Reassessment of the incidence of complex regional pain syndrome type 1 following stroke

Prevalence and predisposing factors of post-stroke complex regional pain syndrome: Retrospective case-control study

INTRODUCTION

Poststroke complex regional pain syndrome (CRPS) is an important complication in stroke survivors. The identification of factors associated with post-stroke CRPS is important for preventive measures and early diagnosis.

METHODS

A total of 141 first-ever stroke survivors in the subacute stage were retrospectively analyzed. Demographic data, diagnosis time, duration of hospitalization, location of brain lesion, etiology, comorbidities, and blood test findings were investigated. Clinical data included Medical Research Council (MRC) grade, Fugl-Meyer assessment (FMA), National Institute for Health Stroke Scale (NIHSS), Berg Balance Scale (BBS).

RESULTS

Among 141 patients with subacute stroke, 22 were diagnosed with CRPS, with a prevalence of 15.6 %. The mean time to diagnosis was 38.6 (±16.5) days. The prevalence according to the degree of paralysis was 33.3 % in MRC grades 0 and 1, 8.6 % in grade 2, and 0 % in grade 3 or higher. The incidence rates within 1 month after stroke were 1.42 % and 22.47 % between 1 and 3 months after stroke, respectively. The independent risk factors for CRPS were hospitalization duration and FMA, NIHSS, and BBS scores. The sensitivity and specificity of the NIHSS score for predicting post-stroke CRPS were 86.4 % and 59.7 %, respectively, with an optimal cutoff value of 7.5.

CONCLUSIONS

CRPS of the affected upper limb in stroke patients is associated with stroke severity, including paralysis, and the incidence increases over time during the subacute phase. Additionally, having sufficient strength to move through a full range of motion against gravity had a protective effect against CRPS.

Biological Mechanism on SIRT1/NLRP3/IL-18 Signaling Pathway of Acupuncture for Treatment of Ischemic Stroke with Center Poststroke Pain

Objective

To evaluate the effect of acupuncture on an animal model of ischemic stroke with central poststroke pain (CPSP) through Sirtuin 1 (SIRT1)/NOD-like receptor thermal protein domain associated protein 3 (NLRP3)/interleukin-18 (IL-18) signaling pathway.

Methods

Data mining was performed with R package “edgeR,” “limma,” “pathview,” etc., from NCBI Gene Expression Omnibus (GEO) database. Sprague Dawley (SD) rats were divided into 4 groups: sham operation group (Sham group, n = 5), poststroke central pain group (CPSP group, n = 5), poststroke central pain + acupuncture group (AP group, n = 5), central pain after stroke + acupuncture + SIRT1 inhibitor EX527 group (EX527 group, n = 5). Pain behavior testing was performed to determine the mechanical withdrawal threshold (MWT). Quantitative real-time PCR (qRT-PCR) was performed to verify the data mining results from the GEO database.

Results

The KEGG key pathway map was created using the R package “pathview” package, demonstrating that the expression levels of NLRP3's downstream inflammatory factors IL-18 were downregulated in both of siSIRT1 group compared to the control group and the NLRP3 reconstituted group compared to NLRP3 KO group. QRT-PCR results on animal models of CPSP ischemic stroke showed that the expression levels of SIRT1 were downregulated, the activation of the NLRP3 inflammasome was upregulated, and the expression levels of IL-18 were upregulated in the brain tissues of the surrounding area of the injury. As the pain threshold of CPSP rats was increased, the expression level of S1RT1 was upregulated, and the activation of NLRP3 inflammasome was downregulated. The expression level of IL-18 was downregulated after acupuncture treatment.

Conclusion

Acupuncture may inhibit CPSP in an animal model of ischemic stroke by upregulating SIRT1 expression levels, inhibition of the activation of the inflammasome, and downregulating IL-18 expression levels.

Effect of abdominal acupuncture combined with routine rehabilitation training on shoulder-hand syndrome after stroke: A randomized controlled trial

Background

Post-stroke shoulder-hand syndrome (SHS) is a common complication after stroke. To date, there is still a lack of consistently effective and good patient compliance methods for SHS.

Methods

Fifty patients with SHS were included in this study. Patients in the control group received rehabilitation training (RT) for 2 weeks; each session was 30 min, 1 time per day, and 5 times per week. Patients in the observation group were additionally given Bo's abdominal acupuncture (BAA) with the same frequency and duration. The primary outcome was the change value in the VAS score from baseline to 2 weeks. The secondary outcomes measured were motor function of the upper limb, shoulder range of motion, ADL, and swelling volume.

