Faculty Profiles - NAKASHIMA Hiroaki

Activities of daily living, behavioral and psychological symptoms of dementia, and cognitive and physical function according to thyroid function in Alzheimer's disease

Fujisawa, C; Fujisawa, H; Matsui, Y; Sugimoto, T; Minakami, M; Watanabe, K; Yamada, Y; Nakashima, H; Komiya, H; Sugimura, Y; Umegaki, H; Sakurai, T

JOURNAL OF ALZHEIMERS DISEASE page： 13872877261424207 2026.2

Verifying Family Authenticity in End-of-Life Care: A Case of Religious Refusal and Ethical Dilemma in an Older Adult With Dementia Open Access

Fujisawa, C; Mizuno, T; Tajima, T; Yamada, Y; Watanabe, K; Nakashima, H; Komiya, H; Umegaki, H

GERIATRICS & GERONTOLOGY INTERNATIONAL Vol. 26 ( 2 ) page： e70387 2026.2

Clinical Outcomes of Patients Who Underwent Palliative Surgery for Spinal Metastases With and Without a History of Radiation: A Multicenter Registry Study Open Access

Kawamura, I; Tominaga, H; Shimada, H; Sasaki, H; Taniguchi, N; Shiratani, Y; Suzuki, A; Terai, H; Shimizu, T; Kakutani, K; Kanda, Y; Ishihara, M; Paku, M; Takahashi, Y; Funayama, T; Miura, K; Shirasawa, E; Inoue, H; Kimura, A; Iimura, T; Moridaira, H; Nakajima, H; Watanabe, S; Akeda, K; Takegami, N; Nakanishi, K; Sawada, H; Matsumoto, K; Funaba, M; Suzuki, H; Funao, H; Oshigiri, T; Hirai, T; Otsuki, B; Kobayakawa, K; Uotani, K; Manabe, H; Tanishima, S; Hashimoto, K; Iwai, C; Yamabe, D; Hiyama, A; Seki, S; Goto, Y; Miyazaki, M; Watanabe, K; Nakamae, T; Kaito, T; Nakashima, H; Nagoshi, N; Kato, S; Imagama, S; Watanabe, K; Inoue, G; Furuya, T

GLOBAL SPINE JOURNAL page： 21925682261426935 2026.2

Language：English Publisher：Global Spine Journal

Study Design: A multicenter retrospective cohort study using prospectively collected data. Objectives: Radiotherapy (RT) is the standard treatment for spinal metastases; however, the optimal timing of RT in patients requiring surgery remains unclear. This study compared the clinical outcomes of palliative surgery according to RT timing. Methods: Among 413 patients screened across 35 centers, 146 patients with spinal metastases limited to the spine who underwent palliative surgery were included. Patients were classified into three groups based on RT timing: preoperative RT, postoperative RT, and no RT. Short-term outcomes were compared among the three groups. Results: Of the 146 patients (preoperative RT: n = 42; postoperative RT: n = 59; no RT: n = 45), baseline characteristics and postoperative functional outcomes were comparable between the postoperative RT and no RT groups. Preoperative opioid use was significantly more frequent in the preoperative RT group. Postoperative complications were more common in the preoperative RT group. Functional outcomes improved in all groups; however, greater improvements in pain and numbness were observed in the nonpreoperative RT group than in the preoperative RT group, with a significant difference noted in numbness improvement. Conclusions: Postoperative recovery after palliative surgery was largely comparable among the three groups. Although greater improvements in pain and numbness were observed in patients who did not receive preoperative RT, the clinical impact of preoperative RT in patients with mechanical instability remains uncertain. Postoperative wound complications were more frequent in the preoperative RT group, but these findings should be interpreted with cautiously given the limited number of events.

