Overexpressions of Vimentin and Integrins in Human Metastatic Spine Tumors

Objective

To comparatively investigate the expression of several integrins in specimens of human bone metastases and degenerative bone tissue.

Methods

Degenerative cancellous tissue was obtained from a sample of human degenerative spine. Thirteen human specimens were obtained from metastatic spine tumors, whose primary cancer was colon cancer (n=3), hepatocellular cancer (n=3), lung cancer (n=4), and breast cancer (n=3). The expression of vimentin and integrins αv, β1, and β3 was assessed in metastatic and degenerative specimens by immunohistochemistry and real-time reverse transcription-polymerase chain reaction (qRT-PCR).

Results

Immunohistochemical staining showed that vimentin and integrin αv was broadly expressed in all tissues examined. By contrast, integrin β1 was weakly expressed only in 38.4% (5/13) of tissues. Integrin β3 was consistently negative in all cases examined. qRT-PCR analysis showed that vimentin gene expression was higher in all metastatic specimens, as compared to degenerative bone. The gene expression of integrin αv in breast specimen was significantly higher than others (p=0.045). The gene expression of integrin β1 was also higher in all metastatic specimens than in degenerative bone tissue. The gene expression of integrin β3 was variable.

Conclusion

Spinal metastatic tumors have mesenchymal characteristics such as increased expression of vimentin. The increased expression of integrin αv and β1 in spine metastatic tumors suggests that adhesive molecules such as integrin may have implications for the prevention of spine metastasis.

Nationwide epidemiology and healthcare utilization of spine tumor patients in the adult Korean population, 2009-2012

Background

The aim of this nationwide study was to describe the incidence and health care utilization of adult Korean patients with primary malignant, primary nonmalignant, and metastatic spine tumors between 2009 and 2012.

Methods

Patients with primary and metastatic spine tumors were identified from the Korean Health Insurance Review and Assessment Service database between January 1, 2009, and December 31, 2012. Demographics, incidence rate, annual medical cost, and annual hospital stay of each new patient were reviewed.

Results

Of 1600 primary spine tumors diagnosed from 2009 to 2012, 373 (23.3%) were malignant, and 1227 (76.7%) were nonmalignant. The most common tumor type was neoplasm of spinal cord among primary malignant (C72.0, 51.5%) and primary nonmalignant (D33.4, 66.2%) spine tumors. Differences in primary malignant, primary nonmalignant, and metastatic spine tumor incidence by sex were significant (P = .004, <.001, and <.001, respectively). The annual incidence rate of primary nonmalignant and metastatic spine tumors increased significantly over the study period (P = .005 and <.001, respectively). Lung, liver/biliary, and breast were the most prevalent original tumor sites for metastatic spine tumors. In 2011, average annual medical costs associated with treatment of primary malignant, primary nonmalignant, and metastatic tumors were US $15 223, $6502, and $16 038, respectively. Average annual hospital stay durations for primary malignant, primary nonmalignant, and metastatic spine tumors in 2011 were 103.4, 61.7, and 79.6 days, respectively.

Conclusions

This is the first nationwide analysis of spine tumors, including metastatic spine tumors, in Asia.

The relationship between diabetes and the reoperation rate after lumbar spinal surgery: a nationwide cohort study

BACKGROUND CONTEXT

Diabetes is present in 5% to 20% of patients undergoing spine surgeries and is a known risk factor for reoperation. Considering the chronicity of diabetes, its influence on the reoperation rate may differ over time.

PURPOSE

To present the relationship between diabetes and the reoperation rate over time.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

A national health insurance database was used to identify a cohort of patients who underwent an initial surgery for lumbar degenerative disease in 2003 (n=34,918).

OUTCOME MEASURES

The primary end point was any type of second lumbar surgery after fusion surgery (n=4,792) or decompression surgery (n=30,126) during the early (0-postoperative 90 days), short-term (91-365 days), and midterm (1-6 years) periods.

