CRPS Bugle | March 2014

bugle-450-pic-rexfeatures-271436732Welcome to the March CRPS Bugle, an update on the latest research into complex regional pain syndrome, also known as reflex sympathetic dystrophy (RSD).

Visit our clinic site here for information about our specialist CRPS Clinics.

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J Foot Ankle Surg. 2014 Mar 5. pii: S1067-2516(14)00007-6. doi: 10.1053/j.jfas.2014.01.006.

Incidence of Complex Regional Pain Syndrome after Foot and Ankle Surgery.

Rewhorn MJ1, Leung AH2, Gillespie A3, Moir JS3, Miller R4.

Abstract
Complex regional pain syndrome (CRPS) is an uncommon complication of orthopedic surgery, and few investigators have considered the incidence in foot and ankle surgery. In the present retrospective cohort study of 390 patients who had undergone elective foot and/or ankle surgery in our department from January to December 2009, the incidence of postoperative CRPS was calculated and explanatory variables were analyzed. A total of 17 patients (4.36%) were identified as meeting the International Association for the Study of Pain criteria for the diagnosis of CRPS. Of the 17 patients with CRPS, the mean age was 47.2 ± 9.7 years, and 14 (82.35%) were female. All the operations were elective, and 9 (52.94%) involved the forefoot, 3 (17.65%) the hindfoot, 3 (17.65%) the ankle, and 2 (11.76%) the midfoot. Twelve patients (70.59%) had new-onset CRPS after a primary procedure, and 5 (29.41%) had developed CRPS after multiple surgeries. Three patients (17.65%) had documented nerve damage intraoperatively and thus developed new-onset CRPS type 2. Blood test results were available for 14 patients (82.35%) at a minimum of 3 months postoperatively, and none had elevated inflammatory markers. Five of the patients (29.41%) were smokers, and 8 (47.06%) had had a pre-existing diagnosis of anxiety and/or depression. From our findings, we recommend that middle-age females and those with a history of anxiety or depression, who will undergo elective foot surgery, should be counseled regarding the risk of developing CRPS during the consent process. We recommend similar studies be undertaken in other orthopedic units, and we currently are collecting data from other orthopedic departments within Scotland

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Rehabil Psychol. 2014 Mar 10.

Thought Intrusion Among Adults Living With Complex Regional Pain Syndrome.

Lohnberg JA, Altmaier EM.

Abstract

Purpose: This study investigated the presence and influence of intrusive thoughts among adults previously diagnosed with complex regional pain syndrome. Method: The present study used an Internet-based survey completed by a sample (N = 326) from two national organizations. Results: After controlling for age, gender, and pain level, intrusive thoughts were significantly related to disability and health-related quality of life. Conclusions/Implications: Intrusive thoughts about the inciting event that caused CRPS uniquely influenced pain and quality of life, suggesting a potential mechanism to target for intervention. Understanding factors that relate to maintenance of CRPS and its resulting disability will help in the development of treatments to improve quality of life.

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Brain. 2013 Jul;136(Pt 7):2038-49. doi: 10.1093/brain/awt150. Epub 2013 Jun 13.

Secondary and primary dystonia: pathophysiological differences.

Kojovic M1, Pareés I, Kassavetis P, Palomar FJ, Mir P, Teo JT, Cordivari C, Rothwell JC, Bhatia KP, Edwards MJ.

Abstract
Primary dystonia is thought to be a disorder of the basal ganglia because the symptoms resemble those of patients who have anatomical lesions in the same regions of the brain (secondary dystonia). However, these two groups of patients respond differently to therapy suggesting differences in pathophysiological mechanisms. Pathophysiological deficits in primary dystonia are well characterized and include reduced inhibition at many levels of the motor system and increased plasticity, while emerging evidence suggests additional cerebellar deficits. We compared electrophysiological features of primary and secondary dystonia, using transcranial magnetic stimulation of motor cortex and eye blink classical conditioning paradigm, to test whether dystonia symptoms share the same underlying mechanism. Eleven patients with hemidystonia caused by basal ganglia or thalamic lesions were tested over both hemispheres, corresponding to affected and non-affected side and compared with 10 patients with primary segmental dystonia with arm involvement and 10 healthy participants of similar age. We measured resting motor threshold, active motor threshold, input/output curve, short interval intracortical inhibition and cortical silent period. Plasticity was probed using an excitatory paired associative stimulation protocol. In secondary dystonia cerebellar-dependent conditioning was measured using delayed eye blink classical conditioning paradigm and results were compared with the data of patients with primary dystonia obtained previously. We found no difference in motor thresholds, input/output curves or cortical silent period between patients with secondary and primary dystonia or healthy controls. In secondary dystonia short interval intracortical inhibition was reduced on the affected side, whereas it was normal on the non-affected side. Patients with secondary dystonia had a normal response to the plasticity protocol on both the affected and non-affected side and normal eye blink classical conditioning that was not different from healthy participants. In contrast, patients with primary dystonia showed increased cortical plasticity and reduced eye blink classical conditioning. Normal motor cortex plasticity in secondary dystonia demonstrates that abnormally enhanced cortical plasticity is not required for clinical expression of dystonia, and normal eye blink conditioning suggests an absence of functional cerebellar involvement in this form of dystonia. Reduced short interval intracortical inhibition on the side of the lesion may result from abnormal basal ganglia output or may be a consequence of maintaining an abnormal dystonic posture. Dystonia appears to be a motor symptom that can reflect different pathophysiological states triggered by a variety of insults.

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Int J Rheum Dis. 2014 Feb;17(2):156-8. doi: 10.1111/1756-185X.12140. Epub 2013 Jun 24.

Antioxidant profile in patients with complex regional pain syndrome type I.

Baykal T1, Seferoglu B, Karsan O, Kiziltunc A, Senel K.

Abstract
OBJECTIVE:
Complex regional pain syndrome (CRPS) type I is one of the most important problems with regard to physical medicine and rehabilitation. CRPS may cause not only higher therapeutic costs but also greater work time loss. The mechanism and pathogenesis of CRPS still remains unknown. Some findings indicating oxidative stress have been reported. This study was carried out to determine the role of oxidative stress in patients with CRPS.
MATERIALS AND METHODS:
Twenty patients (13 women and seven men) with CRPS and 20 age- and sex-matched healthy controls were enrolled in this study. Complex regional pain syndrome was diagnosed according to the modified International Association for the Study of Pain (IASP) criteria. We evaluated demographic, clinical and laboratory characteristics of the patients. Antioxidant enzymatic activities consisting of serum superoxide dismutase (SOD), glutathion peroxidase (GPX) and glutathione S-transferase (GST) activities were measured using appropriate methods and compared with healthy controls.
RESULTS:
The mean age of the patients was 39.5 years and the mean duration of symptoms was 5.5 months. Complex regional pain syndrome devoleped after a traumatic event in 90% of patients. In 10% of patients there were no traumatic events. SOD, GPX and GST levels were significantly higher in patients with CRPS than healthy controls (P = 0.012, P = 0.036 and P = 0.016, respectively).
CONCLUSION:
Our findings suggest a possible role of oxidative stress in the pathogenesis of CRPS

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J Pain. 2014 Feb 11. pii: S1526-5900(14)00565-3. doi: 10.1016/j.jpain.2014.01.500.

The Outcome of Complex Regional Pain Syndrome Type 1: A Systematic Review

Bean DJ1, Johnson MH2, Kydd RR3.

Abstract
The purpose of this systematic review was to examine the outcome of complex regional pain syndrome (CRPS) type-1. We searched Medline, Embase and Psychinfo for relevant studies, and included 18 studies, with 3991 participants, in this review. The following data were extracted: study details, measurement tools used, and rates or severity scores for the symptoms/signs of CRPS at baseline and follow-up, or in groups of patients with different disease durations. A quality assessment revealed significant limitations in the literature, with many studies utilising different diagnostic criteria. The 3 prospective studies demonstrated that for many patients, symptoms improve markedly within 6-13 months of onset. The 12 retrospective studies had highly heterogeneous findings, documenting lasting impairments in many patients. The 3 cross-sectional studies showed that rates of pain and sensory symptoms were highest amongst those with the longest duration of CRPS. Additionally, most studies showed that motor symptoms (stiffness and weakness) were the most likely to persist whilst sudomotor and vasomotor symptoms were the most likely to improve. Overall, this suggests that some CRPS patients make a good early recovery whilst others develop lasting pain and disability. As yet little is known about the prognostic factors that might differentiate between these groups.
PERSPECTIVE:
We found evidence that many CRPS patients recover within 6-13 months, but a significant number experience some lasting symptoms, and some experience chronic pain and disability. The quality of the evidence was poor. Future research should examine the factors associated with recovery and identify those at risk of poor outcomes

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Eur J Neurosci. 2014 Feb;39(3):508-19. doi: 10.1111/ejn.12462

The neurobiology of skeletal pain.

Mantyh PW.

