Search

Few studies have directly compared anterior and posterior surgical approaches in cervical spondylotic myelopathy (CSM) patients with short-segment disease. We aimed to examine and compare surgical outcomes of anterior cervical discectomy with fusion (ACDF) and selective laminoplasty (S-LAMP) in CSM patients with 1- or 2-level disease.Forty-six patients, who received surgeries for CSM, were prospectively investigated; 24 underwent ACDF and 22 underwent S-LAMP. Average follow-up was 3.5 years. The following pre- and postoperative radiographic measurements were recorded: (1) C2-7 angle, (2) local angle (lordotic Cobb angle at operative level), (3) cervical sagittal vertical axis (SVA) (center of gravity of the head-C7 SVA), and (4) C7 slope. Outcomes were evaluated using the Japanese Orthopedic Association scoring system for cervical myelopathy (C-JOA score), neck pain visual analog scale, and neck disability index (NDI).There were no significant differences in patient demographics between the two groups. Postoperatively, C2-7 angle, local angle, cervical SVA, C7 slope, C-JOA score, and neck pain and NDI scores were not significantly different between the two groups; however, the recovery rate of the C-JOA score was superior in the ACDF group (57.5%) compared to the S-LAMP group (42.1%). The recovery rate of the C-JOA score in the local lordosis subgroup (local angle ≥ 0°) showed no significant difference between the two surgical groups. However, in the local kyphosis subgroup (local angle 0°), C-JOA score recovery rate was worse after S-LAMP (20.4%) than ACDF (57.9%); local angle also worsened postoperatively after S-LAMP.In patients with local lordosis at the segments of cervical spondylosis and spinal cord compression, S-LAMP showed equivalent surgical outcomes (neurological recovery, neck pain and NDI scores, and cervical alignment) to ACDF. However, in patients with local kyphosis, S-LAMP worsened the kyphosis and resulted in worse neurological recovery.

Prospective comparative study.To investigate the benefits of postoperative application of lumbosacral orthosis after single-level discectomy for lumbar disc herniation (LDH).Although many surgeons use postoperative lumbosacral orthosis for patients with LDH, there is no clear evidence to support or deny its effectiveness.Ninety-nine consecutive patients who underwent the microscopic discectomy were included. They were divided into two groups: Orthosis group and Non-orthosis group, before surgery. The recurrence rate and reoperation rate were compared between the two groups at 4-week, 6-month and 1-year follow-up. Japanese Orthopaedic Association Score for lumbar spine (L-JOA score) at 2-week and 1-year follow-up, lower extremities and low back pain's visual analog scale (VAS) and Oswestry Disability Index (ODI) at 6-month and 1-year follow-up were compared.Forty-two patients in the Orthosis group and 39patients in the Non-orthosis group were followed up for at least 1-year after surgery. Recurrence occurred in 3 patients (7.1%) in the Orthosis group and 6 (15.4%) in the Non-orthosis group within 1-year. Two patients (4.8%) in the Orthosis group and 2 patients (5.1%) in the Non-orthosis group underwent reoperation. There were no significant intergroup differences in the recurrence rate and in the reoperation rate. No significant difference was also observed between the two groups in L-JOA score, ODI, VAS of low back pain, and leg pain at 1-year after surgery. Furthermore, at any other follow-up period, no significant differences were observed between the two groups in recurrence rate, reoperation rate, L-JOA score, VAS of low back/leg pain, or ODI.Postoperative orthosis did not reduce the recurrence/ reoperation rates, nor improve postoperative clinical symptoms. Routine use of orthosis may not be necessary after single-level lumbar discectomy.

Study design Prospective observational cohort study. Objective To prospectively examine dysphagia after subaxial cervical spine surgery. Summary of background data Although dysphagia after anterior cervical spine surgery is common and well-studied, it has rarely been examined in posterior subaxial cervical spine surgery. Methods This study analyzed 191 consecutive patients (132 male, 59 female; mean age, 64.9 yrs) who underwent subaxial cervical spine surgery for degenerative disease and completed 1 year of follow-up. Anterior decompression with fusion (ADF) was performed in 87 patients, posterior decompression with fusion (PDF) in 21, and laminoplasty (LAMP) in 83. Dysphagia was evaluated by a self-administered questionnaire using the Bazaz dysphagia scale before, 6 months, and 1 year after surgery. Diagnosis, levels and number of operative segments, C2-7 lordotic angle (CL), O-C2 angle (OC2A), C2-7 range of motion (ROM), Japanese Orthopedic Association for cervical myelopathy (C-JOA) score, and neck pain visual analog scale (VAS) were examined. Results Thirty-two patients (16.8%) reported dysphagia before surgery. New dysphagia after surgery, defined as more than or equal to 1 grade worsening of the Bazaz score after surgery compared with the preoperative status, was observed in 38 patients (19.9%) at 6 months and 32 patients (16.8%) at 1 year. The incidence of new dysphagia at 1 year was 25.3% in the ADF group, 23.8% in the PDF group, and 6.0% in the LAMP group. Fusion surgery (ACDF or PDF) and increased CL after surgery were found as risk factors at 1 year in multivariate analysis; receiver operating characteristic analysis determined a postsurgical change in CL cutoff of 5°. Conclusion Fusion surgery and increased CL after surgery were risk factors for development of dysphagia after subaxial cervical spine surgery. Cervical alignment change due to anterior and posterior fusion surgery can cause postoperative dysphagia.Level of Evidence: 3.