DOI： 10.1177/21925682261426935

Changes in Performance Status and Predictive Factors for Poor Improvement Following Surgery for Spinal Metastasis: A Nationwide Multicenter Prospective Cohort Study. International journal

Akinobu Suzuki, Koji Tamai, Shinji Takahashi, Masayoshi Iwamae, Hiroshi Taniwaki, Yuki Shiratani, Takaki Shimizu, Kenichiro Kakutani, Yutaro Kanda, Hiroyuki Tominaga, Ichiro Kawamura, Masayuki Ishihara, Masaaki Paku, Yohei Takahashi, Toru Funayama, Kousei Miura, Eiki Shirasawa, Hirokazu Inoue, Atsushi Kimura, Takuya Iimura, Hiroshi Moridaira, Hideaki Nakajima, Shuji Watanabe, Koji Akeda, Norihiko Takegami, Kazuo Nakanishi, Hirokatsu Sawada, Koji Matsumoto, Masahiro Funaba, Hidenori Suzuki, Haruki Funao, Tsutomu Oshigiri, Takashi Hirai, Bungo Otsuki, Kazu Kobayakawa, Koji Uotani, Hiroaki Manabe, Shinji Tanishima, Ko Hashimoto, Chizuo Iwai, Daisuke Yamabe, Akihiko Hiyama, Shoji Seki, Yuta Goto, Masashi Miyazaki, Kazuyuki Watanabe, Toshio Nakamae, Takashi Kaito, Hiroaki Nakashima, Narihito Nagoshi, Satoshi Kato, Shiro Imagama, Kota Watanabe, Gen Inoue, Takeo Furuya

The spine journal : official journal of the North American Spine Society Vol. 26 ( 2 ) page： 386 - 399 2026.2

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND CONTEXT: Spinal metastasis affects the activities of daily living (ADL) of patients, and spinal surgery is aimed at improving or maintaining ADL. The Eastern Cooperative Oncology Group Performance status (ECOG-PS) is a measure of ADL, and its change after surgery can influence decisions regarding cancer treatment options. However, few detailed, large-scale studies have examined changes in ECOG-PS after surgery for spinal metastases. PURPOSE: (1) To investigate the effects of spinal surgery for metastatic spinal tumors on ECOG-PS, and (2) To identify the risk factors for poor postoperative improvement. STUDY DESIGN: Prospective multicenter cohort study PATIENT SAMPLE: Four hundred and four symptomatic patients who underwent surgical treatment for metastatic spinal tumors. OUTCOME MEASURES: ECOG-PS was designated as the primary outcome and Barthel Index (BI) as the secondary outcome. Both were assessed preoperatively and at 1 and 6 months post-surgery. METHODS: Changes in ECOG-PS and BI were analyzed using the Friedman test or a general mixed-effect model. Poor outcomes were defined as a ECOG-PS score of 3, 4, or death. Preoperative factors associated with poor outcomes were analyzed using multivariate logistic regression analyses with complete or multiple imputed datasets. RESULTS: Preoperative ECOG-PS and BI scores improved at 1 and 6 months postoperatively. Patients with a ECOG-PS score of ≤2 at 1 month had significantly higher rates of receiving systemic therapy than those with a ECOG-PS score of ≥3. No use of bone-modifying agents, Frankel grade ≥ C, ECOG-PS score of ≥ 3, or a high C-reactive protein/albumin ratio (CAR) were the preoperative factors associated with poor PS at 1 month, whereas history of systemic therapy, ECOG-PS score of ≥ 3, primary tumor type, anemia, and high CAR were the preoperative factors associated with poor ECOG-PS at 6 months. CONCLUSION: Spinal surgery can improve ADL in patients with spinal metastases; however, not all patients experience favorable outcomes. The present findings indicate that the preoperative severity of paralysis and ADL impairment, laboratory data, and treatment history are important for predicting ADL after surgery for spinal metastasis.

DOI： 10.1016/j.spinee.2025.10.028

Impact of postoperative C5 palsy on quality of life in patients with cervical ossification of the posterior longitudinal ligament: a prospective study. International journal

Naoki Segi, Hiroaki Nakashima, Shiro Imagama, Satoru Egawa, Kenichiro Sakai, Kazuo Kusano, Shunji Tsutsui, Takashi Hirai, Yu Matsukura, Kanichiro Wada, Keiichi Katsumi, Masao Koda, Atsushi Kimura, Takeo Furuya, Satoshi Maki, Narihito Nagoshi, Norihiro Nishida, Yukitaka Nagamoto, Yasushi Oshima, Sadayuki Ito, Tsutomu Endo, Kanji Mori, Hideaki Nakajima, Kazuma Murata, Masayuki Miyagi, Takashi Kaito, Kei Yamada, Tomohiro Banno, Satoshi Kato, Tetsuro Ohba, Masahiko Takahata, Hiroshi Moridaira, Bungo Otsuki, Hiroyuki Katoh, Haruo Kanno, Hiroshi Taneichi, Yoshiharu Kawaguchi, Katsushi Takeshita, Masaya Nakamura, Masashi Yamazaki, Toshitaka Yoshii