Abstract
Disorders of the skeleton are one of the most common causes of chronic pain and long-term physical disability in the world. Chronic skeletal pain is caused by a remarkably diverse group of conditions including trauma-induced fracture, osteoarthritis, osteoporosis, low back pain, orthopedic procedures, celiac disease, sickle cell disease and bone cancer. While these disorders are diverse, what they share in common is that when chronic skeletal pain occurs in these disorders, there are currently few therapies that can fully control the pain without significant unwanted side effects. In this review we focus on recent advances in our knowledge concerning the unique population of primary afferent sensory nerve fibers that innervate the skeleton, the nociceptive and neuropathic mechanisms that are involved in driving skeletal pain, and the neurochemical and structural changes that can occur in sensory and sympathetic nerve fibers and the CNS in chronic skeletal pain. We also discuss therapies targeting nerve growth factor or sclerostin for treating skeletal pain. These therapies have provided unique insight into the factors that drive skeletal pain and the structural decline that occurs in the aging skeleton. We conclude by discussing how these advances have changed our understanding and potentially the therapeutic options for treating and/or preventing chronic pain in the injured, diseased and aged skeleton

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CRPS Bugle 10/10/13 | #CRPS

CRPS BugleWelcome to The CRPS Bugle–a selection of recent papers to peruse:

Clin J Pain. 2013 Nov;29(11):e33-e34.

Favorable Outcome of an Acute Complex Regional Pain Syndrome With Immunoglobulin Infusions.

Medlin F, Zekeridou A, Renaud S, Kuntzer T.

Abstract

OBJECTIVE::

To emphasize that complex regional pain syndrome (CRPS), a disabling disorder with the implication of aberrant inflammation, vasomotor dysfunction, and maladaptive neuroplasticity, might be treated with a high dose of intravenous immunoglobulin infusions (IVIG).

METHODS::

We describe a patient who presented with CRPS in the acute phase of the disease.

RESULTS::

The CRPS developed secondary to sciatic compression in a young patient and was treated within 10 days by high-dose IVIG (2 g/kg). It resolved completely within days after infusions.

DISCUSSION::

This observational study emphasizes that high-dose IVIG may be a treatment option in the acute phase of CRPS

RS: Interesting but bear in mind that this is a case study with one patient

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Ann Intern Med. 2010 Feb 2;152(3):152-8. doi: 10.7326/0003-4819-152-3-201002020-00006.

Intravenous immunoglobulin treatment of the complex regional pain syndrome: a randomized trial.

Goebel A, Baranowski A, Maurer K, Ghiai A, McCabe C, Ambler G.

Source

University of Liverpool, Clinical Sciences Building, University Hospital Aintree, Liverpool L9 7AL, United Kingdom.

Abstract

BACKGROUND:

Treatment of long-standing complex regional pain syndrome (CRPS) is empirical and often of limited efficacy. Preliminary data suggest that the immune system is involved in sustaining this condition and that treatment with low-dose intravenous immunoglobulin (IVIG) may substantially reduce pain in some patients.

OBJECTIVE:

To evaluate the efficacy of IVIG in patients with longstanding CRPS under randomized, controlled conditions.

DESIGN:

A randomized, double-blind, placebo-controlled crossover trial. (National Research Registry number: N0263177713; International Standard Randomised Controlled Trial Number Registry: 63918259)

SETTING:

University College London Hospitals Pain Management Centre.

PATIENTS:

Persons who had pain intensity greater than 4 on an 11-point (0 to 10) numerical rating scale and had CRPS for 6 to 30 months that was refractory to standard treatment.

INTERVENTION:

IVIG, 0.5 g/kg, and normal saline in separate treatments, divided by a washout period of at least 28 days.

MEASUREMENTS:

The primary outcome was pain intensity 6 to 19 days after the initial treatment and the crossover treatment.

RESULTS:

13 eligible participants were randomly assigned between November 2005 and May 2008; 12 completed the trial. The average pain intensity was 1.55 units lower after IVIG treatment than after saline (95% CI, 1.29 to 1.82; P < 0.001). In 3 patients, pain intensity after IVIG was less than after saline by 50% or more. No serious adverse reactions were reported.

LIMITATION:

The trial was small, and recruitment bias and chance variation could have influenced results and their interpretation.

CONCLUSION:

IVIG, 0.5 g/kg, can reduce pain in refractory CRPS. Studies are required to determine the best immunoglobulin dose, the duration of effect, and when repeated treatments are needed.

RS: this study from 2010 demonstrated reduced pain but in a small group

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Arch Phys Med Rehabil. 2013 Sep 27

Complex regional pain syndrome type I. Incidence and risk factors in patients with fracture of the distal radius.

Jellad A, Salah S, Frih ZB.

Source

University of Monastir Tunisia, Faculty of Medicine, Department of Physical Medicine and Rehabilitation. Electronic address: anisjellad@gmail.com.

Abstract

OBJECTIVE:

To examine the incidence and predictors of complex regional pain syndrome type I (CRPS I) after fracture of the distal radius.

DESIGN:

Prospective study SETTING: University hospital PARTICIPANTS: A consecutive sample of patients (N=90) with fracture of the distal radius treated by closed reduction and casting.

INTERVENTIONS:

Not applicable MAIN OUTCOME MEASURES: Occurrence of CRPS I, pain, wrist and hand range of motion, radiographic measures, Patient-Rated Wrist Evaluation, Hospital Anxiety and Depression scale and The Short Form 36 at baseline and at 1, 3, 6 and 9 months follow-up.

RESULTS:

CRPS I occurred in 29 patients (32.2%) with a mean delay of 21.7±23.7 days from cast removal. Univariate analyses found significant differences between patients with CRPS I and patients without CRPS I at baseline for gender (p=0.021), socio economic level (p=0.023), type of trauma (p=0.05), pain at rest and at activity (p=0.006 and p<0.001), wrist dorsiflexion and pronation (p=0.002 and p=0.001), fingers flexion (p=0.047), thumb opposition (p=0.002), function of the hand (p<0.001), and physical quality of life (p=0.013). Logistic regression showed that risk for CRPS I was higher in cases of female gender (OR:5.774;95%CI:1.391 to 23.966), medium and low energy trauma (OR:7.718;95% CI:1.136 to 52.44), physical quality of life of the short form 36 < 40 (OR:4.931;95%CI:1.428 to 17.025) and patient-rated wrist evaluation pain subscale >16 (OR:12.192;95%CI:4.484 to 43.478).

CONCLUSIONS:

CRPS I occurs frequently during the third and fourth week after cast removal especially in women who report severe pain and impairment of their physical quality of life. Additional prospective studies are required to verify these findings in comminuted and operated fractures of the distal radius

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J Pain. 2013 Sep 21. pii: S1526-5900(13)01130-9. 

Motor Dysfunction of Complex Regional Pain Syndrome Is Related to Impaired Central Processing of Proprioceptive Information.

Bank PJ, Peper CL, Marinus J, Beek PJ, van Hilten JJ.

Source

Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands; Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, The Netherlands. Electronic address: p.j.m.bank@lumc.nl.

Abstract

Our understanding of proprioceptive deficits in complex regional pain syndrome (CRPS) and its potential contribution to impaired motor function is still limited. To gain more insight into these issues, we evaluated accuracy and precision of joint position sense over a range of flexion-extension angles of the wrist of the affected and unaffected sides in 25 chronic CRPS patients and in 50 healthy controls. The results revealed proprioceptive impairment at both the patients’ affected and unaffected sides, characterized predominantly by overestimation of wrist extension angles. Precision of the position estimates was more prominently reduced at the affected side. Importantly, group differences in proprioceptive performance were observed not only for tests at identical percentages of each individual’s range of wrist motion but also when controls were tested at wrist angles that corresponded to those of the patient’s affected side. More severe motor impairment of the affected side was associated with poorer proprioceptive performance. Based on additional sensory tests, variations in proprioceptive performance over the range of wrist angles, and comparisons between active and passive displacements, the disturbances of proprioceptive performance most likely resulted from altered processing of afferent (and not efferent) information and its subsequent interpretation in the context of a distorted “body schema.”

PERSPECTIVE:

The present results point at a significant role for impaired central processing of proprioceptive information in the motor dysfunction of CRPS and suggest that therapeutic strategies aimed at identification of proprioceptive impairments and their restoration may promote the recovery of motor function in CRPS patients.

RS: we know that in many persisting pain cases, especially those with a neuropathic pain mechanism, there is an altered body schema. This must be targeted within the treatment and training programme.

Visit our main clinic page here: Specialist Pain Physio Clinics for persisting pain and injury

 

CRPS Bugle 17th Sept 2013 | #CRPS

CRPS BugleHere are some of the Cochrane Reviews relating to CRPS and chronic pain:

Local anaesthetic sympathetic blockade for complex regional pain syndrome.

Stanton TR, Wand BM, Carr DB, Birklein F, Wasner GL, O’Connell NE.

Cochrane Database Syst Rev. 2013 Aug 19;8:CD004598. doi: 10.1002/14651858.CD004598.pub3.

Source
Neuroscience Research Australia, Randwick, Australia.

Abstract
BACKGROUND:
This is an update of the original Cochrane review published in The Cochrane Library, 2005, Issue 4, on local anaesthetic blockade (LASB) of the sympathetic chain used to treat complex regional pain syndrome (CRPS).

OBJECTIVES:
To assess the efficacy of LASB for the treatment of pain in CRPS and to evaluate the incidence of adverse effects of the procedure.

SEARCH METHODS:
We updated searches of the Cochrane Pain, Palliative and Supportive Care Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library (Issue 11 of 12, 2012), MEDLINE (1966 to 22/11/12), EMBASE (1974 to 22/11/12), LILACS (1982 to 22/11/12), conference abstracts of the World Congresses of the International Association for the Study of Pain (1995 to 2010), and various clinical trial registers (inception to 2012). We also searched bibliographies from retrieved articles for additional studies.