Objective Magnetospinography (MSG) has been developed for clinical application and is expected to be a novel neurophysiological examination. Here, we used an MSG system with sensors positioned in three orthogonal directions to record lumbar canal evoked magnetic fields (LCEFs) in response to peripheral nerve stimulation and to evaluate methods for localizing spinal cord lesions. Methods LCEFs from the lumbar area of seven rabbits were recorded by the MSG system in response to electrical stimulation of a sciatic nerve. LCEFs and lumbar canal evoked potentials (LCEPs) were measured before and after spinal cord compression induced by a balloon catheter. The lesion positions were estimated using LCEPs and computationally reconstructed currents corresponding to the depolarization site. Results LCEFs were recorded in all rabbits and neural activity in the lumbar spinal cord could be visualized in the form of a magnetic contour map and reconstructed current map. The position of the spinal cord lesion could be estimated by the LCEPs and reconstructed currents at the depolarization site. Conclusions MSG can visualize neural activity in the spinal cord and localize the lesion site. Significance MSG enables noninvasive assessment of neural activity in the spinal canal using currents at depolarization sites reconstructed from LCEFs.

Background Surgical procedures for cervical myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) are often chosen based on OPLL size and cervical spine alignment. Recently, cervical sagittal alignment based on sagittal vertical axis (SVA) has received increased attention as an important determinant of radiological and clinical outcomes after surgery. This study aimed to investigate the impact of SVA-based cervical sagittal alignment on surgical treatment for cervical OPLL by reviewing a previous retrospective cohort in which its concept was not taken into account in the surgical procedure choices. Methods We reviewed a total of 96 consecutive patients who underwent surgery for cervical myelopathy caused by OPLL from 2008 to 2014. We performed anterior decompression with fusion (ADF) or posterior decompression with fusion (PDF) on patients with massive OPLL or kyphotic alignment, and we performed laminoplasty (LAMP) on patients without massive OPLL or kyphotic alignment. CSVA (center of gravity of the head - C7 SVA), CL (C2-7 lordotic angle) and C7 slope were measured in cervical X-ray at standing position. Clinical results were evaluated using C-JOA score. We divided patients into two subgroups based on the preoperative CSVA: the Low-CSVA (CSVA Results In the Low-CSVA subgroup, none of the three operations had an effect on the CL. In contrast, in the High-CSVA subgroup, while ADF and PDF had no effect on the CL, LAMP worsened the CL postoperatively. The recovery rates of the C-JOA scores in the Low-CSVA subgroup showed no significant differences among the three operations; however in the High-CSVA subgroup, LAMP resulted in worse recovery rate of the C-JOA score than ADF or PDF. Conclusions LAMP is not suitable for patients with cervical myelopathy caused by OPLL who have high CSVA alignment, even in cases without massive OPLL or kyphotic alignment.

Study Design: Retrospective single-center study. Objectives: K-line is a decision-making tool to determine the appropriate surgical procedures for patients with cervical ossification of the posterior longitudinal ligament (C-OPLL). Laminoplasty (LAMP) is one of the standard surgical procedures indicated on the basis of K-line measurements (+: OPLL does not cross the K-line). We investigated the impact of K-line tilt, a radiographic parameter of cervical sagittal balance measured using the K-line, on surgical outcomes after LAMP. Methods: The study included 62 consecutive patients with K-line (+) C-OPLL who underwent LAMP. The following preoperative and postoperative radiographic measurements were evaluated: (1) the K-line, (2) K-line tilt (an angle between the K-line and vertical line), (3) center of gravity of the head –C7 sagittal vertical axis, (4) C2–C7 lordotic angle, (5) C7 slope, and (6) C2–C7 range of motion. Clinical results were evaluated using the Japanese Orthopedic Association scoring system for cervical myelopathy (C-JOA score). Results: All the patients had non-kyphotic cervical alignment (CL ≥ 0°) preoperatively; however, kyphotic deformity (CL < 0°) was observed in 6 patients (9.7%) postoperatively. The recovery rate of the C-JOA scores was poor in the kyphotic deformity (+) group (7.8%) than in the kyphotic deformity (−) group (47.5%). The K-line tilt was identified to be a preoperative risk factor in the multivariate analysis, and the cutoff K-line tilt for predicting the postoperative kyphotic deformity was 20°. Conclusions: LAMP is not suitable for K-line (+) C-OPLL patients with K-line tilts >20°.

