Alterations of Contralateral Thalamic Perfusion in Neuropathic Pain

Contralateral thalamus, the place of termination of spinothalamic tract, is affected in patients with pain. We employed single photon emission computed tomography (SPECT) to evaluate the thalamic perfusion in patients with spontaneous neuropathic pain. Ten patients with complex regional pain syndrome (CRPS) and eleven radiculopathiy patients were enrolled in this study. Regional cerebral blood flow of thalamus was assessed bilaterally by iodine-123-labelled iodoamphetamine SPECT. To standardize the inter-patient data, we set a contralateral thalamic uptake index (CTUI) for assessing thalamic asymmetry. In one study, we found elevation of CTUI in patients with symptoms of neuropathic pain for less than 12 month, whereas no change was observed in the case of a longer lasting disease. An another study demonstrated decrease of CTUI after pain treatment, even though it was unrelated to the pain intensity prior to treatment. Our SPECT study revealed that neuropathic pain altered thalamic neuronal activity. CTUIs were increased in early stage of the disease but decreased as the disease progressed to the chronic stage. These results suggest that CTUI can be used to improve management of neuropathic pain for proper evaluation of spontaneous pain

Visualization of Painful Experiences Believed to Trigger the Activation of Affective and Emotional Brain Regions in Subjects with Low Back Pain

In the management of clinical low back pain (LBP), actual damage to lower back areas such as muscles, intervertebral discs etc. are normally targeted for therapy. However, LBP may involve not only sensory pain, but also underlying affective pain which may also play an important role overall in painful events. Therefore we hypothesized that visualization of a painful event may trigger painful memories, thus provoking the affective dimension of pain. The present study investigated neural correlates of affect processing in subjects with LBP (n = 11) and subjects without LBP (n = 11) through the use of virtual LBP stimuli. Whole brain functional magnetic resonance imaging (MRI) was performed for all subjects while they were shown a picture of a man carrying luggage in a half-crouching position. All subjects with LBP reported experiencing discomfort and 7 LBP subjects reported experiencing pain. In contrast to subjects without LBP, subjects with LBP displayed activation of the cortical area related to pain and emotions: the insula, supplementary motor area, premotor area, thalamus, pulvinar, posterior cingulate cortex, hippocampus, fusiform, gyrus, and cerebellum. These results suggest that the virtual LBP stimuli caused memory retrieval of unpleasant experiences and therefore may be associated with prolonged chronic LBP conditions

Intradermal administration of magnesium sulphate and magnesium chloride produces hypesthesia to mechanical but hyperalgesia to heat stimuli in humans

<p>Abstract</p> <p>Background</p> <p>Although magnesium ions (Mg²⁺) are known to display many similar features to other 2+ charged cations, they seem to have quite an important and unique role in biological settings, such as NMDA blocking effect. However, the role of Mg²⁺in the neural transmission system has not been studied as sufficiently as calcium ions (Ca²⁺). To clarify the sensory effects of Mg²⁺in peripheral nervous systems, sensory changes after intradermal injection of Mg²⁺were studied in humans.</p> <p>Methods</p> <p>Magnesium sulphate, magnesium chloride and saline were injected into the skin of the anterior region of forearms in healthy volunteers and injection-induced irritating pain ("irritating pain", for short), tactile sensation, tactile pressure thresholds, pinch-pain changes and intolerable heat pain thresholds of the lesion were monitored.</p> <p>Results</p> <p>Flare formation was observed immediately after magnesium sulphate or magnesium chloride injection. We found that intradermal injections of magnesium sulphate and magnesium chloride transiently caused irritating pain, hypesthesia to noxious and innocuous mechanical stimulations, whereas secondary hyperalgesia due to mechanical stimuli was not observed. In contrast to mechanical stimuli, intolerable heat pain-evoking temperature was significantly decreased at the injection site. In addition to these results, spontaneous pain was immediately attenuated by local cooling.</p> <p>Conclusion</p> <p>Membrane-stabilizing effect and peripheral NMDA-blocking effect possibly produced magnesium-induced mechanical hypesthesia, and extracellular cation-induced sensitization of TRPV1 channels was thought to be the primary mechanism of magnesium-induced heat hyperalgesia.</p

The Effect of the Kampo

Background. Preoperative anxiety can lead to unfavorable physiological response such as tachycardia and hypertension. Prevention of preoperative anxiety improves surgical outcome and decreases inpatient stay. Yokukansan is one of prescriptions in Kampo, traditional Japanese herbal medicine, and is known to exert anxiolytic effects. The aim of the present study was to compare the effects of diazepam and Yokukansan on preoperative anxiety, salivary amylase activity, and sedation levels. Methods. Seventy American Society of Anesthesiologists physical status I or II patients presenting for hemicolectomy under general anesthesia combined with epidural anesthesia were enrolled. The Diazepam group received diazepam 5 mg orally and the Yokukansan group received Yokukansan 2.5 g orally. Results. Although levels of anxiety and salivary amylase activity were not different between the two groups, the modified Observer’s Assessment of Alertness/Sedation Scale of the Yokukansan group was significantly higher compared to that of the Diazepam group. Conclusion. Yokukansan alleviated preoperative anxiety without undesirable sedation, when compared with diazepam

Associations between the injustice experience questionnaire and treatment term in patients with acute Whiplash-associated disorder in Japan: Comparison with Canadian data.

