Differences in Neuronal Representation of Mental Rotation in Patients With Complex Regional Pain Syndrome and Healthy Controls

Purpose The purpose of the present study was to investigate the visual attentional behavior towards a pain-affected area and face/body images using eye tracking in complex regional pain syndrome (CRPS) patients. Moreover, we investigated the relationship between visual attentional behavior and clinical symptoms. Patients and methods Eight female patients with CRPS type 1 in their upper limbs and 8 healthy adult women participated in this study. First, the participants were asked to watch videoclips in a relaxed manner (Videoclip 1 featured young adults who introduced themselves; Videoclip 2 featured young adults touching the hand of the other person sitting across from them with their hand.) Eye movement data were tracked with eye-tracking glasses. Results In video clip 1, the fixation duration (FD) and fixation count (FC) on faces tended to be lower in CRPS patients than in healthy controls. This tendency was found in patients with low body cognitive distortions. In video clip 2, CRPS patients displayed significantly lower FD and FC on the unaffected hand while watching a video of the unaffected hand being touched compared with healthy controls. Moreover, patients with low body cognitive distortion displayed significantly longer FD on the affected hand. Conclusion Some CRPS patients differed in visual attentional behavior toward the face and body compared with healthy controls. In addition, our findings suggest that patients with lower body cognitive distortion may have a high visual attention for the affected hand, while patients with higher distortion may be neglecting the affected hand.

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Different patterns in mental rotation of facial expressions in complex regional pain syndrome patients

Medicine ◽

10.1097/md.0000000000007990 ◽

2017 ◽

Vol 96 (39) ◽

pp. e7990 ◽

Cited By ~ 1

Author(s):

Won Joon Lee ◽

Soo-Hee Choi ◽

Joon Hwan Jang ◽

Jee Youn Moon ◽

Yong Chul Kim ◽

...

Keyword(s):

Mental Rotation ◽

Complex Regional Pain Syndrome ◽

Facial Expressions ◽

Pain Syndrome

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Elevated Plasma Levels of sIL-2R in Complex Regional Pain Syndrome: A Pathogenic Role for T-Lymphocytes?

Mediators of Inflammation ◽

10.1155/2017/2764261 ◽

2017 ◽

Vol 2017 ◽

pp. 1-6 ◽

Cited By ~ 15

Author(s):

Krishna D. Bharwani ◽

Maaike Dirckx ◽

Dirk L. Stronks ◽

Willem A. Dik ◽

Marco W. J. Schreurs ◽

...

Keyword(s):

Immune System ◽

T Cell ◽

Complex Regional Pain Syndrome ◽

Interleukin 2 ◽

Cell Activity ◽

Pain Syndrome ◽

High Sensitivity ◽

Healthy Controls ◽

Good Discriminator ◽

Soluble Interleukin 2 Receptor

The immune system has long been thought to be involved in the pathophysiology of complex regional pain syndrome (CRPS). However, not much is known about the role of the immune system and specifically T-cells in the onset and maintenance of this disease. In this study, we aimed to evaluate T-cell activity in CRPS by comparing blood soluble interleukin-2 receptor (sIL-2R) levels between CRPS patients and healthy controls. CRPS patients had statistically significant elevated levels of sIL-2R as compared to healthy controls (median sIL-2R levels: 4151 pg/ml (Q3 − Q1 = 5731 pg/ml − 3546 pg/ml) versus 1907 pg/ml (Q3 − Q1: 2206 pg/ml − 1374 pg/ml), p<0.001, resp.). Furthermore, sIL-2R level seems to be a good discriminator between CRPS patients and healthy controls with a high sensitivity (90%) and specificity (89.5%). Our finding indicates increased T-cell activity in patients with CRPS. This finding is of considerable relevance as it could point towards a T-cell-mediated inflammatory process in this disease. This could pave the way for new anti-inflammatory therapies in the treatment of CRPS. Furthermore, sIL-2R could be a promising new marker for determining inflammatory disease activity in CRPS.

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Heartbeat-enhanced immersive virtual reality to treat complex regional pain syndrome

Neurology ◽

10.1212/wnl.0000000000005905 ◽

2018 ◽

Vol 91 (5) ◽

pp. e479-e489 ◽

Cited By ~ 16

Author(s):

Marco Solcà ◽

Roberta Ronchi ◽

Javier Bello-Ruiz ◽

Thomas Schmidlin ◽

Bruno Herbelin ◽

...