STUDY DESIGN A retrospective case series. OBJECTIVE The aim of this study was to investigate the incidence and clinical features of laminar closure in patients with cervical spondylotic myelopathy (CSM) based on prospectively collected data. SUMMARY OF BACKGROUND DATA Laminar closure after single open-door laminoplasty (LAMP) has been reported to result in poor clinical outcomes. However, no studies to date have examined the underlying mechanisms and frequency of laminar closure after double-door LAMP. METHODS This study prospectively enrolled 128 consecutive patients with CSM scheduled for double-door LAMP without a laminar spacer at our hospital between 2008 and 2013. Sagittal parameters including C2-7 angle, T1 slope, and cervical sagittal vertical axis (C-SVA), which is defined as the distance between the anterior margin of the external auditory canal plumb line and the posterior-cranial corner of the C7 vertebral body on x-ray, were calculated before and after the operation. Laminar angle was also measured on magnetic resonance images preoperatively and at 1 week and 1 year postoperatively. Laminar closure was defined as > 20% decrease in laminar angle at 1 year compared with that at 1 week postoperatively. The Japanese Orthopedic Association score for cervical myelopathy and the recovery rate determined from the preoperative and postoperative scores were evaluated as clinical outcomes. RESULTS In total, 110 patients were completely followed up for at least 1 year (follow-up rate: 85.9%). Laminar closure was observed in six cases (5.5%) at the 1-year follow-up. The recovery rate in these six cases was significantly lower than in cases without laminar closure (16.6% vs. 45.1%, respectively). Logistic regression analysis revealed age and C-SVA as significant risk factors for postoperative laminar closure. CONCLUSION This study is the first to investigate the incidence of laminar closure after double-door LAMP without a laminar spacer. Laminar closure occurred exclusively in elderly patients with kyphotic deformity after LAMP.Level of Evidence: 4.

Diagnosis of nervous system disease is greatly aided by functional assessments and imaging techniques that localize neural activity abnormalities. Electrophysiological methods are helpful but often insufficient to locate neural lesions precisely. One proposed noninvasive alternative is magnetoneurography (MNG); we have developed MNG of the spinal cord (magnetospinography, MSG). Using a 120-channel superconducting quantum interference device biomagnetometer system in a magnetically shielded room, cervical spinal cord evoked magnetic fields (SCEFs) were recorded after stimulation of the lower thoracic cord in healthy subjects and a patient with cervical spondylotic myelopathy and after median nerve stimulation in healthy subjects. Electrophysiological activities in the spinal cord were reconstructed from SCEFs and visualized by a spatial filter, a recursive null-steering beamformer. Here, we show for the first time that MSG with high spatial and temporal resolution can be used to map electrophysiological activities in the cervical spinal cord and spinal nerve.

Background Atlantoaxial subluxation (AAS) is characterized by excessive movement at the junction between the atlas (C1) and axis (C2) as a result of either a bony or ligamentous abnormality. Surgical intervention is a therapeutic choice for AAS. In addition to C1 laminectomy (LAM), surgical fixation for subluxation or instability is performed by various techniques. While surgical treatment options for AAS have increased, the outcomes of different surgical techniques remain unclear. Methods The authors conducted a retrospective analysis of the outcomes of 30 consecutive spinal surgeries performed for AAS patients, C1 LAM in 11 cases and C1/2 fixation in 19 cases. We investigated the correlation between the clinical outcomes and the surgical methods. We also examined the factors related to poor outcomes (the recovery rate of the Japanese Orthopedic Association score for cervical myelopathy

A retrospective analysis of prospectively collected data of 179 consecutive patients who underwent intraoperative neurophysiological monitoring during posterior cervical spine surgery for compression myelopathy.To evaluate preoperative factors in patients with deteriorating spinal cord function due to flexion of the neck during posterior cervical spine surgery by observing changes in waveforms on intraoperative monitoring.We encountered several cases of intraoperative monitoring warning alerts because of neck flexion during posterior cervical spine surgery. We investigated the incidence rate and intraoperative predictors of deteriorating spinal cord function caused by neck flexion based on waveform changes.Subjects were 179 patients who underwent posterior cervical decompression for spinal cord compression. When warning alarms were set off by amplitude changes in the period between skin incision and exposure of the lamina, the neck position was changed from flexion to neutral, and patients whose electrical potentials recovered following cervical repositioning were placed in the flexion-induced potential reduction group. We then analyzed and extracted risk factors for flexion-induced reduction in electrical potentials.In total, 156 patients were analyzed in this study. Monitoring alarms went off intraoperatively for 7 patients (4.5%) at the time of posterior cervical spine exposure. With regard to the most compressed level, the occupancy ratio of the anterior compression component, the kyphotic angle in flexion, and range of motion in the neutral position to flexion were significantly associated with flexion-induced reduction in electrical potentials. Furthermore, logistic regression analysis extracted the occupancy ratio of the anterior compression component at the most compressed level and the kyphotic angle of the most compressed level in flexion.Our findings suggest that a large anterior compression component and large kyphotic angle in neck flexion at the most compressed level are risk factors for intraoperative spinal cord injury during posterior cervical spine surgery.