Results

Compared with baseline values, the mean VAS score at 2 weeks was reduced by 3.68 in the observation group and by 1.92 in the control group, with a difference between the two groups of 1.84 (P < 0.001); the mean MBI score at 2 weeks increased by 10.44 in the observation group and by 4.79 in the control group, with a difference between the two groups of 5.84 (P = 0.032); the mean swelling volume at 2 weeks decreased by 9.64 in the observation group and by 3.29 in the control group, with a difference between the two groups of 6.48 (P < 0.001). BAA-related adverse events were not found during the study.

Conclusions

BAA combined with RT is superior to RT alone in improving shoulder pain, swelling, and ADL in post-stroke SHS patients.

Trial Registration

ChiCTR2100045464 (www.chictr.org.cn).

Prevalence and Related Factors for Poststroke Complex Regional Pain Syndrome: A Retrospective Cross-Sectional Cohort Study

OBJECTIVE

The objective of this study was to evaluate the prevalence of poststroke complex regional pain syndrome (CRPS) to estimate related factors for poststroke CRPS in patients with first-ever stroke.

DESIGN

This was a retrospective cross-sectional cohort study of adult patients (age >18y) with stroke who were admitted to rehabilitation unit from December 2014 to May 2018 in Korea.

SETTING

Single acute rehabilitation unit of university hospital.

PARTICIPANTS

Participants (N=313) diagnosed with first-ever stroke were identified from the stroke rehabilitation registry of our institute.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Prevalence of poststroke CRPS based on clinical features and 3-phase bone scintigraphy and the related factors of poststroke CRPS.

RESULTS

A total of 313 records were analyzed, including demographic, clinical characteristics, and functional variables. Poststroke CRPS was found in 8.94% (28 of 313) patients with first-ever stroke. Logistic regression analysis showed that Fugl Meyer Assessment of Upper Extremity (FMA-UE) score was a significant associated factor for the presence of CRPS (odds ratio, 0.96; 95% confidence interval, 0.94-0.98; P=.003). The cutoff value of 76 points for FMA-UE score yielded moderate accuracy in identifying of poststroke CRPS (92.6% sensitivity, 65.8% specificity, and 0.85 area under the curve).

CONCLUSIONS

The prevalence of poststroke CRPS was 8.94% in patients with first-ever stroke. The FMA-UE score was associated with the poststroke CRPS. Therefore, in patients with low FMA-UE score, prevention and high suspicion of post-stroke CRPS is necessary.

Impact of shoulder subluxation on peripheral nerve conduction and function of hemiplegic upper extremity in stroke patients: A retrospective, matched-pair study

Purpose: To investigate the impact of shoulder subluxation (SS) on peripheral nerve conduction and function of the hemiplegic upper extremity (HUE) in poststroke patients.Methods: Thirty post-stroke patients were selected (SS group: 15 patients, non-SS group: 15 patients, respectively). Evaluation of nerve conduction in upper limbs: the compound muscle action potential (CMAP) amplitude and latency of suprascapular, axillary, musculocutaneous, radial, median, and ulnar nerves; the motor and sensory conduction velocity and the sensory nerve action potential (SNAP) amplitude of median, ulnar, and radial nerves. The Brunnstrom stage scale was used to evaluate the HUE motor function.Results: Compared with the healthy side, the CMAP and SNAP amplitudes of tested nerves on the HUE in both groups were lower, and the CMAP latency of the suprascapular, axillary and musculocutaneous nerves on the HUE in the SS group was longer (P < 0.05). Compared with the HUE in non-SS group, the CMAP amplitude of tested nerves (except ulnar) was decreased more (P < 0.05), the motor conduction velocity of the median nerve was lower (P < 0.05), and the Brunnstrom stage of the HUE was lower in SS group (P < 0.05).Conclusions: Stroke may lead to extensive abnormal nerve conduction on the HUE, and SS may aggravate the abnormality, which may disturb the recovery of upper limb function.

Effectiveness of extracorporeal shock wave for post-stroke shoulder-hand syndrome: A protocol for systematic review and meta analysis

BACKGROUND

Post-stroke shoulder-hand syndrome (PSSHS) is one of the most common sequelae in patients with stroke. Previous studies have reported that extracorporeal shock wave (EPSW) has been used to treat this condition effectively. However, its conclusions are still inconsistent. Therefore, this study will provide evidence to systematically assess the effectiveness and safety of EPSW for the treatment of PSSHS.

