Tomohiko Nishigami

Are tactile acuity and clinical symptoms related to differences in perceived body image in patients with chronic nonspecific lower back pain

Clinically, perceived image of the lower back and the two-point discrimination (TPD) test are used as markers for evaluating alterations of cortical reorganization. The purpose of the present study was to examine whether TPD and selected clinical findings are different in subgroups of individuals with chronic nonspecific lower back pain (CNLBP) based on body image drawings. Forty-two patients with CNLBP and seventeen healthy individuals were recruited. Perceived body image, TPD and clinical profiles was measured. Of the patients with CNLBP, 42.8% had a normal perceived body image, 28.5% an expanded image, and 28.5% a shrunken image. The TPD distance threshold was significantly larger for the expanded subgroup (13.3 ± 6.8 mm) compared with the control (5.5 ± 3.8 mm; Difference, 7.8; 95%CI, 1.83 to 13.66; p < 0.05) and normal subgroups (4.5 ± 5.5 mm; Difference, 8.8; 95%CI, 2.90 to 14.59; p < 0.05). No significant differences in pain intensity, duration of pain, Roland Morris Disability Questionnaire (RDQ), and Pain Catastrophizing Scale (PCS) scores were found between three body image subgroups. Our results suggest that TPD is increased in patients who report an expanded perceived image of the lower back compared with healthy individuals and patients who report a normal image. The effectiveness of new rehabilitation techniques may be evaluated by assessing perceived image of the lower back and TPD values for patients with CNLBP before and after treatment.

Changes in calcitonin gene-related peptide expression following joint immobilization in rats

Long-term immobilization by casting can occasionally cause pathologic pain states in the immobilized side. The underlying neurophysiological mechanisms of immobilization-related pain are not well understood. For this reason, we specifically examined changes of calcitonin gene-related peptide (CGRP) expression in the dorsal root ganglion (DRG), spinal dorsal horn and posterior nuclei (cuneate nuclei) in a long-term immobilization model following casting for 5 weeks. A plastic cast was wrapped around the right limb from the forearm to the forepaw to keep wrist joint at 90 degrees of flexion. In this model, CGRP in immobilized (ipsilateral) side was distributed in larger DRG neurons compared with contralateral side, even though the number of CGRP-immunoreactive (CGRP-IR) neurons did not differ. Spinal laminae III-V, not laminae I-II in ipsilateral side showed significantly high CGRP expression relative to contralateral side. CGRP expression in cuneate nuclei was not significantly different between ipsilateral and contralateral sides. Long-term immobilization by casting may induce phenotypic changes in CGRP expression both in DRG and spinal deep layers, and these changes are partly responsible for pathological pain states in immobilized side.

Development and psychometric properties of knee-specific body-perception questionnaire in people with knee osteoarthritis: The Fremantle Knee Awareness Questionnaire

Background Recent systematic reviews have demonstrated that pain associated with knee osteoarthritis (OA) is a complex phenomenon that involves various contributors. People with knee OA exhibit symptoms of impaired body-perception, including reduced tactile acuity, impairments in limb laterality recognition, and degraded proprioceptive acuity. The Fremantle Back Awareness Questionnaire (FreBAQ) was developed to assess body-perception specific to the back in people with chronic low back pain. The aim of this study was to develop and assess the psychometric properties of a knee-specific version of the FreBAQ-J (FreKAQ-J), determine whether people with knee pain experience perceptual impairments and investigate the relationship between disturbed self-perception and clinical status. Methods Sixty-five people with knee OA completed the FreKAQ-J. A subset of the participants completed the FreKAQ-J again two-weeks later. Rasch analysis was used to assess item order, targeting, category ordering, unidimensionality, person fit, internal consistency, and differential item functioning. Validity was investigated by examining the relationship between the FreKAQ-J and clinical valuables. Results The FreKAQ-J had acceptable internal consistency, unidimensionality, good test-retest reliability, and was functional on the category rating scale. The FreKAQ-J was significantly correlated with pain in motion, disability, pain-related catastrophizing, fear of movement, and anxiety symptomatology. Conclusions We developed FreKAQ-J by modifying the FreBAQ-J. The FreKAQ-J fits the Rasch measurement model well and is suitable for use in people with knee OA. Altered body perception may be worth evaluating when managing people with knee OA.

