Post-stroke Complex Regional Pain Syndrome Research Articles

A decision tree algorithm to identify predictors of post-stroke complex regional pain syndrome

This prospective cohort study aimed to identify the risk factors for post-stroke complex regional pain syndrome (CRPS) using a decision tree algorithm while comprehensively assessing upper limb and lower limb disuse and physical inactivity. Upper limb disuse (Fugl-Meyer assessment of upper extremity [FMA-UE], Action Research Arm Test, Motor Activity Log), lower limb disuse (Fugl-Meyer Assessment of lower extremity [FMA-LE]), balance performance (Berg balance scale), and physical inactivity time (International Physical Activity Questionnaire-Short Form [IPAQ-SF]) of 195 stroke patients who visited the Kishiwada Rehabilitation Hospital were assessed at admission. The incidence of post-stroke CRPS was 15.4% in all stroke patients 3 months after admission. The IPAQ, FMA-UE, and FMA-LE were extracted as risk factors for post-stroke CRPS. According to the decision tree algorithm, the incidence of post-stroke CRPS was 1.5% in patients with a short physical inactivity time (IPAQ-SF < 635), while it increased to 84.6% in patients with a long inactivity time (IPAQ-SF ≥ 635) and severe disuse of upper and lower limbs (FMA-UE score < 19.5; FMA-LE score < 16.5). The incidence of post-stroke CRPS may increase with lower-limb disuse and physical inactivity, in addition to upper-limb disuse. Increasing physical activity and addressing lower- and upper-limb motor paralysis may reduce post-stroke CRPS.

Use of Bioelectrical Impedance Analysis to Explore the Effectiveness of Stellate Ganglion Block in Patients with Post-Stroke Complex Regional Pain Syndrome: A Retrospective Pilot Study.

Post-stroke complex regional pain syndrome (CRPS) poses challenges in pain assessment for survivors. Stellate ganglion block (SGB) is a treatment, but evaluating its effectiveness is difficult for patients with communication limitations. Edema, a prominent symptom, can serve as an evaluation marker. Bioelectrical impedance analysis (BIA), assessing body composition and fluid status, is used independently of patient cooperation. This retrospective, observational pilot study aims to explore BIA's utility as an assessment tool post-SGB, revealing the effects and time courses of a single SGB on the bodily composition of post-stroke CRPS patients. Seven patients received ultrasound-guided SGB with a 5 mL solution containing 4 mL of 0.25% bupivacaine hydrochloride and 40 mg of triamcinolone into the prevertebral muscle space. BIA compared measures between affected and unaffected arms. The affected arm had higher segmental body water (SBW) and extracellular water ratios before SGB (p = 0.028 and p = 0.018, respectively). The SBW of the affected side, the SBW ratio, and the 1 and 5 kHz SFBIA ratios improved over time (p = 0.025, 0.008, 0.001, and 0.005, respectively). Rapid improvement occurred around 3 days post-injection, with maximum effects within approximately 1 week, persisting up to 3 weeks. SGB successfully reduced edema in post-stroke CRPS patients, with BIA serving as a useful tool for follow-up, facilitating the development of efficient treatment plans.

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

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. 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). 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. 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.

Clinical Application of Ultrasound Elastic Imaging in Assessing Poststroke Complex Regional Pain Syndrome (CRPS).