METHODS

We will comprehensively search relevant randomized controlled trials (RCTs) assessing the effectiveness and safety of EPSW for the treatment of PSSHS in the following databases from their start to February 1, 2020 without language and publication date limitations: Cochrane Library, MEDLINE, EMBASE, CINAHL, Web of Science, PsycINFO, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. For trials that meet all inclusion criteria, 2 researchers will independently extract the data from them and appraise study quality by Cochrane risk of bias. Any differences will be solved by discussion with the help of another researcher. All data will be performed and analyzed using RevMan 5.3 software.

RESULTS

We will summarize up-to-date high quality RCTs to evaluate the effectiveness and safety of EPSW for the treatment of PSSHS.

CONCLUSIONS

This study will provide a comprehensive evidence summary to determine whether EPSW is effective and safety for the treatment of PSSHS or not.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42020175630.

Acupuncture for Post-stroke Shoulder-Hand Syndrome: A Systematic Review and Meta-Analysis

Background: Shoulder-hand syndrome (SHS) is prevalent in hemiplegic patients after stroke. Potential benefits of acupuncture were shown in recent clinical trials. This systematic review aimed to comprehensively evaluate the safety and efficacy of acupuncture for SHS in stroke patients.

Methods: Five English databases (PubMed, Embase, CINAHL, CENTRAL, and AMED) and four Chinese databases (CBM, CNKI, CQVIP, and Wanfang) were searched from their inceptions to January 2019. Randomized, controlled trials that evaluated the add-on effects of acupuncture to rehabilitation for post-stroke SHS were identified.

Results: Thirty-eight studies involving 3,184 participants fulfilled the eligible criteria and were included in the review. The overall meta-analysis showed that acupuncture combined with rehabilitation significantly improved motor function (upper-limb Fugl-Meyer Assessment (FMA): 34 studies, mean difference (MD) 8.01, 95% confidence interval (CI) [6.69,9.33]), and reduced pain (visual analog scale (VAS): 25 studies, MD −1.59, 95%CI [−1.86,−1.32]). It also improved activities of daily living (ADL) when compared with rehabilitation alone (ADL: 11 studies, MD 9.99, 95%CI [5.91,14.06]). However, the certainty of evidence of all these outcomes was assessed as “low.” Subgroup analyses of acupuncture stimulation types and treatment duration all showed significant add-on effects comparing with rehabilitation alone. The safety of acupuncture was unclear because there is a lack of detailed reporting of adverse events in most of the included studies.

Conclusions: Acupuncture therapy seems effective for motor function, pain relief and activities of daily living in stroke patients with mild SHS, when it is used in combination with rehabilitation. The low certainty of evidence downgrades our confidence in making recommendations to clinical practice.

Steroid atrophy scarring treated with fat grafting in a patient with complex regional pain syndrome: A case report

Subcutaneous atrophy is a known complication of steroid injections. Excellent results with fat grafting for the treatment of steroid atrophy have been documented. However, the benefit of treating steroid-induced subcutaneous atrophy in an extremity diagnosed with complex regional pain syndrome (CRPS) has not been described. CRPS, known formerly as reflex sympathetic dystrophy or RSD, causalgia, or reflex neurovascular dystrophy, is a severe, progressive musculoskeletal pain syndrome characterized by pain which is disproportionate to the severity of the inciting event, edema, or skin changes. Common treatment modalities include pharmacotherapy, physical therapy, and nerve blocks-each therapy producing varying results. We present a literature review of CRPS and the case of a 15-year-old female who developed CRPS of the left lower leg after arthroscopic debridement with retrograde drilling of an osteochondral lesion. Steroid atrophy of the involved area following a saphenous nerve block complicated the patient's treatment course. The area of atrophy was treated with autologous fat grafting. Following the adipose injection procedure, the patient experienced almost complete resolution of her CPRS-associated pain symptoms, along with improved cosmetic appearance of the area.

Temporary interference over the posterior parietal cortices disrupts thermoregulatory control in humans

The suggestion has recently been made that certain higher-order cortical areas involved in supporting multisensory representations of the body, and of the space around it, might also play a role in controlling thermoregulatory functions. Here we demonstrate that temporary interference with the function of one of these areas, the posterior parietal cortex, by repetitive transcranial magnetic stimulation, results in a decrease in limb temperature. By contrast, interference with the activity of a sensory-specific area (the primary somatosensory cortex) had no effect on temperature. The results of this experiment suggest that associative multisensory brain areas might exert a top-down modulation over basic physiological control. Such a function might be part of a larger neural circuit responsible for maintaining the integrity of the body at both a homeostatic and a psychological level.

