論文

Introduction: The paucity of research concerning the conservative management of spinal cord and cauda equina schwannomas and meningiomas complicates the determination of surgical necessity and its optimal timing. This study aimed to elucidate the clinical and imaging characteristics of schwannomas and meningiomas in the thoracolumbar and lumbar spine that support long-term conservative management strategies. Methods: A retrospective case series of 159 patients with magnetic resonance imaging-confirmed schwannomas or meningiomas was conducted. Patients were categorized into operative (n=125) and conservative (n=34) groups based on whether surgery was performed within one year of diagnosis. Tumor characteristics, clinical symptoms, and imaging data were systematically analyzed. Tumor occupancy was modeled using an ellipsoidal formula to estimate spinal canal involvement. A receiver operating characteristic curve analysis determined the optimal cutoff for predicting treatment decisions. Multivariate logistic regression was employed to identify factors influencing treatment choice. Results: Tumor occupancy emerged as a critical determinant, with a cutoff of 0.42 predicting treatment choice with a sensitivity of 0.79 and a specificity of 0.89 (area under the curve=0.87). Logistic regression analysis revealed significant associations for tumor occupancy (adjusted odds ratio [OR]=9.6×10-5; 95% confidence interval [CI]=6.2×10-7-5.3×10-3; p<0.001), presence of numbness or leg pain (OR=0.022; 95% CI=9.8×10-4-0.18; p=0.002), and male gender (OR=0.19; 95% CI=0.038-0.83; p=0.037). No significant associations were observed for age, decreased manual muscle testing, or imaging heterogeneity. Conclusions: Prolonged conservative management is feasible for female patients who do not have leg pain or numbness and tumors with low occupancy. A tumor occupancy threshold of 0.42 may serve as a valuable clinical indicator to guide treatment decisions, promoting individualized, symptom-driven management strategies tailored to patient characteristics.

Study design: A retrospective observational study. Objectives: To elucidate predictive clinical factors associated with irreversible complete motor paralysis following traumatic cervical spinal cord injury (CSCI). Setting: Hokkaido Spinal Cord Injury Center, Japan. Methods: A consecutive series of 447 traumatic CSCI persons were eligible for this study. Individuals with complete motor paralysis at admission were selected and divided into two groups according to the motor functional outcomes at discharge. Initial findings in magnetic resonance imaging (MRI) and other clinical factors that could affect functional outcomes were compared between two groups of participants: those with and those without motor recovery below the level of injury at the time of discharge. Results: Of the 73 consecutive participants with total motor paralysis at initial examination, 28 showed some recovery of motor function, whereas 45 remained complete motor paralysis at discharge, respectively. Multivariate logistic regression analysis showed that the presence of intramedullary hemorrhage manifested as a confined low intensity changes in diffuse high-intensity area and more than 50% of cord compression on MRI were significant predictors of irreversible complete motor paralysis (odds ratio [OR]: 8.4; 95% confidence interval [CI]: 1.2–58.2 and OR: 14.4; 95% CI: 2.5–82.8, respectively). Conclusion: The presence of intramedullary hemorrhage and/or severe cord compression on initial MRI were closely associated with irreversible paralysis in persons with motor complete paralysis following CSCI. Conversely, subjects with a negligible potential for recovery could be identified by referring to these negative findings.

Study design: Retrospective cohort study. Objectives: Thoracic dumbbell-shaped schwannomas (DS) often require incomplete resection (IR) because of anatomical constraints. This study aimed to compare outcomes between gross total resection (GTR) and IR and to identify factors associated with postoperative regrowth of remnant tumors after IR. Setting: Single academic institution. Methods: Patients with thoracic DS surgically treated between 2002 and 2021 were retrospectively reviewed. All patients underwent at least two postoperative MRI examinations and were followed for a minimum of 2 years. Patients were classified into GTR and IR groups; IR cases were further divided according to the presence or absence of postoperative tumor regrowth (>2 mm). Clinical variables, surgical factors, remnant margin zone, residual tumor volume, and regrowth direction were analyzed. Residual tumor volume was measured using three-dimensional volumetric analysis. Results: Thirty-eight patients were included (24 GTR, 14 IR). Postoperative improvement in visual analog scale scores was significantly greater in the GTR group. Among IR cases, 7 patients showed postoperative tumor regrowth. No significant differences were observed between regrowth and non-regrowth groups in age, Eden classification, surgical approach, or remnant margin zone. Residual tumor volume was significantly larger in cases with regrowth (p = 0.016). Tumor regrowth predominantly occurred in the extraforaminal direction. Conclusions: In thoracic DS, larger residual tumor volume is associated with postoperative regrowth, possibly reflecting complex segmental vascular anatomy. When safely feasible, GTR remains the preferred strategy to minimize the risk of remnant tumor regrowth.

