Masahiko Sumitani

Mirror visual feedback alleviates deafferentation pain, depending on qualitative aspects of the pain: a preliminary report

OBJECTIVES Following lesions in somatosensory pathways, deafferentation pain often occurs. Patients report that the pain is qualitatively complex, and its treatment can be difficult. Mirror visual feedback (MVF) treatment can improve deafferentation pain. We sought to classify the qualities of the pain in order to examine whether the potential analgesic effect of MVF depends on these qualities. METHODS Twenty-two patients with phantom limb pain, or pain related to spinal cord or nerve injury, performed a single MVF procedure. Before and after the MVF procedure, we evaluated phantom limb awareness, movement representation of the phantom or affected/paralysed limb, pain intensity on an 11-point numerical rating scale (0-10) and the qualities of the pain [skin surface-mediated (superficial pain) vs deep tissue-mediated (deep pain)] using lists of pain descriptors for each of the two categories. RESULTS Fifteen of the patients perceived the willed visuomotor imagery of the phantom or affected/paralysed limb after the MVF procedure. In most of the patients, a reduction in pain intensity and a decrease in the reporting of deep-pain descriptors were linked to the emergence of willed visuomotor imagery. CONCLUSIONS In this pilot study, we roughly classified the pain descriptor items into two types for evaluating the qualities of deafferentation pain. We found that visually induced motor imagery by MVF was more effective for reducing deep pain than superficial pain. This suggests that the analgesic effect of MVF treatment does depend on the qualities of the pain. Further research will be required to confirm that this effect is a specific consequence of MVF.

Pathologic pain distorts visuospatial perception

Spatial perception is achieved by integrating multisensory information. Using visual subjective body midline (vSM) judgments in patients with unilateral limb pain (complex regional pain syndrome [CRPS]), we found that their vSM deviated toward the affected side; however, deafferentation of the affected limb caused a transient pain decrease and a transient shift of the vSM deviation toward the unaffected side. Our results indicate that the persistent pain state in CRPS distorts visuospatial perception.

Modulation of neuronal activity after spinal cord stimulation for neuropathic pain; H215O PET study

Spinal cord stimulation (SCS) is an effective therapy for chronic neuropathic pain. However, the detailed mechanisms underlying its effects are not well understood. Positron emission tomography (PET) with H(2)(15)O was applied to clarify these mechanisms. Nine patients with intractable neuropathic pain in the lower limbs were included in the study. All patients underwent SCS therapy for intractable pain, which was due to failed back surgery syndrome in three patients, complex regional pain syndrome in two, cerebral hemorrhage in two, spinal infarction in one, and spinal cord injury in one. Regional cerebral blood flow (rCBF) was measured by H(2)(15)O PET before and after SCS. The images were analyzed with statistical parametric mapping software (SPM2). SCS reduced pain; visual analog scale values for pain decreased from 76.1+/-25.2 before SCS to 40.6+/-4.5 after SCS (mean+/-SE). Significant rCBF increases were identified after SCS in the thalamus contralateral to the painful limb and in the bilateral parietal association area. The anterior cingulate cortex (ACC) and prefrontal areas were also activated after SCS. These results suggest that SCS modulates supraspinal neuronal activities. The contralateral thalamus and parietal association area would regulate the pain threshold. The ACC and prefrontal areas would control the emotional aspects of intractable pain, resulting in the reduction of neuropathic pain after SCS.

Validity and Reliability of the Japanese Version of the painDETECT Questionnaire: A Multicenter Observational Study

Objectives The aim of this study was to evaluate the validity and reliability of the Japanese version of the painDETECT questionnaire (PDQ-J). Materials and Methods The translation of the original PDQ into Japanese was achieved according to the published guidelines. Subsequently, a multicenter observational study was performed to evaluate the validity and reliability of PDQ-J, including 113 Japanese patients suffering from pain. Results Factor analysis revealed that the main component of PDQ-J comprises two determinative factors, which account for 62% of the variance observed. Moreover, PDQ-J revealed statistically significant correlation with the intensity of pain (Numerical Rating Scale), Physical Component Score, and Mental Component Score of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). The Cronbach alpha for the total score was 0.78 and for the main component was 0.80. In the analysis of test–retest method, the intraclass correlation coefficient between the two scores was 0.94. Conclusions We demonstrated the validity and reliability of PDQ-J. We encourage researchers and clinicians to use this tool for the assessment of patients who suffer suspected neuropathic pain.

