Wakaizumi, Kenta



School of Medicine, Department of Anesthesiology (Shinanomachi)




Papers 【 Display / hide

  • Psychosocial, Functional, and Emotional Correlates of Long-Term Opioid Use in Patients with Chronic Back Pain: A Cross-Sectional Case–Control Study

    Wakaizumi K., Vigotsky A.D., Jabakhanji R., Abdallah M., Barroso J., Schnitzer T.J., Apkarian A.V., Baliki M.N.

    Pain and Therapy (Pain and Therapy)  10 ( 1 ) 691 - 709 2021.06

    ISSN  21938237

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    Introduction: The opiate epidemic has severe medical and social consequences. Opioids are commonly prescribed in patients with chronic pain, and are a main contributor to the opiate epidemic. The adverse effects of long-term opioid usage have been studied primarily in dependence/addiction disorders, but not in chronic pain. Here, we examine the added iatrogenic effects, psychology, and brain morphology of long-term opioid use in matched patients with chronic pain with and without opioid use (case–controlled design). Methods: We compared psychosocial, functional, and psychological measures between patients with chronic back pain (CBP) who were managing their pain with or without opioids, thereby controlling for the effect of pain on these outcomes. In addition, we investigated brain morphological differences associated with long-term opioid usage. We recruited 58 patients with CBP, 29 of them on long-term opioids and 29 who did not use opioids, and who were matched in terms of age, sex, pain intensity, and pain duration. Questionnaires were used to assess pain quality, pain psychology, negative and positive emotions, physical, cognitive, sensory, and motor functions, quality of life, and personality traits. Results: Patients with CBP on opioids displayed more negative emotion, poorer physical function, and more pain interference (p < 0.001), whereas there were no statistical differences in cognitive and motor functions and personality traits. Voxel-based morphometry using structural brain imaging data identified decreased gray matter density of the dorsal paracingulate cortex (family-wise error-corrected p < 0.05) in patients with opioids, which was associated with negative emotion (p = 0.03). Finally, a volumetric analysis of hippocampal subfields identified lower volume of the left presubiculum in patients on opioids (p < 0.001). Conclusion: Long-term opioid use in chronic pain is associated with adverse negative emotion and disabilities, as well as decreased gray matter volumes of specific brain regions.

  • Association of work performance and interoceptive awareness of 'body trusting' in an occupational setting: A cross-sectional study

    Tanaka C., Wakaizumi K., Kosugi S., Tanaka S., Matsudaira K., Morisaki H., Mimura M., Fujisawa D.

    BMJ Open (BMJ Open)  11 ( 5 )  2021.05

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    Objectives Work performance has been known to be influenced by both psychological stress (mind) and physical conditions (body). The aim of this study was to investigate the association between work performance and 'body trusting', which is a dimension of interoceptive awareness representing mind-body interactions. Methods A cross-sectional study was conducted among a sample of workers in an industrial manufacturing company in Japan. Participants were assessed with a self-reported questionnaire including evaluations of work performance, body trusting, psychological distress, pain persistence, workplace and home stressors, and workaholism. Participants' sociodemographic, health and lifestyle characteristics were collected from their annual health check data. The association between work performance and body trusting was examined using multivariable regression analyses in the overall sample and in a subsample of people with pain. Results A total of 349 workers participated in the study. A significant association between work performance and body trusting was observed, with higher body trusting representing higher work performance. The association was significant after controlling for psychological distress, workplace and home stress, workaholism and participants' characteristics (p<0.001). Compared with people without pain (n=126, 36.1%), people with pain (n=223, 63.9%) showed less body trusting, which was associated with decreased work performance after controlling for pain-related variables (p<0.001). Conclusions Workers with higher body trusting showed higher work performance, even after controlling for various influencing factors. Body trusting may be an important target to promote work performance and to prevent loss of performance induced by health problems.

  • Antenatal pain, intimate partner violence, and maternal bonding disorder: data from the Japan Environment and Children's Study

    Yamada K., Kimura T., Cui M., Kubota Y., Tanaka E., Wakaizumi K., Ikehara S., Kimura T., Iso H.