Journal of neurosurgery. Spine Vol. 44 ( 2 ) page： 253 - 261 2026.2

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: The impact of C5 palsy on quality of life (QOL) and its relationship with recovery and overall well-being remain poorly understood. In this study, the authors aimed to examine the effects of postoperative C5 palsy on upper extremity function and QOL in patients undergoing cervical ossification of the posterior longitudinal ligament (C-OPLL) surgery, using both objective clinical assessments and patient-reported outcome measures (PROMs). Additionally, this study aimed to explore the correlation between residual C5 palsy and QOL over a 2-year period. METHODS: This retrospective study, using a prospective multicenter database, included 478 patients with myelopathy caused by C-OPLL, treated between 2014 and 2018, with a 2-year follow-up. Thirty-one patients developed postoperative C5 palsy (C5 palsy group), and their outcomes were compared to those of 389 patients without C5 palsy (non-C5 palsy group) using propensity score matching. Within the C5 palsy group, patients were further classified based on their recovery status at 1 year postoperatively. Neurological status was assessed using the Japanese Orthopaedic Association (JOA) score, while PROMs were evaluated using the JOA Cervical Myelopathy Evaluation Questionnaire, which assesses cervical and upper extremity function, bladder function, and overall QOL. Assessments were conducted at 6 months, 1 year, and 2 years postoperatively. RESULTS: C5 palsy occurred in 7.4% of patients, with 61.3% achieving full recovery within 1 year. Patients in the C5 palsy group had significantly poorer upper extremity function and shoulder motor scores than those in the non-C5 palsy group at all postoperative time points. However, no significant differences were observed between the groups in QOL, cervical function, lower extremity function, or bladder function. In contrast, patients with residual C5 palsy had worse QOL as well as upper extremity function compared to patients with recovered C5 palsy. CONCLUSIONS: While postoperative C5 palsy continues to affect motor and upper extremity function beyond 1 year, QOL scores were not significantly lower in the C5 palsy group. However, the impact on QOL in patients with residual C5 palsy may continue to slightly improve over time.

DOI： 10.3171/2025.6.SPINE25368

The decline in cognitive function with age and its changes over time in cognitively normal older adults

Matsui, Y; Fujisawa, C; Minakami, M; Yamada, Y; Watanabe, K; Nakashima, H; Komiya, H; Umegaki, H

EUROPEAN GERIATRIC MEDICINE Vol. 17 ( 1 ) page： 299 - 308 2026.2

Language：English Publisher：European Geriatric Medicine

Aim: The patterns of age-related cognitive decline among cognitively normal older adults and how their cognitive function has changed over the past decade remain unclear. Findings: Attention, processing speed, and working/executive function indices exhibited significant declines beginning in the early 70 s, earlier than in other cognitive domains. A longitudinal analysis from 2013 to 2022 revealed a decline in cognitive trajectories among older adults classified as cognitively normal in certain domains. Message: Even after receiving a classification of normal cognition, individuals in their early 70 s may exhibit cognitive declines in attention, processing speed, and executive/working memory, indicating a need for domain-specific interventions. Cognitively normal older adults may experience cognitive decline over time, suggesting that a classification of “normal” cognition does not guarantee stability and that social and medical interventions may still be necessary.

DOI： 10.1007/s41999-025-01377-8

Prognostic scoring systems reflect the prognosis of patients with metastatic spinal tumors who underwent spinal surgery in recent cases: JASA multicenter prospective study.