Validation of the Japanese version of the Central Sensitization Inventory in patients with musculoskeletal disorders

Background Many musculoskeletal pain conditions are characterized by hypersensitivity, which is induced by central sensitization (CS). A questionnaire, the Central Sensitization Inventory (CSI), was recently developed to help clinicians identify patients whose presenting symptoms may be related to central sensitivity syndrome (CSS). The aims of the present study were to examine criterion validity and construct validity of the Japanese version of the CSI (CSI-J), and to investigate prevalence rates of CS severity levels in patients with musculoskeletal disorders. Methods Translation of the CSI into Japanese was conducted using a forward-backward method. Two hundred and ninety patients with musculoskeletal pain disorders completed the resultant CSI-J. A subset of the patients (n = 158) completed the CSI-J again one week later. The relationships between CSI and clinical symptoms, EuroQol 5-dimension (EQ-5D) and Brief Pain Inventory (BPI), were examined for criterion validity. EQ-5D assesses Health-related QOL and BPI measures pain intensity and pain interference. The psychometric properties were evaluated with analyses of construct validity, factor structure and internal consistency, and subsequently investigate the prevalence rates of CS severity levels. Results The CSI-J demonstrated high internal consistency (Cronbach’s α = 0.89) and test-retest reliability was excellent value (ICC = 0.85). The CSI-J was significantly correlated with EQ-5D (r = −0.44), pain intensity (r = 0.42), and pain interference (r = 0.48) (p < 0.01 for all). Ten percent of the participants were above the cutoff “40”. The exploratory factor analysis resulted in 5-factor model. Conclusions This study reported that the CSI-J was a useful and psychometrically sound tool to assess CSS in Japanese patients with musculoskeletal disorders. The finding of the prevalence rates of CS severity levels in patients with musculoskeletal disorders may help clinicians to decide strategy of treatment.

Psychometric properties of the Japanese version of short forms of the Pain Catastrophizing Scale in participants with musculoskeletal pain: A cross-sectional study

BACKGROUND The Pain Catastrophizing Scale (PCS) is a commonly used as measure of pain catastrophizing. The scale comprises 13 items related to magnification, rumination, and helplessness. To facilitate quick screening and to reduce participants burden, the four-item and six-item short forms of the English version of the PCS were developed. The purpose of the present study was to evaluate the psychometric properties of a Japanese version of the short forms of PCS using a contemporary approach called Rasch analysis. METHODS A total of 216 patients with musculoskeletal disorders were recruited in this study. Participants completed study measures, which included the pain intensity, the Pain Catastrophizing Scale (PCS), and the Tampa Scale of Kinesiophobia (TSK). Furthermore, the four-item (items 3, 6, 8, and 11) and six-item (items 4, 5, 6, 10, 11, and 13) short forms of the Japanese version of PCS were measured. We used Rasch analysis to analyze the psychometric properties of the original, four-item, and six-item short forms of PCS. RESULTS Rasch analysis showed that both short forms of PCS had acceptable internal consistency, unidimensionality, and no notable DIF and were functional on the category rating scale. However, four-item short form of PCS had two misfit items. CONCLUSIONS Six-item short form of PCS has acceptable psychometric properties and is suitable for use in participants with musculoskeletal pain. Thus, six-item can be used as brief instruments to evaluate pain catastrophizing.

Injustice Experience Questionnaire, Japanese Version: Cross-Cultural Factor-Structure Comparison and Demographics Associated with Perceived Injustice

Objective The Injustice Experience Questionnaire (IEQ) assesses injury-related perceived injustice. This study aimed to (1) develop a Japanese version (IEQ-J), (2) examine its factor structure, validity, and reliability, and (3) discover which demographic variable(s) positively contributed to prediction of IEQ-J scores. Methods Data from 71 patients (33 male, 38 female; age = 20+) with injury pain were employed to investigate factor structure by exploratory and confirmatory factor analyses. Concurrent validity was examined by Pearson correlation coefficients among the IEQ-J, Brief Pain Inventory (BPI), and Pain Catastrophizing Scale (PCS). Internal consistency was investigated by Cronbach’s alpha, and test-retest reliability was indicated with intra-class correlations (ICCs) in 42 of 71 patients within four weeks. Relations between demographic variables and IEQ-J scores were examined by covariance analysis and linear regression models. Results IEQ-J factor structure differed from the original two-factor model. A three-factor model with Severity/irreparability, Blame/unfairness, and Perceived lack of empathy was extracted. The three-factor model showed goodness-of-fit with the data and sufficient reliability (Cronbach’s alpha of 0.90 for total IEQ-J; ICCs = 0.96). Pearson correlation coefficients among IEQ-J, BPI, and PCS ranged from 0.38 to 0.73. Pain duration over a year (regression coefficient, 11.92, 95%CI; 5.95–17.89) and liability for injury on another (regression coefficient, 12.17, 95%CI; 6.38–17.96) predicted IEQ-J total scores. Conclusions This study evidenced the IEQ-J’s sound psychometric properties. The three-factor model was the latter distinctive in the Japanese version. Pain duration over a year and injury liability by another statistically significantly increased IEQ-J scores.