Keyword(s):

Virtual Reality ◽

Complex Regional Pain Syndrome ◽

Pain Syndrome ◽

Double Blind Study ◽

Immersive Virtual Reality ◽

Healthy Controls ◽

Mirror Therapy ◽

Class Iii ◽

Double Blind ◽

Pain Ratings

ObjectivesTo develop and test a new immersive digital technology for complex regional pain syndrome (CRPS) that combines principles from mirror therapy and immersive virtual reality and the latest research from multisensory body processing.MethodsIn this crossover double-blind study, 24 patients with CRPS and 24 age- and sex-matched healthy controls were immersed in a virtual environment and shown a virtual depiction of their affected limb that was flashing in synchrony (or in asynchrony in the control condition) with their own online detected heartbeat (heartbeat-enhanced virtual reality [HEVR]). The primary outcome measures for pain reduction were subjective pain ratings, force strength, and heart rate variability (HRV).ResultsHEVR reduced pain ratings, improved motor limb function, and modulated a physiologic pain marker (HRV). These significant improvements were reliable and highly selective, absent in control HEVR conditions, not observed in healthy controls, and obtained without the application of tactile stimulation (or movement) of the painful limb, using a readily available biological signal (the heartbeat) that is most often not consciously perceived (thus preventing placebo effects).ConclusionsNext to these specific and well-controlled analgesic effects, immersive HEVR allows the application of prolonged and repeated doses of digital therapy, enables the automatized integration with existing pain treatments, and avoids application of painful bodily cues while minimizing the active involvement of the patient and therapist.Classification of evidenceThis study provides Class III evidence that HEVR reduces pain and increases force strength in patients with CRPS.

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Different Activation of Opercular and Posterior Cingulate Cortex (PCC) in Patients With Complex Regional Pain Syndrome (CRPS I) Compared With Healthy Controls During Perception of Electrically Induced Pain: A Functional MRI Study

Clinical Journal of Pain ◽

10.1097/ajp.0b013e3181cb4055 ◽

2010 ◽

Vol 26 (4) ◽

pp. 339-347 ◽

Cited By ~ 38

Author(s):

Wolfgang Freund ◽

Arthur P. Wunderlich ◽

Gregor Stuber ◽

Florian Mayer ◽

Peter Steffen ◽

...

Keyword(s):

Complex Regional Pain Syndrome ◽

Functional Mri ◽

Pain Syndrome ◽

Cingulate Cortex ◽

Posterior Cingulate Cortex ◽

Healthy Controls ◽

Posterior Cingulate ◽

Mri Study

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Virtual Reality-Induced Sensorimotor Conflict Evokes Limb-Specific Sensory Disturbances in Complex Regional Pain Syndrome

Frontiers in Virtual Reality ◽

10.3389/frvir.2021.694293 ◽

2021 ◽

Vol 2 ◽

Author(s):

Clémentine Brun ◽

Anne Marie Pinard ◽

Candida S. McCabe ◽

Catherine Mercier

Keyword(s):

Complex Regional Pain Syndrome ◽

Clinical Characteristics ◽

Sensorimotor Integration ◽

Pain Syndrome ◽

Healthy Controls ◽

Body Perception ◽

Item Questionnaire ◽

Sensory Disturbances ◽

Motor Disturbances ◽

Rule Out

The origin of sensory disturbances in complex regional pain syndrome (CRPS) remains unclear. It has been hypothesized that such disturbances are due to attentional effects and/or sensorimotor integration deficits. If sensory disturbances are explained by sensorimotor integration deficits, they would be expected to be specific in terms of the category of sensation evoked and in terms of localization. Objective 1: To test whether sensory disturbances evoked by a unilateral sensorimotor conflict are specific to the painful limb and differ according to the category of sensory disturbances in individuals with a unilateral CRPS compared to healthy controls (HC). Objective 2: To assess the association between clinical characteristics and conflict-induced sensory disturbances. Objective 3: To assess conflict-induced motor disturbances. Ten adults with upper limb (UL) CRPS and 23 HC were recruited. Sensorimotor conflict was elicited with a KINARM exoskeleton interfaced with a 2D virtual environment allowing the projection of a virtual UL that was moving in either a congruent or incongruent manner relative to the actual UL movement. Participants rated sensory disturbances from 0 (no change) to 3 (high change) on a 8-item questionnaire. Items were classified into two Categories (Category 1: pain, discomfort, the feeling of losing a limb, change in weight and temperature; Category 2: feelings of peculiarity, the impression of gaining a limb and losing control). Motor disturbances were quantified as mediolateral drift and changes in amplitude of UL movement. Clinical characteristics included the intensity and duration of pain, proprioception, and body perception. CRPS participants report higher Category 1 than Category 2 disturbances for the Affected limb (while the reverse was observed for HC and for the Unaffected limb). In addition, no difference was observed between the Unaffected limb in CRPS and the Dominant limb in HC for Category 2 disturbances, while higher conflict sensitivity was observed for Category 1 disturbances. Conflict sensitivity was only related to higher pain for Category 1 disturbances in the Affected limb. Finally, no effect on motor disturbances was observed. While they do not completely rule out the attentional hypothesis, these results support the hypothesis of sensorimotor integration deficits.