特集 AI時代の脊椎脊髄画像診断脊髄腫瘍自動診断

伊藤定之, 中島宏彰, 世木直喜, 大内田隼, 小田昌宏, 今釜史郎

脊椎脊髄ジャーナル Vol. 39 ( 1 ) page： 37 - 42 2026.1

Iinuma M, Furuya T, Shiratani Y, Suzuki A, Terai H, Shimizu T, Kakutani K, Kanda Y, Tominaga H, Kawamura I, Ishihara M, Paku M, Takahashi Y, Funayama T, Miura K, Shirasawa E, Inoue H, Kimura A, Iimura T, Moridaira H, Nakajima H, Watanabe S, Akeda K, Takagami N, Nakanishi K, Sawada H, Matsumoto K, Funaba M, Suzuki H, Funao H, Oshigiri T, Hirai T, Otsuki B, Kobayakawa K, Uotani K, Manabe H, Tanishima S, Hashimoto K, Iwai C, Yamabe D, Hiyama A, Seki S, Goto Y, Miyazaki M, Watanabe K, Nakamae T, Kaito T, Nakashima H, Nagoshi N, Kato S, Imagama S, Watanabe K, Inoue G, Ohtori S, Niki H

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2026.1

Language：English Publisher：Journal of Orthopaedic Science

Background: The incidence of cancer and related deaths has increased substantially, with bone commonly serving as a metastatic site. Metastatic spinal tumors severely impair quality of life and activities of daily living. Prognostic scoring systems such as the revised Tokuhashi and Tomita scores are widely used in surgical decision-making for these tumors. However, their accuracy for recent cancer cases is unclear due to advances in cancer therapy. Methods: This multicenter, prospective study by the Japan Association of Spine Surgeons with Ambition analyzed 413 surgical cases for metastatic spinal tumors from October 2018 to March 2021. Of these, 272 cases with complete data were included. The Kaplan–Meier method, log-rank test, and statistical analysis were used to assess the association between survival and prognostic scores. Results: Both the revised Tokuhashi and Tomita scores significantly stratified patients by survival (P < 0.01). The revised Tokuhashi score accurately predicted survival in 60.3 % of patients, underestimated it in 33.1 %, and overestimated it in 6.6 %. Significant score differences were found among groups with different survival durations. However, differentiating between <6-month and 6–12-month survival periods was difficult. Conclusions: The revised Tokuhashi and Tomita scores remain valid tools for predicting prognosis in patients undergoing surgery for metastatic spinal tumors. Nonetheless, these systems tend to underestimate survival in recent cases, particularly in short-term prognoses. Updating the scoring criteria may be necessary to reflect advancements in cancer therapy and extended patient survival.

DOI： 10.1016/j.jos.2026.01.003

Preoperative Hounsfield Units are Associated with Longitudinal Changes in Spinopelvic Parameters after Adult Spinal Deformity Surgery in Middle-Aged and Older Adults -a Multicenter Study of Spinal Deformity in Adults (NSGad study)

Oishi Ryotaro, Nakashima Hiroaki, Ito Sadayuki, Segi Naoki, Ouchida Jun, Yamauchi Ippei, Miyairi Yuichi, Morita Yoshinori, Kanemura Tokumi, Ohara Tetsuya, Tsuji Taichi, Shinjo Ryuichi, Imagama Shiro

Journal of Spine Research Vol. 17 ( 1 ) page： 2 - 9 2026.1

Language：Japanese Publisher：The Japanese Society for Spine Surgery and Related Research

Introduction: Osteoporosis is known to be a risk for loss of correction in corrective surgery for adult spinal deformity (ASD), but it is unclear whether the presence or absence of osteoporosis as assessed by the lumbar spine Hounsfield Units (HU) on preoperative computed tomography makes a difference in longitudinal changes of postoperative spinal alignment after ASD. In this study, we investigated the association between preoperative HU and changes over time in spinopelvic parameters after ASD surgery.Methods: A total of 126 patients aged 65 years or older who had undergone lumbar fusion of three or more vertebrae for ASD and were followed up for at least 2 years after surgery were included in the study. They were divided into two groups: one with pelvic fusion (LPF group) and one without pelvic fusion (LF group). On the basis of previous reports, we used HU135 as the cutoff, divided the osteoporosis group (OP group) with HU less than 135 and the healthy group (N group) with HU greater than 135, and compared spinopelvic parameters immediately after surgery and at 2 years postoperatively.Results: Lumbar lordosis (LL) significantly decreased, and pelvic incidence (PI)-LL and sagittal vertical axis (SVA) increased in the LPF-OP group at 2 years postoperatively, and thoracis kyphosis, pelvic tilt, PI-LL, and SVA increased significantly in the LPF-N group at 2 years postoperatively. PI-LL significantly increased 2 years postoperatively in the LF-OP group, whereas no significant alignment change was observed in the LF-N group.Conclusions: Preoperative HU are associated with longitudinal changes in spinopelvic parameters after ASD surgery, suggesting that HU evaluation may be useful in preoperative planning for corrective surgery for ASD.

