoing life stressors are identified should additionally receive general cognitive-behavioral therapy to address these issues. The psychological component of treatment can work synergistically with medical and physical/occupational therapies to improve function and increase patients' ability to manage the condition successfully.

Treatment of complex regional pain syndrome: functional restoration

In this review, the authors discuss the development of consensus-based treatment guidelines in 1997. They also synthesize the recommendations of a closed workshop held in Budapest in late 2004 that reexamined these treatment guidelines and made further and more detailed recommendations. They explore and develop the rationale for making functional restoration the pivotal treatment algorithm in the management of complex regional pain syndrome, around which all other treatments, such as psychotherapy, drugs, and interventions, revolve. The authors discuss in detail the process of functional restoration and the modalities appropriate to accomplishing that--specifically, the role of the occupational therapist, physical therapist, recreational therapist, and vocational rehabilitation specialist. Medications, interventions, and psychotherapy will be covered in other sections of this series.

[Unintentional total spinal anesthesia during cervical epidural block with ropivacaine]

We present a case of unintentional total spinal anesthesia, which occurred during cervical epidural block. A 34-year-old man with complex regional pain syndrome of the right upper arm was treated with epidural block at C7-T1 interspace. Immediately after test-dose injection of ropivacaine 1.5 ml, he complained of paresthesia of his upper extremities. He developed difficulty talking and breathing. Subsequently he showed a complete paralysis with the loss of consciousness, respiratory arrest, and bilateral midriasis. Mandatory ventilation was started and endotracheal tube was placed. Eighty minutes after the injection of ropivacaine, he recovered consciousness and spontaneous respiration resumed. Checking adequate ventilation, his trachea was extubated. Neurological dysfunction was not seen thereafter. Although test-dose injection is recommended especially in high-risk patients and case of difficulty of epidural space identification, it does not fully prevent complications. For cervical epidural block, local anesthetics should either be given at small doses or not be given as long as a possibility of spinal injection is remaining.

Difficult Pain Syndromes

Cancer pain is prevalent in approximately two thirds of all cancer patients and can undermine the quality of life in this patient population. Uncontrolled pain can cause physical as well as psychological distress in cancer patients. As the disease progresses in cancer, pain and suffering increase. Knowledge about pain management is paramount in the comprehensive treatment of cancer patients. Difficult cancer pain syndromes may arise from interruption of bone, viscera, and neural structures by malignant spread of the disease. Familiarity with opioids, adjuvants, and procedures that can abate pain in cancer patients is discussed in a practical manner for clinical application in this text.

Quantitative Sensory Testing for Spinal Cord Stimulation in Patients With Chronic Neuropathic Pain

OBJECTIVE

A prospective pilot study was conducted, attempting to identify objective tests that would help clinicians to assess the efficacy of spinal cord stimulation (SCS) trial preceding permanent device implantation.

SETTING

Four university hospitals in the United States and Israel.

PARTICIPANTS

Thirteen patients with radicular leg pain due to failed back surgery syndrome (FBSS) or leg pain due to complex regional pain syndrome (CRPS) who were candidates for SCS.

METHODS

PARTICIPANTS underwent a series of quantitative sensory tests prior to, and seven days after the initiation of SCS trial. These tests included: vibration threshold (conducted using the VSA 3000; Medoc Inc., Ramat Ishay, Israel), cold threshold, warm threshold, heat pain threshold, phasic heat pain threshold, tonic heat pain threshold (conducted using the TSA 2001; Medoc Inc.), and electrical pain tolerance at 5, 250 and 2000 Hz (administered using the NerveScan 2000; Neurotron, Inc., Baltimore, MD, USA).

RESULTS

Useful data were obtained from 12 patients. The results of the vibration threshold and the tolerance to electrical stimulation at 5 and 250 Hz changed with an SCS trial. These results also correlated with the decision regarding the permanent implantation, which was made independently of them. In contrast, the results of thermal thresholds and tolerance to electrical stimulation at 2000 Hz tests did not change with the SCS trial.

CONCLUSIONS

Our findings, which agree with those of a few other studies, suggest that the vibration threshold and the tolerance to electrical stimulation at 5 and 250 Hz tests can assist the clinician to select the right patients for permanent stimulation.

[Complex Regional Pain (CRPS) Syndrome type II. Timing for surgery and therapeutic options: neuromodulation]

OBJECTIVE

The object of this study is to evaluate the importance of a correct timing for surgery, the different strategies of therapy and the use of the neuromodulation in the Complex Regional Pain Syndrome (CRPS) type II.

