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Dropped head syndrome (DHS) is presumably caused by focal myopathy in the cervical posterior muscles; however, distinguishable radiological features of the cervical spine in DHS remain unidentified. This study investigated the radiological features of the cervical spine in dropped head syndrome. The records of DHS patients and age- and sex-matched cervical spondylotic myelopathy (CSM) patients were reviewed. Cervical spinal parameters (C2-7, C2-4, and C5-7 angles) were assessed on lateral cervical spine radiographs. Quantitative radiographic evaluation of cervical spine degeneration was performed using the cervical degenerative index (CDI), which consists of four elements: disk space narrowing (DSN), endplate sclerosis, osteophyte formation, and listhesis. Forty-one DHS patients were included. Statistically significant differences were noted between the upper and lower cervical spine in the sagittal angle parameters on the neutral, flexion, and extension radiographs in DHS group, whereas no significant differences were observed in CSM group. CDI comparison showed significantly higher scores of DSN in C3/4, C4/5, C5/6, and C6/7; sclerosis in C5/6 and C6/7; and osteophyte formation in C4/5, C5/6, and C6/7 in DHS group than in CSM group. Comparison of listhesis scores revealed significant differences in the upper levels of the cervical spine (C2/3, C3/4, and C4/5) between two groups. Our results demonstrated that the characteristic radiological features in the cervical spine of DHS include lower-level dominant severe degenerative change and upper-level dominant spondylolisthesis. These findings suggest that degenerative changes in the cervical spine may also play a role in the onset and progression of DHS.

Introduction: Reports indicate that 22%–64% of travelers experience some illness when in a foreign country. To date, no prior study has reported the use of ambulances by travelers or the epidemiology of travel-related injury. Methods: In this retrospective study, we aimed to describe ambulance use by international travelers, including the rates of travel-related injury and illness. To do so, ambulance dispatch data from January 1, 2010 to December 31, 2018 was used. Results: Overall, of the 43201 cases of ambulance use during the study period, 524 (1.2%) were international travelers. Ambulance use by international travelers increased from 0.35% in 2010 (15/4311) to 2.54% in 2018 (125/4913), an average annual increase of 0.27%. Of the international travelers, 392 (74.8%) had minor complaints, 110 cases (21.0%) had moderate complaints, 280 (53.4%) had internal disease, and 223 cases (42.6%) had suffered trauma. Regarding location, 253 (48.3%) were from a hotel/lodge, 83 (15.8%) were from a road/parking, and 30 (5.7%) were in the forest/mountain. Conclusion: Most international travelers use ambulances for minor complaints, typically internal disease or trauma, and approximately half access the service from a hotel or lodge.

We present 3 patients with dropped head syndrome (DHS) caused by thoracolumbar kyphotic deformity who were successfully treated with thoracolumbar corrective surgery only. After the surgery, their symptoms, neck pain, and horizontal gaze difficulty disappeared, and cervical kyphotic alignment was improved indirectly. At the final follow-up, the whole spinal alignment was maintained, and there was no recurrence of symptoms.Surgeons should consider thoracolumbar spine deformity as the possible primary cause of typical DHS symptoms and recognize that thoracolumbar corrective surgery is an effective method for treating DHS patients with thoracolumbar deformity.

Purpose Denosumab reduces bone resorption and improves bone mineral density (BMD). Studies have analyzed subsequent treatment transitioning from bisphosphonates to denosumab based on dual-energy X-ray absorptiometry scanning (DXA). Quantitative computed tomography (QCT) can help assess cortical and trabecular bones separately in three dimensions without the interference of the surrounding osteophytes. In the present study, we analyzed the subsequent treatment transition from bisphosphonates to denosumab using QCT. Methods Thirty-two patients with postmenopausal osteoporosis to be treated with denosumab were recruited. The patients were divided into two groups (15 prior bisphosphonate and 17 naïve) based on their previous treatment. BMD of the lumbar spine and hip were evaluated by DXA and QCT at baseline and 12 months following denosumab treatment. Results The percentage change in volumetric BMD assessed by QCT at 12 months significantly improved in the naïve group compared with that in the prior bisphosphonate group. The region-specific assessment of femur at 12 months revealed that denosumab treatment was effective in both cortical and trabecular bones except the trabecular region of the prior bisphosphonate group. Conclusion Our study suggests that although denosumab treatment was useful in both treatment groups, BMD increase was significantly higher in the naïve group than in the prior-bisphosphonate group. Interestingly, in the prior-bisphosphonate group, denosumab treatment was more effective in the cortical region than the trabecular region. Our study offers insights into the subsequent treatment and permits greater confidence when switching to denosumab from bisphosphonates., Highlights • We analyzed the treatment transition from bisphosphonates to denosumab using QCT. • Percentage change in volumetric BMD at 12 months significantly improved in the naïve group. • Denosumab treatment was more effective on the cortical region than the trabecular region. • Our study offers insights into the subsequent treatment when switching to denosumab.