Study Design. – Prospective multicenter cohort study. Objective. – To evaluate the prevalence, clinical characteristics, and surgical outcomes of neuropathic pain in patients with degenerative cervical myelopathy (DCM), using the Neuropathic Pain Symptom Inventory (NPSI). Summary of Background Data. – Neuropathic pain is increasingly recognized as a major determinant of quality of life (QOL) in DCM. However, few prospective studies have comprehensively evaluated its distribution, severity, and postoperative trajectory. Patients and Methods. – A total of 816 DCM patients from 10 institutions were prospectively enrolled. Preoperative and two-year postoperative assessments included the NPSI, cervical Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS), and 36-Item Short Form Health Survey (SF-36). Correlation and multiple regression analyses were performed to identify associations between NPSI scores and QOL, as well as predictive factors for postoperative improvement. Results. – Preoperatively, 88.5% of patients reported symptoms of neuropathic pain, with paresthesia/dysesthesia being the most prominent subtype. At two years postoperatively, all NPSI subdomains showed significant improvement (P<0.001), though paresthesia/dysesthesia remained most persistent. Higher preoperative NPSI scores were significantly associated with greater postoperative pain reduction (β=−0.556, P<0.001). Total NPSI scores significantly correlated with all SF-36 subdomains both before and after surgery (all P<0.001), indicating a strong relationship between pain and QOL. Conclusion. – This study provides the first large-scale prospective evaluation of neuropathic pain in DCM. While neuropathic pain is prevalent and improves with surgery, residual symptoms—especially paresthesia/dysesthesia—remain common and impactful. These findings highlight the importance of individualized postoperative pain management strategies to optimize long-term QOL.

Study Design. – Prospective multicenter cohort study. Objective. – To compare clinical outcomes between posterior decompression without fusion (PD) and anterior cervical discectomy and fusion (ACDF) in patients with 1- to 2-level degenerative cervical myelopathy (DCM). Summary of Background Data. – While numerous studies have assessed surgical strategies for multilevel DCM, limited evidence is available for cases involving only one or two levels. Methods. – Among 1482 patients with degenerative cervical spine disorders from 10 Japanese institutions, 353 patients with 1- to 2-level DCM treated with either PD (n=233) or ACDF (n=120) and followed for 2 years were included. Clinical outcomes included the Japanese Orthopaedic Association (JOA) score, Visual Analog Scale (VAS), Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and Short Form-36 (SF-36). Group comparisons were adjusted for baseline characteristics and preoperative clinical outcomes using a general linear model. Results. – Perioperative complication and reoperation rates did not significantly differ between groups. ACDF provided significantly greater improvements in VAS scores for neck pain (−22.6 vs. −6.1 mm, P=0.003), upper extremity pain/numbness (−32.7 vs. −18.3 mm, P=0.011), and SF-36 bodily pain (22.8 vs. 10.1, P=0.003) and physical component summary (PCS) scores (9.1 vs. 3.5, P=0.007) compared with the PD group. Conversely, PD yielded greater improvement in the SF-36 social functioning domain (13.3 vs. 2.6, P=0.011). No significant differences were observed in JOA scores, the five domains of JOACMEQ, or other SF-36 domains. Conclusions. – Both PD and ACDF provided comparable improvements in neurological function as measured by JOA and JOACMEQ scores, indicating similar efficacy in treating DCM. ACDF was more effective for alleviating neck and arm pain and enhancing physical health, while PD resulted in social functioning. Given similar complication rates, surgical strategy should be individualized based on each patient’s clinical presentation.