METHODS

All patients were followed up until December 2008. Cox proportional hazards regression modeling was used to assess the adjusted reoperation rates in the diabetic patients.

RESULTS

The incidence of diabetes in the present cohort was 24.5% in the fusion group and 16.9% in the decompression group. Overall, reoperation was performed in 13.2% (631 of 4,792) of the patients after fusion surgery and in 14.0% (4,214 of 30,126) of the patients after decompression surgery. After fusion surgery, diabetes did not make a significant difference in the reoperation rate during the entire follow-up period. After decompression surgery, the reoperation rate was not different during Postoperative Month 3, but diabetic patients showed a 1.2 to 1.4 times higher reoperation rate during postoperative 3 months to 5 years (p<.01).

CONCLUSIONS

The study did not find a relationship between diabetes at the time of surgery and the reoperation rate during the early postoperative period. Thereafter, the reoperation rate was not higher after fusion surgery in diabetic patients, but it was higher after decompression surgery.

Mesial temporal lobe epilepsy with hippocampal sclerosis is a network disorder with altered cortical hubs

OBJECTIVE

Electrophysiologic hubs within the large-scale functional networks in mesial temporal lobe epilepsy (mTLE) with hippocampal sclerosis (HS) have not been investigated. We hypothesized that mTLE with HS has different resting-state network hubs in their large-scale functional networks compared to the hubs in healthy controls (HC). We also hypothesized that the hippocampus would be a functional hub in mTLE patients with HS.

METHODS

Resting-state functional networks, identified by using magnetoencephalography (MEG) signals in the theta, alpha, beta, and gamma frequency bands, were evaluated. Networks in 44 mTLE patients with HS (left mTLE = 22; right mTLE = 22) were compared with those in 46 age-matched HC. We investigated betweenness centrality at the source-level MEG network.

RESULTS

The main network hubs were at the pole of the left superior temporal gyrus in the beta band, the pole of the left middle temporal gyrus in the beta and gamma bands, left hippocampus in the theta and alpha bands, and right posterior cingulate gyrus in all four frequency bands in mTLE patients; all of which were different from the main network hubs in HC. Only patients with left mTLE showed profound differences from HC at the left hippocampus in the alpha band.

SIGNIFICANCE

Our analysis of resting-state MEG signals shows that altered electrophysiologic functional hubs in mTLE patients reflect pathophysiologic brain network reorganization. Because we detected network hubs in both hippocampal and extrahippocampal areas, it is probable that mTLE is a large-scale network disorder rather than a focal disorder. The hippocampus was a network hub in left mTLE but not in right mTLE patients, which may be due to intrinsic functional and structural asymmetries between left and right mTLE patients. The evaluation of cortical hubs, even in the spike-free resting-state, could be a clinical diagnostic marker of mTLE with HS.

Delayed diagnosis of probable radiation induced spinal cord vascular disorders

Occasionally, unexpected neurological deficits occur after lumbar spinal surgery. We report a case of monoparesis after lumbar decompressive surgery. A 63-year-old man, who had undergone decompression of L4-5 for spinal stenosis 4 days previously in the other hospital, visted the emergency department with progressive weakness in the left leg and hypoesthesia below sensory level T7 on the right side. He had been cured of lung cancer with chemotherapy and radiation therapy 10 years previously, but detailed information of radiotherapy was not available. Whole spine magnetic resonance (MR) imaging showed fatty marrow change from T1 to T8, most likely due to previous irradiation. The T2-weighted MR image showed a high-signal T4-5 spinal cord lesion surrounded by a low signal rim, and the T1-weighted MR image showed focal high signal intensity with focal enhancement. The radiological diagnosis was vascular disorders with suspicious bleeding. Surgical removal was refused by the patient. With rehabilitation, the patient could walk independently without assistance 2 months later. Considering radiation induced change at thoracic vertebrae, vascular disorders may be induced by irradiation. If the spinal cord was previously irradiated, radiation induced vascular disorders needs to be considered.

