Annika Reinersmann

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

Summary Supraspinal mechanisms involved in complex regional pain syndrome may contribute to an exacerbation of the “normal” leftward bias of visuospatial attention due to an impaired spatial body representation. 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.

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

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.

Bilateral somatosensory cortex disinhibition in complex regional pain syndrome type I

Objective: In a previous study, we found bilateral disinhibition in the motor cortex of patients with complex regional pain syndrome (CRPS). This finding suggests a complex dysfunction of central motor-sensory circuits. The aim of our present study was to assess possible bilateral excitability changes in the somatosensory system of patients with CRPS. Methods: We measured paired-pulse suppression of somatosensory evoked potentials in 21 patients with unilateral CRPS I involving the hand. Eleven patients with upper limb pain of non-neuropathic origin and 21 healthy subjects served as controls. Innocuous paired-pulse stimulation of the median nerve was either performed at the affected and the unaffected hand, or at the dominant hand of healthy controls, respectively. Results: We found a significant reduction of paired-pulse suppression in both sides of patients with CRPS, compared with control patients and healthy control subjects. Conclusion: These findings resemble our findings in the motor system and strongly support the hypothesis of a bilateral complex impairment of central motor-sensory circuits in CRPS I.

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

Summary Local cytokine changes were analyzed in CRPS I patients. TNF‐&agr;, MIP‐1&bgr;, and IL‐1RA were changed bilaterally but returned to the level of non‐CRPS patients after 6 months. 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 (< 1 year) and after 6 months 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‐&agr;) and the chemokines eotaxin, monocyte chemotactic protein‐1 (MCP‐1), and macrophage inflammatory protein‐1&bgr; (MIP‐1&bgr;). We found bilaterally increased proinflammatory TNF‐&agr; and MIP‐1&bgr; 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‐&agr;, eotaxin, MCP‐1, and MIP‐1&bgr; 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.

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

Summary Integration of a rubber hand into body representation is intact, which indicates intact multimodal integration despite impaired processing of proprioceptive or tactile input in complex regional pain syndrome. 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 &agr; = 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.

Comparable disorder of the body schema in patients with complex regional pain syndrome (CRPS) and phantom pain

In patients with complex regional pain syndrome (CRPS) a disruption of the body schema has been shown in an altered cortical representation of the hand and in delayed reaction times (RT) in the hand laterality recognition task. However, the role of attentional processes or the effect of isolated limb laterality training has not yet been clarified. The performance of healthy subjects (n = 38), CRPS patients (n = 12) and phantom limb pain (PLP) patients (n = 12) in a test battery of attentional performance (TAP) and in a limb laterality recognition task was compared and the effect of limb laterality training in CRPS patients and healthy subjects evaluated. The RTs of both CRPS and PLP patients were significantly slower than those of healthy subjects despite normal TAP values. The CRPS and PLP patients showed bilaterally delayed RTs. Through training RTs improved significantly but the RTs of CRPS patients remained slower than those of healthy subjects. In this study an equal disruption of the body schema was found in both CRPS and PLP patients which cannot be accounted for by attentional processes. For CRPS patients this disorder cannot be fully reversed by isolated limb laterality recognition training.

Vergleichbare Störung des Körperschemas bei Patienten mit komplexem regionalem Schmerzsyndrom (CRPS) oder Phantomschmerz

In patients with complex regional pain syndrome (CRPS) a disruption of the body schema has been shown in an altered cortical representation of the hand and in delayed reaction times (RT) in the hand laterality recognition task. However, the role of attentional processes or the effect of isolated limb laterality training has not yet been clarified. The performance of healthy subjects (n = 38), CRPS patients (n = 12) and phantom limb pain (PLP) patients (n = 12) in a test battery of attentional performance (TAP) and in a limb laterality recognition task was compared and the effect of limb laterality training in CRPS patients and healthy subjects evaluated. The RTs of both CRPS and PLP patients were significantly slower than those of healthy subjects despite normal TAP values. The CRPS and PLP patients showed bilaterally delayed RTs. Through training RTs improved significantly but the RTs of CRPS patients remained slower than those of healthy subjects. In this study an equal disruption of the body schema was found in both CRPS and PLP patients which cannot be accounted for by attentional processes. For CRPS patients this disorder cannot be fully reversed by isolated limb laterality recognition training.

Changes of the Sensory Abnormalities and Cortical Excitability in Patients with Complex Regional Pain Syndrome of the Upper Extremity After 6 Months of Multimodal Treatment.

