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Background/Aim: As opportunities for hands-on surgical training during residency have decreased, off-the-job training before surgery is gaining importance. We developed a training program using a box-trainer for surgical residents. This study aimed to verify the effectiveness of the program. Using task-achievement time, we demonstrated the learning curve through continuous task training and verified the efficiency of our training tasks. In addition, we examined the circularity of the cut circle to evaluate the task accuracy and summarized the questionnaire results. Patients and Methods: A prospective, observational study was conducted at a single center with five trainees from April 2019 to March 2020. The training consisted of four tasks based on the Fundamentals of Laparoscopic Surgery module. The trainees had to achieve expert proficiency time targets. The task-achievement time and circularity of the cut circle were used for objective assessment; subjective evaluation was done using a questionnaire. Results: Although the learning curves of the task-achievement time seemed to reach a plateau between the third and the fifth skills lab, all the trainees achieved expert proficiency times for the three tasks. Circularity of the cut circle tended to be more accurate after training. All trainees perceived an improvement in their skills after the training program. The level of satisfaction of the training program was rated as ‘very satisfied’ or ‘satisfied’. Conclusion: Continuous box-trainer training for 1 year may be effective for improvement in preoperative laparoscopic surgical skills of surgical residents.

Background Total knee arthroplasty (TKA) is an established surgical treatment for advanced knee osteoarthritis by which patients can expect improvement of knee pain and function. Although many surgeons have investigated limb alignment after TKA, changes in coronal positional relation between the femur and tibia are not known well. Methods Radiographs of 105 knees of young Japanese patients between 20 and 49 years-old (60 men and 45 women) without osteoarthritic changes who received arthroscopic surgeries at our hospital were used in this study. Using 2D-templates of the medial pivot design (the FINE total knee), we simulated TKA on a SYNAPSE-PACS software. First, the femoral component was placed in normal knee alignment and then was merged to the medial concave of the insert where the tibial component was placed in neutral alignment. The length of the mediolateral shift of the femoral component was measured as an estimate of lateral shift of the femoral condyle, of which association with radiographic parameters including the femorotibial angle (FTA), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA) was analyzed. Subjects were classified into three groups according to the femoral component size that was chosen in simulation of TKA, and the lateral shift of the femoral condyle was compared between groups. Results The estimated mean lateral shift of the femoral condyle was 5.99 ± 1.98 mm and was greater in males than females (p r = − 0.553, p p Conclusions These results suggest that the coronal positional relation between the femur and tibia is altered and subsequent ligament imbalance may occur after mechanically aligned TKA using the medial pivot design.

BackgroundSolitary death (kodokushi) has recently become recognized as a social issue in Japan. The social isolation of older people leads to death without dignity. With the outbreak of COVID-19, efforts to eliminate solitary death need to be adjusted in line with changes in lifestyle and accompanying changes in social structure. Health monitoring services that utilize wearable devices may contribute to this end. Our goals are to outline how wearable devices might be used to (1) detect emergency situations involving solitary older people and swiftly connect them with medical treatment, to (2) reduce the frequency of deaths that remain undiscovered and (3) to reduce social isolation by promoting social interaction.MethodsTheoretical and philosophical approaches were adopted to examine ethical issues surrounding the application of wearable devices and cloud-based information processing systems to prevent solitary death in the world with/after COVID-19.Main body(1) Technology cannot replace social connections; without social support necessary to foster understanding of the benefits of health management through wearable devices among older adults, such devices may remain unused, or not used properly. (2) Maturity of the technology; systems face the difficult task of detecting and responding to a wide range of health conditions and life-threatening events in time to avert avoidable morbidity and mortality. (3) Autonomy and personhood; promoting the voluntary use of wearable devices that are a part of larger efforts to connect isolated individuals to a community or social services might be effective. Legal force should be avoided if possible. There is some concern that landlords may require an older person to sign a contract agreeing to wear a device. The autonomy of solitary older people should be respected. (4) Governance: policies must be developed to limit access to data from wearables and the purposes for which data can be used.ConclusionIf thoughtfully deployed under proper policy constraints, wearable devices offer a way to connect solitary older people to health services and could reduce cases of solitary death while respecting the personhood of the user.