Risk factor analysis of hinge fusion failure after plate-only open-door laminoplasty

Study Design Retrospective study. Objectives To analyze lamina hinge fusion failure after plate-only open-door laminoplasty. Methods Thirty-one patients who underwent plate-only open-door laminoplasty (110 levels) for cervical myelopathy and who had serial computed tomography (CT) scans at 6 and 12 months were analyzed. Risk factors for fusion failure at 12 months were analyzed, including age, sex, smoking, presence of diabetes mellitus and ossification of posterior longitudinal ligament, bone mineral density (T-score), preoperative cervical curvature, operated levels, presence of a ventral cortical bony continuity, and reflection angle of the lamina hinge. Clinical outcomes were assessed with neck pain score using visual analog scale, neck disability index, and Japanese Orthopedic Association score. Results Hinge fusion occurred in 84% (26/31) of patients at 12 months. A significant risk factor for fusion failure was the absence of a ventral cortical bony continuity at 6 months (p < 0.01; 100 versus 48%). No lamina with ventral cortical bony continuity at 6 months showed depression at 12 months, but two lamina without continuity showed depression of 2.5 and 2.1 mm, respectively, at 12 months. Clinical outcomes were not different between patients with and without hinge fusion. Conclusion Absence of a ventral cortical bony continuity at 6 months is a risk factor for fusion failure at 12 months. However, bicortically defective laminae usually heal with minimal displacement, although it may take longer than 12 months.

Changes in cervical sagittal alignment after single-level posterior percutaneous endoscopic cervical diskectomy

Study Design Case series. Objective Posterior percutaneous endoscopic cervical diskectomy (PECD) can preserve the disk in patients with a foraminal disk herniation. However, progressive angulation at the operated segment is a concern, especially for patients with cervical lordosis < 10 degrees. The change in cervical lordosis after posterior PECD was analyzed. Methods Medical records were reviewed of 32 consecutive patients (22 men, 10 women; mean age, 49 ± 12 years) who had single-level foraminal soft disk herniation. The operation levels were as follows: C4-5 in 1 patient, C5-6 in 12, C6-7 in 18, and C7-T1 in 1. All patients were discharged the day after the operation, and neck motion was encouraged. All patients were followed for 30 ± 7 months (range, 24 to 46 months), and 21/32 patients (66%) had radiographs taken at 25 ± 11 months (range, 12 to 45 months). Radiologic parameters were assessed, including cervical curvature (C2-7), segmental Cobb's angle (SA), and anterior and posterior disk height (AH and PH, respectively) at the operative level. Results At the last follow-up, 29/32 patients (91%) had no or minimal pain, and 3/32 patients had occasional pain. SA, AH, and PH were not significantly changed. Cervical lordosis < 10 degrees was present in 10/21 patients preoperatively and in 3/21 patients at the last follow-up. For patients with cervical lordosis < 10 degrees, cervical curvature changed from -2.5 ± 8.0 to -11.3 ± 9.3 degrees (p = 0.01). For patients with cervical lordosis ≥ 10 degrees, cervical curvature changed from -17.5 ± 5.8 to -19.9 ± 5.7 degrees (p = 0.24). Conclusions Cervical curvature does not worsen after posterior PECD.

A new measure for monitoring intraoperative somatosensory evoked potentials

Objective

To propose a new measure for effective monitoring of intraoperative somatosensory evoked potentials (SEP) and to validate the feasibility of this measure for evoked potentials (EP) and single trials with a retrospective data analysis study.

