A decision tree algorithm to identify predictors of post-stroke complex regional pain syndrome.

This prospective cohort study aimed to identify the risk factors for post-stroke complex regional pain syndrome (CRPS) using a decision tree algorithm while comprehensively assessing upper limb and lower limb disuse and physical inactivity. Upper limb disuse (Fugl-Meyer assessment of upper extremity [FMA-UE], Action Research Arm Test, Motor Activity Log), lower limb disuse (Fugl-Meyer Assessment of lower extremity [FMA-LE]), balance performance (Berg balance scale), and physical inactivity time (International Physical Activity Questionnaire-Short Form [IPAQ-SF]) of 195 stroke patients who visited the Kishiwada Rehabilitation Hospital were assessed at admission. The incidence of post-stroke CRPS was 15.4% in all stroke patients 3 months after admission. The IPAQ, FMA-UE, and FMA-LE were extracted as risk factors for post-stroke CRPS. According to the decision tree algorithm, the incidence of post-stroke CRPS was 1.5% in patients with a short physical inactivity time (IPAQ-SF < 635), while it increased to 84.6% in patients with a long inactivity time (IPAQ-SF ≥ 635) and severe disuse of upper and lower limbs (FMA-UE score < 19.5; FMA-LE score < 16.5). The incidence of post-stroke CRPS may increase with lower-limb disuse and physical inactivity, in addition to upper-limb disuse. Increasing physical activity and addressing lower- and upper-limb motor paralysis may reduce post-stroke CRPS.

Direct Health Care Cost and Work Incapacity Related to Complex Regional Pain Syndrome in Switzerland: A Retrospective Analysis from 2008 to 2015.

OBJECTIVE: First, to determine the number of accident-related complex regional pain syndrome (CRPS) cases from 2008 to 2015 and to identify factors associated with an increased risk for developing CRPS. Second, to analyze the duration of work incapacity and direct health care costs over follow-up periods of two and five years, respectively. DESIGN: Retrospective data analysis. SETTING: Database from the Statistical Service for the Swiss National Accident Insurances covering all accidents insured under the compulsory Swiss Accident Insurance Law. SUBJECTS: Subjects were registered after an accident between 2008 and 2015. METHODS: Cases were retrospectively retrieved from the Statistical Service for the Swiss National Accident Insurances. Cases were identified using the appropriate International Classification of Diseases, 10th Revision, codes. RESULTS: CRPS accounted for 0.15% of all accident cases. Age, female gender (odds ratio [OR] = 1.53, 95% confidence interval [CI] = 1.47-1.60), and fracture of the forearm (OR = 38, 95% CI = 35-42) were related to an increased risk of developing CRPS. Over five years, one CRPS case accumulated average insurance costs of $86,900 USD and treatment costs of $23,300 USD. Insurance costs were 19 times and treatment costs 13 times the average costs of accidents without CPRS. Within the first two years after the accident, the number of days lost at work was 20 times higher in patients with CRPS (330 ± 7 days) than in patients without CRPS (16.1 ± 0.1 days). Two-thirds of all CRPS cases developed long-term work incapacity of more than 90 days. CONCLUSION: CRPS is a relatively rare condition but is associated with high direct health care costs and work incapacity.

Content validation of the Patient-Reported Hamilton Inventory for Complex Regional Pain Syndrome: Validité de contenu du Hamilton Inventory for Complex Regional Pain Syndrome, une mesure des résultats déclarés par le patient.

BACKGROUND: Complex regional pain syndrome (CRPS) is a perplexing neurological condition, and persons with CRPS experience substantial loss of daily roles and activities. A condition-specific measure is being developed to evaluate CRPS. PURPOSE: We describe the use of cognitive interviews to examine content validity of this patient-reported outcome measure for CRPS. METHOD: Interviews with 44 persons with CRPS were analyzed to identify problems with wording and support content validation. Item-total correlations were calculated for proposed subscales, and scores were plotted to consider floor/ceiling effects. FINDINGS: Interviews identified questions where respondents considered factors unrelated to the construct of interest or were underaddressed by the questionnaire, including depression and skin temperature. The symptoms, daily function, and coping/social impact scales demonstrated satisfactory correlations (Cronbach's alpha 0.76-0.86). Despite a sampling bias of severity, no frank floor/ceiling effects were noted. IMPLICATIONS: This study builds a foundation for continuing development and evaluation of the measurement properties of the Patient-Reported Hamilton Inventory for CRPS. It makes explicit the iterative decisions involved in rigorous instrument development.