SELECTION CRITERIA:
We considered for inclusion randomised controlled trials (RCTs) that evaluated the effect of sympathetic blockade with local anaesthetics in children or adults with CRPS.

DATA COLLECTION AND ANALYSIS:
The outcomes of interest were reduction in pain intensity levels, the proportion who achieved moderate or substantial pain relief, the duration of pain relief, and the presence of adverse effects in each treatment arm.

MAIN RESULTS:
We included an additional 10 studies (combined n = 363) in this update. Overall we include 12 studies (combined n = 386). All included studies were assessed to be at high or unclear risk of bias.Three small studies compared LASB to placebo/sham. We were able to pool the results from two of these trials (intervention n = 23). Pooling did not demonstrate significant short-term benefit for LASB (in terms of the risk of a 50% reduction of pain scores).Of two studies that investigated LASB as an addition to rehabilitation treatment, the only study that reported pain outcomes demonstrated no additional benefit from LASB.Eight small randomised studies compared sympathetic blockade to another active intervention. Most studies found no difference in pain outcomes between sympathetic block and other active treatments.Only five studies reported adverse effects, all with minor effects reported.

AUTHORS’ CONCLUSIONS:
This update has found similar results to the original systematic review. There remains a scarcity of published evidence to support the use of local anaesthetic sympathetic blockade for CRPS. From the existing evidence it is not possible to draw firm conclusions regarding the efficacy or safety of this intervention but the limited data available do not suggest that LASB is effective for reducing pain in CRPS

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Cochrane Database Syst Rev. 2013 Sep 2;9:CD002918. [Epub ahead of print]
Cervico-thoracic or lumbar sympathectomy for neuropathic pain and complex regional pain syndrome.
Straube S, Derry S, Moore RA, Cole P.

Source
Institute of Occupational, Social and Environmental Medicine, University Medical Center Göttingen, Waldweg 37 B, Göttingen, Germany, D-37073.

Abstract

BACKGROUND:
This review is an update of a review first published in Issue 2, 2003, which was substantially updated in Issue 7, 2010. The concept that many neuropathic pain syndromes (traditionally this definition would include complex regional pain syndromes (CRPS)) are “sympathetically maintained pains” has historically led to treatments that interrupt the sympathetic nervous system. Chemical sympathectomies use alcohol or phenol injections to destroy ganglia of the sympathetic chain, while surgical ablation is performed by open removal or electrocoagulation of the sympathetic chain or by minimally invasive procedures using thermal or laser interruption.

OBJECTIVES:
To review the evidence from randomised, double blind, controlled trials on the efficacy and safety of chemical and surgical sympathectomy for neuropathic pain, including complex regional pain syndrome. Sympathectomy may be compared with placebo (sham) or other active treatment, provided both participants and outcome assessors are blind to treatment group allocation.

SEARCH METHODS:
On 2 July 2013, we searched CENTRAL, MEDLINE, EMBASE, and the Oxford Pain Relief Database. We reviewed the bibliographies of all randomised trials identified and of review articles and also searched two clinical trial databases, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform, to identify additional published or unpublished data. We screened references in the retrieved articles and literature reviews and contacted experts in the field of neuropathic pain.

SELECTION CRITERIA:

Randomised, double blind, placebo or active controlled studies assessing the effects of sympathectomy for neuropathic pain and CRPS.

DATA COLLECTION AND ANALYSIS:
Two review authors independently assessed trial quality and validity, and extracted data. No pooled analysis of data was possible.

MAIN RESULTS:
Only one study satisfied our inclusion criteria, comparing percutaneous radiofrequency thermal lumbar sympathectomy with lumbar sympathetic neurolysis using phenol in 20 participants with CRPS. There was no comparison of sympathectomy versus sham or placebo. No dichotomous pain outcomes were reported. Average baseline scores of 8-9/10 on several pain scales fell to about 4/10 initially (1 day) and remained at 3-5/10 over four months. There were no significant differences between groups, except for “unpleasant sensation”, which was higher with radiofrequency ablation. One participant in the phenol group experienced post sympathectomy neuralgia, while two in the radiofrequency group and one in the phenol group complained of paraesthesia during needle positioning. All participants had soreness at the injection site.

AUTHORS’ CONCLUSIONS:
The practice of surgical and chemical sympathectomy for neuropathic pain and CRPS is based on very little high quality evidence. Sympathectomy should be used cautiously in clinical practice, in carefully selected patients, and probably only after failure of other treatment options. In these circumstances, establishing a clinical register of sympathectomy may help to inform treatment options on an individual patient basis.

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Psychological therapies for the management of chronic and recurrent pain in children and adolescents

Eccleston C, Palermo TM, Williams AC de C, Lewandowski A, Morley S, Fisher E, Law E
Published Online: August 23, 2013
– See more at: http://summaries.cochrane.org/CD003968/psychological-therapies-for-the-management-of-chronic-and-recurrent-pain-in-children-and-adolescents#sthash.eWN3HPP5.dpuf

Background:
Chronic pain affects many children, who report severe pain, distressed mood, and disability. Psychological therapies are emerging as effective interventions to treat children with chronic or recurrent pain. This update adds recently published randomised controlled trials (RCTs) to the review published in 2009.

Objectives:
To assess the effectiveness of psychological therapies, principally cognitive behavioural therapy and behavioural therapy, for reducing pain, disability, and improving mood in children and adolescents with recurrent, episodic, or persistent pain. We also assessed the risk of bias and methodological quality of the included studies.

Search strategy:
Searches were undertaken of MEDLINE, EMBASE, and PsycLIT. We searched for RCTs in references of all identified studies, meta-analyses and reviews. Date of most recent search: March 2012.

Selection criteria:
RCTs with at least 10 participants in each arm post-treatment comparing psychological therapies with active treatment were eligible for inclusion (waiting list or standard medical care) for children or adolescents with episodic, recurrent or persistent pain.

Data collection and analysis:
All included studies were analysed and the quality of the studies recorded. All treatments were combined into one class: psychological treatments; headache and non-headache outcomes were separately analysed on three outcomes: pain, disability, and mood. Data were extracted at two time points; post-treatment (immediately or the earliest data available following end of treatment) and at follow-up (at least three months after the post-treatment assessment point, but not more than 12 months).

Main results:
Eight studies were added in this update of the review, giving a total of 37 studies. The total number of participants completing treatments was 1938. Twenty-one studies addressed treatments for headache (including migraine); seven for abdominal pain; four included mixed pain conditions including headache pain, two for fibromyalgia, two for pain associated with sickle cell disease, and one for juvenile idiopathic arthritis. Analyses revealed five significant effects. Pain was found to improve for headache and non-headache groups at post-treatment, and for the headache group at follow-up. Mood significantly improved for the headache group at follow-up, although, this should be interpreted with caution as there were only two small studies entered into the analysis. Finally, disability significantly improved in the non-headache group at post-treatment. There were no other significant effects.

Authors’ conclusions:
Psychological treatments are effective in reducing pain intensity for children and adolescents (<18 years) with headache and benefits from therapy appear to be maintained. Psychological treatments also improve pain and disability for children with non-headache pain. There is limited evidence available to estimate the effects of psychological therapies on mood for children and adolescents with headache and non-headache pain. There is also limited evidence to estimate the effects on disability in children with headache. These conclusions replicate and add to those of the previous review which found psychological therapies were effective in reducing pain intensity for children with headache and non-headache pain conditions, and these effects were maintained at follow-up.

Visit our clinic site here: Specialist Pain Physio Clinics

CRPS Bugle | #CRPS | Body perception

CRPS BugleWelcome to the latest Bugle that focuses upon body perception, so often affected in CRPS. Body perception should form part of the assessment in my view, as the construction of this sense by the brain is a feature of the condition and must be addressed.

Evaluation of a prototype tool for communicating body perception disturbances in complex regional pain syndrome

Ailie J. Turton, Mark Palmer, Sharon Grieve, Timothy P. Moss, Jenny Lewis and Candida S. McCabe

Patients with Complex Regional Pain Syndrome (CRPS) experience distressing changes in body perception. However representing body perception is a challenge. A digital media tool for communicating body perception disturbances was developed. A proof of concept study evaluating the acceptability of the application for patients to communicate their body perception is reported in this methods paper. Thirteen CRPS participants admitted to a 2-week inpatient rehabilitation program used the application in a consultation with a research nurse. Audio recordings were made of the process and a structured questionnaire was administered to capture experiences of using the tool. Participants produced powerful images of disturbances in their body perception. All reported the tool acceptable for communicating their body perception. Participants described the positive impact of now seeing an image they had previously only imagined and could now convey to others. The application has provided a novel way for communicating perceptions that are otherwise difficult to convey.

* Full article available on the Frontiers in Human Neuroscience website – click here

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Eur J Pain. 2012 Oct;16(9):1320-30

Perceptions of the painful body: the relationship between body perception disturbance, pain and tactile discrimination in complex regional pain syndrome.

Lewis JS, Schweinhardt P.