Dropped head syndrome (DHS) is presumably caused by focal myopathy in the cervical posterior muscles; however, distinguishable radiological features of the cervical spine in DHS remain unidentified. This study investigated the radiological features of the cervical spine in dropped head syndrome.The records of DHS patients and age- and sex-matched cervical spondylotic myelopathy (CSM) patients were reviewed. Cervical spinal parameters (C2-7, C2-4, and C5-7 angles) were assessed on lateral cervical spine radiographs. Quantitative radiographic evaluation of cervical spine degeneration was performed using the cervical degenerative index (CDI), which consists of four elements: disk space narrowing (DSN), endplate sclerosis, osteophyte formation, and listhesis.Forty-one DHS patients were included. Statistically significant differences were noted between the upper and lower cervical spine in the sagittal angle parameters on the neutral, flexion, and extension radiographs in DHS group, whereas no significant differences were observed in CSM group. CDI comparison showed significantly higher scores of DSN in C3/4, C4/5, C5/6, and C6/7; sclerosis in C5/6 and C6/7; and osteophyte formation in C4/5, C5/6, and C6/7 in DHS group than in CSM group. Comparison of listhesis scores revealed significant differences in the upper levels of the cervical spine (C2/3, C3/4, and C4/5) between two groups.Our results demonstrated that the characteristic radiological features in the cervical spine of DHS include lower-level dominant severe degenerative change and upper-level dominant spondylolisthesis. These findings suggest that degenerative changes in the cervical spine may also play a role in the onset and progression of DHS.

Summary We investigated the relationship between serum 25(OH)D levels, grip strength, and fall score in elderly osteoporotic women for fall risk assessment. Both low serum 25(OH)D and low grip strength were independently associated with increased fall risk. The serum 25(OH)D cutoff specific to increased fall risk was 14 mg/dL (35 nmol/L). Purpose This study aimed to establish a cutoff value of serum 25-hydroxyvitamin D (25(OH)D) for fall assessment and investigate the relationship between serum 25(OH)D, grip strength, and fall score adjusted for age in osteoporotic elderly Japanese women. Methods This is a cross-sectional study utilizing collected data of osteoporotic elderly (age ≥65 years) female patients. A questionnaire for fall risk assessment was used, in which a score ≥ 6 was determined as increased fall risk. Serum 25(OH)D levels and grip strength were measured, and the cutoff points were calculated by receiver operating curve (ROC) analysis. Logistic regression analysis with age adjustment was conducted for potential risk factors for fall. Results After applying eligibility criteria, finally, 349 patients were enrolled. The median patient age was 77.0 years, and the mean serum 25(OH)D level was 15.6 ng/mL (36 nmol/L). Based on the ROC analysis, we defined the cutoff values of serum 25(OH)D level and grip strength as 14 ng/mL (35 nmol/L) and 15 kg, respectively. A multivariate analysis adjusted for age was conducted. Low serum 25(OH)D level and grip strength were independent risk factors for ≥6 fall risk scores. Conclusion Both low serum 25(OH)D level and low grip strength were independently associated with increased fall risk score in osteoporotic elderly women. The appropriate serum 25(OH)D cutoff specific to the increased fall risk group in this population was 14 mg/dL (35 nmol/L). These findings might be used for the identification of patients with high fall risks. These results should be confirmed in other patient groups.

