scholarly journals Attentional Modulation of Neural Dynamics in Tactile Perception of Complex Regional Pain Syndrome (CRPS) Patients

2020 ◽  
Author(s):  
Serena Defina ◽  
Maria Niedernhuber ◽  
Nicholas Shenker ◽  
Christopher Brown ◽  
Tristan Bekinschtein
Keyword(s):  
Complex Regional Pain Syndrome ◽  
Pain Syndrome ◽  
Stimulus Onset ◽  
Task Demands ◽  
The Body ◽  
Neural Representation ◽  
Neural Dynamics ◽  
Control Mechanisms ◽  
Clinical Markers ◽  
Unaffected Side

Body perceptual disturbances are an increasingly acknowledged set of symptoms and possible clinical markers of Complex Regional Pain Syndrome (CRPS), but the neurophysiological and neurocognitive changes that underlie them are still far from being clear. We adopted a novel multivariate and neurodynamical approach to the analysis of EEG modulations evoked by touch, to highlight differences between patients and healthy controls, between affected and unaffected side of the body, and between “passive” (i.e. no task demands and equiprobable digit stimulation) and “active” tactile processing (i.e. where a digit discrimination task was administered and spatial probability manipulated). Contrary to our expectations we found no support for early differences in neural processing between CRPS and healthy participants, however, there was increased decodability in the CRPS group compared to healthy volunteers between 280 and 320 ms after stimulus onset. This group difference seemed to be driven by the affected rather than the unaffected side and was enhanced by attentional demands. These results found support in the exploratory analysis of neural representation dynamics and behavioural modelling, highlighting the need for single participant analyses. Although several limitations impacted the robustness and generalizability of our comparisons, the proposed novel analytical approach yielded promising insights (as well as possible biomarkers based on neural dynamics) into the relatively unexplored alterations of tactile decision-making and attentional control mechanisms in chronic CRPS.

scholarly journals Attentional Modulation of Neural Dynamics in Tactile Perception of Complex Regional Pain Syndrome Patients

2020 ◽  
Author(s):  
Serena Defina ◽  
Maria Niedernhuber ◽  
Nicholas Shenker ◽  
Christopher Brown ◽  
Tristan A. Bekinschtein
Keyword(s):  
Complex Regional Pain Syndrome ◽  
Pain Syndrome ◽  
Stimulus Onset ◽  
Task Demands ◽  
The Body ◽  
Neural Representation ◽  
Neural Dynamics ◽  
Control Mechanisms ◽  
Clinical Markers ◽  
Unaffected Side

AbstractBody perceptual disturbances are an increasingly acknowledged set of symptoms and possible clinical markers of Complex Regional Pain Syndrome (CRPS), but the neurophysiological and neurocognitive changes that underlie them are still far from being clear. We adopted a novel multivariate and neurodynamical approach to the analysis of EEG modulations evoked by touch, to highlight differences between patients and healthy controls, between affected and unaffected side of the body, and between “passive” (i.e. no task demands and equiprobable digit stimulation) and “active” tactile processing (i.e. where a digit discrimination task was administered and spatial probability manipulated). Contrary to our expectations we found no support for early differences in neural processing between CRPS and healthy participants, however, there was increased decodability in the CRPS group compared to healthy volunteers between 280 and 320 ms after stimulus onset. This group difference seemed to be driven by the affected rather than the unaffected side and was enhanced by attentional demands. These results found support in the exploratory analysis of neural representation dynamics and behavioural modelling, highlighting the need for single participant analyses. Although several limitations impacted the robustness and generalizability of our comparisons, the proposed novel analytical approach yielded promising insights (as well as possible biomarkers based on neural dynamics) into the relatively unexplored alterations of tactile decision-making and attentional control mechanisms in chronic CRPS.

Complex Regional Pain Syndrome: The Worst Pain Known to Humankind

2016 ◽  
Author(s):  
Pradeep Chopra
Keyword(s):  
Complex Regional Pain Syndrome ◽  
Pain Syndrome ◽  
Clinical History ◽  
Body Part ◽  
Axial Skeleton ◽  
The Body ◽  
Labor Pain ◽  
Whole Body ◽  
Temperature Differential ◽  
Unaffected Side

Complex regional pain syndrome (CRPS) is the worst pain known to humankind. It has been classified as pain worse than cancer pain, amputation of a digit, or labor pain. The difference is that CRPS is a chronic condition that lasts for many years. As in all medical conditions, the essential piece to diagnosis of CRPS is based on the clinical history and physical examination. The diagnosis of CRPS depends on the following: pain, color and temperature asymmetry, swelling, and nail and hair growth changes. The intensity of the pain is far more than expected from the inciting injury and in some cases from immobilization. The pain spreads to a wider area than the original site. It may spread to the opposite side and even to the whole body, including the viscera. The pain is unrelated to any physical activity but does increase significantly with using the body part. A color differential between the affected and the unaffected side is often very obvious but may not be present continuously. A temperature differential of 1.1ºC between the affected and the unaffected side is considered significant. The color and temperature differential is not as obvious in the torso or the axial skeleton as in CRPS of the abdomen, perineum, or chest wall. The swelling is much more evident in the initial stages of the condition and can vary from a small area of pitting edema to large diffuse swelling to the point of skin becoming thin and glossy and even breaking down. Hair changes may consist of darker, coarser hair or light and sparse hair. Nails may be brittle, discolored, and ridged. There is no gold standard test to diagnose CRPS. Testing may be done to rule out another possible diagnosis.