This study aimed to explore the characteristics and clinical application of ultrasonic elastography in peripheral soft tissue in patients with poststroke complex regional pain syndrome (CRPS). Complex regional pain syndrome (CRPS) type I is also known as shoulder hand syndrome (SHS). Its main symptoms include shoulder pain, limited activity, upper arm, wrist, and knuckle joint pain. Ultrasonic elastic imaging technology is gradually being applied to musculoskeletal system evaluation, primarily for the elastic examination of superficial tissue, as a result of the continual advancements in ultrasound technology. To make up for the absence of conventional imaging, functional state evaluation of the motor system can offer conventional ultrasonic tissue elasticity and hardness data. The purpose of this study was to objectively quantify the soft tissue surrounding the shoulder joint of stroke patients with CRPS using ultrasonic elastic imaging and to determine the diagnostic usefulness of ultrasonic elastic imaging for CRPS in stroke in order to promote its usage in clinical practice. Patients diagnosed with CRPS following a stroke and admitted to the rehabilitation unit at Shanxi Bethune Hospital between January, 2021 to June, 2021 were included in the analysis. The control group consisted of people without pain in their shoulder joints. Each group consisted of 30 patients. A high-frequency wire array probe (frequency = 8-16 Hz) was employed in conjunction with an ultrasonic diagnostic apparatus. A quantitative analytic system determined Young's modulus of the tissue, while the tracking of the shear wave provided an elastin map in real-time. An excitation pulse of acoustic radiation force was used to cause shear waves in the tissue. The Young's modulus of supraspinatus muscle in the study and control groups was 289.16±22.07 Kpa and 231.99±23.61 Kpa, respectively (P <0.01). Young's modulus values of the study group's subscapular biceps were compared to those of the control group (P > 0.05). The supraspinatus shear wave elastographic (SWE) imaging value was 10.01±0.49 m/s in the study group and 7.92±0.50 in the control group (P <0.05). The study and control groups had subscapular muscle SWE values of 15.99±1.95 and 8.64±0.56 m/s, respectively (P <0.05). The average biceps tendon SWE value in the study and control groups was 6.39±0.42 and 4.69±0.36 m/s, respectively (P <0.05). In conclusion, the SWE assessed by ultrasound elastography is useful for early diagnosis and evaluation of the superior shoulder tendon, subscapular tendon, and biceps tendon of CRPS following stroke.

Fire Needling Therapy versus Manual Acupuncture in Post-Stroke Complex Regional Pain Syndrome of the Upper Limb: Study Protocol for a Pilot Randomised Controlled Trial.

Post-stroke complex regional pain syndrome (CRPS) is a devastating disease that causes severe physical and emotional consequences. Conventional therapies are limited due to the insufficient benefits and side effects, and fire needling therapy is considered an alternative for post-stroke CRPS of the upper limb. This is a study protocol for a pilot randomised, two-arm, single-centre, clinical trial at Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University. The trial started in March 2023 and is expected to end in December 2024. A total of 60 patients (aged 40-75 years, male or female) with post-stroke CRPS of the upper limb will be randomly assigned to treatment group (fire needling therapy, 5 sessions per week for 2 weeks) or control group (manual acupuncture, 5 sessions per week for 2 weeks) in a 1:1 ratio using block randomisation and opaque envelopes. Fire needling therapy or manual acupuncture will be performed in ten acupoints. Participants will complete the trial by visiting the research centre at Week 14 for a follow-up assessment. The primary outcome is the response rate. Secondary outcomes include FMA, Barthel Scale/Index (BI), pain threshold (PPT), and muscle elasticity modulus (using shear wave elastography [SWE]). A chi-squared test will be used for response rate. A mixed-effects linear model and a mixed-effects model will be used for FMA, BI, PPT, and SWE, respectively. This is the first standardised protocol to compare the effectiveness of fire needling therapy and manual acupuncture. We will use a rigorous methodology to minimise bias and set up supervising committees to ensure the quality of our study, thus providing trustworthy evidence for better understanding of fire needling therapy in treating post-stroke CRPS of the upper limb.

Post-Stroke Complex Regional Pain Syndrome and Upper Limb Inactivity in Hemiplegic Patients: A Cross-Sectional Study.

PurposeThe purpose of this study was to investigate the prevalence of post-stroke complex regional pain syndrome (CRPS) and to examine the characteristics of inactivity status of the upper limb in post-stroke CRPS patients. In addition, as a sub-analysis, the association between the upper limb inactivity status and pain intensity was investigated in post-stroke CRPS patients.Patients and MethodsThis cross-sectional study included 102 patients with first-ever stroke between April 2019 and February 2020. Each patient was allocated into one of two groups based on the presence or absence of CRPS. Demographic data (age, sex, stroke etiology, lesion side, and number of days since stroke onset) were collected. The following evaluations were performed in all patients: Fugl–Meyer Assessment (FMA), Action Research Arm Test (ARAT), and Motor Activity Log (MAL). The numerical rating scale (NRS) to determine pain intensity was assessed only in patients with post-stroke CRPS.ResultsNineteen and 83 patients were assigned to the post-stroke CRPS and control group, respectively. The prevalence of post-stroke CRPS was 18.6% (19/102). FMA, ARAT, and MAL scores were significantly lower in patients with post-stroke CRPS than those without it. FMA and ARAT scores were significantly correlated with NRS scores, but MAL was almost zero-scored in patients with post-stroke CRPS.ConclusionThe study results indicated that activity status of the affected upper limb was severely deteriorated, and more inactivity of the upper limb was associated with higher pain intensity in patients with post-stroke CRPS. Thus, our results suggest that post-stroke CRPS may be influenced by the degree of upper limb inactivity after stroke.