American and Japanese laws, customs, and practices in end-of-life decision-making differ significantly. We present a case with which one of the authors was involved to illustrate some of the key legal and cultural differences in the declaration of brain death, limiting and withdrawing life-prolonging interventions, and healthcare ethics consultation practices. The analysis presented facilitates understanding of similarities and differences between Japanese and American healthcare ethics specifically in regards to end-of-life care. Further, the analysis provides insights that can aid in developing policies and practices in regions where multiple cultures coexist.

Background Central sleep apnea (CSA) due to occipitocervical compression myelopathy is an extremely rare condition. Here we report a case of surgical treatment for CSA due to occipitocervical compression myelopathy in a patient with Klippel-Feil syndrome. Case Description A 60-year-old man had become aware of a gradually progressive clumsiness and gait disturbance without any cause of injury 5 years before. He had complicated respiratory discomfort during sleep for the previous month and visited our hospital. Neurologic examination revealed severe myelopathy. Polysomnography showed CSA and Cheyne-Stokes respiration. Imaging findings showed C2-3 vertebral fusion and severe spinal cord compression caused by hypoplasia of the C1 posterior arch complicated by an anomaly of the vertebral artery. We diagnosed the patient with CSA due to occipitocervical compression myelopathy complicated by Klippel-Feil syndrome. After a simulation using a full-scale 3-dimensional model, resection of the C1 posterior arch and C4-5 laminoplasty was performed. After surgery, both clumsiness and gait disturbance gradually improved. Polysomnography 1 month after surgery showed that the CSA and the Cheyne-Stokes respiration disappeared. Conclusions Although a recent report has indicated the cause of sleep apnea in patients with rheumatoid arthritis and occipitocervical disorders as obstructive sleep apnea, a significant improvement of CSA was observed with decompression surgery in this case. Appropriate surgical planning resulted in a favorable outcome.

In this article, we perform a thought experiment about living donor kidney transplantation. If a living kidney donor becomes in need of renal replacement treatment due to dysfunction of the remaining kidney after donation, can the donor ask the recipient to give back the kidney that had been donated? We call this problem organ restitution and discussed it from the ethical viewpoint. Living organ transplantation is a kind of ‘designated donation’ and subsequently has a contract-like character. First, assuming a case in which original donor (A) wishes the return of the organ which had been transplanted into B, and the original recipient (B) agrees, organ restitution will be permissible based on contract-like agreement. However, careful and detailed consideration is necessary to determine whether this leaves no room to question the authenticity of B’s consent. Second, if B offers to give back the organ to A, then B’s act is a supererogatory act, and is praiseworthy and meritorious. Such an offer is a matter of virtue, not obligation. Third, if A wishes B to return the organ, but B does not wish/allow this to happen, it is likely difficult to justify returning the organ to A by violating B’s right to bodily integrity. But B’s refusal to return the donated organ cannot be deemed praiseworthy, because B forgets the great kindness once received from A. Rather than calling this an obligation, we encourage B to consider such virtuous conduct.

Background Intradural extramedullary spinal metastasis is a relatively rare condition. Furthermore, there are few reports with the initial presentation being a neurological symptom from an intradural metastasis. We report a case of a patient with metastasis to the cauda equina from breast cancer found due to neurological symptoms as the initial presentation. Case presentation A 76-year-old Japanese woman who was previously healthy presented to our hospital with bilateral severe buttock and lower extremity pain without any history of injury. A solitary intradural cauda equina mass was found by magnetic resonance imaging at the L2/3 level, and we suspected a schwannoma initially. The patient hoped to undergo surgery due to the severe pain. However, the chest computed tomographic scan obtained to assess the patient’s general status showed the suspected breast cancer of the left side and a lung metastasis. Hence, we considered the possibility of cauda equina tumor metastatic from the breast cancer. We performed an L1–3 laminectomy and tumor extirpation. The pathology revealed adenocarcinoma. After surgery, she had relief from pain, and her status remained satisfactory until she died 9 months after surgery. Conclusions It is difficult to clarify whether the cauda equina tumor is benign or malignant based only on Magnetic resonance imaging findings. Clinicians should consider the possibility of metastasis when planning the surgery for intradural cauda equina tumor extirpation.

