Early Complex Regional Pain Syndrome Research Articles

Sympathetic Dysfunction in Long-term Complex Regional Pain Syndrome

Malfunction of the sympathetic nervous system (SNS) is common in early complex regional pain syndrome type I (CRPS I). This study was designed to evaluate the function of the SNS in patients with chronic CRPS I and to correlate the obtained data with hand function measurements. Thirty-two patients of both the sexes in whom the diagnosis of CRPS I of the upper extremity had been established for at least 3 years before they were included in the study. Besides a hand outcomes questionnaire [Michigan Hand Outcome Questionnaire, (MHQ)] the patients underwent a standardized testing of the peripheral sympathetic nervous system (pSNS) using laser Doppler flowmetry (LDF). Mean time since initial diagnosis was 4.6+/-2.1 years. The mean MHQ score of the affected limb was 57.3+/-17 compared with 69.4+/-13.7 for the unaffected hand (P=0.002). Twenty patients (62.5%) still demonstrated pathologic results regarding the pSNS function (mean sympathetic reflex 0.18+/-0.11, normal range>0.38). We found no statistically significant correlation between pSNS function either with the clinical outcome as measured by MHQ (r=0.246; P=0.175), or with the level of pain (r=0.132; P=0.473). Even 5 years after the diagnosis of CRPS I of the upper extremity we detected significant impairments of the pSNS in nearly two thirds of our patients. Patients still have pain and present with a significant deterioration of their hand function in comparison with the not affected hand. In our study we could not identify any correlation between pSNS function and clinical outcome as measured by MHQ.

The fascination of complex regional pain syndrome

Complex regional pain syndrome (CRPS) is a pain disorder involving the somatosensory, the somatomotor and the sympathetic nervous systems. Based on experiments conducted by Bove (2009), it is suggested that changes in impulse activity in small-diameter afferents and postganglionic axons generated by neuritis can contribute to signs of early CRPS. The potential mechanisms involved are discussed. These mechanisms include the possibility that CRPS, a disorder of the central nervous system, may be caused by a nerve inflammation.

Efficacy of Ketamine in Anesthetic Dosage for the Treatment of Refractory Complex Regional Pain Syndrome: An Open-Label Phase II Study

Advanced complex regional pain syndrome (CRPS) remains very difficult to treat. While subanesthetic low-dose ketamine has shown promise in early localized CRPS, its use in advanced CRPS has not been as effective. Since ketamine's analgesic potency and duration of effect in neuropathic pain are directly dose-dependant, we investigated the efficacy of ketamine in anesthetic dosage in refractory CRPS patients that had failed available standard therapies. Twenty ASA I-III patients suffering from refractory CRPS received ketamine in anesthetic dosage over 5 days. Outcome criteria were pain relief, effect on the movement disorder, quality of life, and ability to work at baseline and up to 6 months following treatment. Significant pain relief was observed at 1, 3, and 6 months following treatment (93.5 +/- 11.1%, 89.4 +/- 17.0%, 79.3 +/- 25.3%; P < 0.001). Complete remission from CRPS was observed at 1 month in all patients, at 3 months in 17, and at 6 months in 16 patients. If relapse occurred, significant pain relief was still attained at 3 and 6 months (59.0 +/- 14.7%, P < 0.004; 50.2 +/- 10.6%, P < 0.002). Quality of life, the associated movement disorder, and the ability to work significantly improved in the majority of patients at 3 and 6 months. This open-label trial suggests benefit in pain reduction, associated CRPS symptoms, improved quality of life and ability to work following anesthetic ketamine in previously refractory CRPS patients. However, a randomized controlled trial will be necessary to prove its efficacy.

Treatment of Early Complex Regional Pain Syndrome Type 1 by A Combination of Mannitol and Dexamethasone

A total of 75 patients, 68 women (91%) and seven men (9%), with a mean age of 58 (range 38-82) years with early Complex Regional Pain Syndrome Type 1 (CRPS Type 1), present for less than 4 months, were given in-patient treatment with 10% mannitol 2 x 250 ml per day and 8 mg dexamethasone per day for 1 week. Measurements assessed included the pain, the range of finger movements, grip strength and our own clinical severity scoring system for CRPS Type 1 (CRPS score). The results were assessed at 1 week and, finally, at a mean of 9 (range 8-12) months. At 1-week assessment, all variables decreased significantly: pain from a mean Visual Analogue Scale (VAS) of 6.7 to 2.3, loss of finger flexion (6-0.3 cm) and the CRPS score (7.6-2.2 points). Total grip strength did not improve. At the final assessment of 70 patients, the VAS score was a mean of 1.8, loss of finger flexion a mean of 0.1 cm, the CRPS score was a mean of 1.6 and grip strength a mean of 34% of the strength of the unaffected hand. All these variables showed statistically significant improvement.

