Distribution of signs and symptoms of complex regional pain syndrome type I in patients meeting the diagnostic criteria of the International Association for the Study of Pain.

The aim of the present study was to describe the occurrence of signs and symptoms in CRPS I patients meeting the IASP (Orlando) criteria, assess the occurrence of signs and symptoms in relation to disease duration and compare these to historical data based on a different diagnostic criteria set. Six hundred and ninety-two ambulatory patients meeting the IASP criteria for CRPS I referred to the outpatient clinics of five participating centers were included in this cross-sectional study. Characteristics were recorded in a standardized fashion and categorized according to the factor structure proposed by Bruehl/Harden. Subgroups were classified according to the duration of complaints and compared to historical data as described by Veldman et al. The Chi-square test corrected for multiple comparisons was used for statistical analysis. The prevalence of sensory signs was higher in patients with longer disease duration, especially for the allodynia's and hyperalgesia (all p<0.001). Signs in vasomotor (color difference; p=0.0007) and sudomotor (edema; p<0.0001) subgroups were less frequently present in patients with longer disease duration (i.e. >6 months). Prevalences of signs in the motor subgroup were all higher (p<0.0001) in patients with longer disease duration, except for limited range of motion. Occurrence of signs was significantly lower (<0.001) than those reported by Veldman et al., except for hyperesthesia and dystonia. Occurrence rates may vary at different time points after onset of CRPS, which may be of influence for diagnosing patients with novel derived diagnostic criteria. We argue for a mechanism based description of CRPS I based on one set of uniform generally accepted diagnostic criteria in future studies.

Repetitive transcranial magnetic stimulation is efficacious as an add-on to pharmacological therapy in complex regional pain syndrome (CRPS) type I.

UNLABELLED: Single-session repetitive transcranial magnetic stimulation (rTMS) of the motor cortex (M1) is effective in the treatment of chronic pain patients, but the analgesic effect of repeated sessions is still unknown. We evaluated the effects of rTMS in patients with refractory pain due to complex regional pain syndrome (CRPS) type I. Twenty-three patients presenting CRPS type I of 1 upper limb were treated with the best medical treatment (analgesics and adjuvant medications, physical therapy) plus 10 daily sessions of either real (r-) or sham (s-) 10 Hz rTMS to the motor cortex (M1). Patients were assessed daily and after 1 week and 3 months after the last session using the Visual Analogical Scale (VAS), the McGill Pain Questionnaire (MPQ), the Health Survey-36 (SF-36), and the Hamilton Depression (HDRS). During treatment there was a significant reduction in the VAS scores favoring the r-rTMS group, mean reduction of 4.65 cm (50.9%) against 2.18 cm (24.7%) in the s-rTMS group. The highest reduction occurred at the tenth session and correlated to improvement in the affective and emotional subscores of the MPQ and SF-36. Real rTMS to the M1 produced analgesic effects and positive changes in affective aspects of pain in CRPS patients during the period of stimulation. PERSPECTIVE: This study shows an efficacy of repetitive sessions of high-frequency rTMS as an add-on therapy to refractory CRPS type I patients. It had a positive effect in different aspects of pain (sensory-discriminative and emotional-affective). It opens the perspective for the clinical use of this technique.

[History, classification and clinic of the complex regional pain syndrome (CRPS)]. / Geschichte, Stadieneinteilung und Klinik des komplexen regionalen Schmerzsyndroms (CRPS).

Almost 150 years are gone since the first description of the classic symptoms, what is today summarized under the term CRPS. From a big number of different names, it has been agreed in 1986 to this term and has also defined more exactly the corresponding terms to it. In the pathophysiology of this complex of symptoms is today accepted that it is a combination of inflammatory, vegetative and central-nervous processes in different size and weight as a key position. There are hardly new findings in epidemiology and frequency. In opposite to this a number of results are produced by better methods for examination which let appear the connections in a new view and make new therapy options possible.

Development of Korean Academy of Medical Sciences guideline-rating the impairment in pain.

Pain-related impairment assessment by the fifth edition of the American Medical Association Guides had many ambiguous points, and therefore, it was not applicable directly in Korea. Several disputable pain disorders were excluded from the list of impairment evaluation, and complex regional pain syndrome was chosen as the first object of impairment evaluation. Scales such as Korean version of modified Barthel index for assessing the activity of daily livings and Beck Depression Inventory for assessing depression were added, and pain severity, pain treatment, pain behavior, etc. were scored. In order to objectify as much as possible and to remove the room for misuse, we develop a new rating system based on the concept of total score.

Is reflex sympathetic dystrophy/complex regional pain syndrome type I a small-fiber neuropathy?