Methods

The proposed new measure (hereafter, a slope-measure) was defined as the relative slope of the amplitude and latency at each EP peak compared to the baseline value, which is sensitive to the change in the amplitude and latency simultaneously. We used the slope-measure for EP and single trials and compared the significant change detection time with that of the conventional peak-to-peak method. When applied to single trials, each single trial signal was processed with optimal filters before using the slope-measure. In this retrospective data analysis, 7 patients who underwent cerebral aneurysm clipping surgery for unruptured aneurysm middle cerebral artery (MCA) bifurcation were included.

Results

We found that this simple slope-measure has a detection time that is as early or earlier than that of the conventional method; furthermore, using the slope-measure in optimally filtered single trials provides warning signs earlier than that of the conventional method during MCA clipping surgery.

Conclusion

Our results have confirmed the feasibility of the slope-measure for intraoperative SEP monitoring. This is a novel study that provides a useful measure for either EP or single trials in intraoperative SEP monitoring.

Kinematic changes in swallowing after surgical removal of anterior cervical osteophyte causing Dysphagia: a case series

This retrospective case series included five patients who underwent surgical resection of the cervical anterior osteophyte due to dysphagia. Videofluoroscopic swallowing studies (VFSSs) were performed before and after surgery on each patient, and kinematic analysis of the video clips from the VFSS of a 5-mL liquid barium swallow was carried out. Functional oral intake improved after surgery in 3/4 patients who had required a modified diet before surgery. Kinematic analysis showed increases in the maximal hyoid vertical movement length (13.16±5.87 to 19.09±4.77 mm, p=0.080), hyoid movement velocities (170.24±84.71 to 285.53±104.55 mm/s, p=0.043), and upper esophageal sphincter opening width (3.97±0.42 to 6.39±1.32 mm, p=0.043) after surgery. In conclusion, improved upper esophageal sphincter opening via enhancement of hyoid movement after cervical anterior osteophyte resection may be the kinetic mechanism of improved swallowing function.

Impaired pre-attentive auditory processing in fibromyalgia: A mismatch negativity (MMN) study

OBJECTIVE

Fibromyalgia (FM) patients often show deficits in cognitive functions such as attention and working memory. We assumed that pre-attentive information processing, a crucial element in human perception and cognition, would be altered in FM patients. Thus, the objective of this study was to determine whether FM patients exhibit alterations in pre-attentive processing as assessed by auditory mismatch negativity (MMN).

METHODS

Auditory evoked magnetic fields were recorded in FM patients (n=18) and healthy control subjects (n=21) during a duration-deviant auditory oddball paradigm. The magnetic mismatch negativity (MMNm) was obtained by subtracting responses to standard tones from responses to deviant tones. Pressure pain thresholds over the thenar and trapezius muscles were determined using an algometer.

RESULTS

MMNm peak amplitudes in right hemispheres were attenuated, and the directional asymmetry coefficient of the MMNm amplitude was lower in FM patients, indicating a more leftward asymmetry than in healthy control subjects. Smaller right MMNm amplitude was associated with lower pressure pain thresholds of thenar muscles in FM patients.

CONCLUSIONS

Our results suggested that pre-attentive processing of auditory information is impaired in FM patients.

SIGNIFICANCE

This study provided neurophysiological evidence of impaired pre-attentive sensory change detection in FM.

Abnormal functional brain network in epilepsy patients with focal cortical dysplasia

PURPOSE

Focal cortical dysplasia (FCD) is the second most common pathological entity in surgically treated neocortical focal epilepsy. Despite the recent increase of interest in network approaches derived from graph theory on epilepsy, resting state network analysis of the FCD brain has not been adequately investigated. In this study, we investigated the difference in the resting state functional network between epilepsy patients with FCD and healthy controls using whole-brain magnetoencephalography (MEG) recordings.

METHODS

Global mutual information (MIglob) and global efficiency (Eglob) were calculated for theta (4-7 Hz), alpha (8-12 Hz), beta (13-30 Hz), and gamma (31-45 Hz) bands in 35 epilepsy patients with FCD and 23 healthy controls.