A hypothesis for the cause of complex regional pain syndrome-type I (reflex sympathetic dystrophy): pain due to deep-tissue microvascular pathology

Complex regional pain syndrome-type I (CRPS-I; reflex sympathetic dystrophy) is a chronic pain condition that usually follows a deep-tissue injury such as fracture or sprain. The cause of the pain is unknown. We have developed an animal model (chronic post-ischemia pain) that creates CRPS-I-like symptomatology. The model is produced by occluding the blood flow to one hind paw for 3 hours under general anesthesia. Following reperfusion, the treated hind paw exhibits an initial phase of hyperemia and edema. This is followed by mechano-hyperalgesia, mechano-allodynia, and cold-allodynia that lasted for at least 1 month. Light microscopic analyses and electron microscopic analyses of the nerves at the site of the tourniquet show that the majority of these animals have no sign of injury to myelinated or unmyelinated axons. However, electron microscopy shows that the ischemia-reperfusion injury produces a microvascular injury, slow-flow/no-reflow, in the capillaries of the hind paw muscle and digital nerves. We propose that the slow-flow/no-reflow phenomenon initiates and maintains deep-tissue ischemia and inflammation, leading to the activation of muscle nociceptors, and the ectopic activation of sensory afferent axons due to endoneurial ischemia and inflammation. These data, and a large body of clinical evidence, suggest that in at least a subset of CRPS-I patients, the fundamental cause of the abnormal pain sensations is ischemia and inflammation due to microvascular pathology in deep tissues, leading to a combination of inflammatory and neuropathic pain processes. Moreover, we suggest a unifying idea that relates the pathogenesis of CRPS-I to that of CRPS-II. Lastly, our hypothesis suggests that the role of the sympathetic nervous system in CRPS-I is a factor that is not fundamentally causative, but may have an important contributory role in early-stage disease.

Familial occurrence of complex regional pain syndrome

BACKGROUND

The etiology of complex regional pain syndrome (CRPS) is unknown. Different environmental and genetic factors have been postulated to contribute to CRPS.

METHODS

We reviewed the clinical data from a cohort of 69 patients with CRPS. Four families were identified with two or more members affected with CRPS yielding a total of nine patients. Six more patients reported the presence of pain symptoms in their family members, however; this could not be clinically confirmed.

RESULTS

The case histories of the nine individuals with 'familial' CRPS suggested a younger age at onset and more frequent history of migraine versus the non-familial patients. A pattern of inheritance could not be ascertained.

CONCLUSION

This data supports the hypothesis that CRPS can be familial and hence may have a genetic basis in some families. Larger studies will be needed to ascertain clearer patterns of inheritance and to determine whether the clinical features of 'familial' CRPS are the same as the sporadic form.

Space-based, but not arm-based, shift in tactile processing in complex regional pain syndrome and its relationship to cooling of the affected limb

Complex regional pain syndrome (CRPS) occurs after stroke, but most cases develop after peripheral trauma and without evidence of brain trauma. However, CRPS is associated with symptoms that appear similar to those observed in patients suffering from hemispatial neglect. Ten participants (four males) with CRPS of one arm performed temporal order judgements of pairs of vibrotactile stimuli, one delivered to each hand, at one of 10 possible stimulus onset asynchronies, under two conditions: arms held each side of the midline and arms crossed over the midline. Participants released a foot switch to indicate which hand had been stimulated first. The order of conditions was randomized and the foot under which the switch was positioned was counterbalanced. There were two blocks of 150 trials in each condition. The stimulus onset asynchronicity at which the participants were equally likely to select either hand, the point of subjective simultaneity (PSS), was compared between conditions and between those with left or right-sided symptoms. When arms were not crossed, the participants prioritized stimuli from the unaffected limb over those from the affected limb (mean +/- SD PSS = 25 +/- 7.5 ms) and the magnitude of the PSS strongly related to the degree to which the affected hand was cooler than the unaffected hand (r = 0.942, P < 0.001). When the arms were crossed, the effect was reversed: the participants prioritized stimuli from the affected limb over those from the unaffected limb [PSS = -18 +/- 13 ms; main effect of condition F (1, 9) = 98.6, P < 0.001]. There was no effect of the side of symptoms. These results show that CRPS is associated with a deficit in tactile processing that is defined by the space in which the affected limb normally resides, not by the affected limb itself, and which relates to the relative cooling of the affected limb. This pattern is consistent with data from those with hemispatial neglect after stroke and raises the possibility that chronic CRPS involves a type of spatial neglect.