Neurologist S. Weir Mitchell first described "causalgia" following wartime nerve injury, with its persistent distal limb burning pain, swelling, and abnormal skin color, temperature, and sweating. Similar post-traumatic symptoms were later identified in patients without overt nerve injuries after trauma. This was labeled reflex sympathetic dystrophy (RSD; now complex regional pain syndrome type I [CRPS-I]). The pathophysiology of symptoms is unknown and treatment options are limited. We propose that persistent RSD/CRPS-I is a post-traumatic neuralgia associated with distal degeneration of small-diameter peripheral axons. Small-fiber lesions are easily missed on examination and are undetected by standard electrophysiological testing. Most CRPS features-spreading pain and skin hypersensitivity, vasomotor instability, osteopenia, edema, and abnormal sweating-are explicable by small-fiber dysfunction. Small fibers sense pain and temperature but also regulate tissue function through neuroeffector actions. Indeed, small-fiber-predominant polyneuropathies cause CRPS-like abnormalities, and pathological studies of nerves from chronic CRPS-I patients confirm small-fiber-predominant pathology. Small distal nerve injuries in rodents reproduce many CRPS features, further supporting this hypothesis. CRPS symptoms likely reflect combined effects of axonal degeneration and plasticity, inappropriate firing and neurosecretion by residual axons, and denervation supersensitivity. The resulting tissue edema, hypoxia, and secondary central nervous system changes can exacerbate symptoms and perpetuate pathology. Restoring the interest of neurologists in RSD/CRPS should improve patient care and broaden our knowledge of small-fiber functions.

Development of Korean Academy of Medical Sciences Guideline-Rating the Impairment in Pain

Pain-related impairment assessment by the fifth edition of the American Medical Association Guides had many ambiguous points, and therefore, it was not applicable directly in Korea. Several disputable pain disorders were excluded from the list of impairment evaluation, and complex regional pain syndrome was chosen as the first object of impairment evaluation. Scales such as Korean version of modified Barthel index for assessing the activity of daily livings and Beck Depression Inventory for assessing depression were added, and pain severity, pain treatment, pain behavior, etc. were scored. In order to objectify as much as possible and to remove the room for misuse, we develop a new rating system based on the concept of total score.

Patients initially diagnosed as 'warm' or 'cold' CRPS 1 show differences in central sensory processing some eight years after diagnosis: a quantitative sensory testing study.

We used quantitative sensory testing (QST) to gain further insight into mechanisms underlying pain in CRPS 1. Specific goals were: (1) to identify altered patterns of sensory processing some 8 years after diagnosis, (2) to document differences in sensory processing between 'warm' and 'cold' diagnostic subgroups, (3) to determine relationships between changed sensory processing and disease progression regarding pain. The study was performed on a cohort of patients (n=47) clinically diagnosed with CRPS 1 of one upper extremity approximately 8 years previously. Pain was quantified by VAS and MacGill Pain Questionnaire (MPQ), and all subjects underwent electrical and mechanical QST. Cold patients (n=13) had poorer MPQ scores than warm ones (n=34), and more pain on electrical stimulation. Their evoked pain increased with disease progression and correlated with clinical pain measures. For both diagnostic subgroups, thresholds to pressure pain were lower on the affected extremity and with disease progression. Eight years after original diagnosis, cold CRPS 1 patients have poorer clinical pain outcomes and show persistent signs of central sensitisation correlating with disease progression. The latter is not the case for warm CRPS 1 patients. Both diagnostic subgroups show greater pressure hyperalgesia on the affected limb and with disease progression. QST may prove useful in the subdiagnosis of CRPS 1 and in quantifying its progression, with both applications warranting further investigation for clinical and research use.

Complex regional pain syndrome I in the upper extremity.

Complex regional pain syndrome (CRPS) I, formerly known as reflex sympathetic dystrophy (RSD), is a painful neuropathic condition that most commonly affects a traumatized extremity. It is characterized by pain that is out of proportion to the original injury, has a distal predominance, and is not attributable to a specific peripheral nerve injury. The name RSD has been changed to CRPS I reflecting the fact that although sympathetic dysfunction can maintain the painful state, it is not the essential pathophysiologic lesion. Successful treatment hinges on early recognition of suspected cases, prompt referral to pain specialists, and ultimately pain control and return of limb function. Treatments range from noninvasive medications and therapies to sympathetic ganglion blockade and sympathectomy. The sports medicine physician is in an ideal position to recognize CRPS I in its earliest stages postinjury, and is advised to make prompt referral to a pain specialist when suspected.

Scoring system in the assessment of the clinical severity of reflex sympathetic dystrophy of the hand.

A scoring classification for assessment of the clinical severity of reflex sympathetic dystrophy (RSD) and rating the presence and clinical expression of each feature is proposed. The following were included: pain, reduction of finger flexion, swelling, temperature changes, discoloration, sensory disturbances, shoulder pain and loss of movement, increased sweating, and hair/nail growth changes. For most of these features one point was assigned for strong expression, half a point for moderate expression, and zero points if the feature was absent. A score of four points was assumed, empirically, to indicate a minimal degree of RSD, and the maximum score of 10.5 to indicate fully symptomatic condition. One hundred forty-six patients with RSD of the hand were classified according to those criteria. Seventy-four patients (51%) had a score of 4-6, 51 patients (35%) of 6.5-8, and 21 patients (14%) of 8.5-10. This classification was then used to investigate the influence of clinical severity of RSD on the intensity of uptake of the tracer in three-phase bone scintigraphy. No correlation between RSD score values and intensity of fixation of the radionuclide was found.