PATIENTS AND METHODS

The last 2 years we observed 8 patients with the clinical picture of a CPRS type II, due to previous peripheral nerve lesions of the upper extremity. All the patients followed a therapeutic protocol of neuromodulation and reconstructive surgical repair.

RESULTS

Six patients out of eight had almost a complete recovery of the symptoms 6 months after the surgery.

CONCLUSIONS

Our study demonstrates that the patients who underwent surgical repair followed by neuromodulation didn't present any recurrence of the symptoms.

Pathophysiology of complex regional pain syndrome

Complex regional pain syndrome (CRPS) most often follows injury to peripheral nerves or their endings in soft tissue. A combination of prostanoids, kinins and cytokines cause peripheral nociceptive sensitization. In time, the Mg(2+) block of the N-methyl-D-aspartate receptor is removed, pain transmission neurons (PTN) are altered by an influx of Ca(2+) that activates kinases for excitation and phosphatases for depression, activity-dependent plasticity that alters the firing of PTN. In time, these neurons undergo central sensitization that lead to a major physiological change of the autonomic, pain and motor systems. The role of the immune system and the sickness response is becoming clearer as microglia are activated following injury and can induce central sensitization while astrocytes may maintain the process.

Interventional Therapies in the Management of Complex Regional Pain Syndrome

Invasive procedures have long held a place in the therapeutic armamentarium for the management of complex regional pain syndrome (CRPS). However, this has evolved considerably, particularly as research into the mechanisms of CRPS has called into question long-held presumptions about the key role of sympathetic dysfunction in the syndrome. This review summarizes some of the key information currently available about interventional treatments, including nerve blocks, spinal cord and peripheral nerve stimulation, chemical and surgical sympathectomies, and deep brain stimulation. The potential roles for these procedures in facilitating functional rehabilitation goals that are primary to the treatment of CRPS are emphasized.

Repeated lumbar sympathetic blockade with lidocaine and clonidine attenuates pain in complex regional pain syndrome type 1 patients--a report of two cases

Repeated lumbar sympathetic blockade (LSB) with local anesthetics is generally used in complex regional pain syndrome (CRPS) of the lower extremities if the initial block has been successful. However, the symptoms of CRPS may inevitably recur in spite of repeated LSB. Clonidine, an alpha2-adrenoceptor agonist, has both anesthetic and analgesic sparing effects, and when added to local anesthetics may enhance peripheral and central neural block due to its local or central analgesic effects. It is reasonable that clonidine has been used in chronic pain conditions such as neuropathic and sympathetically maintained pain. Here we report two cases of CRPS type 1 who got excellent analgesia and alleviation of clinical symptoms after receiving an LSB with lidocaine and clonidine.

Management of Pediatric Patients With Complex Regional Pain Syndrome

This review summarizes current information about diagnosis and treatment of complex regional pain syndrome (CRPS) in children. Although it has been widely held that CRPS in children is intrinsically different from adults, there appear to be relatively few differences. However, there is a marked preponderance of lower extremity cases in children. Historically, psychological factors have been invoked to explain the genesis and persistence of CRPS in children, but the evidence is not compelling. Treatment outcome studies are limited but indicate that children generally respond to a primary focus on physical therapy. Multidisciplinary treatment reports are particularly encouraging. The general perception that children have a milder course may relate to the potentially greater willingness of children to actively participate in appropriately targeted treatment rather than to innate differences in the disease process itself. Recurrence rates appear higher than in adults, but response to reinitiation of treatment seems to proceed efficiently. Clinical judgment dictates the extent of medication or interventional therapy added to the treatment to facilitate rehabilitation. In many ways, the approach to the treatment of children mirrors that of adults, with perhaps greater restraint in the use of medications and invasive procedures. The rehabilitation of children with CRPS, like that of adults with CRPS, needs further rigorous investigation.

Complex regional pain syndrome after transradial cardiac catheterization

Complex regional pain syndrome (CRPS) is a disease with unclear pathophysiology. The condition is characterized by pain, soft tissue change, vasomotor change, and even psychosocial disturbance. It may affect the upper more than the lower extremities, and the distal more than the proximal. The trigger factors include carpal tunnel release, Dupuytren's repair, tendon release procedures, knee surgery, crush injury, ankle arthrodesis, amputation, and hip arthroplasty. Rarely, it has been associated with stroke, mastectomy, pregnancy, and osteogenesis imperfecta. Herein, we present a rare case of a patient who was diagnosed with CRPS after transradial cardiac catheterization. CRPS was first diagnosed due to hand swelling, allodynia, paresthesia, and the limited range of motion of interphalangeal, metacarpophalangeal, and wrist joints, with the preceding factor of transradial cardiac catheterization, and was then confirmed by a three-phase bone scan. After intensive physical therapy with hydrotherapy, manual soft tissue release, and occupational therapy for the hand function, there was much improvement in range of motion and hand function. There was no allodynia or painful sensation in the follow-up. After training, the functional status of this patient was adequate for daily activity.