In the midst of the ongoing Covid‐19 pandemic, researchers across the globe are still working to develop effective vaccines. To expedite this process even further, human challenge trials have been proposed by the World Health Organization (WHO) as an alternative to conventional approaches. In such trials, healthy volunteers are deliberately infected with the pathogen of interest, enabling scientists to study the infection process and facilitate further research on treatments or prophylactics, including vaccines. While human challenge trials would offer a collective benefit to society, minimizing the risks is always difficult. Ethical controversy thus inevitably surrounds these trials. Typically, healthy young adults are recruited to serve as the first candidate subjects for human challenge trials because they are generally considered to represent a low‐risk population. Here, we present three reasons for doubt about this healthy‐young‐adults‐first criterion and give justification for also recruiting healthy older adults (or not‐young adults), meaning those over 30 years of age, to participate in such trials for SARS‐CoV‐2.

BackgroundThe FINE total knee was developed in Japan and clinical use began in 2001. It has unique design features, including an oblique 3ofemorotibial joint line that reproduces anatomical geometry. Although 20 years have passed since the FINE knee was clinically used for the first time in Japan, a formal clinical evaluation including patient-reported and radiographic outcomes has not been undertaken.MethodsA total of 175 consecutive primary cruciate-retaining (CR)-FINE total knee arthroplasties (TKAs) at our hospital between February 2015 and March 2017 were included in this study. Three years postoperatively, range of motion (ROM), Knee Society Score (KSS), Knee Injury and Osteoarthritis Outcome Score (KOOS) and Forgotten Joint Score (FJS) were recorded and compared with preoperative scores. Radiographic analyses including mechanical alignment, component alignment, and incidence of radiolucent lines also were undertaken based on the radiographs 3 years postoperatively.ResultsOne-hundred twenty-two knees (70%) were available for 3-year follow-up data using KOOS, except for the sports subscale. Postoperative KOOS-symptom, −pain and -ADL were > 85 points, but KOOS-sports, −QOL and FJS were less satisfactory. ROM, KSS and all the subscales of KOOS were significantly improved compared with preoperative scores. Postoperative mean FJS was 66 and was significantly correlated with all the subscales of KOOS, but not with postoperative ROM. Radiolucent lines ≧1 mm wide were detected in five knees (4.1%). There were no major complications needing revision surgeries.ConclusionsPatient-reported outcomes (PROs) for symptoms, pain and ADL after the CR-FINE TKA were generally improved, but those for sports, QOL and FJS were improved less. The incidence of radiolucent lines was rare but detected around the femoral components. With the mid- to long-term follow-up, improvements of surgical technique will be necessary to achieve better PROs from patients receiving the FINE knee.

We have established and also implemented a nondestructive online monitoring system for measuring the stripper foil degradation, such as foil thinning and pinhole outbreak, for the first time during beam operation in a high-intensity proton accelerator. We aimed to achieve a realistic and longer lifetime of a stripper foil by ensuring proper uses and determining its end of usefulness without any failure. A stripper foil is used for negative hydrogen (${\mathrm{H}}^{\ensuremath{-}}$) stripping to proton (p) for multiturn charge-exchange injection in high-intensity proton accelerators. A longer foil lifetime is expected, while foil failure during operation should be avoided, as it reduces the accelerator availability and also has serious issues for regular accelerator maintenance. A proper use of the foil should also be ensured to minimize the replacement of the foil magazine, as it involves unhealthy radiation exposure to the workers. We have measured the partially stripped ${\mathrm{H}}^{0}$ and unstripped ${\mathrm{H}}^{\ensuremath{-}}$ charge fractions of the injection ${\mathrm{H}}^{\ensuremath{-}}$ beam out of the stripper foil to understand details of foil degradation, such as foil thinning and pinhole formation due to high-intensity beam irradiation, which are believed to be foil breaking signals. We used two independent beam monitoring devices and precisely measured both ${\mathrm{H}}^{0}$ and unstripped ${\mathrm{H}}^{\ensuremath{-}}$ charge fractions by each monitor. As a result, we obtained a detail of foil degradation during operation to determine a realistic end of its usefulness by successfully achieving a record of nearly 2 yr of operation with a single foil without any failures. The detailed measurement result of the foil degradation also gives strong feedback for producing stronger and durable stripper foils. The present research was done by using simple and ordinary beam diagnostic devices including a nondestructive one, which can be easily applied to overcome the stripper foil issues in any similar existing and next-generation further higher-intensity accelerators.

The issue of incidental findings encountered in medical researches and in clinical practices becomes controversial in recent years. In what situations should researchers and clinicians disclose incidental findings to study participants or patients? According to previous studies, the concept of "actionability" is one of most important notions in determining the management of incidental findings, however, the understanding of this concept is also inconsistent among people and the inconsistency can affect the management of incidental findings. That is why we surveyed the difference in conceptual understanding of "actionability" for incidental findings with genomic researches in Japan.