Abstract
BACKGROUND:
Disturbances in body perception are increasingly acknowledged as a feature of complex regional pain syndrome (CRPS). Conventional treatments have limited success particularly among those with long-standing disease. Understanding the relationship between body perception disturbance, pain and tactile acuity might provide insight into alternative avenues for treatment. The aim of this study was to test the hypotheses that (1) body perception disturbance is positively related to pain and (2) decreased tactile acuity is related to increased body perception disturbance.
METHODS:
A controlled observational design was used to measure these features among those with CRPS of one arm. The extent of body perception disturbance was assessed using the Bath CRPS body perception disturbance scale and pain was measured using the neuropathic pain symptom inventory. Two-point discrimination threshold testing was performed as a measure of tactile acuity.
RESULTS:
Findings confirmed both hypotheses. Body perception disturbance was found to positively correlate with pain such that those in greater pain had more extensive body perception disturbance (r = 0.57, p < 0.01). Furthermore, a positive correlation was revealed between body perception disturbance and two-point discrimination thresholds (r = 0.5, p < 0.025) so those with greater body perception disturbance had worse tactile acuity. Interestingly, those with longer disease duration had significantly greater body perception disturbance (r = 0.66, p < 0.001).
CONCLUSION:
Aberrant central processing is suggested as the neural correlate of body perception disturbance and tactile impairment. The exact relationship between body perception disturbance, pain and tactile acuity and how they may be modulated for pain relief requires further exploration.

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Pain. 2012 Nov;153(11):2174-81

Impaired spatial body representation in complex regional pain syndrome type 1 (CRPS I).

Reinersmann A, Landwehrt J, Krumova EK, Ocklenburg S, Güntürkün O, Maier C.

Abstract
Recently, a shift of the visual subjective body midline (vSM), a correlate of the egocentric reference frame, towards the affected side was reported in patients with complex regional pain syndrome (CRPS). However, the specificity of this finding is as yet unclear. This study compares 24 CRPS patients to 21 patients with upper limb pain of other origin (pain control) and to 24 healthy subjects using a comprehensive test battery, including assessment of the vSM in light and dark, line bisection, hand laterality recognition, neglect-like severity symptoms, and motor impairment (disability of the arm, shoulder, and hand). Statistics: 1-way analysis of variance, t-tests, significance level: 0.05. In the dark, CRPS patients displayed a significantly larger leftward spatial bias when estimating their vSM, compared to pain controls and healthy subjects, and also reported lower motor function than pain controls. For right-affected CRPS patients only, the deviation of the vSM correlated significantly with the severity of distorted body perception. Results confirm previous findings of impaired visuospatial perception in CRPS patients, which might be the result of the involvement of supraspinal mechanisms in this pain syndrome. These mechanisms might accentuate the leftward bias that results from a right-hemispheric dominance in visuospatial processing and is known as pseudoneglect. Pseudoneglect reveals itself in the tendency to perceive the midpoint of horizontal lines or the subjective body midline left of the centre. It was observable in all 3 groups, but most pronounced in CRPS patients, which might be due to the cortical reorganisation processes associated with this syndrome.

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Specialist Pain Physio Clinics, London

CRPS Bugle 13 Aug #CRPS

CRPS BugleWelcome to the latest CRPS Bugle

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Acute and chronic phases of complex regional pain syndrome in mice are accompanied by distinct transcriptional changes in the spinal cord.

Mol Pain. 2013 Aug 8;9(1):40.

Gallagher JJ, Tajerian M, Guo T, Shi X, Li W, Zheng M, Peltz G, Kingery W, Clark JD.

Abstract

BACKGROUND:

CRPS is a painful, debilitating, and often-chronic condition characterized by various sensory, motor, and vascular disturbances. Despite many years of study, current treatments are limited by our understanding of the underlying mechanisms. Little is known on the molecular level concerning changes in gene expression supporting the nociceptive sensitization commonly observed in CRPS limbs, or how those changes might evolve over time.

RESULTS:

We used a well-characterized mouse tibial fracture/cast immobilization model of CRPS to study molecular, vascular and nociceptive changes. We observed that the acute (3 weeks after fracture) and chronic (7 weeks after fracture) phases of CRPS-like changes in our model were accompanied by unique alterations in spinal gene expression corresponding to distinct canonical pathways. For the acute phase, top regulated pathways were: chemokine signaling, glycogen degradation, and cAMP-mediated signaling; while for the chronic phase, the associated pathways were: coagulation system, granzyme A signaling, and aryl hydrocarbon receptor signaling. We then focused on the role of CcL2, a chemokine that we showed to be upregulated at the mRNA and protein levels in spinal cord tissue in our model. We confirmed its association with the nociceptive sensitization displayed in this model by demonstrating that the spinal but not peripheral administration of a CCR2 antagonist (RS504393) in CRPS animals could decrease mechanical allodynia. The spinal administration of CcL2 itself resulted in mechanical allodynia in control mice.

CONCLUSIONS:

Our data provide a global look at the transcriptional changes in the spinal cord that accompany the acute and chronic phases of CRPS as modeled in mice. Furthermore, it follows up on one of the top-regulated genes coding for CcL2 and validates its role in regulating nociception in the fracture/cast model of CRPS.

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An older paper identifying the effects of immobilisation that are similar to CRPS and the role of substance P in the vascular changes.

Substance P signalling contributes to the vascular and nociceptive abnormalities observed in a tibial fracture rat model of complex regional pain syndrome type I.

Pain. 2004 Mar;108(1-2):95-107.

Guo TZ, Offley SC, Boyd EA, Jacobs CR, Kingery WS.

Source

Physical Medicine and Rehabilitation Service, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA.

Abstract

Wrist and ankle fractures are the most frequent causes of complex regional pain syndrome (CRPS type I). The current study examined the temporal development of vascular, nociceptive and bony changes after distal tibial fracture in rats and compared these changes to those observed after cast immobilization in intact normal rats. After baseline testing the right distal tibial was fractured and the hindlimb casted. A control group was simply casted without fracturing the tibia. After 4 weeks the casts were removed and the rats retested. Subsequent testing was performed at 6, 8, 10, 16, and 20 weeks after onset of treatment. Distal tibial fracture or cast immobilization alone generated chronic hindlimb warmth, edema, spontaneous protein extravasation, allodynia, and periarticular osteoporosis, changes resembling those observed in CRPS. Hindlimb warmth and allodynia resolved much more quickly after cast immobilization than after fracture. Previously we observed that the substance P receptor (NK(1)) antagonist LY303870 reversed vascular and nociceptive changes in a sciatic section rat model of CRPS type II. Postulating that facilitated substance P signaling may also contribute to the vascular and nociceptive abnormalities observed after tibial fracture or cast immobilization, we attempted to reverse these changes with LY303870. Hindpaw warmth, spontaneous extravasation, edema, and allodynia were inhibited by LY303870. Collectively, these data support the hypotheses that the distal tibial fracture model simulates CRPS, immobilization alone can generate a syndrome resembling CRPS, and substance P signaling contributes to the vascular and nociceptive changes observed in these models.

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Pain-related fear, perceived harmfulness of activities, and functional limitations in complex regional pain syndrome type I.

J Pain. 2011 Dec;12(12):1209-18. doi: 10.1016/j.jpain.2011.06.010.

de Jong JR, Vlaeyen JW, de Gelder JM, Patijn J.

Source

Department of Rehabilitation, University Hospital Maastricht, Maastricht, The Netherlands. jeroen.dejong@mumc.nl

Abstract

Numerous studies have shown that pain-related fear is one of the strongest predictors of pain disability in patients with chronic musculoskeletal pain, and there is evidence that the reduction of pain-related fear through an exposure treatment can be associated with restoration of functional abilities in patients with complex regional pain syndrome type I (CRPS-I). These findings suggest that pain-related fear may be associated with functional limitations in neuropathic pain as well. The aim of the current study was to test whether the debilitating role of pain-related fear generalizes to patients with CRPS-I. The results of 2 studies are presented. Study I includes a sample of patients with early CRPS-I referred to an outpatient pain clinic. In Study II, patients with chronic CRPS who are members of a patients’ association were invited to participate. The results show that in early CRPS-I, pain severity but not fear of movement/(re)injury as measured with the Tampa Scale for Kinesiophobia was related to functional limitations. In patients with chronic CRPS-I, however, perceived harmfulness of activities as measured with the pictorial assessment method significantly predicted functional limitations beyond and above the contribution of pain severity. Not fear of movement/(re)injury in general, but the perceived harmfulness of activities appears a key factor that might be addressed more systematically in the clinical assessment of patients with CRPS-I. These results support the idea that pain-related fear might be a promising concept in the understanding of pain disability in patients with neuropathic pain.

PERSPECTIVE:

This is the first study showing that perceived harmfulness of activities contribute to the functional limitations in CRPS-I. The current findings may help clinicians customizing cognitive-behavioral treatments for patients with chronic neuropathic pain.

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Please visit our clinic site for further information on treatment, training & coaching for CRPS (RSD): Specialist Pain Physio Clinics, London or call us on 07932 689081

#CRPS Bugle | 28th July

CRPS BugleImpaired Recognition of Social Emotion in Patients With Complex Regional Pain Syndrome.

J Pain. 2013 Jul 19.

Shin NY, Kang DH, Jang JH, Park SY, Hwang JY, Kim SN, Byun MS, Park HY, Kim YC.