Tactile localization training for pain, sensory disturbance, and distorted body image: a case study of complex regional pain syndrome

This report presents a case of complex regional pain syndrome. The patient presented with severe pain, sensory disturbance, and distorted body image at the site of initial injury and other body sites. Tactile localization training (TLT) at only the site of initial injury decreased severe pain at the site of initial injury and the secondary affected sites, whereas TLT at secondary affected sites had no effect. These results highlighted the importance of assessing changes in patients’ pain processes to determine the part of the body where TLT should be applied.

Effects of a Hardness Discrimination Task in Failed Back Surgery Syndromewith Severe Low Back Pain and Disturbed Body Image: Case study

A 20-year-old woman began experiencing low back pain (LBP) in September 2008 and dysesthesia, pain in the left leg, muscle weakness, and gait disturbance in January 2009. Three low back surgery were performed in April, May and July 2009, respectively. However, her symptoms were relieved for only a few days, eventually re-emerging and intensifying. On our initial examination, on physical contact, a sharp increase in pain was experienced in the left lower back (numerical rating scale: NRS = 10). Loss of body image in the left lower back with severe pain was presented. Lying in the supine position, independent upright sitting, and trunk flexion to the left beyond a certain point were impossible. Motor imagery and tactile discrimination training were performed. However the training was not effective. Next, the patient was asked to determine the various degrees of hardness of the sponge material that was placed on the left lower back of another person; she was simultaneously instructed to imagine it being placed on her own left lower back. Hardness discrimination training was performed for 20 min a day, 6 days a week for 4 weeks. EEG was performed to determine the cortical activation in the somatosensory cortex during motor imagery and the hardness discrimination task. Four weeks after hardness discrimination training, on contact with the left lower back, left LBP decreased from 10/10 to 5/10 on the subjective NRS. In addition, perception of body image in the left lower back improved. Lying in the supine position, independent upright sitting, and trunk flexion to the left became possible. Neural activity was observed in the right somatosensory cortex in the hardness discrimination task compared with the control task. These results raised the possibility that hardness discrimination training decreased pain through reorganization of the somatosensory cortex.

A pilot feasibility study for immediate relief of referred knee pain by hip traction in hip osteoarthritis

Abstract It is generally accepted that osteoarthritis of the hip is a common cause of pain and disability. In clinical practice, a variety of conservative and surgical methods are available for patients with hip osteoarthritis. Nonsurgical interventions are recommended as the first-line treatment for hip osteoarthritis [1]. As one of the conservative therapies used in nonsurgical interventions, physical therapy, including hip traction and stretching, has been shown to reduce pain and improve hip function in patients with hip osteoarthritis [2]. Pain originating from the hip joint is distributed not only in the groin area but also in the buttocks, anterior thighs, and knees [3, 4]. Knee pain arising from the hip joint is one of the characteristics of referred pain in hip osteoarthritis. However, the effects of physical therapy on referred pain have not been well documented. We developed an original hip traction technique using a lumbar traction machine. Of note, patients treated with this method experienced immediate relief of referred knee pain. This study describes the results of immediate relief of referred knee pain because using hip traction.

Development and psychometric properties of short form of central sensitization inventory in participants with musculoskeletal pain: A cross-sectional study

Background The central sensitization inventory (CSI) comprises 25 items and is commonly used to measure somatic and emotional symptoms related to central sensitization symptoms. CSI was developed as an easy-to-administer screening instrument for patients at high risk of developing central sensitization in whom it was essential to quickly evaluate the condition. The purpose of the present study was to develop a short form of CSI and evaluate its psychometric properties using a contemporary approach called Rasch analysis. Methods A total of 505 patients with musculoskeletal disorders were recruited in this study. The CSI, pain intensity, pain interference, and the health-related quality of life (QOL) were evaluated for each participant. The original CSI items were consecutively analyzed using the Rasch model. Successive Rasch analyses were performed until a final set of items satisfied the model fit requirements. We also analyzed the psychometric properties of the original and short forms of CSI. Results Four consecutive Rasch analyses identified the removable items. Finally, the shortest questionnaire obtained that maintained the correct psychometric properties based on the Rasch model contained only 9 items (CSI-9). Rasch analysis showed that the CSI-9 had acceptable internal consistency, exhibited unidimensionality, had no notable differential item functioning, and was functional on the category rating scale. Conclusions The nine-item short form of CSI has acceptable psychometric properties and is suitable for use for patients with musculoskeletal pain. Thus, the CSI-9 can be used as a brief instrument to evaluate central sensitization.