A Meta-Analysis and Meta-Regression of Frequency and Risk Factors for Poststroke Complex Regional Pain Syndrome.

Background and Objectives: This article aimed to investigate the risk factors for poststroke complex regional pain syndrome (CRPS). Materials and Methods: We searched electronic databases including PubMed, Medline, Web of Science, Cochrane Library, and Embase up to 27 October 2021. We enrolled analytical epidemiological studies comprising cohort, case-control, and cross-sectional studies. A quality assessment was performed using the Newcastle–Ottawa Quality Assessment Scale for cohort and case-control studies and the Joanna Briggs Institute critical appraisal checklist for analytical cross-sectional studies. Binary outcomes were reported as odds ratios (ORs), and continuous outcomes were described as standardized mean differences (SMDs) with 95% confidence intervals. For the meta-regression, beta coefficient and p value were adopted. Results: We included 21 articles comprising 2225 participants. Individuals with shoulder subluxation and spasticity were found to have higher risks for poststroke CRPS. Spasticity with higher modified Ashworth scale score, lower Brunnstrom hand stage, and inferior Barthel index scores were observed in patients with poststroke CRPS. The pooled incidence proportion in nine articles was 31.7%, and a correlation was found between effect sizes and the ratio of women and the proportion of left hemiparesis. The summarized prevalence in nine cross-sectional studies was 33.1%, and a correlation was observed between prevalence and the subluxation ratio and Brunnstrom stage. Conclusions: Based on our meta-analysis, being female, left hemiparesis, shoulder subluxation, spasticity, a lower Brunnstrom stage of distal upper limb, and an inferior Barthel index are all features for poststroke CRPS. Larger studies with greater statistical power may confirm our findings and clarify some other unknown risk factors for poststroke CRPS.

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

ObjectiveThe 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. DesignThis 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. SettingSingle acute rehabilitation unit of university hospital. ParticipantsParticipants (N=313) diagnosed with first-ever stroke were identified from the stroke rehabilitation registry of our institute. InterventionsNot applicable. Main Outcome MeasuresPrevalence of poststroke CRPS based on clinical features and 3-phase bone scintigraphy and the related factors of poststroke CRPS. ResultsA 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). ConclusionsThe 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.

Neuroanatomical correlates of poststroke complex regional pain syndrome: a voxel-based lesion symptom-mapping study

Complex regional pain syndrome (CRPS) is a common poststroke complication. However, the neural substrates associated with CRPS remain unclear. We investigated the neural correlates associated with poststroke CRPS using voxel-based lesion‒symptom mapping (VLSM) analysis. Among 145 patients with ischemic stroke, 35 were diagnosed with CRPS and categorized into the poststroke CRPS group, and the remaining 110 into the control group. We compared the clinical characteristics between the groups. VLSM analysis was performed to identify the brain region associated with the development of poststroke CRPS. The clinical findings suggested that the poststroke CRPS group had lower muscle strength; lower scores on Fugl‒Meyer assessment, Manual Function Test, Mini-Mental Status Examination; and higher incidence of absent somatosensory evoked potentials in the median nerve than the control group. The head of the caudate nucleus, putamen, and white matter complexes in the corona radiata were significantly associated with poststroke CRPS development in ischemic stroke patients. These results facilitate an understanding of poststroke CRPS pathophysiology. Monitoring patients with lesions in these structures may aid the prevention and early treatment of poststroke CRPS.