Abstract

Multiple brain areas involved in nociceptive, autonomic, and social-emotional processing are disproportionally changed in patients with complex regional pain syndrome (CRPS). Little empirical evidence is available involving social cognitive functioning in patients with chronic pain conditions. We investigated the ability of patients with CRPS to recognize the mental/emotional states of other people. Forty-three patients with CRPS and 30 healthy controls performed the Reading Mind in the Eyes Test, which consists of photos in which human eyes express various emotional and mental states. Neuropsychological tests, including the Wisconsin Card Sorting Test, the stop-signal test, and the reaction time test, were administered to evaluate other cognitive functions. Patients with CRPS were significantly less accurate at recognizing emotional states in other persons, but not on other cognitive tests, compared with control subjects. We found a significant association between the deficit in social-emotion recognition and the affective dimension of pain, whereas this deficit was not related to the sensory dimension of pain. Our findings suggest a disrupted ability to recognize others’ mental/emotional states in patients with CRPS.

PERSPECTIVE:

This article demonstrated a deficit in inferring mental/emotional states of others in patients with CRPS that was related to pain affect. Our study suggests that additional interventions directed toward reducing distressful affective pain may be helpful to restore social cognitive processing in patients with CRPS.

RS – addressing all the dimensions of pain is vital in a comprehensive treatment & training programme: physical, emotional & cognitive. Awareness of deficits such as ‘inferring mental/emotional states of others’, as seen in this study, allows clinicians to account for certain behaviours and responses that can be seen during the assessment process and treatment sessions. Subsequently, the therapy choice can be made on an individual basis to target the deficits.

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Altered Resting-State Functional Connectivity in Complex Regional Pain Syndrome.

J Pain. 2013 Jun 18.

Bolwerk A, Seifert F, Maihöfner C.

Abstract

This study explored the functional connectivity between brain regions implicated in the default mode network, the sensorimotor cortex (S1/M1), and the intraparietal sulcus (IPS/MIP) at rest in patients with complex regional pain syndrome. It also investigated how possible alterations are associated with neuropathic pain. Our group used functional magnetic resonance imaging to investigate functional brain connectivity in 12 complex regional pain syndrome patients in comparison with that in 12 age- and sex-matched healthy controls. Data were analyzed using a seed voxel correlation analysis and an independent component analysis. An analysis of covariance was employed to relate alterations in functional connectivity with clinical symptoms. We found significantly greater reductions in functional default mode network connectivity in patients compared to controls. The functional connectivity maps of S1/M1 and IPS/MIP in patients revealed greater and more diffuse connectivity with other brain regions, mainly with the cingulate cortex, precuneus, thalamus, and prefrontal cortex. In contrast, controls showed greater intraregional connectivity within S1/M1 and IPS/MIP. Furthermore, there was a trend for correlation between alterations in functional connectivity and intensity of neuropathic pain. In our findings, patients with complex regional pain syndrome have substantial spatial alterations in the functional connectivity between brain regions implicated in the resting-state default mode network, S1/M1, and IPS/MIP; these alterations show a trend of correlation with neuropathic pain intensity.

PERSPECTIVE:

This article presents spatial alterations in the functional resting-state connectivity of complex regional pain syndrome patients. Our results add further insight into the disease states of CRPS and into the functional architecture of the resting state brains of pain patients in general.

RS: Pain emerges from the body. That is where we feel it undoubtedly. It can be a difficult leap to understand that the neural correlate sits within the brain. There is no pain centre but rather a widespread group of neurons in different brain regions that when activated, create a neurotag or neurosignature that manifests as pain where the brain perceives a threat that requires protection. It is no surprise therefore, to see a further study highlight altered activity within the brain in CRPS patients compared to a control group. From a clinical perspective, it demonstrates that we have to ‘think brain’ within the reasoning behind the design of a rehabilitation programme and in appropriate cases use therapies such as graded motor imagery

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A Disturbance in Sensory Processing on the Affected Side of the Body Increases Limb Pain in Complex Regional Pain Syndrome.

Clin J Pain. 2013 Jun 19.

Drummond PD, Finch PM.

Abstract

OBJECTIVES::

The aim of this study was to determine whether a central disturbance in somatosensory processing contributes to limb pain in complex regional pain syndrome (CRPS).

METHODS::

In 37 patients with CRPS, the effect of cooling the ipsilateral forehead on pain in the affected limb was compared with the effect of cooling the contralateral forehead. In addition, symptoms associated with cold-evoked limb pain were explored.

RESULTS::

Limb pain generally increased when the ipsilateral side of the forehead was cooled but did not change when the contralateral side of the forehead was cooled. Increases were greatest in patients with heightened sensitivity to cold, brushing, and pressure-pain in the ipsilateral forehead, in patients with heightened sensitivity to pressure-pain in the limbs, and in patients with chronic symptoms. In contrast, sensitivity to light touch was diminished in the CRPS-affected limb of patients whose limb pain remained unchanged or decreased during ipsilateral forehead cooling.

CONCLUSIONS::

These preliminary findings suggest that a central disturbance in sensory processing and pain modulation, which extends beyond the affected limb to the ipsilateral forehead, contributes to symptoms in a subgroup of patients with CRPS.

RS: A number of patients who present with pain that is underpinned by a component of central sensitisation will also, being given the chance, describe pain in other body regions and body systems. Being vigilant to this possibility is fundamental to a complete assessment, the conclusions of which will guide the treatment programme.

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Local cytokine changes in complex regional pain syndrome type I (CRPS I) resolve after 6months.

Pain. 2013 Jun 27.

Lenz M, Uçeyler N, Frettlöh J, Höffken O, Krumova EK, Lissek S, Reinersmann A, Sommer C, Stude P, Waaga-Gasser AM, Tegenthoff M, Maier C.

Abstract

There is evidence that inflammatory processes are involved in at least the early phase of complex regional pain syndrome (CRPS). We compared a panel of pro- and antiinflammatory cytokines in skin blister fluids and serum from patients with CRPS and patients with upper-limb pain of other origin (non-CRPS) in the early stage (< 1year) and after 6months of pain treatment. Blister fluid was collected from the affected and contralateral nonaffected side. We used a multiplex-10 bead array cytokine assay and Luminex technology to measure protein concentrations of the cytokines interleukin-1 receptor antagonist (IL-1RA), IL-2, IL-6, IL-8, IL-10, IL-12p40, and tumor necrosis factor-alpha (TNF-α) and the chemokines eotaxin, monocyte chemotactic protein-1 (MCP-1), and macrophage inflammatory protein-1β (MIP-1β). We found bilaterally increased proinflammatory TNF-α and MIP-1β and decreased antiinflammatory IL-1RA protein levels in CRPS patients compared to non-CRPS patients. Neither group showed side differences. After 6 months under analgesic treatment, protein levels of all measured cytokines in CRPS patients, except for IL-6, significantly changed bilaterally to the level of non-CRPS patients. These changes were not related to treatment outcome. In serum, only IL-8, TNF-α, eotaxin, MCP-1, and MIP-1β were detectable without intergroup differences. Blister fluid of CRPS patients showed a bilateral proinflammatory cytokine profile. This profile seems to be relevant only at the early stage of CRPS. Almost all measured cytokine levels were comparable to those of non-CRPS patients after 6 months of analgesic treatment and were not related to treatment outcome.

RS: ‘Blister fluid of CRPS patients showed a bilateral proinflammatory cytokine profile. This profile seems to be relevant only at the early stage of CRPS’. In some patients there is an inflammatory profile that should be noted and treated as early as possible. On-going inflammation will cause a persisting bombardment of danger signals to the spinal cord and to the higher centres. The brain does want to know about inflammation and when detected it typically hurts, the purpose being that we need to know (consciously) so that we take appropriate action. Tackling inflammation early may have a beneficial effect upon this process.

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Limb-specific autonomic dysfunction in complex regional pain syndrome modulated by wearing prism glasses.

Pain. 2013 Jul 22.

Lorimer Moseley G, Gallace A, Di Pietro F, Spence C, Iannetti GD.

Abstract

In unilateral upper limb complex regional pain syndrome (CRPS), the temperature of the hands is modulated by where the arms are located, relative to the body midline. We hypothesized that this effect depends on the perceived location of the hands, not on their actual location, nor on their anatomical alignment. In two separate cross-sectional randomized experiments, ten (6 female) unilateral CRPS patients wore prism glasses that laterally shifted the visual field by 20°. Skin temperature was measured before and after nine-minute periods in which the position of one hand was changed. Placing the affected hand on the healthy side of the body midline increased its temperature (Δ°C =0.47 ± 0.14°C), but not if prism glasses made the hand appear to be on the body midline (Δ°C =0.07 ± 0.06°C). Similarly, when prism glasses made the affected hand appear to be on the healthy side of the body midline, even though it was not, the affected hand warmed up (Δ°C =0.28 ± 0.14°C). When prism glasses made the healthy hand appear to be on the affected side of the body midline, even though it was not, the healthy hand cooled down (Δ°C = -0.30 ± 0.15°C). Friedman’s ANOVA and Wilcoxon’s pairs tests upheld the results (p <0.01 for all). We conclude that, in CRPS, cortical mechanisms responsible for encoding the perceived location of the limbs in space modulate the temperature of the hands.

And, another paper here:

Spatially defined modulation of skin temperature and hand ownership of both hands in patients with unilateral complex regional pain syndrome.

Brain. 2012 Dec;135(Pt 12):3676-86.

Moseley GL, Gallace A, Iannetti GD.