RESULTS

Resting state FCD brains had stronger functional connectivity (MIglob) in the beta and gamma bands and higher functional efficiency (Eglob) in the beta and gamma bands than those of the controls (p<0.05). The MIglob and Eglob values of FCD type I and II brains in the beta band were higher than those of healthy control brains (p<0.05). In the gamma band, the values of FCD type II brains were higher than those of control and FCD type I brains (p<0.05).

CONCLUSIONS

FCD brains had increased functional connectivity in the beta and gamma frequency bands at the resting state compared with those in healthy controls. In addition, patients exhibited different network characteristics depending on the type of FCD. The resting state network analysis could be useful in a clinical setting because we observed network differences even when there was no prominent interictal spike activity.

Power spectral aspects of the default mode network in schizophrenia: an MEG study

Background

Symptoms of schizophrenia are related to deficits in self-monitoring function, which may be a consequence of irregularity in aspects of the default mode network (DMN). Schizophrenia can also be characterized by a functional abnormality of the brain activity that is reflected in the resting state. Oscillatory analysis provides an important understanding of resting brain activity. However, conventional methods using electroencephalography are restricted because of low spatial resolution, despite their excellent temporal resolution.

The aim of this study was to investigate resting brain oscillation and the default mode network based on a source space in various frequency bands such as theta, alpha, beta, and gamma using magnetoencephalography. In addition, we investigated whether these resting and DMN activities could distinguish schizophrenia patients from normal controls. To do this, the power spectral density of each frequency band at rest was imaged and compared on a spatially normalized brain template in 20 patients and 20 controls.

Results

The spatial distribution of DMN activity in the alpha band was similar to that found in previous fMRI studies. The posterior cingulate cortex (PCC) and lateral inferior parietal cortex were activated at rest, while the medial prefrontal cortex (MPFC) was deactivated at rest rather than during the task. Although the MPFC and PCC regions exhibited contrasting activation patterns, these two regions were significantly coherent at rest. The DMN and resting activities of the PCC were increased in schizophrenia patients, predominantly in the theta and alpha bands.

Conclusions

By using MEG to identify the DMN regions, predominantly in the alpha band, we found that both resting and DMN activities were augmented in the posterior cingulate in schizophrenia patients. Furthermore, schizophrenia patients exhibited decreased coherence between the PCC and MPFC in the gamma band at rest.

Preoperative weakness and demyelination of the corticospinal tract in meningioma patients : changes in diffusion parameters using diffusion tensor imaging

Objective

Differentiation of demyelination in white matter from axonal damage can be determined using diffusion tensor imaging (DTI). In this study using meningioma patients an attempt was made to evaluate the relationship between preoperative weakness and the changes of diffusion parameters in the corticospinal tract (CST) using DTI.

Methods

Twenty-six patients with meningioma were enrolled in this study. Eleven of them suffered from objective motor weakness and were classified as Group 1. The remaining 15 patients did not present motor weakness and were classified as Group 2. Fiber tractography and CST diffusion parameters were obtained using DTIStudio. The ratios (lesion side mean value/contralateral side mean value) of CST diffusion parameters were compared with 1.0 as a test value using a one-sample t-test.

Results

In Group 1, fractional anisotropy (FA), tensor trace (TT), and radial diffusivity (RD, λ2 and λ3) of the CST were significantly different between two hemispheres, but axial diffusivity (AD, λ1) of the CST was not significantly different between two hemispheres. In Group 2, FA and λ3 of CST did not differ significantly between the hemispheres. In Group 2, TT, λ1, and λ2 of CST in the ipsilateral hemisphere were significantly higher than those of the unaffected hemisphere. However, the differences were small.

Conclusion

Motor weakness was related to a low FA and high TT resulting from increased RD of the CST fibers. CST diffusion changes in patients with weakness are similar to those for demyelination.