Clinical expression profiles of complex regional pain syndrome, fibromyalgia and a-specific repetitive strain injury: More common denominators than pain?

PURPOSE

To systematically evaluate and compare the clinical manifestations, disease course, risk factors and demographic characteristics of Complex Regional Pain Syndrome type 1 (CRPS), fibromyalgia (FM) and a-specific Repetitive Strain Injury (RSI).

METHOD

A literature search was performed using terms related to the aforementioned topics and diseases. Only original clinical studies that included at least 20 subjects were eligible.

RESULTS

Fifty-nine studies on CRPS, 73 on FM and 7 on a-specific RSI were identified. The diseases show similarities in age distribution, male-female ratio, pain characteristics and sensory signs and symptoms. Motor, autonomic and trophic changes are frequently reported in CRPS, but only occasionally in FM and RSI. Systemic symptoms are found in patients with CRPS and FM, and in a subgroup of patients with RSI. In all three disorders, symptoms usually start locally, but may spread to other body regions later, which, in the case of FM, is a prerequisite for diagnosis. Disease onset is always, usually, or occasionally of traumatic origin in RSI, CRPS and FM, respectively. Anxiety and depression are more frequent in patients compared to controls, but probably not very different from patients with other pain conditions or chronic diseases.

CONCLUSIONS

Apart from some obvious differences between CRPS, FM and RSI, the similarities are conspicuous. The common features of CRPS, FM and a-specific RSI may suggest that a common pathway is involved, but until patients with these type of symptoms are assessed with a uniform assessment procedure, a thorough comparison cannot be made. A systematic evaluation of patients with a suspected diagnosis of CRPS, FM or RSI, may lead to a better appreciation of the differences and similarities in these diseases and help to unravel the underlying mechanisms.

Mirror Therapy in Complex Regional Pain Syndrome Type 1 of the Upper Limb in Stroke Patients

Background. Complex regional pain syndrome type 1 (CRPSt1) of the upper limb is a painful and debilitating condition, frequent after stroke, and interferes with the rehabilitative process and outcome. However, treatments used for CRPSt1 of the upper limb are limited. Objective. This randomized controlled study was conducted to compare the effectiveness on pain and upper limb function of mirror therapy on CRPSt1 of upper limb in patients with acute stroke. Methods. Of 208 patients with first episode of unilateral stroke admitted to the authors’ rehabilitation center, 48 patients with CRPSt1 of the affected upper limb were enrolled in a randomized controlled study, with a 6-month follow-up, and assigned to either a mirror therapy group or placebo control group. The primary end points were a reduction in the visual analogue scale score of pain at rest, on movement, and brush-induced tactile allodynia. The secondary end points were improvement in motor function as assessed by the Wolf Motor Function Test and Motor Activity Log. Results. The mean scores of both the primary and secondary end points significantly improved in the mirror group ( P < .001). No statistically significant improvement was observed in any of the control group values ( P > .001). Moreover, statistically significant differences after treatment ( P < .001) and at the 6-month follow-up were found between the 2 groups. Conclusions. The results indicate that mirror therapy effectively reduces pain and enhances upper limb motor function in stroke patients with upper limb CRPSt1.

Acute autonomic dysfunction contralateral to acute strokes: a prospective study of 100 consecutive cases