Relationship between health literacy, health information access, health behavior, and health status in Japanese people

OBJECTIVE To examine the relationship between health literacy (HL), health information access, health behavior, and health status in Japanese people. METHODS A questionnaire survey was conducted at six healthcare facilities in Japan. Eligible respondents aged 20-64 years (n=1218) were included. Path analysis with structural equation modeling was performed to test the hypothesis model linking HL to health information access, health behavior, and health status. RESULTS The acceptable fitting model indicated that the pathways linking HL to health status consisted of two indirect paths; one intermediated by health information access and another intermediated by health behavior. Those with higher HL as measured by the 14-item Health Literacy Scale (HLS-14) were significantly more likely to get sufficient health information from multiple sources, less likely to have risky habits of smoking, regular drinking, and lack of exercise, and in turn, more likely to report good self-rated health. CONCLUSION HL was significantly associated with health information access and health behavior in Japanese people. HL may play a key role in health promotion, even in highly educated countries like Japan. PRACTICE IMPLICATIONS In order to enhance the effects of health promotion interventions, health professionals should aim at raising HL levels of their target population groups.

Development of comprehensive diagnostic criteria for complex regional pain syndrome in the Japanese population

&NA; Complex regional pain syndrome (CRPS) is a syndrome that describes a broad spectrum of sensory, motor and autonomic‐like features with unproven etiology. The International Association for the Study of Pain (IASP) diagnostic criteria of CRPS shows high sensitivity but poor specificity. Using statistical‐pattern‐recognition methods, American researchers have suggested a new set of criteria offering acceptable sensitivity and high specificity. However, non‐American CRPS patients present distinct subsets of CRPS‐related signs/symptoms from those of American patients. Here, we followed a series of American studies to develop a set of CRPS diagnostic criteria that would be most suitable for the Japanese population. A standardized sign/symptom checklist was used in patient evaluations to obtain data on CRPS‐related signs/symptoms in 195 participants meeting the IASP criteria. Using factor analysis, we grouped CRPS‐related signs/symptoms into five distinct subgroups (trophic change, motor dysfunction, abnormal pain processing, asymmetric sudomotor activity and asymmetric edema). Discriminant function analysis of these subgroups, regarding their ability to discriminate between CRPS and non‐CRPS etiology, indicated that modifying the IASP criteria could increase clinical diagnostic accuracy in the Japanese population. Our diagnostic criteria are not exactly the same as the American criteria, indicating a need for more regionally based CRPS diagnostic criteria. Different sets of CRPS diagnostic criteria could lead to dissimilar patients being diagnosed as CRPS, however, presenting problems for translation of therapeutic effects found in various studies. Therefore, we further recognize a need for a global set of common CRPS diagnostic criteria.

Development of an android robot for psychological support in medical and welfare fields

In this paper, we report an android robot system to support medical and welfare fields using communication, and a demonstration experiment using this system at a pain clinic. An android which consist of the system is Actroid-F very similar to real female and can exhibit various facial expressions such as smile, anger and surprise. Since the android and an air-servo control system are light, compact and noiseless, it is easy to introduce them into the medical and welfare fields. The android system has various operation methods. For example, the android can be controlled based on target persons head and facial motion captured by a camera. Using this system, we examined patients impressions for the android which nod and smile at patients in a medical examination room as a bystander at a pain clinic. As a result, it was revealed that about 30% of 70 patients preferred the presence of the android, and about 80% had no aversion. Elderly patients showed to have positive impressions for the android. Female patients tended to have more positive impressions compared to male. These results show the potentiality of the android in a medical examination room.