Study Design. A prospective longitudinal magnetic resonance imaging (MRI) study. Objective. The objective of this study was to describe the progression of intervertebral disk (IVD) degeneration in patients who underwent posterior decompression surgery for lumbar spinal canal stenosis (LSS). Summary of Background Data. IVD degeneration contributes to the pathogenesis of LSS; however, the long-term consequences of degenerative changes after decompression surgery remain unknown. Materials and Methods. Of 258 consecutive patients who underwent posterior lumbar decompression surgery for LSS, 62 who underwent MRI at their 10-year follow-up were included; 17 age-matched asymptomatic volunteers were analyzed as controls. Three MRI findings representing IVD degeneration were graded on their severity: decrease in signal intensity, posterior disk protrusion (PDP), and disk space narrowing (DSN). Clinical outcome was assessed using the low back pain (LBP) score from the Japanese Orthopaedic Association scoring system. We examined the association between the progression of degenerative changes on MRI and LBP/associated factors using logistic regression adjusting for age at baseline and sex. Results. The severity of IVD degeneration tended to be higher in patients with LSS than asymptomatic volunteers at both baseline and follow-up. IVD degeneration progressed in all patients during the 10-year follow-up period. Progression of decrease in signal intensity and PDP was observed at L1/2 in 73% and at L2/3 in 34%, respectively (the highest frequencies in the lumbar spine). Progression of DSN was highest at L4/5 in 42%. The rates of PDP and DSN progression during the 10-year follow-up period tended to be greater in patients with LSS than in asymptomatic volunteers. No significant difference in the proportion of LBP deterioration was evident for individuals with and without MRI findings of progression. Conclusions. Our study reveals a natural history of the long-term postoperative course of IVD degeneration after posterior decompression surgery for LSS. Compared with healthy controls, patients with LSS seemed to be predisposed to IVD degeneration. Lumbar decompression surgery may promote the progression of DSN; however, progression of IVD degeneration after lumbar decompression surgery was not associated with worsening LBP scores.

Purpose: Adolescent idiopathic scoliosis (AIS) is a complex, three-dimensional (3D) spinal deformity characterized by both coronal curvature and axial rotation. Traditional radiographic measurements primarily reflect the internal spinal alignment but do not fully capture external surface asymmetry or rotational components. Moreover, patients’ perceptions of their trunk deformity often diverge from radiographic findings. This discrepancy may be attributed to various sources of bias in patient self-assessment. The present study aimed to investigate the relationship between preoperative 3D body surface measurements and body image perception in patients with AIS. Methods: We conducted a retrospective analysis of patients diagnosed with Lenke type 1 AIS who were scheduled to undergo posterior spinal correction and fusion surgery at our institution between April 2022 and April 2024. Preoperative trunk asymmetry was assessed as the height difference of the 3D back surface using a 3D back scanner (Sanamedi, Tokyo, Japan). Radiographic parameters and patient-reported outcomes were compared with 3D surface measurements. Correlation analyses were performed using Pearson’s correlation coefficient or Spearman’s rank correlation coefficient, depending on the distribution of the data. Results: A total of 52 female patients were included, with a mean age of 15.4 ± 2.3 years. Analysis of all cases indicated that 3D surface measurements were moderately correlated with the Cobb angle (ρ = 0.51, p <.001). In contrast, no significant correlations were found between 3D surface measurements and any domain of the Scoliosis Research Society-22 questionnaire. Weak to moderate correlations were observed in the Walter reed visual assessment scale (ρ = 0.29–0.40, p <.05). Conclusion: This study demonstrated that 3D surface measurements correlate with radiographic parameters, supporting their validity in assessing spinal deformity. Although 3D surface measurements showed statistically significant but weak to moderate correlations with radiographic parameters, discrepancies were observed between objective assessments and patients’ subjective perception. Further research involving a broader range of deformity type is warranted to better clarify these relationships.

Background: Surgical strategies for spinal deformities associated with neurofibromatosis type 1(NF-1) have been still controversial due to the wide variety of pathologies, particularly, for deformities with severe dystrophic changes in pediatric patients remained challenging with high complication and reoperation rates. The purpose of this study was to validate our surgical strategies by evaluating clinical and radiographical outcomes. Methods: We retrospectively evaluated 22 cases who underwent correction surgeries for spinal deformities in our institute. The investigations included patient background, presence of dystrophic changes and paravertebral tumors, surgical procedure, number of surgeries, complications and reoperation, and radiographical parameters including Cobb angle and T1-S1 length. Results: The mean age at the first surgery was 11.6 ± 5.5 years. The mean follows up period was 84.3 ± 50.2 months. Of the 22 cases, 4 cases had cervical kyphosis and 18 cases had deformity in thoracic and/or lumbar spine. Dystrophic changes of spine were observed in all 4 cases with cervical kyphosis and 15 cases with spinal deformity in thoracic and/or lumbar spine. All cases with cervical kyphosis underwent posteroanterior fusion following halo gravity traction preoperatively. The mean local kyphosis of cervical spine improved from 83.7 ± 5.9° to 16.9 ± 2.4° after surgery and 19.4 ± 2.5° at final follow up, and 2 cases required unplanned surgery due to pseudarthrosis. In cases of deformity in thoracic and/or lumbar spine, 11 cases underwent posteroanterior fusion, 4 cases underwent only posterior fusion, and 3 cases underwent conventional growing-rod, of which 4 cases underwent halo gravity traction before correction surgery. The mean Cobb angle of scoliosis in thoracic and/or lumbar spine improved from 73.2 ± 16.9° to 30.9 ± 15.8° after surgery and 29.5 ± 13.3° at final follow up, and that of T1-S1 growth increased from 338.3 ± 13.3 mm to 406.3 ± 8.9 mm at final follow up. Four cases required unplanned surgery due to pseudarthrosis (n = 2) or progression of deformity (n = 2). Conclusion: The fundamental of surgical treatment for NF-1-related spinal deformity is extensive rigid spinal fusion by adequate bone grafting. Even if these surgeries are performed, in some cases additional surgery could be necessary due to progression of deformity. Level of Evidence: Level III, retrospective cohort study.