DOI： 10.34371/jspineres.2024-0034

CiNii Research

Machine Learning-Based Prognostic Scoring for Spinal Metastases: A JASA Multicenter Prospective Study Integrating Modern Oncologic Advances. International journal

Sadayuki Ito, Hiroaki Nakashima, Naoki Segi, Jun Ouchida, Yuki Shiratani, Akinobu Suzuki, Hidetomi Terai, Takaki Shimizu, Kenichiro Kakutani, Yutaro Kanda, Hiroyuki Tominaga, Ichiro Kawamura, Masayuki Ishihara, Masaaki Paku, Yohei Takahashi, Toru Funayama, Kousei Miura, Eiki Shirasawa, Hirokazu Inoue, Atsushi Kimura, Takuya Iimura, Hiroshi Moridaira, Hideaki Nakajima, Shuji Watanabe, Koji Akeda, Norihiko Takegami, Kazuo Nakanishi, Hirokatsu Sawada, Koji Matsumoto, Masahiro Funaba, Hidenori Suzuki, Haruki Funao, Tsutomu Oshigiri, Takashi Hirai, Bungo Otsuki, Kazu Kobayakawa, Koji Uotani, Hiroaki Manabe, Shinji Tanishima, Ko Hashimoto, Chizuo Iwai, Daisuke Yamabe, Akihiko Hiyama, Shoji Seki, Yuta Goto, Masashi Miyazaki, Kazuyuki Watanabe, Toshio Nakamae, Takashi Kaito, Narihito Nagoshi, Satoshi Kato, Kota Watanabe, Shiro Imagama, Gen Inoue, Takeo Furuya

Spine 2026.1

Language：English Publishing type：Research paper (scientific journal)

STUDY DESIGN: Large multicenter prospective study. OBJECTIVE: We aimed to develop and validate a novel machine learning-based prognostic scoring system for spinal metastases. SUMMARY OF BACKGROUND DATA: Spinal metastases, common complications in patients with advanced cancer, significantly affect neurological function, pain, and quality of life. Although surgery plays a crucial role in selected cases, the accurate prediction of patient prognosis remains challenging. Traditional scoring systems, developed for older treatment paradigms, do not fully reflect the impact of modern oncologic therapies. METHODS: This multicenter prospective study, conducted by the Japan Association of Spine Surgeons with Ambition, included 401 patients who underwent surgery for spinal metastases at 35 medical centers between 2018 and 2021. Patient demographics, tumor burden, performance status, and treatment history data were collected. Least Absolute Shrinkage and Selection Operator (LASSO) logistic regression was used to identify significant predictors of one-year survival, followed by stepwise variable selection. The model performance was assessed using the area under the receiver operating characteristic curve (AUROC) and calibration plots. RESULTS: Among the 401 patients, 67.1% survived for one year, whereas 32.9% did not. Survivors had better performance status, lower tumor burden, and lower opioid use than non-survivors. LASSO regression identified five key predictors of one-year survival: age ≥75 years, poor performance status (≥3), presence of other bone metastases, preoperative opioid use, and lower preoperative Vitality Index. The final model demonstrated a strong predictive performance (AUROC=0.762). Based on the key prognostic factors, a simplified risk stratification system was developed to classify patients into low- (one-year survival 82.2%), intermediate- (67.2%), and high-risk (34.2%) groups. CONCLUSION: We developed a clinically applicable prognostic scoring system for patients with spinal metastases using machine learning techniques to enhance predictive accuracy. This model provides a practical risk assessment tool to aid surgical decision-making and optimize postoperative management. LEVEL OF EVIDENCE: 2.