Aim: Tacrolimus (TAC) is an important drug for inflammatory diseases. However, TAC has several limitations, such as variable trough concentrations among individuals and a high medication frequency. In this study, we created NK61060, a novel micellar TAC formulation, to circumvent these disadvantages. Materials & methods: Immunosuppressive activity of NK61060 was determined in the collagen-induced arthritis rat model, mannan-induced arthritis mouse model and dextran sodium sulfate-induced colitis mouse model. The pharmacokinetics and toxicology of NK61060 were evaluated in those models. Results: In arthritis and colitis models, NK61060 exhibited superior immunosuppressive activity compared with that of TAC. Pharmacokinetic and toxicological analyses indicated that NK61060 had a wider safety margin and could be administered at a reduced medication frequency. Conclusion: NK61060 mitigates the trough concentration variability and the medication frequency and it may be a safer and more effective option for use in clinical settings. Further studies are needed to determine its clinical usefulness.

The use of human embryos in genome editing research has recently been approved in China and the United Kingdom. In Japan, the debate on regulations on genome editing research studies using human embryos is underway, but is becoming increasingly entangled, to the point of deadlock. One main reason for this is the misalignment between the Japanese government and the research communities, in their awareness surrounding these regulations. In this article, we report on this ongoing and entangled debate in Japan concerning the regulations on genome editing technology using human embryos. The most critically needed next step is a grassroots level discussion among various experts such as those in the arts and humanities.

The 3-GeV rapid-cycling synchrotron at the Japan Proton Accelerator Research Complex has achieved the high-power beam operation equivalent to 1 MW. As a next step, a study of an upgrade is in progress to mitigate the dose exposure of the maintenance workers in a high residual dose environment and realize the further high intensity beam power. Regarding the upgrade plan's provisions for radiation protection, a new injection scheme has been proposed to make space available for radiation shielding. The total length of the two shift bump magnets of the four magnets is reduced for this purpose, while the other two magnets in the injection straight section remain unchanged. As a result, the two types of pulse magnets are connected separately in series and are excited by two independent power supplies, which are made possible by splitting the presently installed power supply. A structural analysis of the new shift bump magnet is in progress, including simulations of the effects of eddy currents and the coil temperatures by OPERA-3D. This paper describes preliminary results of this analysis and the outlines the modified power supply design.

Ursin (2019) asserts the situation dependency of judgments pertaining to withholding and withdrawal of medical care at the end of life, criticizing the radical application of the equivalence princi...

The beam dump at the beam injection area in the J-PARC 3-GeV rapid cycling synchrotron (RCS) accepts beams that pass through the charge exchange foil without ideal electron stripping during the multi-turn beam injection. The injection beam dump consists of the beam pipe, beam stopper, radiation shield, and cooling mechanism. The ideal beam power into the injection beam dump is 400 W in the case of design RCS extraction beam power of 1 MW with a healthy foil, which has 99.7 % charge stripping efficiency. On the other hand, as a radiation generator, the RCS is permitted to be operated with maximum average beam power of 4 kW into the injection beam dump based on the radiation shielding calculation, in consideration of lower charge stripping efficiency due to the foil deterioration. In this research, to evaluate the health of the RCS injection beam dump system from the perspective of the heat generation, a thermal analysis was performed based on the actual configuration with sufficiently large region, including the surrounding concrete and soil. The calculated temperature and heat flux density distribution showed the validity of the mesh spacing and model range. The calculation result showed that the dumped 4 kW beam causes the temperature to increase up to 330, 400, and 140 °C at the beam pipe, beam stopper, and radiation shield, respectively. Although these high temperatures induce stress in the constituent materials, the calculated stress values were lower than the ultimate tensile strength of each material. Transient temperature analysis of the beam stopper, which simulated the sudden break of the charge stripper foil, demonstrated that one bunched beam pulse with the maximum beam power does not lead to a serious rise in the temperature of the beam stopper. Furthermore, from the measured outgassing rate of stainless steel at high temperature, the rise in beam line pressure due to additive outgassing from the heated beam pipe was estimated to have a negligible effect on beam line pressure. The flow and results of the evaluation in this analysis would provide a good indication for both the verification of the existing beam dumps, and the design of beam dumps in new accelerators with higher intensity beam.

