Complex Regional Pain Syndrome—A Multifaceted Disorder Requiring Multidimensional Care: Case Study

Increased calcium-mediated cerebral processes after peripheral injury: possible role of the brain in complex regional pain syndrome

Background

Among various diseases that accompany pain, complex regional pain syndrome (CRPS) is one of the most frustrating for patients and physicians. Recently, many studies have shown functional and anatomical abnormalities in the brains of patients with CRPS. The calcium-related signaling pathway is important in various physiologic processes via calmodulin (CaM) and calcium-calmodulin kinase 2 (CaMK2). To investigate the cerebral mechanism of CRPS, we measured changes in CaM and CaMK2 expression in the cerebrum in CRPS animal models.

Methods

The chronic post-ischemia pain model was employed for CRPS model generation. After generation of the animal models, the animals were categorized into three groups based on changes in the withdrawal threshold for the affected limb: CRPS-positive (P), CRPS-negative (N), and control (C) groups. Western blot analysis was performed to measure CaM and CaMK2 expression in the rat cerebrum.

Results

Animals with a decreased withdrawal threshold (group P) showed a significant increment in cerebral CaM and CaMK2 expression (P = 0.013 and P = 0.021, respectively). However, groups N and C showed no difference in CaM and CaMK2 expression.

Conclusions

The calcium-mediated cerebral process occurs after peripheral injury in CRPS, and there can be a relationship between the cerebrum and the pathogenesis of CRPS.

Complex [corrected] regional pain syndrome: what specialized rehabilitation services do patients require?

Complex [corrected] regional pain syndrome (CRPS) is a complex disorder, the optimal treatment of which requires an interdisciplinary approach encompassing medical, interventional, psychological, and rehabilitation services that emphasize the role of physical and occupational therapies. The central focus of treatment is the restoration of function, utilizing a systematic, coordinated, and progressive set of therapeutic strategies. The poorly delineated pathophysiology and variable course of CRPS suggest that individualized strategies are required for optimal management, but also mean that carefully controlled trials of physiotherapy are difficult to conduct. This article presents a brief review of the nature and pathophysiology of CRPS, the medical and psychological approaches that have been found to be effective, and a review of the current trends in rehabilitation.

[Efficacy of a topical treatment protocol with dimethyl sulfoxide 50% in type 1 complex regional pain syndrome]

OBJECTIVE

Evaluate the efficacy of a topical treatment protocol with DMSO 50% to alleviate inflammatory processes in type 1 complex regional pain syndrome (CRPS) with a course of less than 1 year.

METHOD

Retrospective study performed in a traumatology hospital on patients with type 1 CRPS for whom a standard treatment algorithm was prescribed with stepwise administration of oral drugs and interventional techniques. Patients also received topical DMSO 50% cream as a magistral formula. The follow-up period, lasting until patient discharge, or during 1 year for persistent cases, included 6 visits: baseline, 15 days, 1 month, 3 months, 6 months, and 1 year. The evaluation was performed using a visual analogue scale (VAS) as the main efficacy variable. Secondary variables were the Likert scale for quality of life and the limb capacity variable (range of motion, strength, overall limb function). A questionnaire designed for the study was also given.

RESULTS

Overall decrease in VAS score in the 29 patients was 3.09 points. The Likert scale score increased by 1.36 points. The scores measuring limb capacity increased to 12.03 for range of motion and to 3 in strength with overall function rated «moderate».

CONCLUSIONS

Topical application of DMSO 50% associated with a treatment algorithm decreased pain intensity according to the VAS score with results approaching absence of pain, and led to higher scores on the quality of life questionnaire. Topical DMSO 50% is an additional tool for use in treating CRPS I. Its side effects are scarce and it provides an overall sense of relief and lessens rigidity.

Preliminary evaluation of an educational model for promoting positive team attitudes and functioning among pain medicine fellows

OBJECTIVE

In response to the Accreditation Council for Graduate Medical Education's (ACGME) new pain medicine fellowship requirement, which emphasizes multidisciplinary training strategies aimed at providing improved clinical care for pain patients, we developed a multidisciplinary team training education model for trainees in our institution's Fellowship Program in Pain Medicine. Although the biopsychosocial model guides the delivery of care by multidisciplinary pain teams, there is a gap on how to improve team attitudes and functioning within an already extensive pain medicine curriculum. The current study aimed to fill that gap by developing and incorporating an educational model that focuses on interpersonal relationships among team members and strategies for improving team performance over time.

DESIGN, SETTING, PARTICIPANTS, INTERVENTION, AND OUTCOME MEASURES

Here, we provide a brief overview of our institution's pain medicine fellowship training program highlighting how we have included a team training component into lectures, interdisciplinary case conferences, and journal club articles that focus on topics in the ACGME pain medicine curriculum. We present data from a team attitude and functioning assessment battery administered to 11 pain medicine fellows at the outset and end of their fellowship.

RESULTS AND CONCLUSIONS

Mean assessment scores increased from the beginning of the fellowship to the end of the fellowship on interdisciplinary pain team knowledge, current team skills, and attitude toward health care teams. The current study demonstrated effective ways for assessing team attitudes and functioning and including this educational component into a 1-year pain medicine curriculum. Based on our results, we will continue to teach and model effective teamwork in an effort to enhance our trainees' attitudes toward working on an interdisciplinary pain team.

Regulation of peripheral blood flow in complex regional pain syndrome: clinical implication for symptomatic relief and pain management

BACKGROUND

During the chronic stage of Complex Regional Pain Syndrome (CRPS), impaired microcirculation is related to increased vasoconstriction, tissue hypoxia, and metabolic tissue acidosis in the affected limb. Several mechanisms may be responsible for the ischemia and pain in chronic cold CPRS.

DISCUSSION

The diminished blood flow may be caused by either sympathetic dysfunction, hypersensitivity to circulating catecholamines, or endothelial dysfunction. The pain may be of neuropathic, inflammatory, nociceptive, or functional nature, or of mixed origin.

SUMMARY

The origin of the pain should be the basis of the symptomatic therapy. Since the difference in temperature between both hands fluctuates over time in cold CRPS, when in doubt, the clinician should prioritize the patient's report of a persistent cold extremity over clinical tests that show no difference. Future research should focus on developing easily applied methods for clinical use to differentiate between central and peripheral blood flow regulation disorders in individual patients.

Effect of tadalafil on blood flow, pain, and function in chronic cold complex regional pain syndrome: a randomized controlled trial

Background

This double-blind, randomized, controlled trial investigated the effect of the phosphodiesterase-5 inhibitor tadalafil on the microcirculation in patients with cold Complex Regional Pain Syndrome (CRPS) in one lower extremity.

Methods

Twenty-four patients received 20 mg tadalafil or placebo daily for 12 weeks. The patients also participated in a physical therapy program. The primary outcome measure was temperature difference between the CRPS side and the contralateral side, determined by measuring the skin temperature with videothermography. Secondary outcomes were: pain measured on a Visual Analogue Scale, muscle force measured with a MicroFet 2 dynamometer, and level of activity measured with an Activity Monitor (AM) and walking tests.

Results

At the end of the study period, the temperature asymmetry was not significantly reduced in the tadalafil group compared with the placebo group, but there was a significant and clinically relevant reduction of pain in the tadalafil group. Muscle force improved in both treatment groups and the AM revealed small, non-significant improvements in time spent standing, walking, and the number of short walking periods.

Conclusion

Tadalafil may be a promising new treatment for patients that have chronic cold CRPS due to endothelial dysfunction, and deserves further investigation.

Trial Registration

The registration number in the Dutch Trial Register is ISRCTN60226869.