Complex painful reflex syndrome is sometimes described in the chronic phase of stroke. Acute autonomic dysfunction (AAD), which is occasionally present in cases of acute stroke, has not been studied prospectively. The aim of the study was to investigate AAD on the hemibody contralateral to the lesion in the acute phase of stroke. One hundred consecutive patients (median age +/- interquartile range, 74 +/- 21; range 19-93; 51 women: 80 +/- 17 and 49 men: 70 +/- 17 years) in the acute phase of stroke were studied prospectively. Changes in skin temperature or coloration, diaphoresis, pain, or edema were noted in the first 3 days post-stroke. Associations between AAD and topography (cortical pre- and/or post-central, insular, corona radiata, basal ganglia, internal capsule, thalamus, and brainstem), age, gender, ischemic or hemorrhagic etiology, or the presence of sensorimotor deficits or ataxia were examined using the chi-squared or Fisher's exact test and logistic regression analysis. AAD was found in 71% of the patients and showed a significant positive association with the presence of a lesion in the post-central cortex (P = 0.037), internal capsule (P = 0.005), basal ganglia (P = 0.002), or insula (P = 0.011) and a negative association with the presence of a lesion in the brainstem (P = 0.004). Multivariate logistic regression analysis including all studied topographic variables showed that only brainstem lesions were significantly associated with a decreased risk of developing AAD (odds ratio = 0.08, 95% confidence interval: 0.01-0.69, P = 0.022). AAD was not associated with age, gender, the ischemic or hemorrhagic nature of the lesion, the side of lesion, hypertonic or hypotonic paresis, or hyperreflexia or hyporeflexia. AAD was found in association with sensory deficits (P = 0.001) and contralateral hyperkinesia (P = 0.004). Acute AAD is significantly more likely to occur in the presence of hemispheric lesions involving sensory pathways from the cortex to the internal capsule and insula and is significantly less prevalent in the presence of brainstem lesions.

Comparison of prednisolone with piroxicam in complex regional pain syndrome following stroke: a randomized controlled trial

BACKGROUND

Complex regional pain syndrome (CRPS) following stroke aggravates morbidity. CRPS is categorized as CRPSI when no clear nerve injury is defined, and CRPSII when associated with clear nerve injury.

AIM

To compare the effect of prednisolone with that of piroxicam in patients with CRPSI following stroke.

DESIGN

Randomized controlled trial.

METHODS

Patients with CRPSI fulfilling the inclusion criteria (n = 60) underwent a detailed neurological examination, cranial CT scan, radiograph of chest and shoulder joint, blood counts and serum chemistry. Severity of stroke was assessed by the Canadian Neurological Scale (CNS), CRPS by scoring sensory, autonomic and motor symptoms, and activity of daily living by Barthel index (BI) score. Patients were randomly assigned prednisolone 40 mg or piroxicam 20 mg daily, and outcome was assessed at 1 month on the basis of CRPS and BI score.

RESULTS

Mean patient age was 56 years and 20 were female. Baseline clinical and radiological parameters were comparable between the two groups. In the prednisolone group, 83.3% patients showed significant improvement, compared to 16.7% in the piroxicam group. The mean change in CRPS score in prednisolone group was 6.47 (95%CI 4.37-7.36), whereas in piroxicam group it was only 0.47. The mean change in BI score was 7.9 (95%CI 0.82-5.98) in the prednisolone group, and 4.5 in the piroxicam group.

DISCUSSION

In this patient group, prednisolone resulted in significant improvement in the symptoms and signs of CRPSI following stroke, compared to piroxicam. Both drugs produced an improvement in the BI score.

Complex regional pain syndrome as a stress response

A man in his 50's with a prior traumatic brain injury and multiple psychiatric disorders developed acute pain and swelling in his left leg distal to the mid shin. These symptoms arose during an exacerbation of his post-traumatic stress disorder (PTSD). Among his traumatic memories, he reported having witnessed the combat injury and death of a friend who had lost his left leg distal to the mid shin. A diagnosis of conversion disorder was technically excluded because the findings met criteria for Complex Regional Pain Syndrome (CRPS) type I. Based on recent research into the neurobiology of CRPS, PTSD and conversion disorder, we propose a supraspinal mechanism which could explain how emotional stress can produce both symptoms and signs.

Complex regional pain syndrome--diagnostic, mechanisms, CNS involvement and therapy

Complex regional pain syndromes (CRPS, formerly reflex sympathetic dystrophy and causalgia) are neuropathic pain conditions of one extremity developing inadequately after a trauma. The initiating trauma affects primarily the extremity, but can also be a central lesion (e.g., spinal cord injury, stroke). CRPS is clinically characterized by sensory, autonomic and motor disturbances. Pathophysiologically there is evidence for functional changes within the central nervous system and for involvement of peripheral inflammatory processes. The sympathetic nervous system plays a key role in maintaining pain and autonomic dysfunction in the affected extremity. After a primary central lesion, secondary peripheral changes in the paretic extremity are suggested to be important in initiating a CRPS. Though there is no diagnostic gold standard, careful clinical evaluation and additional test procedures should lead to an adequate diagnosis. An early diagnosis and an interdisciplinary approach are important for optimal and successful treatment.