Vukov (2018) argues that in cases for which it is unclear whether a patient has consciousness or not, a patient's potential consciousness (PC) must be considered along with actual levels of conscio...

Objective:The objective of this study is to assess public attitudes toward pharmaceutical companies’ secondary uses of patient records and public preferences regarding consent approaches.Method:3000 responses to an online survey were collected from adults in Japan. The questionnaire included 32 items related to (1) awareness of “clinical trials”; (2) awareness of the processes of drug development, such as cost, time, and the number of candidate substances in a new drug; (3) knowledge of the laws and regulations for use of patient records in Japan; (4) assessment of the public benefit of the secondary use of patient records; (5) preferences for consent for the secondary use of patient records; and (6) basic characteristics of the respondents.Results:The public benefit from secondary use of records by academic institutions for scientific research was rated highest. All of the activities by pharmaceutical companies were rated higher than those by governmental institutions and other for-profit companies. Regarding consent approaches, 37.9% preferred an “opt-in” approach for new drug development by pharmaceutical companies, 79.7% of whom would change their preference to an “opt-out” approach under specific conditions, such as ensuring intended uses only.Conclusion:Our respondents consider the “public benefit” as dependent on the relative distance from “promoting public health” when assessing the secondary purpose of patient record use. Pharmaceutical companies should include the beneficial purposes when using patient records with “opt-out” approach. Policy makers should pay more attention to the purposes of use when developing personal information protection policies.

Background Unilateral laminectomy for bilateral decompression (ULBD) for lumbar spinal stenosis (LSS) is a less invasive technique compared to conventional laminectomy. Recently, several authors have reported favorable results of low back pain (LBP) in patients of LSS treated with ULBD. However, the detailed changes and localization of LBP before and after ULBD for LSS remain unclear. Furthermore, unsymmetrical invasion to para-spinal muscle and facet joint may result in the residual unsymmetrical symptoms. To clarify these points, we conducted an observational study and used detailed visual analog scale (VAS) scores to evaluate the characteristics and bilateral changes of LBP and lower extremity symptoms. Methods We included 50 patients with LSS treated with ULBD. A detailed visual analogue scale (VAS; 100 mm) score of LBP in three different postural positions: motion, standing, and sitting, and bilateral VAS score (approached side versus opposite side) of LBP, lower extremity pain (LEP), and lower extremity numbness (LEN) were measured. Oswestry Disability Index (ODI) was used to quantify the clinical improvement. Results Detailed LBP VAS score before surgery was 51.5 ± 32.5 in motion, 63.0 ± 30.1 while standing, and 37.8 ± 31.8 while sitting; and showed LBP while standing was significantly greater than LBP while sitting (p

Decoded neurofeedback is a new technology that allows the improvement or modification of human cognitive and moral capacities and has a wide range of potential applications. As decoded neurofeedback will have an impact on society, ethical concerns about this technology should be examined. As decoded neurofeedback modifies the default mode network due to a voxel-based pattern analysis, it enables a tailor-made intervention. However, it is difficult to assess the safety and efficacy of decoded neurofeedback-based interventions in clinical trials because of a shortage of reliable preclinical data. Decoded neurofeedback used for moral enhancement is a noninvasive intervention with a high selectivity for the targeted brain state, and therefore, moral uniformity, the most often discussed problem, can be avoided. However, it remains uncertain whether decoded neurofeedback is reversible, safe, or efficacious.

Improvement in injection beam quality at the Japan Proton Accelerator Research Complex 3-GeV rapid cycle synchrotron is to mitigate beam loss at the injection section. We developed a charge-exchange type scraper system with a thin carbon foil to collimate the beam halo in the injection beam line of the synchrotron. The key issue to realize the scraper is a reduction of the beam loss induced by the multiple-scattering effect of charge-exchange foil placed at the scraper head. In order to determine the adequate foil thickness, a charge-exchange efficiency of a carbon foil and particle-tracking simulation study of the collimated beam have been performed assuming a realistic halo at the scraper section. Using the results of this study, we chose the thickness of a 520 μ g / cm 2 as the scraper foils to mitigate radiation dose around the L3BT scraper section. A charge-exchange scraper system that prevents the emission of radioactive fragments of the carbon foil was build. The system was put into operation to prove its effectiveness in eliminating the beam halo. From the result of a preliminary beam experiments, we confirmed that the installed scrapers eliminate a transverse beam tail or halo. After two days of operation with beam collimation, the radiation dose level around the scraper section was a tolerable one for the hands-on maintenance.