Objective To establish a method to measure cauda equina action fields (CEAFs) and visualize the electrical activities of the cauda equina in a broadly aged group of healthy adults. Methods Using a 124-channel magnetospinography (MSG) system with superconducting interference devices, the CEAFs of 43 healthy volunteers (22–64 years of age) were measured after stimulation of the peroneal nerve at the knee. Reconstructed currents were obtained from the CEAFs and superimposed on the X-ray image. Conduction velocities were also calculated from the waveform of the reconstructed currents. Results The reconstructed currents were successfully visualized. They flowed into the L5/S1 foramen about 8.25–8.95 ms after the stimulation and propagated cranially along the spinal canal. In 32 subjects (74%), the conduction velocities of the reconstructed currents in the cauda equina could be calculated from the peak latency at the L2–L5 level. Conclusions MSG visualized the electrical activity of the cauda equina after peroneal nerve stimulation in healthy adults. In addition, the conduction velocities of the reconstructed currents in the cauda equina could be calculated, despite previously being difficult to measure. Significance MSG has the potential to be a novel and noninvasive functional examination for lumbar spinal disease.

In Japan, the ‘earthquake-resistant pipe ratio’ and the ‘amount of stored water for emergency’ have been used to evaluate the anti-earthquake performance of water supply facilities. In the past, however, those evaluations were made mainly from the viewpoint of the supplier, and evaluations from the customer9s (citizen9s) viewpoint have been insufficient. For simpler explanations to customers, the evaluation model based on ‘living conditions,’ related to emergency water use in the restoration period, has been established and a verification study has been conducted using an analysis model for evaluating the effect of various seismic upgrade measures adopted in Kobe City. Verification results show that the seismic improvement measures would produce a shorter restoration period compared with the time for the 1995 Great Hanshin–Awaji earthquake and that a greater amount of water would be available in the restoration period, leading to wider and more frequent use of water by citizens.

Superficial siderosis (SS) of the CNS is a rare disease caused by repeated hemorrhages in the subarachnoid space. The subsequent deposition of hemosiderin in the brain and spinal cord leads to the progression of neurological deficits. The causes of bleeding include prior intradural surgery, carcinoma, arteriovenous malformation, nerve root avulsion, and dural abnormality. Recently, surgical treatment of SS associated with dural defect has been reported. The authors of the present report describe 2 surgically treated SS cases and review the literature on surgically treated SS. The patients had dural defects with fluid-filled collections in the spinal canal. In both cases, the dural defects were successfully closed, and the fluid collection was resolved postoperatively. In one case, the neurological symptoms did not progress postoperatively. In the other case, the patient had long history of SS, and the clinical manifestations partially deteriorated after surgery, despite the successful dural closure. In previously reported surgically treated cases, the dural defects were closed by sutures, patches, fibrin glue, or muscle/fat grafting. Regardless of the closing method, dural defect closure has been shown to stop CSF leakage and subarachnoid hemorrhaging. Successfully repairing the defect can halt the disease progression in most cases and may improve the symptoms that are associated with CSF hypovolemia. However, the effect of the dural closure may be limited in patients with long histories of SS because of the irreversibility of the neural tissue damage caused by hemosiderin deposition. In patients with SS, it is important to diagnose and repair the dural defect early to minimize the neurological impairments that are associated with dural defects.

STUDY DESIGN A retrospective single-center study. OBJECTIVE To investigate how functional recovery is influenced by anterior compression of the spinal cord (ACS) and instability at the level of ACS after laminoplasty in patients with cervical spondylotic myelopathy. SUMMARY OF BACKGROUND DATA There have been many reports that patients whose spinal cord cannot be decompressed sufficiently after laminoplasty are likely to show unsatisfactory neurologic outcomes. Notably, postoperative ACS is well known to cause problems. Clinically, however, it remains unknown how functional recovery is inhibited by postoperative ACS. METHODS Sixty-four consecutive patients who underwent expansive laminoplasty for the treatment of myelopathy at our hospital between 1998 and 2005 were reviewed. All 64 patients were available for follow-up. The average follow-up period was 97 months (60-156 months). Patients were divided into 2 groups: the ACS(+) group comprised 16 patients who had ACS 3 years postoperatively, and the ACS(-) group comprised 48 patients with no ACS. Clinical outcome was compared in terms of the Japanese Orthopaedic Association score (mean total score, mean score of each item, and recovery rates). RESULTS Demographics were similar between the 2 groups. Mean Japanese Orthopaedic Association score at final follow-up was 12.1 points (recovery rate 34.0%) in the ACS(+) group and 13.8 points (recovery rate 56.6%) in the ACS(-) group, and there was a significant difference in recovery rate between the groups (P < 0.05). Notably, a significant difference was found between the 2 groups in improvement of upper extremity motor function (P < 0.05). In addition, we found that not only the presence of ACS but also postoperative hypermobility of the intervertebral segment with ACS influenced clinical outcome negatively. CONCLUSION These results demonstrate that ACS after laminoplasty could be a risk factor for clinical outcome and might prevent improvement in upper extremity motor function in patients with myelopathy.