Acute effects of contrast bath on sympathetic skin response in patients with poststroke complex regional pain syndrome

Purpose Complex regional pain syndrome (CRPS) is one of the common complications in stroke patients. Sympathetic dysfunction is usually considered underlying pathology. The evidence for contrast bath (CB) used in the treatment of CRPS is limited. The aim of the study is to investigate the possible effects of CB on the sympathetic activity in poststroke CRPS. Materials and methods Stroke patients with CRPS (CRPS group) and without CRPS (control group) were included in the study. Age, gender, duration of stroke, aetiology, plegic side, dominant hand, spasticity level, Brunnstrom stages, and comorbidities were recorded. CB was performed for one session to the plegic side of the CRPS and control groups. Sympathetic skin responses (SSR) was recorded from the plegic and healthy hands of participants at pre-CB and post-CB. Results Each group consisted of 20 participants. No significant difference was detected in stroke duration, aetiology, and Brunnstrom stages between groups. Elbow spasticity level was significantly higher in CRPS group (p = .034). SSR amplitudes of plegic hands were significantly decreased after CB in CRPS and control groups (p = .0002, p = .013 respectively). Also, CB reduced the SSR amplitude of healty side in CRPS group (p = .003). There was no statistically significant change in SSR latency or percentage changes of SSR amplitude and latency after CB in both groups. Conclusion CB leads to a significant reduction in sympathetic activity of plegic side of stroke patients. Also, CB to the plegic side has an inhibitory effect on sympathetic activity of healty side in poststroke CRPS. ClinicalTrials.gov ID: NCT04198532

Post-stroke complex regional pain syndrome and related factors: Experiences from a tertiary rehabilitation center

ObjectiveIn this study, it is aimed to determine the risk factors associated with CRPS after stroke and the clinical parameters of the patients and the treatment agents used for CPRS Method213 hemiplegic patients with CRPS diagnosed in Group 1 and 213 hemiplegic patients without CRPS in group 2 (control group) were included in the study designed retrospectively. Demographic data of the patients, Brunnstrom stage, Modified Ashworth scale, Barthel index were recorded from patients files. Associated risk faktors with CRPS such as Shoulder subluxation, adhesive capsulitis, fracture, deep vein thrombosis, spasticity, neglect, visual field defect, heterotopic ossification, entrapment neuropathies, brachial plexus damage, pressure wound, lower respiratory tract infection (LRTI), urinary tract infection, epilepsy, and depression were questioned. In addition, clinical findings, medical treatments, and physical therapy agents used were recorded. ResultsThe average age of the participants was 67.9 ± 10.3 in group 1 and 66.1 ± 9.9 in group 2. According to the multivariate logistic regression analysis, the presence of the duration of hemiplegi, the duration of hospitalization, shoulder subluxation, soft tissue lesion, adhesive capsulitis, spasticity, entrapment neuropathy, brachial plexus ınjury, protein energy malnutrition, LRTI, urinary infection, depression, coronary artery disease were significantly increased the development of CRPS (p<0.05). As a clinical parameter, edema was present in 95.3% of the patients, while trophic change was the lowest in 1.9%. While sensory reeducation was used in all patients in physical therapy, ganglion blockade was the lowest with 0.9% of patients. In medical treatment, the use of oral paracetamol was 28.2%, while the use of gabapentin was the last with 8.9%. ConclusionsIn our study, the risk factors of CRPS after hemiplegia, which are as important as its treatment, as well as its diagnosis and prevention, are shown.

Application of Segmental Phase Angle for Assessment of Post-Stroke Complex Regional Pain Syndrome

Application of Segmental Phase Angle for Assessment of Post-Stroke Complex Regional Pain Syndrome

Neural substrates for poststroke complex regional pain syndrome type I: a retrospective case-control study using voxel-based lesion symptom mapping analysis.