Longitudinal changes in seizure outcomes after resection of cerebral cavernous malformations in patients presenting with seizures: a long-term follow-up of 46 patients

BACKGROUND

Seizure is the most common presentation in patients with cerebral cavernous malformations (CCMs). Although many articles have documented seizure outcomes after resection of CCM, few have conducted long-term follow-ups; thus, the fluctuating seizure outcomes have been neglected. The purpose of this study is to describe long-term postoperative seizure outcomes in patients with CCM and to compare seizure outcomes between patients with sporadic seizures and those with chronic seizures.

METHODS

Forty-six patients with CCM presenting with seizures underwent surgery. The male-to-female ratio was 1:1, and the average age at initial seizure onset was 27.6 years. The mean preoperative seizure duration was 42.7 months. Patients were divided into two groups: a chronic group (N = 20) and a sporadic group (N = 26) according to seizure frequency and duration. The mean postoperative follow-up duration was 96.3 months, and the postoperative seizure outcomes were checked annually based upon Engel's classification.

RESULTS

After the first year of follow-up, 80.8 % of the sporadic group and 75.0 % of the chronic group were evaluated as Engel class I. These rates increased to 100.0 % and 90.0 %, respectively, at the eighth year of follow-up. Overall, 29 (63.0 %) of the 46 patients experienced changes in seizure outcomes over the follow-up period. Despite their delayed improvements, the chronic group showed less favorable outcomes throughout follow-up (p = 0.025).

CONCLUSIONS

Long-term follow-up is indispensable for accurately assessing postoperative seizure outcomes because these outcomes change continuously. We recommend earlier surgery to achieve seizure-free status in patients with CCM. However, even in the chronic group, surgery is recommended, considering the overall delayed improvement.

The time-dependent effect of ibandronate on bone graft remodeling in an ovariectomized rat spinal arthrodesis model

BACKGROUND CONTEXT

In osteoporotic patients undergoing spinal arthrodesis, the use of bisphosphonates (BPs) remains controversial with regard to bone fusion. There is no consensus about the appropriate time to give BPs to patients with osteoporosis undergoing spinal arthrodesis.

PURPOSE

We aimed to study the effect of BPs, given at different times, on the bone response to osteoporotic spinal arthrodesis.

STUDY DESIGN/SETTING

Radiological, histologic, and molecular assessments of bone formation after the different administration time of ibandronate in an ovariectomized (OVX) rat spinal fusion model.

METHODS

Female Sprague-Dawley rats (n=100) were OVX (n=80) or non-OVX operated (n=20) and randomized into five groups: non-OVX, osteoporosis, and osteoporosis with early, simultaneous, and late BP groups. Eight weeks after ovariectomy, lumbar spinal arthrodesis was performed using autologous tailbones. Animals were killed 4 and 8 weeks after arthrodesis, and bone formation was assessed by measuring bone mineral density (BMD), messenger RNA expression, manual palpation, radiological evaluation, and histomorphometry.

RESULTS

Compared with late administration, early administration of ibandronate increased femur BMD in OVX rats and did not hinder bone fusion. Radiological analysis showed that groups given early ibandronate had increased bone volume in the grafted site 8 weeks after surgery. Histomorphometric analysis showed that ibandronate positively affected endochondral and intramembranous ossification. In the OVX groups, ibandronate increased bone turnover to a level similar to that in the non-OVX group. These findings suggested that early administration of ibandronate did not inhibit osteogenesis, including endochondral and intramembranous ossification and fusion rate.

CONCLUSIONS

Our results suggest that the early administration of BPs may not hinder the bone fusion of osteoporotic patients undergoing spinal arthrodesis.