Validity and Reliability of the Japanese Version of the Newest Vital Sign: A Preliminary Study

Health literacy (HL) refers to the ability to obtain, process, and understand basic health information and services, and is thus needed to make appropriate health decisions. The Newest Vital Sign (NVS) is comprised of 6 questions about an ice cream nutrition label and assesses HL numeracy skills. We developed a Japanese version of the NVS (NVS-J) and evaluated the validity and reliability of the NVS-J in patients with chronic pain. The translation of the original NVS into Japanese was achieved as per the published guidelines. An observational study was subsequently performed to evaluate the validity and reliability of the NVS-J in 43 Japanese patients suffering from chronic pain. Factor analysis with promax rotation, using the Kaiser criterion (eigenvalues ≥1.0), and a scree plot revealed that the main component of the NVS-J consists of three determinative factors, and each factor consists of two NVS-J items. The criterion-related validity of the total NVS-J score was significantly correlated with the total score of Ishikawa et al.s self-rated HL Questionnaire, the clinical global assessment of comprehensive HL level, cognitive function, and the Brinkman index. In addition, Cronbachs coefficient for the total score of the NVS-J was adequate (alpha = 0.72). This study demonstrated that the NVS-J has good validity and reliability. Further, the NVS-J consists of three determinative factors: “basic numeracy ability,” “complex numeracy ability,” and “serious-minded ability.” These three HL abilities comprise a 3-step hierarchical structure. Adequate HL should be promoted in chronic pain patients to enable coping, improve functioning, and increase activities of daily living (ADLs) and quality of life (QOL).

Using the intact hand for objective assessment of phantom hand‐perception

After amputation, most patients experience a phenomenon known as a phantom limb (PL). A variety of PL experiences appear to be associated with neural plasticity within the CNS. However, due to the subjective nature of PL experiences, there was no definitive way to reliably assess PL experiences other than using patients’ direct reports. Here, we were able to obtain patients’ indirect responses to PL experiences, for a more objective evaluation. First, we conducted a study with normals and 17 non‐PL patients experiencing pathological pain in one hand. We took digital photographs of their affected and unaffected hands, altered the sizes of the images digitally, and then asked each subject to choose the image that most closely matched the actual size of their own hands (from a series of images presented on a video screen). Subjective size perceptions of the hands were homologous, regardless of the pathological condition of one hand (p < 0.0001, Spearman R2= 0.82). Next, we used the same method for total 19 patients with a phantom hand. The intact hand‐size perception was linearly correlated with phantom hand‐size perception (weighted linear regression analysis: p < 0.0001, R2 = 0.75, adjusted R2 = 0.73, F‐value = 50.1, degree of freedom = 18). Thus, without requiring a subjective description about PL, the patients’ evaluation of the intact hand‐size precisely but indirectly indicated whether the PL was perceived to be telescoped (shrunken), normal or enlarged. This more objective evaluation of PL phenomena could become a key tool for disentangling the neural mechanisms involved.

Novel 3-dimensional motion analysis method for measuring the lumbar spine range of motion: repeatability and reliability compared with an electrogoniometer.

Study Design. Repeatability and reliability for measuring methods for real-time lumbar range of motion. Objective. We established a novel set of marker positions for 3-dimensional motion analysis (VICON system) to determine lumbar spine range of motion (LROM) and lumbar motion precisely; we compared the repeatability and reliability of VICON system with those of an electrogoniometer. Summary of Background Data. The assessment of the LROM using x-ray is still one of the most precise methods, despite the radiation exposure. To avoid this, alternative methods, such as the VICON system and electrogoniometer, have been widely used. No study has reported the repeatability and reliability of LROM measurements using a VICON system and electrogoniometer. Methods. The VICON system and electrogoniometer measured LROM and lumbar motion in 7 healthy males during 7 days. Differences between both systems were analyzed using Bland-Altman plots. Repeatability and reliability of the LROM measurements was assessed using coefficients of multiple correlations and intraclass correlation coefficients, respectively. Standard error of measurement was calculated to quantify the systematic error in LROM measurements. Results. The mean maximum LROM values using the VICON system/electrogoniometer were 42°/52° for flexion, 17°/24° for extension, 16°/16° for lateral bending, and 8°/2° for axial rotation, respectively. Between VICON system and the electrogoniometer, Bland-Altman plots revealed no discrepancies in LROM values except for flexion. Coefficients of multiple correlations for LROM showed excellent repeatability. LROM measurements with VICON system showed excellent reliability for flexion and extension and fair-to-good reliability for other motions. LROM measurements with the electrogoniometer showed excellent reliability for flexion and fair-to-good reliability for other motions. Except for axial rotation, maximum intraclass correlation coefficients using VICON system were more reliable than the electrogoniometer for measuring lumbar motion. Conclusion. VICON system with our novel marker set allows practical and reliable longitudinal assessment of dynamic LROM. Level of Evidence: N/A