scholarly journals Distinct Proximal and Distal Corticospinal Signals Embed Limb Dynamics Through the Modulation of Stiffness

2019 ◽  
Author(s):  
R. L. Hardesty ◽  
P. H. Ellaway ◽  
V. Gritsenko
Keyword(s):  
Nervous System ◽  
Physical Properties ◽  
Neural Control ◽  
Primary Motor Cortex ◽  
Equations Of Motion ◽  
Task Demands ◽  
The Body ◽  
Control Mechanisms ◽  
Neural Signals ◽  
Limb Dynamics

AbstractThe complexities of the human musculoskeletal system and its interactions with the environment creates a difficult challenge for the neural control of movement. The consensus is that the nervous system solves this challenge by embedding the dynamical properties of the body and the environment. However, the modality of control signals and how they are generated appropriately for the task demands are a matter of active debate. We used transcranial magnetic stimulation over the primary motor cortex to show that the excitability of the corticospinal tract is modulated to compensate for limb dynamics during reaching tasks in humans. Surprisingly, few profiles of corticospinal modulation in some muscles and conditions reflected Newtonian parameters of movement, such as kinematics or active torques. Instead, the overall corticospinal excitability was differentially modulated in proximal and distal muscles, which corresponded to different stiffness at proximal and distal joints. This suggests that the descending corticospinal signal determines the proximal and distal impedance of the arm for independent functional control of reaching and grasping.Significance StatementThe nervous system integrates both the physical properties of the human body and the environment to create a rich repertoire of actions. How these calculations are happening remains poorly understood. Neural activity is known to be correlated with different variables from the Newtonian equations of motion that describe forces acting on the body. In contrast, our data show that the overall activity of the descending neural signals is less related to the individual Newtonian variables and more related to limb impedance. We show that the physical properties of the arm are controlled by two distinct proximal and distal descending neural signals modulating components of limb stiffness. This identifies distinct neural control mechanisms for the transport and manipulation actions of reach.

scholarly journals Disputing space-based biases in unilateral complex regional pain syndrome

2020 ◽  
Author(s):  
Monika Halicka ◽  
Axel D Vittersø ◽  
Hayley McCullough ◽  
Andreas Goebel ◽  
Leila Heelas ◽  
...  
Keyword(s):  
Spatial Cognition ◽  
Complex Regional Pain Syndrome ◽  
Motor Function ◽  
Motor Impairment ◽  
Pain Syndrome ◽  
Body Representation ◽  
Visuospatial Attention ◽  
Unaffected Side ◽  
Affected Relative ◽  
Pathological Pain

AbstractThere is some evidence that people with Complex Regional Pain Syndrome (CRPS) show reduced attention to the affected relative to unaffected limb and its surrounding space, resembling hemispatial neglect after brain injury. These neuropsychological symptoms could be related to central mechanisms of pathological pain and contribute to its clinical manifestation. However, the existing evidence of changes in spatial cognition is limited and often inconsistent. We examined visuospatial attention, the mental representation of space, and spatially-defined motor function in 54 people with unilateral upper-limb CRPS and 22 pain-free controls. Contrary to our hypotheses and previous evidence, individuals with CRPS did not show any systematic spatial biases in visuospatial attention to or representation of the side of space corresponding to their affected limb (relative to the unaffected side). We found very little evidence of directional slowing of movements towards the affected relative to unaffected side that would be consistent with motor neglect. People with CRPS were, however, slower than controls to initiate and execute movements with both their affected and unaffected hands, which suggests disrupted central motor networks. Finally, we found no evidence of any clinical relevance of changes in spatial cognition because there were no relationships between the magnitude of spatial biases and the severity of pain or other CRPS symptoms. The results did reveal potential relationships between CRPS pain and symptom severity, subjective body perception disturbance, and extent of motor impairment, which would support treatments focused on normalizing body representation and improving motor function. Our findings suggest that previously reported spatial biases in CRPS might have been overstated.

scholarly journals Altered updating of bodily and spatial representations following tool-use in Complex Regional Pain Syndrome

2019 ◽  
Author(s):  
Axel D. Vittersø ◽  
Gavin Buckingham ◽  
Monika Halicka ◽  
Michael J. Proulx ◽  
Janet H. Bultitude
Keyword(s):  
Complex Regional Pain Syndrome ◽  
Upper Limb ◽  
Tool Use ◽  
Pain Syndrome ◽  
Peripersonal Space ◽  
The Body ◽  
Lower Limbs ◽  
Spatial Representations ◽  
Hand Temperature ◽  
Free People