Quantitative evaluation of very acute stage of complex regional pain syndrome after stroke using three-phase bone scintigraphy

Three-phase bone scintigraphy (TPBS) is an objective diagnostic test for complex regional pain syndrome (CRPS). The diagnostic importance of an increased uptake on the delayed phase has been proven in early CRPS, but that of the vascular and blood pool phases has not. The purpose of this study is to improve the diagnostic strength of the very acute stage of CRPS after stroke through a combined quantitative evaluation of each TPBS phase. Quantitative TPBS analysis was performed in 26 post-stroke hemiplegic patients with very acute stage of CRPS and in 12 controls with no CRPS after brain lesion. Regions of interest (hands without fingers--carpal bones, metacarpal bones and metacarpopharyngeal joints) were selected and the count ratios of the affected to unaffected sides were calculated. The maximum values of control in each phase were used as the criteria of positive findings of each TPBS phase. Eleven patients in the vascular phase, 13 in the blood pool phase and 17 in the delayed phase had a higher assumption than the maximum values and a sensitivity of 42.3%, 50% and 65.4%, respectively. Twenty-one of 26 patients were interpreted as abnormal when at least one phase showed a positive finding. As a result, increased sensitivity of 80.8% and identical specificity of 100% were achieved. These findings suggest that the combination of quantitative evaluation of each TPBS phase can improve the diagnostic strength of the very acute stage of CRPS after stroke.

A Management of Early CRPS I Caused by Ankle Sprain: A Case Report

We present a case of a 13-year-old boy who developed signs and symptoms of neuropathic pain/early Complex Regional Pain Syndrome (CRPS) Type I, formerly known as Reflex Sympathetic Dystrophy (RSD), after spraining his ankle while wrestling. Aggressive pain control, using medications and sympatholytic blocks, with physical therapy and rehabilitation, led to the resolution of his painful condition. This prevented the disease from possibly progressing to a full-blown case of CRPS I (RSD) that is very challenging to treat.

MULTIDISCIPLINARY PAIN ABSTRACTS: 36 . Neurology (36)

In this study, the authors assessed mirror visual feedback (MVF) to test the hypothesis that incongruence between motor output and sensory input produces complex regional pain syndrome (CRPS) (type I) pain. Eight subjects were studied over 6 weeks with assessments including two controls (no device and viewing a non‐reflective surface) and the intervention (MVF). Pain severity and vasomotor changes were recorded. The control stages had no analgesic effect. MVF in early CRPS had an immediate analgesic effect and in intermediate disease led to a reduction in stiffness. At 6 weeks, normalization of function and thermal differences had occurred. No change was found in chronic CRPS. In early CRPS (type I), visual input from a moving, unaffected limb re‐establishes the pain‐free relationship between sensory feedback and motor execution. Trophic changes and a less plastic neural pathway preclude this in chronic disease.

Intravenous regional guanethidine blockade in the treatment of post-traumatic complex regional pain syndrome type 1 (algodystrophy) of the hand

A total of 57 patients, aged between 23 and 86 years, with complex regional pain syndrome (CRPS) type 1 nine weeks after an isolated closed fracture of the distal radius, was randomised to receive either serial intravenous regional blockade (IVRB) with 15 mg of guanethidine in 30 ml of 0.5% prilocaine or serial IVRB with 30 ml of normal saline at weekly intervals until the tenderness in their fingers had resolved or they had received a maximum of four IVRBs. The analgesic efficacy was assessed at 24 hours, 48 hours and one week after each procedure by the dolorimetry ratio and verbal pain scores, and at intervals up to six months after the fracture. There was no significant difference in the number of IVRBs administered or in finger tenderness, stiffness or grip strength between the two groups. The guanethidine group experienced more pain in the affected hand (p = 0.025) and at six months had more vasomotor instability (p &lt; 0.0001) compared with the control group. IVRB using guanethidine offers no significant analgesic advantage over a normal saline placebo block in the treatment of early CRPS type 1 of the hand after fracture of the distal radius. It does not improve the outcome of this condition and may delay the resolution of vasomotor instability when compared with the placebo.

Complex regional pain syndrome (reflex sympathetic dystrophy and causalgia): management with the calcium channel blocker nifedipine and/or the α-sympathetic blocker phenoxybenzamine in 59 patients

Complex Regional Pain Syndrome (CRPS) is the new name for entities formerly known mostly as Reflex Sympathetic Dystrophy and Causalgia. Treatment of CRPS with either the calcium channel blocker nifedipine or the α-sympathetic blocker phenoxybenzamine was assessed in 59 patients, 12 with early stages of CRPS, 47 with chronic stage CRPS. In the early stage CRPS patients, 3 of 5 were cured with nifedipine and 8 of 9 (2 of whom had earlier received nifedipine) with phenoxybenzamine, for a cure rate of 92% (11 out of 12). In the chronic stage CRPS patients, 10 of 30 were cured with nifedipine; phenoxybenzamine cured 7 of 17 patients when administered as a first choice and another 2 ofof 7 patients who received nifedipine earlier, for a total late stage success rate of 40% (19 out of 47). The most common side effects necessitating discontinuing the drug were headaches for nifedipine and orthostatic dizziness, nausea and diarrhoea for phenoxybenzamine. All male patients on phenoxybenzamine experienced impotence, but this did not lead to discontinuing this agent and immediately disappeared after stopping the drug. These results once again stress the importance of early recognition of CRPS, and treatment with either of these drugs could be considered as a first choice for early CRPS, especially because in this series this treatment was not combined with physical therapy making it very cost-effective. In the chronic stage of CRPS, treatment with these drugs was much less successful (40%), even though it was always combined with physical therapy, but it can still be considered, either as a first choice or when other types of treatment have failed.