Poststroke complex regional pain syndrome (CRPS) is characterized by swelling, pain, and changes in the skin that appear on the affected wrist and hand. In this retrospective study, we analyzed the relationship between poststroke CRPS and the location of stroke lesion. From all patients admitted to our hospital from 2009 to 2019, we recruited 80 patients affected by their first unilateral stroke who met the inclusion/exclusion criteria. Thirty-eight patients diagnosed with CRPS after stroke were assigned to the experimental group according to the "Budapest criteria" adopted by the International Association for the Study of Pain, and 42 patients without CRPS were included as controls. Regions of interest were manually drawn on T1-weighted magnetic resonance images, and data were normalized to a standard brain template. In the poststroke CRPS group, the relationship between the location of brain lesion and pain severity was analyzed using Freedman-Lane multivariable regression adjusting for Medication Quantification Scale rating, which was the only parameter to show a statistically significant correlation with pain intensity. A threshold of P < 0.01 was considered statistically significant for all voxel-based lesion symptom mapping tests, corrected for multiple comparisons with 5000 permutations. Analyses using voxel-wise subtraction and Liebermeister statistics indicated that the corticospinal tract (CST) was associated with the development of poststroke CRPS. Statistically significant correlations were found between pain intensity and the CST and the adjacent lentiform nucleus. Our results suggest that the CST may be a relevant neural structure for development of poststroke CRPS and the intensity of pain caused by the syndrome.

Validity of the Budapest Criteria For Poststroke Complex Regional Pain Syndrome.

Complex regional pain syndrome-1 is a chronic neuropathic disorder, and poststroke complex regional pain syndrome (PS-CRPS) is not a rare complication. There is a lack of study implementing the Budapest criteria for PS-CRPS diagnosis. Thus, the present study investigated the validity of the Budapest criteria for PS-CRPS diagnosis and assessed the PS-CRPS-related factors in stroke patients with an affected upper extremity. The study included 72 patients with first-ever stroke resulting in hemiplegia. The prevalence of PS-CRPS and diagnostic validity were compared among the Budapest clinical criteria, Budapest research criteria, modified Budapest criteria (removal of the motor factor from the motor/trophic category), and International Association for the Study of Pain (IASP) criteria in patients diagnosed with PS-CRPS according to the Budapest clinical criteria. PS-CRPS was diagnosed in 6 (8.3%), 1 (1.4%), 6 (8.3%), and 11 patients (15.3%) according to the Budapest clinical criteria, Budapest research criteria, modified Budapest criteria, and IASP criteria, respectively. The Budapest criteria and IASP criteria had sensitivities of 0.99 and 1.00, respectively, and specificities of 0.68 and 0.41, respectively, for PS-CRPS diagnosis. There were no differences in risk factors between PS-CRPS patients and non-PS-CRPS patients when the diagnosis was based on the Budapest clinical criteria. However, there were differences in muscle strength and Brunnstrom stage between PS-CRPS patients and non-PS-CRPS patients when the diagnosis was based on the IASP criteria. Our findings indicate that the diagnostic validity of the current Budapest clinical criteria for PS-CRPS is low. Thus, the current Budapest criteria might not be appropriate for PS-CRPS diagnosis.

The Effectiveness of Fluidotherapy in Poststroke Complex Regional Pain Syndrome: A Randomized Controlled Study

Objective: To evaluate whether combining fluidotherapy to conventional rehabilitation program provides additional improvements on pain severity, upper extremity functions, and edema volume in patients with poststroke complex regional pain syndrome (CRPS). Design: Randomized controlled trial. Setting: Training and research hospital. Participants: Thirty hemiplegic patients with subacute stage CRPS type-1 of the upper extremity. Interventions: The patients randomly divided into 2 groups. Both groups received a 3 week conventional rehabilitation program (5 days/week, 2-4 hours/day). Experimental group received 15 sessions additional fluidotherapy application to the affected upper extremity (40 °C, 20 minutes in continuous mode, 5 sessions/week). Main Outcome Measures: We evaluated the distal upper arm edema with a volumeter. Other used clinical assessment scales were Brunnstrom recovery stages of the arm and hand for motor recovery, motor items of the functional independence measure for functional status, visual analog scale for pain severity, and the painDETECT questionnaire for presence and the severity of neuropathic pain. Results: The mean age of the participants was 64.3 ± 11.66 (28-84). At the post-treatment evaluation, significant improvements were revealed regarding to the edema volume, pain visual analog scale, painDETECT and functional independence measure scores, and the Brunnstrom stages of upper extremity and hand in both groups (P < .05). But among the parameters mentioned above, only the decrease in edema volume and the painDETECT scores were greater in fluidotherapy group than the control group (P < .05). Conclusions: Addition of the fluidotherapy to the conventional rehabilitation program provides better improvements on neuropathic pain and edema volume in subacute stage poststroke CRPS.