Abstract

Numerous clinical conditions, including complex regional pain syndrome, are characterized by autonomic dysfunctions (e.g. altered thermoregulation, sometimes confined to a single limb), and disrupted cortical representation of the body and the surrounding space. The presence, in patients with complex regional pain syndrome, of a disruption in spatial perception, bodily ownership and thermoregulation led us to hypothesize that impaired spatial perception might result in a spatial-dependent modulation of thermoregulation and bodily ownership over the affected limb. In five experiments involving a total of 23 patients with complex regional pain syndrome of one arm and 10 healthy control subjects, we measured skin temperature of the hand with infrared thermal imaging, before and after experimental periods of either 9 or 10 min each, during which the hand was held on one or the other side of the body midline. Tactile processing was assessed by temporal order judgements of pairs of vibrotactile stimuli, delivered one to each hand. Pain and sense of ownership over the hand were assessed by self-report scales. Across experiments, when kept on its usual side of the body midline, the affected hand was 0.5 ± 0.3°C cooler than the healthy hand (P < 0.02 for all, a common finding in cold-type complex regional pain syndrome), and tactile stimuli delivered to the healthy hand were prioritized over those delivered to the affected hand. Simply crossing both hands over the midline resulted in (i) warming of the affected hand (the affected hand became 0.4 ± 0.3°C warmer than when it was in the uncrossed position; P = 0.01); (ii) cooling of the healthy hand (by 0.3 ± 0.3°C; P = 0.02); and (iii) reversal of the prioritization of tactile processing. When only the affected hand was crossed over the midline, it became warmer (by 0.5 ± 0.3°C; P = 0.01). When only the healthy hand was crossed over the midline, it became cooler (by 0.3 ± 0.3°C; P = 0.01). The temperature change of either hand was positively related to its distance from the body midline (pooled data: r = 0.76, P < 0.001). Crossing the affected hand over the body midline had small but significant effects on both spontaneous pain (which was reduced) and the sense of ownership over the hand (which was increased) (P < 0.04 for both). We conclude that impaired spatial perception modulated temperature of the limbs, tactile processing, spontaneous pain and the sense of ownership over the hands. These results show that complex regional pain syndrome involves more complex neurological dysfunction than has previously been considered.

RS: very cool research unravelling the complex mechanisms that underpin CRPS

Come and visit our clinic site here: Specialist Pain Physio Clinics, London for treatment and training for complex and chronic pain

CRPS Bugle 21st June

For some time studies have suggested that cortical reorganisation underpins certain features of complex regional pain syndrome. Also termed the body schema, this is in essence how we ‘feel’ ourselves and is constructed by the brain. However, the actual sense emerges from the physical body, the tissues despite the fact that the neural correlate is within the brain.

Many patients who come to the clinic with CRPS describe an altered sense of the affected area – detached, ‘not mine’, change in size perception

The study by Lorimer Moseley in 2004 outlined below looked at why those with complex regional pain syndrome tend to be slower at recognising the affected hand. This is a common finding when I assess a CRPS patient, an issue in body schema that requires addressing with a therapeutic training strategy.

Neurology. 2004 Jun 22;62(12):2182-6.

Why do people with complex regional pain syndrome take longer to recognize their affected hand?

Moseley GL.

Abstract

BACKGROUND:

People with complex regional pain syndrome (CRPS) take longer to recognize the laterality of a pictured hand when it coincides with their affected hand. The author explored two aspects of this phenomenon: whether the duration of symptoms relates to the extent of the delay and whether guarding-type mechanisms are involved.

METHODS:

Eighteen patients with CRPS type 1 of the wrist and 18 matched control subjects performed a hand laterality recognition task. McGill pain questionnaire, Neuropathic Pain Scale, and response time (RT) to recognize hand laterality were analyzed. Regressions related 1) mean RT for patients to the duration of symptoms and to pain intensity; and 2) mean RT for each picture to the predicted pain on executing that movement as judged by the patient, and to the awkwardness of the movement that would be required.

RESULTS:

For patients, the duration of symptoms correlated with mean RT (Spearman rho = 0.44; p = 0.02). Predicted pain rating explained 45% of the variance in RT for each picture for each patient (p < 0.01).

CONCLUSIONS:

The results suggest that in patients with complex regional pain syndrome type 1, delayed recognition of hand laterality is related to the duration of symptoms and to the pain that would be evoked by executing the movement. The former is consistent with chronic pain and disuse and may involve reorganization of the cortical correlate of body schema. The latter is consistent with a guarding-type response that probably occurs upstream of the motor cortex at a motor planning level.

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Neurosci Lett. 2010 Dec 17;486(3):240-5. doi: 10.1016/j.neulet.2010.09.062. Epub 2010 Sep 29.

Left is where the L is right. Significantly delayed reaction time in limb laterality recognition in both CRPS and phantom limb pain patients.

Reinersmann A, Haarmeyer GS, Blankenburg M, Frettlöh J, Krumova EK, Ocklenburg S, Maier C.

Abstract

The body schema is based on an intact cortical body representation. Its disruption is indicated by delayed reaction times (RT) and high error rates when deciding on the laterality of a pictured hand in a limb laterality recognition task. Similarities in both cortical reorganisation and disrupted body schema have been found in two different unilateral pain syndromes, one with deafferentation (phantom limb pain, PLP) and one with pain-induced dysfunction (complex regional pain syndrome, CRPS). This study aims to compare the extent of impaired laterality recognition in these two groups. Performance on a test battery for attentional performance (TAP 2.0) and on a limb laterality recognition task was evaluated in CRPS (n=12), PLP (n=12) and healthy subjects (n=38). Differences between recognising affected and unaffected hands were analysed. CRPS patients and healthy subjects additionally completed a four-day training of limb laterality recognition. Reaction time was significantly delayed in both CRPS (2278±735.7ms) and PLP (2301.3±809.3ms) compared to healthy subjects (1826.5±517.0ms), despite normal TAP values in all groups. There were no differences between recognition of affected and unaffected hands in both patient groups. Both healthy subjects and CRPS patients improved during training, but RTs of CRPS patients (1874.5±613.3ms) remain slower (p<0.01) than those of healthy subjects (1280.6±343.2ms) after four-day training. Despite different pathomechanisms, the body schema is equally disrupted in PLP and CRPS patients, uninfluenced by attention and pain and cannot be fully reversed by training alone. This suggests the involvement of complex central nervous system mechanisms in the disruption of the body schema.

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J Int Neuropsychol Soc. 2010 Jul;16(4):603-12. doi: 10.1017/S1355617710000299. Epub 2010 Apr 12.

Mental motor imagery and chronic pain: the foot laterality task.

Coslett HB, Medina J, Kliot D, Burkey A.

Abstract

Several lines of evidence suggest that mental motor imagery is subserved by the same cognitive operations and brain structures that underlie action. Additionally, motor imagery is informed by the anticipated sensory consequences of action, including pain. We reasoned that motor imagery could provide a useful measure of chronic leg or foot pain. Forty subjects with leg pain (19 bilateral, 11 right, and 10 left leg pain), 42 subjects with chronic pain not involving the legs, and 38 controls were shown 12 different line drawings of the right or left foot and asked to indicate which foot was depicted. Previous work suggests that subjects perform this task by mentally rotating their foot to match the visually presented stimulus. All groups of subjects were slower and less accurate with stimuli that required a greater degree of mental rotation of their foot. Subjects with leg pain were both slower and less accurate than normal and pain control subjects in responding to drawings of a painful extremity. Furthermore, subjects with leg pain exhibited a significantly greater decrement in performance for stimuli that required larger amplitude mental rotations. These data suggest that motor imagery may provide important insights into the nature of the pain experience.

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Eur J Pain. 2010 Nov;14(10):1007-13. Full article here

Mental motor imagery indexes pain: the hand laterality task.

Coslett HB, Medina J, Kliot D, Burkey AR.

Abstract

Mental motor imagery is subserved by the same cognitive systems that underlie action. In turn, action is informed by the anticipated sensory consequences of movement, including pain. In light of these considerations, one would predict that motor imagery would provide a useful measure pain-related functional interference. We report a study in which 19 patients with chronic musculoskeletal or radiculopathic arm or shoulder pain, 24 subjects with chronic pain not involving the arm/shoulder and 41 normal controls were asked to indicate if a line drawing was a right or left hand. Previous work demonstrated that this task is performed by mental rotation of the subject’s hand to match the stimulus. Relative to normal and pain control subjects, arm/shoulder pain subjects were significantly slower for stimuli that required greater amplitude rotations. For the arm/shoulder pain subjects only there was a correlation between degree of slowing and the rating of severity of pain with movement but not the non-specific pain rating. The hand laterality task may supplement the assessment of subjects with chronic arm/shoulder pain.

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Brain Res. 2010 Oct 8;1355:104-11. Full article here

Contributions of efference copy to limb localization: evidence from deafferentation.

Medina J, Jax SA, Brown MJ, Coslett HB.