High-accuracy brain-machine interfaces using feedback information

Sensory feedback is very important for movement control. However, feedback information has not been directly used to update movement prediction model in the previous BMI studies, although the closed-loop BMI system provides the visual feedback to users. Here, we propose a BMI framework combining image processing as the feedback information with a novel prediction method. The feedback-prediction algorithm (FPA) generates feedback information from the positions of objects and modifies movement prediction according to the information. The FPA predicts a target among objects based on the movement direction predicted from the neural activity. After the target selection, the FPA modifies the predicted direction toward the target and modulates the magnitude of the predicted vector to easily reach the target. The FPA repeats the modification in every prediction time points. To evaluate the improvements of prediction accuracy provided by the feedback, we compared the prediction performances with feedback (FPA) and without feedback. We demonstrated that accuracy of movement prediction can be considerably improved by the FPA combining feedback information. The accuracy of the movement prediction was significantly improved for all subjects (P<0.001) and 32.1% of the mean error was reduced. The BMI performance will be improved by combining feedback information and it will promote the development of a practical BMI system.

Functional connectivity of resting state EEG and symptom severity in patients with post-traumatic stress disorder

OBJECTIVES

Post-traumatic stress disorder (PTSD) is thought to be a brain network disorder. This study aimed to examine the resting-state functional connectivity (FC) in patients with PTSD.

METHODS

Thirty-three PTSD patients and 30 age- and gender-matched healthy controls were recruited. Symptom severity of the PTSD patients was assessed, and 62-channel EEG was measured. EEGs were recorded during the resting state, with the eyes closed. Three nodal network measures to assess nodal centrality [nodal degree (Dnodal; connection strength), nodal efficiency (Enodal; communication efficiency), and betweenness centrality (BC; connection centrality)] were calculated in the delta, theta, alpha, beta, and gamma bands.

RESULTS

Dnodal and Enodal of the beta and gamma bands were decreased in PTSD patients compared to healthy controls. These decreased nodal centrality values were observed primarily at the frontocentral electrodes. In addition, Dnodal of the beta and gamma bands was significantly correlated with depressive symptoms and increased arousal symptoms, respectively. Enodal of the beta and gamma bands was significantly correlated with re-experience, increased arousal, and the severity and frequency of general PTSD symptoms.

CONCLUSION

Compared to controls, patients with PTSD were found to have decreased resting-state FC, and these FC measures were significantly correlated with PTSD symptom severity. Our results suggest that resting-state FC could be a useful biomarker for PTSD.

Epidemiological survey of ossification of the posterior longitudinal ligament in an adult Korean population: three-dimensional computed tomographic observation of 3,240 cases

The prevalence rates of ossification of the posterior longitudinal ligament (OPLL) in the Korean population were reported as 3.4 and 0.6%. However, these studies were performed before the era of three-dimensional computed tomography (3D CT). We investigated the prevalence of cervical OPLL on the basis of 3D CT and features of OPLL distribution in an adult Korean population. During 2011 and 2012, a total of 3,240 patients were enrolled who had undergone thyroid 3D CT. A total of 1,084 men and 2,156 women were included. Axial and sagittal reconstruction images were used for observations. More than 2 mm thickness in an axial image was the criterion for the presence of OPLL. The prevalence rate was adjusted according to a standardized population according to Statistics Korea. The OPLL prevalence rate was 5.7%. The standardized prevalence rate was 4.60%. The standardized prevalence rates in men and women were 6.43 and 3.61%, respectively. The over-70 age group had the highest OPLL prevalence. Age and prevalence rate were positively correlated in men and women (correlation coefficient 0.991 and 0.991, P<0.001 and P<0.0001, respectively). Among OPLL types, the multiple segmental type was most frequent (37.3%). The most commonly involved level was C5 (4.8% in men, 2.2% in women), C4 (4.6% in men, 1.2% in women), and C6 (3.7% in men, 2.4% in women) segments, in decreasing order. To our knowledge, this study is the first 3D CT-based epidemiologic study on cervical OPLL in a Korean population.