STUDY DESIGN Retrospective analysis of prospectively collected data from consecutive patients undergoing 2 methods of transcranial electrical motor evoked potential (TCE-MEP) monitoring during cervical spine surgery. OBJECTIVE To investigate the efficacy of biphasic transcranial electric stimulation, the deviation rate, amplitude of TCE-MEPs, complications, and sensitivity and specificity of TCE-MEP monitoring were compared between the biphasic and conventional monophasic stimulation methods. SUMMARY OF BACKGROUND DATA With biphasic stimulation, unlike monophasic stimulation, measurement time can be reduced considerably because a single stimulation elicits bilateral responses almost simultaneously. However, no study has yet reported a detailed comparison of the 2 methods. METHODS Examination 1: Amplitude and derivation rate of TCE-MEPs was compared for monophasic and biphasic stimulation in the same 31 patients with cervical compression myelopathy. Examination 2: Sensitivity, specificity, and complications of TCE-MEP monitoring were compared in 200 patients with cervical compression myelopathy who received monophasic or biphasic stimulation (100 patients each) during intraoperative monitoring. RESULTS Examination 1: Derivation rates of biphasic stimulation in the deltoid, biceps brachii, abductor digiti minimi, and flexor hallucis brevis muscles were the same or higher than for monophasic stimulation. TCE-MEP amplitudes elicited by biphasic stimulation compared with monophasic stimulation were significantly larger in the biceps (paired t, P < 0.0001), but similar in the other 3 muscles. Examination 2: In the biphasic and monophasic stimulation groups, warnings were issued to surgeons in 10 and 11 cases, for a sensitivity of 100% for both groups and specificity of 97.8% and 96.7%, respectively. No complications related to stimulation were observed in any of the 200 patients. CONCLUSION Biphasic stimulation had similar or higher derivation rates and equivalent sensitivity and specificity than monophasic stimulation. No complications were observed for either stimulation method. Biphasic stimulation is an effective TCE-MEP monitoring method for cervical spine surgery that may also reduce measurement time. LEVEL OF EVIDENCE 4.

Superficial siderosis (SS) of the CNS is a rare disease caused by repeated hemorrhages in the subarachnoid space. The subsequent deposition of hemosiderin in the brain and spinal cord leads to the progression of neurological deficits. The causes of bleeding include prior intradural surgery, carcinoma, arteriovenous malformation, nerve root avulsion, and dural abnormality. Recently, surgical treatment of SS associated with dural defect has been reported. The authors of the present report describe 2 surgically treated SS cases and review the literature on surgically treated SS. The patients had dural defects with fluid-filled collections in the spinal canal. In both cases, the dural defects were successfully closed, and the fluid collection was resolved postoperatively. In one case, the neurological symptoms did not progress postoperatively. In the other case, the patient had long history of SS, and the clinical manifestations partially deteriorated after surgery, despite the successful dural closure. In previously reported surgically treated cases, the dural defects were closed by sutures, patches, fibrin glue, or muscle/fat grafting. Regardless of the closing method, dural defect closure has been shown to stop CSF leakage and subarachnoid hemorrhaging. Successfully repairing the defect can halt the disease progression in most cases and may improve the symptoms that are associated with CSF hypovolemia. However, the effect of the dural closure may be limited in patients with long histories of SS because of the irreversibility of the neural tissue damage caused by hemosiderin deposition. In patients with SS, it is important to diagnose and repair the dural defect early to minimize the neurological impairments that are associated with dural defects.

STUDY DESIGN A prospective analysis OBJECTIVE Our aim was to investigate the efficacy of new synthetic porous/dense composite hydroxyapatite (HA) for use in anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA Iliac crest bone graft (ICBG) has been traditionally used as the "gold standard" for ACDF. The significant complication rate associated with harvesting tricortical ICBG, however, has encouraged development of alternative graft substitutes. METHODS The morphology of the porous/dense HA was observed by scanning electron microscopy (SEM), and the in vitro compressive strength of the composite HA was measured. From April 2005, 51 consecutive patients underwent 81 levels of ACDF using the composite HA with percutaneously harvested trephine bone chips. Clinical and radiological evaluation was performed during the postoperative hospital stay and at follow-up. Furthermore, the outcomes in ACDF using the composite HA were compared with those using tricortical ICBG. RESULTS The SEM images demonstrated 100- to 300-μm pores (approximately 40% of porosity) in the porous layers of the HA. The compressive strength of the composite HA was 203.1 ± 4.1 MPa. In the clinical study, the demographic data of the patients were similar in HA and ICBG groups. The fusion rates in HA group were comparable with those in ICBG group. The cervical lordosis was enhanced postoperatively in both groups and well preserved at 2-year follow-up without significant differences between the groups. The intraoperative blood loss in HA group was significantly lesser than that in ICBG group. Donor site complications were found in 29.2% of the patients in ICBG group, whereas no donor site morbidity was found in HA group. No major collapse or fragmentation of the composite HA was found. CONCLUSION The hybrid graft of composite HA and percutaneously harvested trephine chips seemed promising as a graft substitute for ACDF. LEVEL OF EVIDENCE 4.