Abstract

CRPS BuglePrevious research with deafferented subjects suggests that efference copy can be used to update limb position. However, the contributions of efference copy to limb localization are currently unclear. We examined the performance of JDY, a woman with severe, longstanding proprioceptive deficits from a sensory peripheral neuropathy, on a reaching task to explore the contribution of efference copy to trajectory control. JDY and eight healthy controls reached without visual feedback to a target that either remained stationary or jumped to a second location after movement initiation. JDY consistently made hypermetric movements to the final target, exhibiting significant problems with amplitude control. Despite this amplitude control deficit, JDY’s performance on jump trials showed that the angle of movement correction (angle between pre- and post-correction movement segments) was significantly correlated with the distance (but not time) of movement from start to turn point. These data suggest that despite an absence of proprioceptive and visual information regarding hand location, JDY derived information about movement distance that informed her movement correction on jump trials. The same type of information that permitted her to correct movement direction on-line, however, was not available for control of final arm position. We propose that efference copy can provide a consistent estimate of limb position that becomes less informative over the course of the movement. We discuss the implications of these data for current models of motor control.

Visit our main site here: Specialist Pain Physio Clinics for information about our neuroscience based treatment programmes for CRPS

CRPS & Pain Bugle 17th June

Continuum (Minneap Minn). 2012 Feb;18(1):106-25. doi: 10.1212/01.CON.0000411570.79827.25.

Painful small fiber neuropathies.

McArthur JC.

Abstract

PURPOSE OF REVIEW:

This article reviews the clinical features, pathophysiology, and treatment of small fiber sensory neuropathy.

RECENT FINDINGS:

Neuropathic pain is prevalent among patients with peripheral neuropathies of diverse etiologies. For example, in one recent study using the sensitive Neuropathic Pain Symptom Inventory as a screening tool, neuropathic pain was reported in 94% of patients with different peripheral nervous system diseases. Neuropathic pain is frequently underrecognized or inadequately treated. Furthermore, the paucity of clinical signs with small fiber neuropathy may delay recognition of an organic process. Pain, or uncomfortable symptoms, typically results from damage to small unmyelinated nerve fibers (C fibers) or thinly myelinated nerve fibers (A delta fibers). Recent research has helped discover the location of the “pain generators” within the injured peripheral nerves. Small fiber neuropathies are relatively common in clinical practice, but until recently most of the available neurodiagnostic tests focused on large caliber nerve fibers. In the past two decades, the widespread use of quantitative sensory testing and punch skin biopsies to evaluate small caliber nerve fibers has substantially changed the neurologist’s ability to diagnose and manage small fiber sensory neuropathy.

SUMMARY:

Neuropathic pain from small fiber neuropathy is prevalent and is caused by a wide variety of disorders, many of which are treatable, especially if recognized early in the process

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Pain. 2013 Jun 5. pii: S0304-3959(13)00297-2. doi: 10.1016/j.pain.2013.06.004. [Epub ahead of print]

Interventional management of neuropathic pain: NeuPSIG recommendations.

Dworkin RH, O’Connor AB, Kent J, Mackey SC, Raja SN, Stacey BR, Levy RM, Backonja M, Baron R, Harke H, Loeser JD, Treede RD, Turk DC, Wells CD.

Abstract

Neuropathic pain (NP) is often refractory to pharmacologic and non-interventional treatment. On behalf of the International Association for the Study of Pain Neuropathic Pain Special Interest Group (NeuPSIG), the authors evaluated systematic reviews, clinical trials, and existing guidelines for the interventional management of NP. Evidence is summarized and presented for neural blockade, spinal cord stimulation (SCS), intrathecal medication, and neurosurgical interventions in patients with the following peripheral and central NP conditions: herpes zoster and postherpetic neuralgia (PHN); painful diabetic and other peripheral neuropathies; spinal cord injury NP; central post-stroke pain; radiculopathy and failed back surgery syndrome (FBSS); complex regional pain syndrome (CRPS); and trigeminal neuralgia and neuropathy. Due to the paucity of high-quality clinical trials, no strong recommendations can be made. Four weak recommendations based on the amount and consistency of evidence, including degree of efficacy and safety, are: (1) epidural injections for herpes zoster; (2) steroid injections for radiculopathy; (3) SCS for FBSS; and (4) SCS for CRPS type 1. Based on the available data, we recommend not to use sympathetic blocks for PHN nor RF lesions for radiculopathy. No other conclusive recommendations can be made due to the poor quality of available of data. Whenever possible, these interventions should either be part of randomized clinical trials or documented in pain registries. Priorities for future research include randomized clinical trials; long-term studies; and head-to-head comparisons among different interventional and non-interventional treatments.

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Pain Res Manag. 2012 May-Jun;17(3):150-8. – FULL ARTICLE HERE

Evidence-based guideline for neuropathic pain interventional treatments: spinal cord stimulation, intravenous infusions, epidural injections and nerve blocks.

Mailis A, Taenzer P.

Source

Department of Medicine, University of Toronto, Toronto, Canada. angela.mailis@uhn.on.ca

Abstract

BACKGROUND:

The Special Interest Group of the Canadian Pain Society has produced consensus-based guidelines for the pharmacological management of neuropathic pain. The society aimed to generate an additional guideline for other forms of neuropathic pain treatments.

OBJECTIVE:

To develop evidence-based recommendations for neuropathic pain interventional treatments.

METHODS:

A task force was created and engaged the Institute of Health Economics in Edmonton, Alberta, to survey the literature pertaining to multiple treatments. Sufficient literature existed on four interventions only: spinal cord stimulation; epidural injections; intravenous infusions; and nerve blocks. A comprehensive search was conducted for systematic reviews, randomized controlled trials and evidence-based clinical practice guidelines; a critical review was generated on each topic. A modified United States Preventive Services Task Force tool was used for quality rating and grading of recommendations.

RESULTS:

Investigators reviewed four studies of spinal cord stimulation, 19 studies of intravenous infusions, 14 studies of epidural injections and 16 studies of nerve blocks that met the inclusion criteria. The task force chairs rated the quality of evidence and graded the recommendations. Feedback was solicited from the members of the task force.

CONCLUSION:

There is sufficient evidence to support recommendations for some of these interventions for selected neuropathic pain conditions. This evidence is, at best, moderate and is often limited or conflicting. Pain practitioners are encouraged to explore evidence-based treatment options before considering unproven treatments. Full disclosure of risks and benefits of the available options is necessary for shared decision making and informed consent.

Here is the conclusion from the paper: Available data support some evidence-based recommendations for SCS, epidural injections, certain nerve blocks and IV injections for selected neuropathic pain conditions. However, the evidence for most interventions is weak/limited or insufficient. Many nonpharmacological treatment options currently in use for neuropathic pain, including many forms of interventional therapy, have not been investigated using high-quality clinical trial methods. The CPS NePSIG encourages practitioners to explore evidence-based treatment options before considering unproven treatments. Full and careful disclosure of the known and unknown risks and benefits of available options is necessary for shared decision making and truly informed consent.

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For further information on our treatment, training & coaching programmes for CRPS and other persisting pain problems, please visit our clinic website here: Specialist Pain Physio Clinics, London

#CRPS Bugle | 30th May

Pain. 2013 Apr 6. CRPS Bugle

The rubber hand illusion in complex regional pain syndrome: Preserved ability to integrate a rubber hand indicates intact multisensory integration.

Reinersmann A, Landwehrt J, Krumova EK, Peterburs J, Ocklenburg S, Güntürkün O, Maier C.

Source

Department of Pain Medicine, Ruhr-University Bochum, BG Universitätsklinikum Bergmannsheil GmbH, Germany. Electronic address: Annika.Reinersmann@rub.de.

Abstract

In patients with complex regional pain syndrome (CRPS) type 1, processing of static tactile stimuli is impaired, whereas more complex sensory integration functions appear preserved. This study investigated higher order multisensory integration of body-relevant stimuli using the rubber hand illusion in CRPS patients. Subjective self-reports and skin conductance responses to watching the rubber hand being harmed were compared among CRPS patients (N=24), patients with upper limb pain of other origin (N=21, clinical control group), and healthy subjects (N=24). Additionally, the influence of body representation (body plasticity [Trinity Assessment of Body Plasticity], neglect-like severity symptoms), and clinical signs of illusion strength were investigated. For statistical analysis, 1-way analysis of variance, t test, Pearson correlation, with α=0.05 were used. CRPS patients did not differ from healthy subjects and the control group with regard to their illusion strength as assessed by subjective reports or skin conductance response values. Stronger left-sided rubber hand illusions were reported by healthy subjects and left-side-affected CRPS patients. Moreover, for this subgroup, illness duration and illusion strength were negatively correlated. Overall, severity of neglect-like symptoms and clinical signs were not related to illusion strength. However, patients with CRPS of the right hand reported significantly stronger neglect-like symptoms and significantly lower illusion strength of the affected hand than patients with CRPS of the left hand. The weaker illusion of CRPS patients with strong neglect-like symptoms on the affected hand supports the role of top-down processes modulating body ownership. Moreover, the intact ability to perceive illusory ownership confirms the notion that, despite impaired processing of proprioceptive or tactile input, higher order multisensory integration is unaffected in CRPS.

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Pain. 2012 Nov;153(11):2174-81.

Impaired spatial body representation in complex regional pain syndrome type 1 (CRPS I).

Reinersmann A, Landwehrt J, Krumova EK, Ocklenburg S, Güntürkün O, Maier C.