Stereotactic radiosurgery compared with external radiation therapy as a primary treatment in spine metastasis from renal cell carcinoma: a multicenter, matched-pair study

The aim of this multicenter, matched- pair study was to compare the outcome of stereotactic radiosurgery (SRS) with that of external radiation therapy (RT) when used as a primary treatment in spine metastasis from renal cell carcinoma (RCC). From 2005 to 2012, 13 patients underwent SRS as a primary treatment in spine metastasis from RCC. Thirteen patients who underwent RT as the primary treatment of RCC spine metastasis were paired with the SRS patients based on age, number of spine metastasis, time interval from original tumor diagnosis to spine metastasis, Eastern Cooperative Oncology Group status, and year of treatment. The primary outcomes of interest were pain relief and progression free survival. Secondary outcomes were treatment toxicities and need for further treatment. The perioperative VAS score decrease was larger in the SRS group than that in the RT group (P = 0.04). More SRS patients had complete or partial pain relief although the difference was not significant. There was a significant difference in progression free survival between the two groups (P = 0.01). The percentage of patients with toxicities was 38.5 % (5/13) in the SRS group and 53.9 % (7/13) in the RT group, but the difference was not significant. There were 2 SRS patients and 3 RT patients who received further intervention at the index segment. This study showed that, when performed as a primary treatment in spine metastasis from RCC, SRS provides relatively better pain relief and better local control than that obtained from RT.

Primary diffuse leptomeningeal glioneuronal tumors

Diffuse leptomeningeal disseminated glioneuronal tumor (DL-GNT) is a rare brain tumor that presents as a plaque-like subarachnoid tumor, commonly involving the basal cisterns and interhemispheric fissure of children but lacking intraparenchymal tumor. Histologically, the tumors are composed of sheets of monotonous rounded cells. Here, we report three cases of DL-GNTs, focusing on clinicopathologic features. Two patients were adult male, but one patient was child. The patients presented with seizures (n = 1) or headaches (n = 2). In all patients, radiography revealed characteristic leptomeningeal thickening and enhancement with minor superficial parenchymal lesions. All three cases were diffusely positive for both GFAP and synaptophysin, and scattered positive for OLIG2 and NeuN, but negative for IDH-1 (H09). Electron microscopic examination showed astrocytic and neuronal differentiation. The patient with the anaplastic tumor died due to aggressive progression of the tumor, but the remaining two patients were stable without tumor recurrence for 23 and 37 months. Thus, these findings suggest that DL-GNT can occur in both children and adult and both supra- and infra-tentorial leptomeninges. It has unique radiological and histopathological features and biological behavior. Further clinicopathological data with molecular genetic study are required for establishing DL-GNT as a unique entity.

Melody effects on ERANm elicited by harmonic irregularity in musical syntax

Recent studies have reported that early right anterior negativity (ERAN) and its magnetic counterpart (ERANm) are evoked by harmonic irregularity in Western tonal music; however, those studies did not control for differences of melody. Because melody and harmony have an interdependent relationship and because melody (in this study melody is represented by the highest voice part) in a chord sequence may dominate, there is controversy over whether ERAN (or ERANm) changes arise from melody or harmony differences. To separate the effects of melody differences and harmonic irregularity on ERANm responses, we designed two magnetoencephalography experiments and behavioral test. Participants were presented with three types of chord progression sequences (Expected, Intermediate, and Unexpected) with different harmonic regularities in which melody differences were or were not controlled. In the uncontrolled melody difference experiment, the unexpected chord elicited a significantly largest ERANm, but in the controlled melody difference experiment, the amplitude of the ERANm peak did not differ among the three conditions. However, ERANm peak latency was delayed more than that in the uncontrolled melody difference experiment. The behavioral results show the difference between the two experiments even if harmonic irregularity was discriminated in the uncontrolled melody difference experiment. In conclusion, our analysis reveals that there is a relationship between the effects of harmony and melody on ERANm. Hence, we suggest that a melody difference in a chord progression is largely responsible for the observed changes in ERANm, reaffirming that melody plays an important role in the processing of musical syntax.