    Pain (Pain)  162 ( 3 ) 749 - 759 2021.03

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    ABSTRACT: This prospective study examined (1) whether antenatal pain is associated with postnatal maternal bonding disorder (MBD) through postnatal depression and (2) whether intimate partner violence (IPV) has a moderating effect on the association between antenatal pain and postnatal MBD. We analyzed 77,326 pregnancies of women who completed self-report questionnaires including the SF-8 bodily pain item, the Edinburgh Postnatal Depression Scale, the Mother-to-Infant Bonding Scale, and an assessment of IPV. We conducted a mediation analysis to assess whether postnatal depression mediated the association between antenatal pain and MBD 1 year after delivery. A moderated mediation model was used to examine the conditional effect of IPV during pregnancy on the association between antenatal pain and postnatal MBD, operating through postnatal depression. All analyses were adjusted for demographic factors, socioeconomic factors, perinatal and infant factors, medical history, and psychological status. Of the 77,326 pregnancies, 5420 (7.0%) were characterized by persistent moderate-to-severe pain. The total effect of antenatal pain on MBD was significant (standardized path coefficient = 0.06, 95% confidence interval, 0.05-0.06) and postnatal depression dominantly mediated the association between antenatal pain and postnatal MBD (70.8% mediation). Contrary to our hypothesis, IPV during pregnancy did not moderate the association between antenatal pain and postnatal MBD. However, IPV during pregnancy did have independent negative effects on both postnatal depression and MBD. Our findings suggest that antenatal pain and postnatal depression should be assessed and treated with consideration of the presence of IPV during pregnancy to better monitor and prevent the development of MBD.

  • Reorganization of functional brain network architecture in chronic osteoarthritis pain

    Barroso J., Wakaizumi K., Reis A.M., Baliki M., Schnitzer T.J., Galhardo V., Apkarian A.V.

    Human Brain Mapping (Human Brain Mapping)  42 ( 4 ) 1206 - 1222 2021.03

    ISSN  10659471

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    Osteoarthritis (OA) manifests with chronic pain, motor impairment, and proprioceptive changes. However, the role of the brain in the disease is largely unknown. Here, we studied brain networks using the mathematical properties of graphs in a large sample of knee and hip OA (KOA, n = 91; HOA, n = 23) patients. We used a robust validation strategy by subdividing the KOA data into discovery and testing groups and tested the generalizability of our findings in HOA. Despite brain global topological properties being conserved in OA, we show there is a network wide pattern of reorganization that can be captured at the subject-level by a single measure, the hub disruption index. We localized reorganization patterns and uncovered a shift in the hierarchy of network hubs in OA: primary sensory and motor regions and parahippocampal gyrus behave as hubs and insular cortex loses its central placement. At an intermediate level of network structure, frontoparietal and cingulo-opercular modules showed preferential reorganization. We examined the association between network properties and clinical correlates: global disruption indices and isolated degree properties did not reflect clinical parameters; however, by modeling whole brain nodal degree properties, we identified a distributed set of regions that reliably predicted pain intensity in KOA and generalized to hip OA. Together, our findings reveal that while conserving global topological properties, brain network architecture reorganizes in OA, at both global and local scale. Network connectivity related to OA pain intensity is dissociated from the major hub disruptions, challenging the extent of dependence of OA pain on nociceptive signaling.

  • Pain medications during pregnancy: data from the Japan environment and children’s study

    Yamada K., Kimura T., Ikehara S., Cui M., Kubota Y., Wakaizumi K., Takeda T., Iso H.

    Journal of Anesthesia (Journal of Anesthesia)  34 ( 2 ) 202 - 210 2020.04

    ISSN  09138668

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    Purpose: Analgesic medication epidemic during pregnancy is an important issue in Western countries. However, no large epidemiological study involving pregnant women with pain and their medication use has been conducted in Japan. This study examined the current situation of medication use for non-cancer pain during the perinatal period in Japan using national cohort data. Methods: We analyzed 94,649 pregnant women who completed a self-report questionnaire investigating bodily pain and an interview-based medication use survey. Medication use before and during pregnancy and new medication administration/discontinuation during pregnancy were compared between women with and without pain during pregnancy using multivariable covariance analysis. Results: Mild pain was reported by 50.4% of pregnant women in the first trimester (survey 1) and 61.8% in the second/third trimester (survey 2). Moderate-to-severe pain was reported by 15.4% of women in survey 1 and 22.4% in survey 2. In survey 1, 6.2% of women used prescribed analgesics and 1.6% used over-the-counter analgesics. In survey 2, prescribed and over the counter analgesics were used by 12.2% and 0.8% of women, respectively. Other pain-related medications were rarely used (< 1.0%). Pregnant women with moderate-to-severe pain showed a lower proportion of discontinuation of analgesics and a higher proportion of new administration of prescription and transdermal analgesics compared with those without pain. Conclusions: Although a large proportion of pregnant women experience pain, medication use for pain during pregnancy is low in Japan compared with Western countries (50–60%). Adequate treatment or support may be necessary for pregnant women experiencing pain in Japan.

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Reviews, Commentaries, etc. 【 Display / hide

Research Projects of Competitive Funds, etc. 【 Display / hide

  • Development of Japanese version of the multidimensional evaluation scale for patient impression change for non-cancer pain


    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Early-Career Scientists , Principal investigator