Source

Department of Pain Management, Ruhr-University Bochum, BG Universitätsklinikum Bergmannsheil GmbH, Bochum, Germany. Annika.reinersmann@rub.de

Abstract

Recently, a shift of the visual subjective body midline (vSM), a correlate of the egocentric reference frame, towards the affected side was reported in patients with complex regional pain syndrome (CRPS). However, the specificity of this finding is as yet unclear. This study compares 24 CRPS patients to 21 patients with upper limb pain of other origin (pain control) and to 24 healthy subjects using a comprehensive test battery, including assessment of the vSM in light and dark, line bisection, hand laterality recognition, neglect-like severity symptoms, and motor impairment (disability of the arm, shoulder, and hand). Statistics: 1-way analysis of variance, t-tests, significance level: 0.05. In the dark, CRPS patients displayed a significantly larger leftward spatial bias when estimating their vSM, compared to pain controls and healthy subjects, and also reported lower motor function than pain controls. For right-affected CRPS patients only, the deviation of the vSM correlated significantly with the severity of distorted body perception. Results confirm previous findings of impaired visuospatial perception in CRPS patients, which might be the result of the involvement of supraspinal mechanisms in this pain syndrome. These mechanisms might accentuate the leftward bias that results from a right-hemispheric dominance in visuospatial processing and is known as pseudoneglect. Pseudoneglect reveals itself in the tendency to perceive the midpoint of horizontal lines or the subjective body midline left of the centre. It was observable in all 3 groups, but most pronounced in CRPS patients, which might be due to the cortical reorganisation processes associated with this syndrome.

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Pain. 2012 Jul;153(7):1484-94.

Intact 2D-form recognition despite impaired tactile spatial acuity in complex regional pain syndrome type I.

Reiswich J, Krumova EK, David M, Stude P, Tegenthoff M, Maier C.

Source

Department of Pain Management, BG Universitätsklinikum Bergmannsheil GmbH, Ruhr University Bochum, Bochum, Germany.

Abstract

Tactile acuity measured by 2-point discrimination performance is impaired in patients with complex regional pain syndrome type I (CRPS-I). This is mirrored by pain-associated shrinkage of the cortical representation of the affected limb. We investigated whether, also, more complex tactile performance assessed by a dynamic 2D-form perception task is disturbed in CRPS-I patients. Therefore, we developed a Braille-like recognition task (BT) for geometrical dot pattern identification by dynamic touch. We studied 47 healthy volunteers (Study I) and compared them to 16 CRPS-I patients (Study II). Besides recognition time and error quote of the BT, we assessed static 2-point discrimination thresholds (TPDT). In healthy subjects, the performance in the BT correlated significantly with age and TPDT. In CRPS patients, TPDT was significantly increased on the affected side compared to sex- and age-matched controls from study I (2.98 ± 0.84 mm vs 2.05 ± 0.82 mm, P<0.01). The performance in the BT was not impaired in CRPS-I patients (compared to sex- and age-matched controls from study I) and was not correlated to the TPDT. The intact 2D-form recognition ability in CRPS-I patients might be explained by intact dynamic tactile and proprioceptive functions, which appear to be uncompromised by the impaired static tactile perception, provided that the spacing of the dot pattern is above the individual tactile acuity. These intact 2D-form perception capacities may also be related to higher sensory integration functions like the visual system and intact semantic understanding, which may be spared by the cortical reorganization phenomena in CRPS-I.

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J Clin Neurosci. 2011 Dec;18(12):1596-601.

The rubber hand illusion and its application to clinical neuroscience.

Ramakonar H, Franz EA, Lind CR.

Source

Department of Neurosurgery, Neurosurgical Service of Western Australia, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands, Western Australia 6009, Australia.

Abstract

The rubber hand illusion (RHI) is a perceptual experience which often occurs when an administered tactile stimulation of a person’s real hand hidden from view, occurs synchronously with a corresponding visual stimulation of an observed rubber hand placed in full vision of the person in a position corresponding to where their real hand might normally be. The perceptual illusion is that the person feels a sense of “ownership” of the rubber hand which they are looking at. Most studies have focused on the underlying neural properties of the illusion and the experimental manipulations that lead to it. The illusion could also be used for exploring the sense of limb and prosthetic ownership for people after amputation. Cortical electrodes such as those used in sensorimotor stimulation surgery for pain may provide an opportunity to further understand the cortical representation of the illusion and possibly provide an opportunity to modulate the individual’s sense of body ownership. Thus, the RHI might also be a critical tool for development of neurorehabilitative interventions that will be of great interest to the neurosurgical and rehabilitation communities.

CRPS Bugle 27th May

CRPS BugleBr J Clin Pharmacol. 2013 May 23. doi: 10.1111/bcp.12157.

Prolonged ketamine infusion as a therapy for Complex Regional Pain Syndrome: Synergism with antagonism?

Pickering AE, McCabe CS.

Source

School of Physiology & Pharmacology, Medical Sciences Building, University of Bristol, BS8 1TD.

Abstract

Complex regional pain syndrome (CRPS) remains a troubling and often refractory pain condition for which the existing treatments are inadequate. The review by Niesters et al in this journal highlights the interesting findings of several recent studies of the NMDA receptor antagonist ketamine in the treatment of CRPS. These studies report a robust analgesic effect that outlasts the period of infusion by weeks. However set against these positive findings are the issues presented by Ketamine pharmacokinetics, side effects and also the observation that these analgesic benefits are not mirrored by improvements in function or affect. In this commentary we consider the wider perspective of the potential for developing and evaluating this sort of NMDA antagonist therapy for the long-term management of CRPS patients.

RS: The authors conclude by saying that ketamine has transitory analgesic benefit but that there are the challenges of the risk profile to tackle. To determine whether the benefits outweigh the risks, further high quality studies are required.

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Clin Neurophysiol. 2013 May 18. pii: S1388-2457(13)00310-6. doi: 10.1016/j.clinph.2013.03.029.

Deficient muscle activation in patients with Complex Regional Pain Syndrome and abnormal hand postures: An electromyographic evaluation.

Bank PJ, Peper CL, Marinus J, Beek PJ, van Hilten JJ.

Source

Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands; Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, The Netherlands.

Abstract

OBJECTIVE:

Motor abnormalities in Complex Regional Pain Syndrome (CRPS) are common and often characterized by a restricted active range of motion (AROM) and an increased resistance to passive movements, whereby the affected body part preferably adopts an abnormal posture. The objective of the present study was to obtain a better understanding of the factors that are associated with these abnormal postures and limitations of the AROM, and to investigate whether these motor impairments reflect dystonia.

METHODS:

We evaluated characteristics of surface EMG of the flexor carpi radialis and extensor carpi radialis muscles during active maintenance of various flexion-extension postures of the wrist of the affected and unaffected side in 15 chronic CRPS patients, and in 15 healthy controls.

RESULTS:

Deviant joint postures in chronic CRPS – at least in those patients with some range of active movement – were not characterized by sustained muscle contractions, and limitations of the AROM were not attributable to excessive co-contraction. Rather, the agonistic muscle and its antagonist were activated in normal proportions, albeit over a limited range.

CONCLUSIONS:

The AROM limitations and abnormal postures that are often observed in chronic CRPS patients are not associated with excessive muscle activity and hence do not exhibit the characteristics typical of dystonia.

SIGNIFICANCE:

We hypothesize that structural alterations in skeletal muscle tissue and pain-induced adaptations of motor function may contribute to the observed motor impairments. Our findings may have important clinical implications, since commonly prescribed treatments are aimed at reducing excessive muscle contraction.

RS:  This study highlights the point that any treatment programme must be individualised to address the pain, other symptoms, deficits and limitations. A number of people with CRPS have movement disorders and the reasons can vary. Our job is to identify why the movement patterns have changed and address the problem accordingly with sensorimotor retraining.

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J Physiol. 2008 Mar 1;586(5):1247-56. Epub 2007 Dec 20. – Full article here

Properties of human spinal interneurones: normal and dystonic control.

Marchand-Pauvert V, Iglesias C.

Source

INSERM, U731, Paris, F-75651 France. veronique.marchand@chups.jussieu.fr

Abstract

The muscles that control wrist posture receive large inputs from reflexes driven by hand afferents. In several studies, we have investigated these reflexes by electrical stimulation of cutaneous (median nerve) and proprioceptive (ulnar nerve) afferents from the hand. Median stimulation produced short latency inhibition in all motor nuclei investigated, possibly through inhibitory propriospinal-like interneurones. Ulnar stimulation produced similar inhibition but only in wrist extensors. In the other motor nuclei, ulnar stimulation produced short latency excitation mediated by group I motoneuronal drive through both monosynaptic and non-monosynaptic pathways involving excitatory propriospinal-like interneurones. This was followed by late excitations mediated through spinal group II and trans-cortical group I pathways. These results show that these pathways are concerned with the integration of afferent inputs, proprioceptive and cutaneous, to control of wrist posture during hand movements. Patients with focal hand dystonia exhibit abnormal postures. To investigate whether these spinal pathways contribute to these conditions, the effects of ulnar stimulation on wrist muscle activity during voluntary tonic contraction were examined in patients who suffer writer’s cramp. Ulnar-induced inhibition of the wrist extensors was reduced on the dystonic side of patients compared with their normal side and controls. In patients who exhibited abnormal wrist posture, group II excitation of the wrist flexors was also modified on the dystonic side. Cutaneous stimuli, by contrast, increased wrist flexor EMG on both sides and only in patients who exhibited normal posture. We conclude that spinal interneurones have a significant role in integrating afferent inputs from the hand to control wrist posture during hand movements and that altered function in these spinal networks is associated with the complex pathophysiology of writer’s cramp.

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