Spine fractures in patients with ankylosing spondylitis frequently extend to all 3 columns, which can lead to displacement and deformity with severe instability. Cervical spine fractures occasionally cause severe kyphotic deformities, such as chin-on-chest deformities. In such cases, the patients typically exhibit a chronic progression of hyperkyphosis after the traumatic event. This article describes a unique case of ankylosing spondylitis associated with an acute chin-on-chest deformity following a spine fracture due to a vertebral locking lesion. A 60-year-old man fell while walking and sustained a compression fracture of the C6 vertebra. Two weeks later, the patient acutely developed an inability to raise his head, difficulties with chewing and swallowing, and a horizontal gaze. Radiographs demonstrated a severe kyphosis in the cervical spine with a locking lesion between the anterior wall of the C5 and C6 vertebrae. The patient also presented with neurological impairment in his hands. Because the anterior approach to the spine was anatomically impossible, halo traction was initially applied under a close observation of neurological symptoms. Three days after halo traction, release of the vertebral locking lesion and realignment of the spine were seen. The patient subsequently underwent spinal fusion using a combined anterior–posterior approach. Postoperatively, neurological dysfunction improved, and solid fusion was confirmed at 6 months. In cases of acute kyphotic deformity following cervical spine fracture in ankylosing spondylitis patients, halo traction followed by circumferential spine fusion is a safe and effective approach for improving the alignment and stability of the spine.

STUDY DESIGN Paravertebral muscle activity measurement by surface electromyography (EMG) in lumbar degenerative patients and healthy volunteers. OBJECTIVE Muscle activity was tested in the standing position, and the influence of low back pain and alignment of the lumbar spine was assessed in the patients with lumbar kyphosis (LDK) or canal stenosis. SUMMARY OF BACKGROUND DATA The number of kyphosis patients has increased as the population has grown older. Advanced kyphosis can cause difficulties in maintaining a standing position and affect daily living activities. The most direct cause is the atrophy of erector spinae muscles. The activity of these muscles has not yet been sufficiently evaluated and needs to be assessed objectively for the purpose of diagnosis and treatment. METHODS The subjects were kyphosis patients who were 60 years of age or older, age-matched lumbar spinal canal stenosis patients, and healthy volunteers. Muscular activity at the L1-L2 and the L4-L5 intervertebral areas was recorded by surface EMG in the resting standing position and also with a weight load held in the standing position. Muscle activity and muscle fatigue, and the association between the Visual Analogue Scale, the Japanese Orthopaedic Association score for low back pain, and muscle activity, were analyzed. RESULTS Kyphosis patients had a greater muscle activity in the lower back in the resting standing position and more severe muscle fatigue at the upper lumbar spine in comparison with patients with lumbar spinal canal stenosis. There was no association between muscle activity and clinical findings in patients with LDK although. CONCLUSIONS Our study revealed the constant activity of paravertebral muscles and the susceptibility to muscle fatigue in patients with LDK. The quantification of muscle activity by surface EMG may show the pathology of LDK, and the decrease in muscle activity in the standing position may be a potentially useful index for guiding treatment.

STUDY DESIGN A retrospective analysis of prospectively collected data from consecutive patients undergoing transcranial electrical motor-evoked potential (TCE-MEP: compound muscle action potentials) monitoring during cervical spine surgery. OBJECTIVE.: To divide the warning threshold of TCE-MEP amplitude changes on the basis of origin into the spinal tract and spinal segments and decide warning thresholds for each. SUMMARY OF BACKGROUND DATA The parameter commonly used for the warning threshold in TCE-MEP monitoring is wave amplitude, but amplitude changes have not been examined by anatomical origin. METHODS Intraoperative TCE-MEP amplitude changes were reviewed for 357 patients with cervical myelopathy. Most of the patients were monitored by transcranial electrical stimulated spinal-evoked potential combined with TCE-MEP. The warning threshold of TCE-MEP was taken as waveform disappearance. For each patient, amplitude changes were separated, according to origin, into the spinal tract and spinal segments and compared with clinical outcome. RESULTS Assessable TCE-MEP waves were obtained in 350 cases. Disappearance of TCE-MEP waves, which were innervated by the spinal levels exposed to the surgical invasion, was seen in 11 cases. Disappearance of TCE-MEPs, which were innervated by the spinal levels inferior to them, was seen in 43 cases. There was no postoperative motor deficit in those cases. However, such deficits caused by spinal segment injury were seen in 2 cases, which showed that intraoperative amplitude decreased to 4.5% and 27%. CONCLUSION If we had established the warning threshold as 30% of the control amplitude, we would likely have prevented both cases of postoperative motor deficits, but 106 (30.3%) cases would have become positive cases. If we had established the warning threshold separately as wave disappearance for the spinal tract and 30% of the control amplitude for the spinal segments, sensitivity and specificity would have been 100% and 83.7%, respectively. Dividing the warning threshold on the basis of origin of amplitude changes could reduce false-positive cases and prevent intraoperative injuries.