Comparison of tonic spinal cord stimulation, high-frequency and burst stimulation in patients with complex regional pain syndrome: a double-blind, randomised placebo controlled trial.

BACKGROUND: Complex Regional Pain Syndrome (CRPS) is a disabling disease that is sometimes difficult to treat. Although spinal cord stimulation (SCS) can reduce pain in most patients with CRPS, some do not achieve the desired reduction in pain. Moreover, the pain reduction can diminish over time even after an initially successful period of SCS. Pain reduction can be regained by increasing the SCS frequency, but this has not been investigated in a prospective trial. This study compares pain reduction using five SCS frequencies (standard 40 Hz, 500 Hz, 1200 Hz, burst and placebo stimulation) in patients with CRPS to determine which of the modalities is most effective. DESIGN: All patients with a confirmed CRPS diagnosis that have unsuccessfully tried all other therapies and are eligible for SCS, can enroll in this trial (primary implantation group). CRPS patients that already receive SCS therapy, or those previously treated with SCS but with loss of therapeutic effect over time, can also participate (re-implantation group). Once all inclusion criteria are met and written informed consent obtained, patients will undergo a baseline assessment (T0). A 2-week trial with SCS is performed and, if successful, a rechargeable internal pulse generator (IPG) is implanted. For the following 3 months the patient will have standard 40 Hz stimulation therapy before a follow-up assessment (T1) is performed. Those who have completed the T1 assessment will enroll in a 10-week crossover period in which the five SCS frequencies are tested in five periods, each frequency lasting for 2 weeks. At the end of the crossover period, the patient will choose which frequency is to be used for stimulation for an additional 3 months, until the T2 assessment. DISCUSSION: Currently no trials are available that systematically investigate the importance of variation in frequency during SCS in patients with CRPS. Data from this trial will provide better insight as to whether SCS with a higher frequency, or with burst stimulation, results in more effective pain relief. TRIAL REGISTRATION: Current Controlled Trials ISRCTN36655259.

Rehabilitation perspectives of neuromodulation.

Chronic pain is one of the most prevalent and costly health care problems in the United States today. Two conditions, failed back surgery syndrome (FBSS) and complex regional pain syndrome (CRPS), in particular have been difficult to manage, resulting in increased disability and poorer quality of life measures for patients as well as increased treatments cost for payers. Given the cost of chronic pain management and overall subjectivity of analog pain scores, many payers are emphasizing the importance of functional outcomes as a means of assessing efficacy of treatment. Neuromodulation devices such as spinal cord stimulators are shown to be cost effective and able to improve functional outcomes and quality of life. Specific rehabilitation therapies also demonstrate improved functional outcomes. This article aims to discuss the role of rehabilitation in the patient with a neuromodulatory device. From the available data and our clinical experience, we recommend incorporating rehabilitation after placement of a neuromodulation device in order to optimize functional outcomes.

Infrared thermographic imaging in the assessment of successful block on lumbar sympathetic ganglion.

This study examined the net changes in temperature at various regions of the lower extremities in an attempt to identify the regions demonstrating the most significant temperature changes following a lumbar sympathetic ganglion block (LSGB). Thermography was performed before and after the LSGB in 26 sympathetic nerve system disorder cases. The inspection points were the anterior and posterior surfaces of the thigh, the knee and leg, and the dorsal and plantar surfaces of the feet. The net increases in skin temperature following the LSGB (deltaT(net)) at the plantar and dorsal surfaces of the feet, were 6.2 +/- 2.68 degrees C (mean +/- SD) and 3.9 +/- 1.89 degrees C, respectively, which were higher than those observed in the other regions of the lower extremities (p < 0.05). The areas, in order of decreasing deltaT(net), are as follows: the plantar surface of the foot, the dorsal surface of the foot, the shin, the anterior surface of the knee, the calf, the posterior surface of the knee, the anterior surface of the thigh, and the posterior surface of the thigh. There was one case of orthostatic hypotension during the thermography procedure. In conclusion, thermographic imaging is a useful method for demonstrating the success of a LSGB in various diseases. An evaluation of the deltaT(net) on the plantar surface of the feet using thermographic imaging is the most effective, simple, and safe method for assessing a successful LSGB.