Complex regional pain syndrome: manifestations and the role of neurostimulation in its management

The hallmark of complex regional pain syndrome (CRPS) is excruciating pain (aching, burning, pricking, or shooting). Diagnosis should be established as soon as possible, as response to treatment is adversely affected by any delay. Treatment of CRPS is aimed at improving function, using an interdisciplinary, time-dependent, patient-dependent approach that encompasses rehabilitation, psychological therapy, and pain management. If no response to conventional treatment (e.g., pharmacotherapy) is noted within 12-16 weeks, a more interventional technique such as spinal cord stimulation (SCS) should be used. SCS has been shown to be highly effective in the treatment of CRPS type I, resulting in a significant, long-term reduction in pain and improvement in quality of life. SCS is particularly effective at helping to restore function in affected extremities, especially if applied early in the course of the disease. SCS is also cost effective and improves health-related quality of life.

Hyperbaric oxygen therapy in chronic pain management

Chronic pain is one of the frequently encountered clinical problems that is difficult to cure. Hyperbaric oxygen (HBO) therapy has been reported in chronic pain syndromes with promising results. In this review, we focus on the effectiveness of HBO in fibromyalgia syndrome, complex regional pain syndrome, myofascial pain syndrome, migraine, and cluster headaches. HBO may be beneficial if appropriate patients are selected. HBO is a reliable method of treatment. However, physicians performing HBO must be aware of oxygen toxicity. Another problem regarding HBO is the scarcity of centers administering it. Further research is required focusing on the optimal treatment protocol, the cost/benefit ratio, and the safety of HBO in chronic pain management.

Complex regional pain syndrome in pediatric sports: a case series of three young athletes

SETTING

Outpatient Sports Medicine Clinic.

PATIENTS

Three adolescent young female athletes who developed clinical findings compatible with complex regional pain syndrome (CRPS) after lower extremity trauma.

INTERVENTION

Based on the clinical picture, the patients were identified and treated with physical therapy, which included desensitization techniques, stress loading, edema control, early mobilization and electrical stimulation. It was combined with pharmacotherapeutic measures such as non-steroidal anti-inflamatories, oral corticosteroids and gabapentin. One of the patients required serotonin selective reuptake inhibitors, opioid analgesics and acupuncture as an adjunctive treatment.

RESULTS

All three patients had involvement of the lower extremities, with a degree of pain and edema exceeding the expected for the nature of their injury. They exhibited a good response to conservative treatment, with physical therapy playing a significant role on the treatment plan. One of the patients, whose diagnosis and treatment was delayed due to late referral, had a more severe presentation and protracted recovery.

CONCLUSION

CRPS is a challenging disease that may affect young active and athletic patients. In this population, early clinical suspicion and aggressive treatment may lead to excellent clinical results and the avoidance of invasive procedures or long-term disability. Laboratory and imaging studies should be used to discard other conditions with clinical presentations similar to CRPS.

Sympathetic skin responses in reflex sympathetic dystrophy

This study was performed to determine the utility of sympathetic skin response (SSR) in evaluating the sympathetic function and to follow up the effects of sympathetic blockade in reflex sympathetic dystrophy (RSD). Thirty patients having RSD with upper extremity involvement were randomly divided into two groups. Besides medical therapy and exercise, physical therapy agents were applied to both the groups. In addition to this treatment protocol, stellar ganglion blockade was done by diadynamic current in Group II. The normal sides of the patients were used for the control group. SSRs were measured in all the patients before and after the therapy. The amplitude was found to be increased and the latency was found to be decreased in the affected side in both the groups before the therapy. After the therapy, the amplitude was decreased and latency was increased in both the groups. But, the differences in amplitude (P = 0.001) and latency (P = 0.002) before and after the therapy were significantly higher in Group II. (Before the treatment, SSRs were significantly different between the normal and the affected sides in both the groups. The observed change in SSRs after the treatment was higher in Group II.) It was concluded that, SSR can be a useful and noninvasive method in diagnosing the sympathetic dysfunction in RSD and can be used for evaluating the response to sympathetic blockade and other treatment modalities.

The Challenge to Manage Reflex Sympathetic Dystrophy/Complex Regional Pain Syndrome

The challenge to understand reflex sympathetic dystrophy/complex regional pain syndrome may require a better understanding of the complex relationship between the central and peripheral nervous systems. There is no comprehensive hypothesis that clearly explains the etiology and no uniformly successful treatment method. This brief summary of the challenge reviews some of what is known, hypothesizes a possible etiologic mechanism, and proposes 10 common-sense principles for management that recognizes the handicap of limited knowledge.