Amyotrophic lateral sclerosis is a fatal neurodegenerative disease characterized by progressive motoneuron loss. Redistribution of transactive response deoxyribonucleic acid-binding protein 43 from the nucleus to the cytoplasm and the presence of cystatin C-positive Bunina bodies are considered pathological hallmarks of amyotrophic lateral sclerosis, but their significance has not been fully elucidated. Since all reported rodent transgenic models using wild-type transactive response deoxyribonucleic acid-binding protein 43 failed to recapitulate these features, we expected a species difference and aimed to make a non-human primate model of amyotrophic lateral sclerosis. We overexpressed wild-type human transactive response deoxyribonucleic acid-binding protein 43 in spinal cords of cynomolgus monkeys and rats by injecting adeno-associated virus vector into the cervical cord, and examined the phenotype using behavioural, electrophysiological, neuropathological and biochemical analyses. These monkeys developed progressive motor weakness and muscle atrophy with fasciculation in distal hand muscles first. They also showed regional cytoplasmic transactive response deoxyribonucleic acid-binding protein 43 mislocalization with loss of nuclear transactive response deoxyribonucleic acid-binding protein 43 staining in the lateral nuclear group of spinal cord innervating distal hand muscles and cystatin C-positive cytoplasmic aggregates, reminiscent of the spinal cord pathology of patients with amyotrophic lateral sclerosis. Transactive response deoxyribonucleic acid-binding protein 43 mislocalization was an early or presymptomatic event and was later associated with neuron loss. These findings suggest that the transactive response deoxyribonucleic acid-binding protein 43 mislocalization leads to α-motoneuron degeneration. Furthermore, truncation of transactive response deoxyribonucleic acid-binding protein 43 was not a prerequisite for motoneuronal degeneration, and phosphorylation of transactive response deoxyribonucleic acid-binding protein 43 occurred after degeneration had begun. In contrast, similarly prepared rat models expressed transactive response deoxyribonucleic acid-binding protein 43 only in the nucleus of motoneurons. There is thus a species difference in transactive response deoxyribonucleic acid-binding protein 43 pathology, and our monkey model recapitulates amyotrophic lateral sclerosis pathology to a greater extent than rodent models, providing a valuable tool for studying the pathogenesis of sporadic amyotrophic lateral sclerosis.

Study design A case report of a patient with adhesive arachnoiditis after combined spinal and epidural anesthesia. Objective To report an extremely rare case of paraplegia due to adhesive arachnoiditis with extensive syringomyelia (ES) and a giant anterior arachnoid spinal cyst (AASC) after spinal and epidural anesthesia for obstetric surgery. Summary of background data Progressive inflammation of the arachnoid mater due to trauma, infection, or hydrocortisone was reported as early as the 1970s. However, coexistence of ES and a giant AASC after spinal and epidural anesthesia is extremely rare. Methods A 29-year-old woman suffered from sudden anuresis 5 months after spinal and epidural anesthesia for a cesarean section and subsequently experienced paraplegia and numbness below the chest. Magnetic resonance imaging showed an AASC compressing the spinal cord at T1-T6 and an adhesive lesion at T7. Posterior laminectomy at T6-T7 and adhesiolysis for arachnoid adhesion at T7 were performed. Although there was slight recovery of locomotive function postoperatively, it gradually worsened until 3 years after surgery. Magnetic resonance imaging at that time demonstrated a giant AASC and ES at the lower-thoracic cord. The cord compressed by the AASC became thinner sagittally. Secondary surgery involving posterior laminectomy at T5-T6 and insertion of a cyst-peritoneal shunt into the AASC was performed. Results The patient could walk without a cane 3 years after the shunt operation, although numbness and motor weakness of the lower extremities remained. Magnetic resonance imaging 3 years after the shunt operation showed a reduction of the AASC and decompression of the cord despite no improvement in ES. Conclusion This is the first report of a patient with a giant AASC and ES caused by spinal and epidural anesthesia. Although the optimal surgical treatment for these conditions remains unclear, shunting of the cyst effectively prevented the progression of symptoms.