Objective. The most prominent sensory sign of the complex regional pain syndrome (CRPS) is blunt hyperalgesia, but longitudinal studies on its relation to the outcome of long-term multimodal treatment are lacking. Methods. We examined 24 patients with CRPS type I using standardized Quantitative Sensory Testing on the affected hand and the contralateral hand at baseline and 6 months following treatment. Somatosensory evoked potentials after single and paired-pulse stimulation of the median nerve were performed to assess the paired-pulse suppression (n = 19). Treatment response at follow-up was defined as pain relief > 30% and improved hand function. Statistics: Wilcoxon test, Pearson correlation. Results. At baseline, similar to previous studies, the pressure pain threshold (PPT) was significantly decreased and the pain response to repeated pinprick stimuli was significantly increased, while all detection thresholds were within the normal range without any difference between the later treatment responders and non-responders. After 6 months of treatment, the PPT increased significantly in the whole study group. However, the pressure hyperalgesia improved only in treatment responders (n = 17, P < 0.05), whereas there was no improvement in non-responders (n = 7). The rest of the sensory profile remained nearly unchanged. There was a correlation between the paired-pulse suppression and the PPT only at follow-up (r = 0.49, P < 0.05), but not at baseline, where low pressure pain threshold was associated with impaired paired-pulse suppression. Conclusion. Thus, the persistence of blunt hyperalgesia seems to be associated with impaired paired-pulse suppression, both representing maladaptive central nervous changes in CRPS, which may account for the treatment non-response in this subgroup.

Zum Zusammenhang zwischen Körperschema und sozio-emotionalem Verhalten bei umschriebenen Entwicklungsstörungen der Wahrnehmung und Motorik

Our body is both, the object experiencing the world and the subject of our self- experience. As an object, the body provides sensory information via the bodily surface, which is processed and integrated into a coherent representation of the body, the body schema. This representation is considered to form a crucial structure underlying bodily self-identification. The process of integrating multimodal information into a coherent body representation has received extensive research interest with the aim to further clarify its neuronal correlates and functioning in health and disease. However, little is known about the ontogenetic functioning of body schema or multisensory integration processing and their role in the development of socio-emotional in children. This narrative overview discusses implication of a dysfunctional body schematic functioning for socio-emotional competencies. A general introduction on body schematic processes is followed by a narrative review of current findings on the maturation of the body schema and multisensory integration. We finally outline implications for the self- and socio-emotional development in children and discuss possible implications for a role of disrupted body schema functions in developmental disorders.

Spiegeltherapie zur Behandlung von Phantomschmerzen nach beidseitiger Oberschenkelamputation

ZusammenfassungVorgestellt wird erstmalig der Fall einer erfolgreichen Spiegeltherapie starker Phantomschmerzen nach beidseitiger Oberschenkelamputation wegen Durchblutungsstörungen. Eine medikamentöse Schmerztherapie war aufgrund kardiovaskulärer Komorbidität nicht möglich. Innerhalb von Wochen kam es nach einem zeitlich gestuften Imaginations-, Lateralisationstraining und Spiegeltherapie zu einer anhaltenden 85%igen Reduktion der durchschnittlichen Schmerzen und zu einer >90%igen Reduktion der Attacken pro Tag. Es wird detailliert beschrieben, wie es gelang, mittels einer Habitusprothese, die für die Spiegeltherapie notwendige Illusion zu erzeugen. Eindrücklich illustriert dieser Fall zugleich die Wirkmechanismen der Spiegeltherapie auf Grundlage der Erkenntnisse über charakteristische Störungen des Körperschemas bei Patienten mit Phantomschmerzen.AbstractThis case study is the first to report successful treatment of bilateral phantom limb pain (PLP) in a patient with bilateral thigh amputation and inefficacious medical treatment using a protocol of graded interventions including mirror therapy (MT). MT is a common treatment for PLP but requires the induction of a visual illusion of an intact limb in the mirror, usually achieved by mirroring the healthy extremity. Here, we illustrate how application of a unilateral prosthesis sufficed to induce the necessary illusion. After sequential imagery, then lateralization training, which alleviated pain attacks, the patient received a further 3-week treatment of mirror treatment. Pain intensity was reduced by more than 85 %; the number of attacks were decreased by more than 90% per day. The analgesic efficacy lasted until the unexpected death of the patient several months later. This case illustrates the mechanisms of MT through overcoming the sensory incongruences underlying the distorted body schema and its efficacy in patients with bilateral amputation.This case study is the first to report successful treatment of bilateral phantom limb pain (PLP) in a patient with bilateral thigh amputation and inefficacious medical treatment using a protocol of graded interventions including mirror therapy (MT). MT is a common treatment for PLP but requires the induction of a visual illusion of an intact limb in the mirror, usually achieved by mirroring the healthy extremity. Here, we illustrate how application of a unilateral prosthesis sufficed to induce the necessary illusion. After sequential imagery, then lateralization training, which alleviated pain attacks, the patient received a further 3-week treatment of mirror treatment. Pain intensity was reduced by more than 85 %; the number of attacks were decreased by more than 90% per day. The analgesic efficacy lasted until the unexpected death of the patient several months later. This case illustrates the mechanisms of MT through overcoming the sensory incongruences underlying the distorted body schema and its efficacy in patients with bilateral amputation.