Spinal cord injury (SCI) causes irreversible motor and sensory deficits, and no therapy currently restores the damaged neural circuitry. Previous work has shown that transplantation of induced pluripotent stem cell (iPSC)-derived neural stem/progenitor cells (NS/PCs) restored motor function in preclinical models of subacute SCI; however, the safety of this approach in humans remains unknown. Here we report results from a first-in-human, open-label study of iPSC-NS/PC transplantation in four patients with subacute cervical complete SCI. The primary safety end point was achieved, with no tumor formation or graft-related adverse events observed during 2–4 years of follow-up and stable graft sites on imaging. Exploratory efficacy was assessed as a secondary end point. Median improvement in the International Standards for Neurological Classification of Spinal Cord Injury motor score from baseline (2 weeks after injury) to week 52 was 13 points (range 10–40), with two patients improving in American Spinal Injury Association Impairment Scale (grade A → C and A → D). These gains were numerically greater than spontaneous recovery observed in a registry-based cohort. This study provides clinical evidence that transplantation of human iPSC-NS/PCs into the injured spinal cord is feasible and safe under short-term immunosuppression, with findings supporting further clinical evaluation. The trial is registered at UMIN000035074, UMIN000050104 and jRCTa031190228.

Study Design: Retrospective comparative study. Objectives: This study aimed to determine whether the severity of preoperative gait disturbance remains after surgical resection in patients with intramedullary spinal cord tumors (IMSCTs), and to identify any factors influencing poor improvement in postoperative gait disturbance. Methods: The study included a total of 128 patients with IMSCTs requiring surgical excision between 2006 and 2019. Based on the degree of preoperative gait disturbance assessed by the modified McCormick scale (MMCS) grade, patients were categorized into Mild (I-II) and Severe (III-V) groups. The mean postoperative follow-up period was 55.5 ± 34.3 months, and demographic and surgical characteristics were compared between the two groups. Results: Significant differences were observed in age at surgery, tumor location, tumor size, estimated blood loss, intraoperative motor-evoked potential disappearance, extent of resection, and tumor histopathology between the Mild and Severe groups. In the Mild group, at the final follow-up, only 7.3% of patients experienced improvement, 56.0% showed no changes, and 36.7% experienced deterioration. Conversely, in the Severe group, 26.3% of patients experienced improvement, 31.6% showed no changes, and 42.1% experienced deterioration. Tumor location and age at surgery were identified as factors correlated with poor improvement in postoperative gait disturbance in the Mild group. Conclusions: Irrespective of the preoperative gait disturbance degree, approximately 40% of patients with IMSCTs experienced deterioration in gait after tumor resection. For preoperative MMCS grade I-II cases, older age at surgery and thoracic IMSCTs would be important factors associated with poor improvement in postoperative gait disturbance.

The features of non-neoplastic lesions are often similar to those of intramedullary tumors, and a differential diagnosis is challenging to obtain in some cases. A surgical biopsy, which is performed on highly invasive tumors, should be avoided in cases of non-neoplastic lesions. Therefore, an accurate diagnosis is important prior to treatment. We evaluated 43 patients suspected of having spinal cord tumors and, finally, were diagnosed with non-neoplastic intramedullary lesions via magnetic resonance imaging. The patients commonly presented with myelitis. The patients with non-neoplastic neurological diseases had a significantly shorter symptom duration than those with intramedullary astrocytomas. The proportion of patients with non-neoplastic neurological diseases who presented with lesions at the cervical spinal level and focal lesions on axial imaging but without a spinal cord enlargement was significantly higher than that of patients with intramedullary astrocytomas. The current study aimed to distinguish spinal cord tumors from non-neoplastic intramedullary lesions based on their distinct features.