Is poststroke complex regional pain syndrome the combination of shoulder pain and soft tissue injury of the wrist?: A prospective observational study: STROBE of ultrasonographic findings in complex regional pain syndrome.

Patients with poststroke complex regional pain syndrome (CRPS) show different symptoms compared to other types of CRPS, as they usually complain of shoulder and wrist pain with the elbow relatively spared. It is thus also known by the term “shoulder-hand syndrome.”The aim of this study is to present a possible pathophysiology of poststroke CRPS through ultrasonographic observation of the affected wrist before and after steroid injection at the extensor digitorum communis (EDC) tendon in patients suspected with poststroke CRPS.Prospective evaluation and observation, the STROBE guideline checklist was used.Twenty-three patients diagnosed as poststroke CRPS in accordance to clinical criteria were enrolled. They had a Three Phase Bone Scan (TPBS) done and the cross-sectional area (CSA) of EDC tendon was measured by using ultrasonography. They were then injected with steroid at the EDC tendon. The CSA of EDC tendon, visual analogue scale (VAS), and degree of swelling of the wrist were followed up 1 week after the injection.TPBS was interpreted as normal for 4 patients, suspected CRPS for 10 patients, and CRPS for 9 patients. Ultrasonographic findings of the affected wrist included swelling of the EDC tendon. After the injection of steroid to the wrist, CSA and swelling of the affected wrist compared to that before the treatment was significantly decreased (P < 0.001). The VAS score declined significantly after the injection (P < 0.001).Our results suggest that the pathophysiology of poststroke CRPS might be the combination of frozen shoulder or rotator cuff tear of shoulder and soft tissue injury of the wrist caused by the hemiplegic nature of patients with stroke.

Absent median somatosensory evoked potential is a predictor of type I complex regional pain syndrome after stroke

Purpose: The objective was to determine whether the abnormal finding of somatosensory evoked potentials (SEPs) associated with the development of type I complex regional pain syndrome (CRPS) after stroke. Methods: This was a retrospective study conducted from January, 2003, to December, 2007. Seventy patients were confirmed as CRPS type I, and one hundred and eighty-two patients were assigned to the control group. The initial clinical data were reviewed including age, gender, main type of stroke, lateralization and location of the lesion, presence of glenohumeral subluxation, and the development of CRPS. Somatosensory evoked potentials tests (SEP) in median nerve (N20) and posterior tibial nerve (P37) were performed. Results: CRPS groups revealed significantly higher incidence of the absent and abnormal hemiplegic median SEP, hemorrhagic stroke, and glenohumeral subluxation (GHS). Binary logistic regression analysis indicated that GHS (exp.(B) = 4.083, p < 0.01) with the absent median SEP (exp.(B) = 3.246, p < 0.01) were significant independent predictors of CRPS onset. Conclusions: In conclusion, GHS and the absent median SEP at sub-acute phase of stroke were primary predictors of the onset of post-stoke CRPS.Implications for RehabilitationRecent investigations have suggested that autonomic, motor and somatosensory abnormalities of CRPS are impairments involving the central nervous system (CNS) as well as the peripheral neurogenic inflammatory process. However, the understanding of the pathophysiology of CRPS is still far from complete.The absence of SEP at the sub-acute stage of stroke correlated with the onset of post-stroke CRPS type I.The SEP evaluation at the sub-acute period after stroke might be generally used for predicting the concomitant development of post-stroke CRPS type I as well as functional recovery after stroke.

Interventions for treating pain and disability in adults with complex regional pain syndrome.