There is growing interest in "osteosarcopenia" as the coexistence of osteoporosis and sarcopenia exacerbates negative outcomes. However, limited information is available regarding the risk factors of osteosarcopenia development in patients with osteoporosis. Therefore, we retrospectively reviewed 276 consecutive patients with postmenopausal osteoporosis who regularly visited Showa University Hospital. Patients were eligible for the study if they were ≥65 years of age and underwent dual-energy X-ray absorptiometry, blood sampling, and physical performance assessment. Patients were divided into the osteosarcopenia and osteoporosis alone groups according to the diagnostic criteria of the Asian Working Group for Sarcopenia. Of the 276 patients with osteoporosis, 54 patients (19.6%) had osteosarcopenia. Patients in the osteosarcopenia group had a greater risk of frailty than did those in the osteoporosis alone group (odds ratio 2.33; 95% confidence interval, 1.13-4.80, P = 0.028). Low body mass index seemed to be the strongest factor related to the development of osteosarcopenia, and none of the patients in the osteosarcopenia group were obese (BMI ≥27.5 kg/m2). Multiple logistic analyses revealed that patients aged 65-74 years who had comorbidities such as kidney dysfunction and high levels of HbA1c were at risk of developing osteosarcopenia. Thus, we strongly recommend the assessment of the key components of the diagnosis of osteosarcopenia in an osteoporosis clinic for patients with low body mass index. Furthermore, appropriate assessments, including comorbidities, will help in identifying patients at greater risk of developing osteosarcopenia.

Prospective feasibility study on consecutive patients.The aim of this study was to investigate the ability of regional BMD around the pedicle screw to predict the screw fixation.Pedicle screw fixation is the gold standard technique for spinal fusion. Despite the advantage of biomechanical stability, screw loosening is a common complication. In previous studies, pullout strength and screw insertional torque were correlated, and most importantly, affected by bone mineral density (BMD). Although the density and structure of the vertebral body are not homogeneous, no study has yet evaluated the relationship between screw insertional torque and regional BMD around the pedicle screw in vivo.Consecutive 50 patients, scheduled for transpedicular fixation, were evaluated preoperatively for BMD measured by dual-energy absorptiometry (DXA) and quantitative computed tomography (QCT). Regional volumetric BMD around the pedicle screw (PS-vBMD) using the novel QCT technique was also evaluated. Among all patients, 190 screws (diameter, 7.5 to 8.5 mm; length, 40 to 45 mm, inserted from L1 to L5) were eligible for this study and were analyzed to identify factors contributing to insertional torque. The following factors were investigated: age, body mass index, laboratory data, pedicle diameter, screw diameter, screw length, and 5 types of bone mineral density measures [DXA: spine-areal BMD (aBMD), total hip-aBMD, femoral neck-aBMD, QCT: central-vBMD, PS-vBMD].Insertional torque was significantly correlated with each BMD measurement and strongest with PS-vBMD (r=0.61, P0.001). Multiple regression analysis showed PS-vBMD was most strongly correlated with screw insertional torque (stdβ=0.494; P0.001). A model containing the following 5 predictors was significantly associated with screw insertional torque: age, pedicle diameter, screw diameter, screw length, and PS-vBMD.The preoperative measurement of PS-vBMD was technically feasible and reliably predictive of screw insertional torque during transpedicular fixation in a clinical setting.

Discontinuation of denosumab during osteoporosis treatment leads to rapid loss of bone mineral density and induces a bone turnover rebound effect. Previous studies have reported analysis based on dual-energy X-ray absorptiometry scanning (DXA). Here, we report the first case involving analysis of three-dimensional bone mineral density and bone strength, measured by quantitative computed tomography (QCT) after discontinuation of denosumab. An 82-year-old woman who discontinued denosumab because of patient’s wish was administered the fifth dose after a gap of 14 months. Her bone mineral density evaluated by DXA and QCT, bone strength, and bone turnover marker levels showed significant rebound phenomenon. The levels of the cortical parameters of the hip were also decreased indicating an increased risk of femoral fractures after denosumab interruption. Our case highlights the increased risk of fractures after discontinuation of denosumab. Therefore, denosumab must be used judiciously without interruption in the dosage schedule.