AbstractDistorted representations of the body and peripersonal space are common in Complex Regional Pain Syndrome (CRPS), and might modulate its symptoms (e.g. asymmetric limb temperature). In pain-free people, such representations are malleable, and update when we interact with objects in our environment (e.g. during tool-use). Distortions are also common after immobilisation, but quickly normalise once movement is regained. We tested the hypothesis that people with CRPS have problems updating bodily and spatial representations, which contributes to the maintenance of their distorted representations by preventing normalization. We also explored spatially defined modulations of hand temperature asymmetries, and any influence of updating bodily and spatial representations on this effect. Thirty-six people with unilateral CRPS (18 upper limb, 18 lower limb) and 36 pain-free controls completed tool-use tasks considered to alter body and peripersonal space representations (measured using tactile distance judgements and a visuotactile crossmodal congruency task, respectively). We also tested how the arrangement (crossed, uncrossed) of the hands and tools affected hand temperature. In upper limb CRPS the non-affected arm representation updated normally, but the affected arm representation updated in the opposite to normal direction. A similar pattern was seen in lower limbs CRPS, although not significant. Furthermore, people with CRPS showed more pronounced updating of peripersonal space than the controls. We did not observe any modulation of hand temperature asymmetries by the arrangement of hands or tools. Our findings suggest enhanced malleability of bodily and spatial representations in CRPS, potentially implicating central mechanisms in the aetiology of this condition.

Co-morbidity between trigeminal autonomic cephalalgias and complex regional pain syndrome: Two case reports

Cephalalgia ◽  
2021 ◽  
pp. 033310242110582
Author(s):  
Peter D Drummond ◽  
Philip M Finch
Keyword(s):  
Complex Regional Pain Syndrome ◽  
Upper Limb ◽  
Case Reports ◽  
Stellate Ganglion ◽  
Pain Syndrome ◽  
Pain Modulation ◽  
The Body ◽  
Trigeminal Autonomic Cephalalgias ◽  
Mechanical Stimuli ◽  
Co Morbidity

Background Trigeminal autonomic cephalalgias and complex regional pain syndrome are rare conditions, and their co-occurrence has not been reported previously. Clinical findings: In two patients, ipsilateral trigeminal autonomic cephalalgias developed after the onset of upper limb complex regional pain syndrome. Hyperalgesia to thermal and mechanical stimuli extended beyond the affected limb to encompass the ipsilateral forehead, and was accompanied by ipsilateral hyperacusis and photophobia. In addition, examination of the painful limb and bright light appeared to aggravate symptoms of trigeminal autonomic cephalalgias. Detailed examination of the association between facial and upper limb pain indicated that both sources of pain cycled together. Furthermore, in one case, stellate ganglion blockade inhibited pain for an extended period not only in the affected limb but also the face. Conclusions These findings suggest some overlap in the pathophysiology of complex regional pain syndrome and trigeminal autonomic cephalalgias. Specifically, central sensitization and/or disruption of inhibitory pain modulation on the affected side of the body in complex regional pain syndrome might trigger ipsilateral cranial symptoms and increase vulnerability to trigeminal autonomic cephalalgias.

Complex Regional Pain Syndrome of the Upper and Lower Extremity

2018 ◽  
Author(s):  
Agnes Stogicza ◽  
Bartha Peter Tohotom ◽  
Edit Racz ◽  
Andrea Trescot ◽  
Alan Berkman
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Complex Regional Pain Syndrome ◽  
Medication Management ◽  
Pain Syndrome ◽  
The Body ◽  
Loss Of Function ◽  
Early Presentation ◽  
Temperature Changes ◽  
Sympathetic Nervous

Complex regional pain syndrome (CRPS) is a chronic debilitating pain condition of the extremities; it can affect, less commonly, other areas of the body (face, pelvis, abdomen). Its early presentation—pain disproportionate to the injury, skin temperature changes, hyperalgesia, allodynia—is often not recognized, delaying treatment. In later phases, with sympathetic nervous system involvement, it presents with skin and muscle atrophy, hair loss, allodynia, loss of function, and decreased range of motion. In severe cases, it can spread from one area to the other. Imaging findings (X-ray, MRI, bone scintigraphy) are nonspecific. They are used to support the diagnosis, and to exclude conditions that can present similarly. Treatment is challenging and includes physical therapy, psychologic support, medication management, and minimally invasive interventions to decrease pain, to positively influence the sympathetic nervous system, and to preserve function. A multidisciplinary approach is likely to be the most beneficial.

scholarly journals ATTENTIONAL MODULATION OF NEURAL DYNAMICS IN TACTILE PERCEPTION OF COMPLEX REGIONAL PAIN SYNDROME PATIENTS

2021 ◽  
Author(s):  
Serena Defina ◽  
Maria Niedernhuber ◽  
Nicholas Shenker ◽  
Christopher Brown ◽  
Tristan A. Bekinschtein
Keyword(s):  
Complex Regional Pain Syndrome ◽  
Pain Syndrome ◽  
Tactile Perception ◽  
Neural Dynamics ◽  
Attentional Modulation
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