Trustworthiness as a Clinical Variable: The Problem of Trust in the Management of Chronic, Nonmalignant Pain

The subjective nature of pain leads to many treatment difficulties. These problems can often be resolved if we know that the patient is trustworthy. Trustworthiness should be assessed as a distinct clinical variable. This is more easily achieved if we examine the three components of trustworthiness: the patient's subjective reports, which we call testimony; the reason that the patient seeks treatment, which we call motive; and the patient's adherence with efforts to get well, which we call responsibility. Because of difficulties with assessing testimony and motive, we propose that establishing the patient's responsibility is the key to assessing trustworthiness.

Computed tomography guided lumbar sympathetic block for complex regional pain syndrome in a child: a case report and review

The aim of this paper is to describe the first reported use of computed tomography (CT) guided lumbar sympathetic block as treatment of a case of complex regional pain syndrome (CRPS) in a child. The potential aetiology of CRPS is discussed in relation to the mechanism of action of local anaesthetics used in the block. Based on the successful treatment of this child and the documented success of its use in adults, we conclude that despite the minimal dose of radiation given, CT guided lumbar sympathetic block is an important treatment option in CRPS in children.

Chronic neuropathic pain. Mechanisms, diagnosis, and treatment

BACKGROUND

The management of chronic pain represents a significant public health issue in the United States. It is both costly to our health care system and devastating to the patient's quality of life. The need to improve pain outcomes is reflected by the congressional declaration of the present decade as the "Decade of Pain Control and Research," and the acknowledgment in January 2001 of pain as the "fifth vital sign" by the Joint Commission of Healthcare Organizations.

REVIEW SUMMARY

At present, therapeutic options are largely limited to drugs approved for other conditions, including anticonvulsants, antidepressants, antiarrhythmics, and opioids. However, treatment based on the underlying disease state (eg, postherpetic neuralgia, diabetic neuropathy) may be less than optimal, in that 2 patients with the same neuropathic pain syndrome may have different symptomatology and thus respond differently to the same treatment. Increases in our understanding of the function of the neurologic system over the last few years have led to new insights into the mechanisms underlying pain symptoms, especially chronic and neuropathic pain.

CONCLUSIONS

The rapidly evolving symptom- and mechanism-based approach to the treatment of neuropathic pain holds promise for improving the quality of life of our patients with neuropathic pain.

Complex regional pain syndrome

Complex regional pain syndrome (CRPS) may develop after limb trauma and is characterized by pain, sensory-motor and autonomic symptoms. Most important for the understanding of the pathophysiology of CRPS are recent results of neurophysiological research. Major mechanism for CRPS symptoms, which might be present subsequently or in parallel during the course of CRPS, are trauma-related cytokine release, exaggerated neurogenic inflammation, sympathetically maintained pain and cortical reorganisation in response to chronic pain (neuroplasticity). The recognition of these mechanisms in individual CRPS patients is the prerequisite for a mechanism-oriented treatment.

Cortical reorganization during recovery from complex regional pain syndrome

OBJECTIVE

To characterize reorganization of the primary somatosensory cortex (S1) during healing process in complex regional pain syndrome (CRPS).

BACKGROUND

Recently, the authors showed extensive reorganization of the S1 cortex contralateral to the CRPS affected side. Predictors for these plastic changes were CRPS pain and the extent of mechanical hyperalgesia. It is unclear how these S1 changes develop following successful therapy.

METHODS

The authors used magnetic source imaging to explore changes in the cortical representation of digits (D) 1 and 5 in relation to the lower lip on the unaffected and affected CRPS side in 10 patients during a year or more of follow-up.

RESULTS

Cortical reorganization reversed coincident with clinical improvement. A reduction of CRPS pain correlated with recovery from cortical reorganization.

CONCLUSIONS

Changes of the somatotopic map within the S1 cortex may depend on CRPS pain and its recovery.

Complex regional pain syndrome: the case for spinal cord stimulation (a brief review)

Complex regional pain syndrome is a disabling disorder with an unknown mechanism which is extremely resistant to conventional pharmaceutical and therapeutic therapies. In this paper we present the underlying theories of this disorder. We present spinal cord stimulation as an alternative to conventional interventions in the management of this disabling condition spinal cord stimulation significantly improves pain, reduces narcotic intake and improves activity levels and overall quality of life. There is now a significant body of evidence to support the utilization of spinal cord stimulation in the management of complex regional pain syndrome.