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A Historical Review of Complex Regional Pain Syndrome in the “Guides Library”

Guides Newsletter ◽

10.1001/amaguidesnewsletters.2009.novdec01 ◽

2009 ◽

Vol 14 (6) ◽

pp. 1-9

Author(s):

Robert J. Barth

Keyword(s):

Differential Diagnosis ◽

Complex Regional Pain Syndrome ◽

Reflex Sympathetic Dystrophy ◽

International Association ◽

Historical Review ◽

Pain Syndrome ◽

Sixth Edition

Abstract Complex regional pain syndrome (CRPS) is a controversial, ambiguous, unreliable, and unvalidated concept that, for these very reasons, has been justifiably ignored in the “AMA Guides Library” that includes the AMAGuides to the Evaluation of Permanent Impairment (AMA Guides), the AMA Guides Newsletter, and other publications in this suite. But because of the surge of CRPS-related medicolegal claims and the mission of the AMA Guides to assist those who adjudicate such claims, a discussion of CRPS is warranted, especially because of what some believe to be confusing recommendations regarding causation. In 1994, the International Association for the Study of Pain (IASP) introduced a newly invented concept, CRPS, to replace the concepts of reflex sympathetic dystrophy (replaced by CRPS I) and causalgia (replaced by CRPS II). An article in the November/December 1997 issue of The Guides Newsletter introduced CRPS and presciently recommended that evaluators avoid the IASP protocol in favor of extensive differential diagnosis based on objective findings. A series of articles in The Guides Newsletter in 2006 extensively discussed the shortcomings of CRPS. The AMA Guides, Sixth Edition, notes that the inherent lack of injury-relatedness for the nonvalidated concept of CRPS creates a dilemma for impairment evaluators. Focusing on impairment evaluation and not on injury-relatedness would greatly simplify use of the AMA Guides.

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Peripheral Nerve and Brachial Plexus Impairment, AMA Guides, Sixth Edition

Guides Newsletter ◽

10.1001/amaguidesnewsletters.2017.marapr01 ◽

2017 ◽

Vol 22 (2) ◽

pp. 3-5

Author(s):

James B. Talmage ◽

Jay Blaisdell

Keyword(s):

Peripheral Nerve ◽

Brachial Plexus ◽

Complex Regional Pain Syndrome ◽

Lower Extremities ◽

Pain Syndrome ◽

Upper Extremities ◽

Motor Deficits ◽

Type I ◽

Sixth Edition ◽

Nerve Entrapments

Abstract Physicians use a variety of methodologies within the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition, to rate nerve injuries depending on the type of injury and location of the nerve. Traumatic injuries that cause impairment to the peripheral or brachial plexus nerves are rated using Section 15.4e, Peripheral Nerve and Brachial Plexus Impairment, for upper extremities and Section 16.4c, Peripheral Nerve Rating Process, for lower extremities. Verifiable nerve lesions that incite the symptoms of complex regional pain syndrome, type II (similar to the former concept of causalgia), also are rated in these sections. Nerve entrapments, which are not isolated traumatic events, are rated using the methodology in Section 15.4f, Entrapment Neuropathy. Type I complex regional pain syndrome is rated using Section 15.5, Complex Regional Pain Syndrome for upper extremities or Section 16.5, Complex Regional Pain Syndrome for lower extremities. The method for grading the sensory and motor deficits is analogous to the method described in previous editions of AMA Guides. Rating the permanent impairment of the peripheral nerves or brachial plexus is similar to the methodology used in the diagnosis-based impairment scheme with the exceptions that the physical examination grade modifier is never used to adjust the default rating and the names of individual nerves or plexus trunks, as opposed to the names of diagnoses, appear in the far left column of the rating grids.

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Challenges in the Diagnostic Conceptualization of CRPS-1 (Formerly Conceptualized as RSD)

Guides Newsletter ◽

10.1001/amaguidesnewsletters.2006.marapr01 ◽

2006 ◽

Vol 11 (2) ◽

pp. 1-3, 9-12

Author(s):

Robert J. Barth ◽

Tom W. Bohr

Keyword(s):

Clinical Practice ◽

Complex Regional Pain Syndrome ◽

Somatoform Disorders ◽

International Association ◽

Pain Syndrome ◽

Somatoform Disorder ◽

Syndrome Type ◽

Previous Issue

Abstract From the previous issue, this article continues a discussion of the potentially confusing aspects of the diagnostic formulation for complex regional pain syndrome type 1 (CRPS-1) proposed by the International Association for the Study of Pain (IASP), the relevance of these issues for a proposed future protocol, and recommendations for clinical practice. IASP is working to resolve the contradictions in its approach to CRPS-1 diagnosis, but it continues to include the following criterion: “[c]ontinuing pain, which is disproportionate to any inciting event.” This language only perpetuates existing issues with current definitions, specifically the overlap between the IASP criteria for CRPS-1 and somatoform disorders, overlap with the guidelines for malingering, and self-contradiction with respect to the suggestion of injury-relatedness. The authors propose to overcome the last of these by revising the criterion: “[c]omplaints of pain in the absence of any identifiable injury that could credibly account for the complaints.” Similarly, the overlap with somatoform disorders could be reworded: “The possibility of a somatoform disorder has been thoroughly assessed, with the results of that assessment failing to produce any consistencies with a somatoform scenario.” The overlap with malingering could be addressed in this manner: “The possibility of malingering has been thoroughly assessed, with the results of that assessment failing to produce any consistencies with a malingering scenario.” The article concludes with six recommendations, and a sidebar discusses rating impairment for CRPS-1 (with explicit instructions not to use the pain chapter for this purpose).

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