DOI： 10.1097/BRS.0000000000005603

Longitudinal changes in spinal kyphosis, lordosis, and range of motion in aging populations: a 10-year study. International journal

Hiroaki Nakashima, Shunsuke Kanbara, Sadayuki Ito, Naoki Segi, Jun Ouchida, Ippei Yamauchi, Yoshinori Morita, Shiro Imagama

European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society Vol. 35 ( 1 ) page： 125 - 133 2026.1

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: This study aimed to assess longitudinal changes in spinal alignment and range of motion (ROM) across different age groups over 10 years, focusing on thoracic kyphosis (TK), lumbar lordosis (LL), and spinal inclination angle (SIA), identify key inflection points in age-related spinal changes, and explore their clinical implications for maintaining postural control and preventing falls in older adults. METHODS: This was a longitudinal cohort study including 96 healthy adult participants who underwent spinal assessments during 2007-2009 and 2017-2019 as part of an annual health checkup. Spinal alignment and ROM were measured using SpinalMouse® in upright standing and dynamic flexion/extension postures. TK (T1-T12), LL (L1-S1), and SIA were assessed using radiography. RESULTS: TK (T1-T12) significantly increased from 38.9° ± 10.3° to 41.3° ± 9.9° (p < 0.01), whereas LL (L1-S1) significantly decreased from 21.8° ± 9.9° to 18.6° ± 11.2° (p < 0.01). The SIA increased significantly, indicating a forward-shifted posture. Flexion ROM slightly increased in the thoracic spine (T5-T12), but extension ROM significantly decreased in the upper thoracic region (T1-T5), reflecting age-related spinal rigidity. CONCLUSION: This study revealed significant age-related changes in spinal alignment and ROM over 10 years, particularly the increase in TK, reduction in LL, and decline in extension ROM. These findings may support the potential value of early interventions aimed at preserving spinal flexibility and posture, though further research is needed to confirm their effectiveness in improving outcomes.

DOI： 10.1007/s00586-025-09386-8

Association of BMI-Adjusted Calf Circumference and Age-Specific Cutoff Values With In-Hospital Falls Among Older Adults: A Multicenter Prospective Study Open Access

Miyahara, S; Maeda, K; Satake, S; Nagae, M; Nakashima, H; Takeya, Y; Umeda-Kameyama, Y; Umegaki, H

GERIATRICS & GERONTOLOGY INTERNATIONAL Vol. 26 ( 1 ) page： e70354 2026.1

Language：English Publisher：Geriatrics and Gerontology International

Aim: Calf circumference (CC) is a simple surrogate marker of muscle mass. Body mass index (BMI) adjustment and age-specific cutoffs for low CC have been proposed to optimize its use in clinical practice. This study aimed to clarify the association of BMI-adjusted CC and age-specific cutoffs with in-hospital falls among older adults. Methods: This study was conducted using data from the Japan Hospital Acquired Complications (J-HAC) project, a multicenter cohort study. In this analysis, we included adults aged ≥ 65 years. CC was measured on admission, and the occurrence of falls was assessed and recorded by medical personnel throughout the hospitalization. BMI adjustment and age-specific cutoffs for low CC were applied based on previous studies. Multivariable logistic regression models were developed to examine the association between in-hospital falls and BMI-adjusted CC and age-specific low CC cutoffs, adjusting for age and comorbidities. Results: A total of 808 patients (mean age 83.7 ± 6.6 years, 57.2% females) were analyzed. In females, higher BMI-adjusted CC was significantly associated with a lower risk of in-hospital falls after adjusting for age and comorbidities (adjusted OR = 0.88, 95% CI: 0.77–0.998). Furthermore, low BMI-adjusted CC, as defined by age-specific cutoff values, was independently associated with an increased fall risk in the multivariable model (adjusted OR = 2.39, 95% CI: 1.03–5.54). In contrast, no significant associations were observed in males regardless of CC adjustment or cutoff criteria. Conclusions: BMI-adjusted CC and age-specific cutoffs showed a stronger association with in-hospital falls among older females than unadjusted CC. Further validation in diverse populations and outcomes is required to confirm their usefulness.

DOI： 10.1111/ggi.70354