#CRPS Research Update | Summer 2012 (1)

Pain. 2012 Sep;153(9):1847-51.

Nondermatomal somatosensory deficits in chronic pain patients: Are they really hysterical?

Egloff N, Maecker F, Stauber S, Sabbioni ME, Tunklova L, von Känel R.


Patients with chronic pain disorders frequently show nondermatomal somatosensory deficits (NDSDs) that are considered to be functional. Typically, NDSDs show quadratomal or hemibody distribution ipsilateral to the areas of chronic pain. According to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition and the International Classification of Diseases, 10th revision, such functional somatosensory deficits are classified in the chapter “conversion disorder.” Many publications also used the term “hysterical sensory loss.” However, doubts are increasing about this one-sided psychiatric view. We aimed to better characterize the biopsychosocial factors associated with NDSDs. Therefore, we compared 2 groups of inpatients with chronic pain disorder, of whom 90 suffered from NDSDs and 90 did not. The patients with NDSDs all showed widespread somatosensory deficits with hemibody distribution. On logistic regression analysis, history of a prior physical trauma was positively predictive for patients with NDSDs. Personality disorder and adverse childhood experiences were positively predictive for the control group with chronic pain disorders without NDSDs. The frequencies of comorbid depression and anxiety disorder did not differ statistically between groups. In conclusion, pain patients with NDSDs are, psychopathologically, by no means more noticeable personalities than patients with chronic pain disorder without NDSDs. Similar to complex regional pain syndromes, we assume a multifactorial etiology of NDSDs, including stress. Based on our observations, terms like “hysteric” should not be applied any longer to patients with NDSDs who suffer from chronic pain.


Arch Dis Child. 2012 Aug 1. [Epub ahead of print]

Complex regional pain syndrome following immunisation.

Richards S, Chalkiadis G, Lakshman R, Buttery JP, Crawford NW.


Complex regional pain syndrome type 1 (CRPS-1) is a clinical syndrome that affects one or more extremities and is characterised by persistent pain disproportionate to any inciting event, and at least one sign of autonomic dysfunction in the affected limb(s). The pathogenesis of this syndrome is poorly understood, but its onset is often precipitated by a physical injury, such as minor trauma, fracture, infection or a surgical procedure. In the literature, there are reports of CRPS-1 following immunisation with rubella and hepatitis B vaccines. Here we present a case series of CRPS-1 following immunisation in adolescents, with either diphtheria-tetanus-acellular pertussis (1 case), or human papillomavirus vaccines (4 cases). Enhanced awareness of this syndrome and its potential to occur following immunisation in the paediatric population is vital to the prompt and effective management of this condition.


Pain. 2012 Jul 27. [Epub ahead of print]

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.


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.


Pain. 2012 May;153(5):1063-73. Epub 2012 Mar 16.

Cognitive correlates of “neglect-like syndrome” in patients with complex regional pain syndrome.

Kolb L, Lang C, Seifert F, Maihöfner C.


Patients with complex regional pain syndrome (CRPS) often show distinct neurocognitive dysfunctions, which were initially termed “neglect-like symptoms.” So far, particularly the patients’ feelings about the affected extremity, motor, and sensory aspects of the “neglect-like symptoms” have been investigated, possibly pointing to a disturbed body schema. Because patients with classical neurological neglect show diminished awareness regarding the perception of their body, as well as of the space around them, our hypothesis was that CRPS patients exhibit some signs of personal neglect and extrapersonal visuospatial problems over and beyond those seen in patients simply suffering from limb pain. We used quantitative sensory testing and motor assessment aimed at detecting motor and sensory loss, a standardized questionnaire calculating a neglect score, and applied a detailed neuropsychological test battery assessing different parietal lobe functions, including visual neglect. We examined 20 CRPS patients and 2 matched control groups, one consisting of healthy subjects and the other one of patients with limb pain other than CRPS. Results show significant higher neglect scores for CRPS patients and the pain control group, but interestingly, CRPS patients and pain patients were indistinguishable. The results of the neuropsychological test battery did not demonstrate systematic variances, which would be indicative of a classical neurological neglect in CRPS patients, even though there were 3 CRPS patients who differed ≥ 2 SD from the mean of our healthy control group, with poorer results in ≥ 3 different tests. We assume that the “neglect-like syndrome” in most CRPS patients is different from typical neglect.


J Neuroinflammation. 2012 Jul 23;9(1):181. [Epub ahead of print]

Keratinocyte expression of inflammatory mediators plays a crucial role in substance P-induced acute and chronic pain.

Wei T, Guo TZ, Li WW, Hou S, Kingery W, Clark JD.


ABSTRACT: Tibia fracture in rats followed by cast immobilization leads to nociceptive, trophic, vascular and bone-related changes similar to those seen in Complex Regional Pain Syndrome (CRPS). Substance P (SP) mediated neurogenic inflammation may be responsible for some of the signs of CRPS in humans. We therefore hypothesized that SP acting through the SP receptor (NK1) leads to the CRPS-like changes found in the rat model. In the present study, we intradermally injected rats with SP and monitored hindpaw mechanical allodynia, temperature, and thickness as well as tissue levels of tumor necrosis factor-alpha (TNF-alpha), interleukin 1beta (IL-1beta), interleukin 6 (IL-6), and nerve growth factor-beta (NGF) for 72 h. Anti-NGF antibody was utilized to block the effects of SP-induced NGF up-regulation. Fracture rats treated with the selective NK1 receptor antagonist LY303870 prior to cast removal were assessed for BrdU, a DNA synthesis marker, incorporation in skin cells to examine cellular proliferation. Bone microarchitecture was measured using micro computed tomography (muCT). We observed that: (1) SP intraplantar injection induced mechanical allodynia, warmth and edema as well as the expression of nociceptive mediators in the hindpaw skin of normal rats, (2) LY303870 administered intraperitoneally after fracture attenuated allodynia, hindpaw unweighting, warmth, and edema, as well as cytokine and NGF expression, (3) LY303870 blocked fracture-induced epidermal thickening and BrdU incorporation after fracture, (4) anti-NGF antibody blocked SP-induced allodynia but not warmth or edema, and (5) LY303870 had no effect on bone microarchitecture. Collectively our data indicate that SP acting through NK1 receptors supports the nociceptive and vascular components of CRPS, but not the bone-related changes.



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