Denosumab is a fully human monoclonal antibody against the receptor activator of nuclear factor-κB ligand (RANKL) that is used for the treatment of osteoporosis. Denosumab-induced hypocalcemia is a rare but important adverse event, which is usually asymptomatic in patients with osteoporosis. It is also known that hypocalcemia is common in patients with bone metastases and severe renal impairment. Here we report a case of symptomatic hypocalcemia following administration of 60 mg of denosumab in a patient with high bone turnover and no renal impairment (estimated glomerular filtration rate [eGFR], 71 mL/min), despite prophylactic oral vitamin D administration. This report supports our observation that there is a risk of protracted and marked denosumab-induced hypocalcemia in patients with high bone turnover, irrespective of their degree of renal impairment.

We demonstrate an interferometric dynamic displacement measurement that uses a partially unjacketed probe fiber and high-frequency phase modulation. Tens-of-nanometer scale displacement is measured only at the unjacketed section with a time resolution of 100 ns.

This work presents a novel actuation mechanism using the large abrupt change of magnetization ΔM in a metamagnetic Ni-Co-Mn-In film during first order phase transformation. Free-standing polycrystalline films of the composition Ni50.4Co3.7Mn32.8In13.1 are fabricated by RF magnetron sputtering on a sacrificial polyvinyl alcohol (PVA) substrate. The film composition is tailored to exhibit an abrupt change of magnetization ΔM of 26 emu/g at 50 mT with narrow hysteresis below 8 K well above room temperature. A demonstrator is presented consisting of a polyimide cantilever that carries the film material at the front end. When placed between stationary heat source and heat sink, heat transfer gives rise to thermal self-actuation at a cycling frequency of 2 Hz. Design optimization allows for frequency up-conversion to resonant oscillatory motion at frequencies above 160 Hz.

In a tens-of-nanometer-scale dynamic displacement measurement system based on a fiber interferometer using high-frequency phase modulation for the reference light, we introduce active change of operation point for the phase modulator. It is experimentally demonstrated that dynamic displacement measurement is possible independent of the initial operation point.

Mechanical stiffness in piezoelectric actuators restrains their output property and suppresses the output energy in general. We aimed to enhance the output energy of displacement amplified piezoelectric actuators (DAPAs) by employing rolling joint mechanisms with high energy transmissibility. By using the proposed design method for the shape of the rolling joints, we developed a DAPA with a novel output. In the new design, the influence of stiffness on the DAPA's output force was significantly reduced. In this paper we show the design method and the DAPA's novel output characteristics. In addition, we suggest the great potential of the design to enhance the utilization of piezoelectric energy in DAPAs.

Ni-Mn-In films containing cobalt were deposited on a poly-vinyl alcohol (PVA) substrate using a dual magnetron sputtering apparatus with Ni45Mn40In15 and Co targets. The RF power for the Ni-Mn-In target was kept at 200 W, and the DC power for the cobalt target was 8 W. The thicknesses of the deposited films were 1 and 5 µm. After deposition, the films were annealed at 1123 K for 3.6 ks for 1 µm and 1023 K for 3.6 ks + 1173 K for 3.6 ks for 5 µm. The crystallinity of the films was affected by the heat treatment, and the films showed layered structures, such as 10M- and 14M-type structures. The martensitic transformation and magnetic phase transition influence each other, and both have a magnetic field dependence. In particular, the 5 µm film shows a metamagnetic phase transition with small transition temperature hysteresis. The magnetization experiments for the 5 µm film reveal a drastic magnetization change ΔM of 26 emu/g at 0.05 T and a martensitic transformation finish temperature change ΔM f of −8.5 K at 5 T.

We demonstrate a simple and precise measurement system of dynamic displacement for more-than-10-MHz high-frequency vibration. An interferometer using high-frequency phase modulation and simple data processing achieved a small error of better than 0.7 nm.

A new method for thermal energy harvesting at small temperature difference and high cycling frequency is presented that exploits the unique magnetic properties and actuation capability of magnetic shape memory alloy (MSMA) films. Polycrystalline films of the Ni50.4Co3.7Mn32.8In13.1 alloy are tailored, showing a large abrupt change of magnetization and low thermal hysteresis well above room temperature. Based on this material, a free-standing film device is designed that exhibits thermomagnetically induced actuation between a heat source and sink with short heat transfer times. The cycling frequency of the device is tuned by mechanical frequency up-conversion to over 200 Hz. An integrated pick-up coil converts the thermally induced change of magnetization as well as the kinetic energy to electricity. For a temperature change of 10 K, the maximum peak power density is in the order of 5 mW cm-3.