Study design A prospective, comparative study. Objective We developed a hybrid graft (HBG) of porous β-tricalcium phosphate ceramics/percutaneously harvested bone sticks/autologous bone marrow aspirate for lumbar posterolateral fusion (PLF). The aim of this study was to investigate the efficacy of the HBG as a substitute for conventional corticocancellous iliac autografts. Summary of background data Iliac crest bone graft (ICBG) has been traditionally used as the golden standard for lumbar spinal fusion. The significant complication rate associated with harvesting corticocancellous ICBG, however, has encouraged development of alternative graft substitutes. Methods From September 2005, 61 consecutive patients underwent decompressive laminotomy and 1-level instrumented PLF. Each patient in this study had the constructs of the HBG placed on 1 side of the intertransverse process gutter. An autologous local bone graft (LBG) harvested during decompressive laminotomy was placed on the other side as a control. Radiographic evaluation was performed at 6 months, 1 year after surgery, and subsequently on an annual basis. The fusion statuses on either side of vertebra were compared. Results The flexion-extension motion in the dynamic x-rays at the target level decreased over time. Only 1 case exhibited over 5° of angular motion 2 years after surgery. In the evaluation of fusion status, the fusion rate for the HBG side (68.9% at 6 months, 83.6% at 1 year, 93.5% at 2 years) was higher than that for the LBG side (49.2% at 6 months, 75.4% at 1 year, 89.1% at 2 years) with a significant difference at 6 months after surgery. No significant complications at the donor site were found postoperatively. Conclusion The HBG promoted posterolateral spinal fusion without significant donor site morbidity. Because of its efficacy and safety, this hybrid construct seems promising as an alternative to conventional iliac bone grafts for lumbar spinal fusion.

Objective To measure neuromagnetic evoked fields in the lumbar spinal canal. Methods Using a newly developed superconducting quantum interference device (SQUID) fluxmeter, neuromagnetic fields of 5 healthy male volunteers were measured at the surface of the lower back after stimulation of the tibial nerves at the ankles. For validation, we inserted a catheter-type electrode percutaneously in the lumbar epidural space in 2 of the subjects and measured cauda equina action potentials after tibial nerve stimulation. Results Neuromagnetic fields propagating from the intervertebral foramina into the spinal canal were measured, and the latencies of the magnetic fields corresponded largely with those of the cauda equina action potentials. Conclusions We successfully measured ascending neuromagnetic fields originating at the nerve root and the cauda equina with high spatial resolution. Future studies will determine whether neuromagnetic field measurement of the lumbar spine can be a useful diagnostic method for the identification of the disordered site in spinal nerves. Significance We successfully measured neuromagnetic fields in the lumbar spinal canal, which have previously been difficult to verify. Future studies will determine whether neuromagnetic field measurement of the lumbar spine can be a useful diagnostic method for identifying disorders of spinal nerves.

Heme oxygenase-1 (HO-1) is an antioxidant enzyme and is believed to protect against oxidative stress-induced tissue injury. Renal ischemia-reperfusion (IR) injury seems at least in part to be caused by the oxidative stress. The aim of this study was to improve the renal IR injury by clinically available means. When littermate hemolysate was intravenously administered into rats, HO-1 was markedly induced in the kidneys. To investigate whether prior induction of HO-1 by the hemolysate injection ameliorates the subsequent renal IR injury, we assessed the levels of blood urea nitrogen (BUN) and serum creatinine (SCr), markers for renal injury, in rats with 45 min of ischemia followed by 18 h of reperfusion. To avoid the nephrotoxicity induced by hemolysate, small but effective amounts of hemolysate was injected into rats at 48 h prior to the ischemia. The levels of BUN and SCr values were significantly improved as compared to the rats with renal IR injury alone. Administration of HO inhibitor abolished the efficacy of hemolysate pretreatment. Our findings indicated that the prior induction of HO-1 by treatment of littermate hemolysate ameliorated the subsequent renal IR injury. Prior injection of self-hemolysate would be clinically useful for the protection against the renal IR injury induced by kidney transplantation and kidney surgery without immunological and infectious problems.

The aim of this studywas to develop amethod for functional imaging of human nerve electrical activities in the lumbar spine from evoked neuromagnetic measurements. The source reconstruction of nerve electrical activities was carried out over a curved surface that contained the nerve fiber in the lumbar spine. This curved surface was determined by using subject’s lateral X-ray image. We proposed to apply the Unit-Gain Constraint MinimumNorm filter with a Recursively Update Gram matrix spatial filter to reconstruct source activities on this surface. Reconstructed source intensity reflected cauda equine travel. This linewas determined by using reconstructed source imaging of the front direction. Reconstructed sources propagated from caudal to rostral along the lumbar spinal canal. During the time courses at five selected voxels along the nerve travel, each time course showed a clear peak and into latency indicated the instants when nerve activity arrived at five voxel locations. Our proposed imaging method can clearly visualize the dynamics and the temporal intensity changes of nerve electrical activities in the lumbar spine.