There is currently no strong consensus regarding the optimal management of complex regional pain syndrome although a multitude of interventions have been described and are commonly used. To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the effectiveness of any therapeutic intervention used to reduce pain, disability or both in adults with complex regional pain syndrome (CRPS). We identified Cochrane reviews and non-Cochrane reviews through a systematic search of the following databases: Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), Ovid MEDLINE, Ovid EMBASE, CINAHL, LILACS and PEDro. We included non-Cochrane systematic reviews where they contained evidence not covered by identified Cochrane reviews. The methodological quality of reviews was assessed using the AMSTAR tool.We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes of quality of life, emotional well being and participants' ratings of satisfaction or improvement. Only evidence arising from randomised controlled trials was considered. We used the GRADE system to assess the quality of evidence. We included six Cochrane reviews and 13 non-Cochrane systematic reviews. Cochrane reviews demonstrated better methodological quality than non-Cochrane reviews. Trials were typically small and the quality variable.There is moderate quality evidence that intravenous regional blockade with guanethidine is not effective in CRPS and that the procedure appears to be associated with the risk of significant adverse events.There is low quality evidence that bisphosphonates, calcitonin or a daily course of intravenous ketamine may be effective for pain when compared with placebo; graded motor imagery may be effective for pain and function when compared with usual care; and that mirror therapy may be effective for pain in post-stroke CRPS compared with a 'covered mirror' control. This evidence should be interpreted with caution. There is low quality evidence that local anaesthetic sympathetic blockade is not effective. Low quality evidence suggests that physiotherapy or occupational therapy are associated with small positive effects that are unlikely to be clinically important at one year follow up when compared with a social work passive attention control.For a wide range of other interventions, there is either no evidence or very low quality evidence available from which no conclusions should be drawn. There is a critical lack of high quality evidence for the effectiveness of most therapies for CRPS. Until further larger trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult.

Efficacy of Ultrasonography Guided Stellate Ganglion Blockade in the Stroke Patients with Complex Regional Pain Syndrome

ObjectiveTo compare the efficacy of ultrasonography guided stellate ganglion block (US-SGB) with that of blind SGB in management of the stroke patients with complex regional pain syndrome (CRPS) type 1.MethodForty-two patients with post-stroke CRPS were randomly assigned to either US-guided SGB (22 patients) or blind SGB group (20 patients). The mean age of US-guided SGB and blind SGB groups was 61.3±5.6 years and 59.1±4.5 years. We performed two blockades at 7-day intervals on the affected side of patients with CRPS. Pain intensity, using a visual analog score (VAS), score of CRPS clinical severity, and the amounts of affected hand swelling with a hand volumeter were assessed before, 2 weeks and 4 weeks after treatment.ResultsIn both groups, VAS and the amount of hand swelling were significantly decreased after 2 weeks and after 4 weeks. Between two groups, VAS difference of US-guided SGB group and that of blind SGB group were 2.61±1.09, 1.88±0.62 at 2 weeks and 3.67±1.03, 3.13±0.62 at 4 weeks, respectively. US-guided SGB group showed more significant improvement in mean change of VAS compared to the blind SGB group (p-value<0.05).ConclusionBoth US-guided SGB and blind SGB techniques were effective in relieving pain in subacute stroke patients with CRPS. US-guided SGB was better in pain relief but has no advantages in reduction of hand swelling in this study.

Poststroke Complex Regional Pain Syndrome

Poststroke Complex Regional Pain Syndrome (CRPS) affects a significant number of moderate to severely impaired stroke survivors. Until recently, advances in the assessment and management of CRPS have been limited due to the lack of a consensus on diagnostic criteria; however, with the development of the International Association for the Study of Pain diagnostic criteria, the medical and scientific communities are poised to make significant strides. Biomechanical factors and microtrauma to the hemiparetic shoulder may have a significant role in the genesis of CPRS, although the exact pathophysiology that links these triggers to the observed disease manifestation remains uncertain. Sympathetic dysfunction has historical importance in the CRPS literature. However, this appears to be only one of several possible pathophysiologic mechanisms; somatic nervous system dysfunction, inflammation, hypoxia, and psychological factors are also likely contributors to the disease process. There is no definitive treatment for CRPS, and most patients are treated empirically. Nevertheless, there is consensus that the treatment approach should be interdisciplinary with the goals of edema and pain control, maintenance of joint and muscle biomechanics, and functional restoration. As more rigorous clinical trials emerge, the treatment approach will become more rational with selection of interventions based on a specific mechanism or a combination of mechanisms responsible for a given individual’s disease manifestation.