INTRODUCTION:This study aimed to investigate the differences in the Injustice Experience Questionnaire (IEQ) scores during the early period after the diagnosis of Whiplash-associated disorder (WAD) between Japanese and Canadian samples, and the associations between the IEQ scores and treatment terms in Japanese patients with acute WAD. METHODS:We used secondary data for the IEQ scores of Canadian patients with acute WAD. In Japan, we collected data from 85 consecutively enrolled patients with acute WAD, and their treatment terms were collected; these referred to the number of days between the date of injury and the closure date of the insurance claim and the number of treatment visits. Before treatment, the Numeric Rating Scale, Neck Disability Index, Hospital Anxiety and Depression Scale, IEQ, and Euro Quality of Life five-dimensional questionnaire were administered. The variables were subjected to multivariate analysis with each treatment term. RESULTS:The IEQ scores were higher in Japan than in Canada. Through multiple regression analysis, IEQ scores were independently correlated with treatment terms. The optimal cutoff point of the IEQ scores for a prolonged treatment term was 21 and 22 points, respectively. CONCLUSIONS:The IEQ scores were associated with treatment terms in patients with acute WAD in Japan

Factors influencing outcomes among patients with whiplash-associated disorder: A population-based study in Japan.

IntroductionOnly a few, large population-based studies, have reported on whiplash-associated disorder (WAD). However, none of them have investigated the influence of crash severity on WAD outcome. In the present study, we aimed to determine whether crash severity predicts outcomes among patients with no-fault government insurance for acute WAD.MethodsWe utilized data from a compulsory, no-fault government automobile liability insurance agency in Japan. Individuals involved in a car accident between April 2001 and June 2015 with residual disabilities reported at the end of the treatment between October 2014 and September 2015 were included. Crash severity was assessed based on property damage costs, size of the other vehicle (large car, medium car, small car, or two-wheeled vehicles), and collision types (rear-end collision, contact with vehicle moving in the same direction, or in the opposite direction). Outcomes included the time to claim closure and the number of treatment visits.ResultsWe analyzed data for a total of 52,251 individuals (28,571 male and 23,680 female) with a median age of 44 years (range: 2-95 years). The median time to claim closure was 220 days (range: 1-4,938 days), and the median number of treatment visits was 102 (range: 1-2,492). There was no significant association between outcomes and property damage costs or size of the other vehicle. Collision types exhibited no consistent association with outcomes. However, older age and affected body parts, in addition to the neck, were independent risk factors for delayed claim closure and a large number of visits, although, all odds ratios were low (often less than 2.0).ConclusionsThere was no obvious association of outcomes with property damage costs, size of the other vehicle, or collision types in acute WAD patients. Further studies should investigate the influence of psychological factors, compensation systems, and cultural conditions

Associations between Degenerative Lumbar Scoliosis Structures and Pain Distribution in Adults with Chronic Low Back Pain

Background: This study aimed to investigate the location and distribution of pain in adults with chronic low back pain (LBP) with degenerative lumbar scoliosis (DLS) according to coronal deformities. Methods: We enrolled 100 adults with chronic LBP and DLS, dividing them into two groups, a right-convex DLS group (n = 50) and a left-convex DLS group (n = 50). Dominant pain location was analyzed by dividing it into three parts—left side, right side, and center—and pain areas were identified using the pain drawing method; then, a heat map was created for each group. An association between pain location and convex side was analyzed as the primary outcome. Additionally, we assessed pain characteristics and radiological parameters, such as the curve structure and degree of degeneration. We used the Mann–Whitney U test or the chi-squared test to compare the clinical characteristics of the two groups, and generalized linear models were utilized to determine which variables were associated with pain severity or pain area. Results: The results indicated that there was no significant difference between the two groups in terms of the association between the curve structure, pain severity and location. In multivariate analysis, although we did not find any variables associated with pain severity, we observed that age and a left-convex DLS were negatively correlated with pain area among all participants. The heat map demonstrated that individuals with chronic LBP frequently experienced pain in the central lumbar region, regardless of the coronal curve structure. Conclusions: Our findings suggest that degenerative coronal lumbar deformities may not have a specific pain pattern associated with a curved structure

Stool consistency is significantly associated with pain perception

<div><p>Background</p><p>Commensal as well as pathogenic bacteria can influence a variety of gut functions, thereby leading to constipation and diarrhea in severe cases. In fact, several researchers have reported evidence supporting the association between stool consistency or constipation and the Gut microbiome (GM) composition and dysbiosis. GM influences the human health and disease via the gut-brain axis. We thus hypothesized that the pathogenic bacteria increases pain perception to some extent, which means that there could be an association between stool consistency or constipation and pain perception of healthy subjects.</p><p>Design</p><p>Observational study.</p><p>Objectives</p><p>The aim of the present study was to investigate the association between stool consistency or constipation and pain perception of healthy subjects.</p><p>Methods</p><p>Thirty-eight healthy subjects participated in this study. The participants were assessed on their usual stool form (the Bristol Stool Form Scale: BSFS), constipation (the Cleveland Clinic Constipation score: CCS), degree of obesity, pain perception by mechanical stimulus, cold pain threshold, and a questionnaire on psychological state.</p><p>Results</p><p>The BSFS was significantly and positively associated with pain perception, and showed a significant association with anxiety states. Furthermore, pain perception was significantly associated with anxiety states. However, there were no significant associations between the CCS and any independent variables. In addition, we found that a significant predictor to the pain perception was BSFS. Moreover, there were significant relationships among the psychological states, BSFS and obesity.</p><p>Conclusion</p><p>These results suggest that the stool form is associated with pain perception and anxiety status.</p></div