Nonlinear optical frequency conversion has been challenged to move down to the extreme ultraviolet and x-ray region. However, the extremely low signals have allowed researchers to only perform transmission experiments of the gas phase or ultrathin films. Here, we report second harmonic generation (SHG) of the reflected beam of a soft x-ray free-electron laser from a solid, which is enhanced by the resonant effect. The observation revealed that the double resonance condition can be met by absorption edges for transition metal oxides in the soft x-ray range, and this suggests that the resonant SHG technique can be applicable to a wide range of materials. We discuss the possibility of element-selective SHG spectroscopy measurements in the soft x-ray range.

A new PET detector module which has a unified interface is proposed. The detector module consists of a scintillator array, a multi-pixel photon counter (MPPC) array and a front-end circuit. While a general PET detector module has three kinds of interface; power, control and data, the proposed detector has only one Ethernet cable. Power of the detector module is fed by a Power over Ethernet (PoE) method, which is configured to pass electric power along with data on twisted pair Ethernet cable. The clock used in the module is recovered from the serial data and the recovered clock is used to acquire and send the data back. The synchronization can be done using IEEE1588 or customized package with hardware assistance and software correction. Data are transmitted through User Datagram Protocol (UDP) to an uplink. The uplink can send the request with current timestamp to a module, the module responds in a fixed time delay, and the uplink detects the response and compare to the current timestamp. The difference detected by the uplink would be the fixed delay plus cable delay. Using proposed modules, it is expected flexible, scalable and upgradable systems can be easily constructed.

The 3-GeV rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC) is the world's highest class of high-power pulsed proton driver, aiming for an output beam power of 1 MW. The most important issues in realizing such a high-power beam operation are to control and minimize beam loss for maintaining machine activations within permissible levels. In RCS, numerical simulation was successfully utilized along with experimental approaches to isolate the mechanism of beam loss and find its solution. By iteratively performing actual beam experiments and numerical simulations, and also by several hardware improvements, we have recently established a 1-MW beam operation with very low fractional beam loss of a couple of 10$^{-3}$. In this paper, our recent efforts toward realizing such a low-loss high-intensity beam acceleration are presented., RCSは、1MWのビーム出力を目指す世界最高クラスの大強度陽子加速器である。こうした加速器では、ビーム損失により生じる機器の放射化がビーム出力を制限する最大の要因となる。ビーム損失の原因(誤差磁場、空間電荷効果、像電荷効果等)は多様で、複数の効果が絡み合った複雑な機構でビーム損失が生じるため、その解決を果たすには、高度なビームの運動学的研究が必要となる。RCSでは、実際のビーム試験と共に、計算機上での数値シミュレーションを精力的に行ってきた。実験と計算の一致は良好で、観測されたビーム損失の発生機構の解明、また、その解決策を議論するうえで、数値シミュレーションが重大な役割を果たしている。ハードウェア系の改良と共に、こうしたビーム試験と数値シミュレーションを反復的に行うアプローチにより、RCSでは、10$^{-3}$という極めて少ないビーム損失で1MW相当のビーム加速を達成したところである。本論文では、RCSのビーム増強過程で顕在化したビーム損失の発生機構やその低減に向けた取り組みなど、大強度加速器におけるビーム物理に関する話題を中心に、RCSビームコミッショニングにおけるここ数年の成果を時系列的に紹介する。

To determine levels of biomarkers reflecting damage to axon, myelin, astrocytes, and neuron in cerebrospinal fluid (CSF) of patients with cervical compression myelopathy. We collected 69 CSF samples from patients before spinal surgery for acutely worsening compression myelopathy (AM, 20), chronic compression myelopathy (CM, 20), and lumbar canal stenosis (LCS 29; control). We measured levels of phosphorylated neurofilament subunit H (pNF-H), tau (reflecting axonal damage), myelin basic protein (MBP) (reflecting demyelination), S100b (reflecting astrocyte damage), and neuron-specific enolase (NSE) (reflecting neuronal damage). Change of neurological function by surgery was determined using a Japanese Orthopaedic Association (JOA) score for cervical myelopathy. Significantly higher levels of pNF-H were detected in AM compared with those in either CM or LCS (P