Deep learning-based prediction model for postoperative complications of cervical posterior longitudinal ligament ossification.

PURPOSE: Postoperative complication prediction helps surgeons to inform and manage patient expectations. Deep learning, a model that finds patterns in large samples of data, outperform traditional statistical methods in making predictions. This study aimed to create a deep learning-based model (DLM) to predict postoperative complications in patients with cervical ossification of the posterior longitudinal ligament (OPLL). METHODS: This prospective multicenter study was conducted by the 28 institutions, and 478 patients were included in the analysis. Deep learning was used to create two predictive models of the overall postoperative complications and neurological complications, one of the major complications. These models were constructed by learning the patient's preoperative background, clinical symptoms, surgical procedures, and imaging findings. These logistic regression models were also created, and these accuracies were compared with those of the DLM. RESULTS: Overall complications were observed in 127 cases (26.6%). The accuracy of the DLM was 74.6 ± 3.7% for predicting the overall occurrence of complications, which was comparable to that of the logistic regression (74.1%). Neurological complications were observed in 48 cases (10.0%), and the accuracy of the DLM was 91.7 ± 3.5%, which was higher than that of the logistic regression (90.1%). CONCLUSION: A new algorithm using deep learning was able to predict complications after cervical OPLL surgery. This model was well calibrated, with prediction accuracy comparable to that of regression models. The accuracy remained high even for predicting only neurological complications, for which the case number is limited compared to conventional statistical methods.

Natural history and surgical outcomes of idiopathic spinal cord herniation.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: Although surgery is frequently selected for the treatment of idiopathic spinal cord herniation (ISCH), its impact on functional outcomes has yet to be fully understood given the limited number of patients in previous studies. This study aims to evaluate the symptomatic history and surgical outcomes of ISCH. SETTING: Three institutions in Japan. METHODS: A total of 34 subjects with ISCH were retrospectively enrolled and followed up for at least 2 years. Demographic information, imaging findings, and clinical outcomes were collected. Functional status was assessed using the JOA score. RESULTS: The types of neurologic deficit were monoparesis, Brown-Sequard, and paraparesis in 5, 17, and 12 cases, with their mean disease duration being 1.2, 4.2, and 5.8 years, respectively. Significant differences in disease duration were observed between the monoparesis and Brown-Sequard groups (p < 0.01) and between the monoparesis and paraparesis groups (p = 0.04). Surgery promoted significantly better recovery rates from baseline. Correlations were observed between age at surgery and recovery rate (p < 0.01) and between disease duration and recovery rate (p = 0.04). The mean recovery rates were 82.6%, 51.6%, and 29.1% in the monoparesis, Brown-Sequard, and paraparesis groups, respectively. The monoparesis group had a significantly higher recovery rate than did the Brown-Sequard (p = 0.045) and paraparesis groups (p < 0.01). CONCLUSIONS: Longer disease duration was correlated with the progression of neurologic deficit. Older age, and worse preoperative neurologic status hindered postoperative functional recovery. These results highlight the need to consider surgical timing before neurologic symptoms deteriorate.

Targeted embolisation for coexisting conus medullaris arteriovenous malformation and cauda equina arteriovenous fistulas with a varix on a shared drainer†.

BACKGROUND: The coexistence of vascular malformations in the conus medullaris and cauda equina has been rarely reported, and the complex angioarchitecture in multiple arteriovenous lesions remains poorly understood. CASE DESCRIPTION: A 17-year-old woman presented with a sudden-onset, stepwise worsening of weakness and pain in the bilateral legs. Angiography revealed conus medullaris arteriovenous malformation and cauda equina arteriovenous fistulas. One of the drainers was shared between the coexisting lesions and harboured a varix. Targeted embolisation of a fistulous point in the conus lesion was performed with precaution to prevent occluding the common drainage route, which led to symptom improvement with angiographical diminishment of the varix. CONCLUSIONS: Recognising that communications between drainers can be observed in multiple spinal arteriovenous lesions is important in facilitating a safe embolisation. Cautious assessment of angiogram with fusion images of cone-beam computed tomography and volumetric T2 magnetic resonance imaging can help in establishing the diagnosis and treatment strategy.

Persistent low bone mineral density in adolescent idiopathic scoliosis: A longitudinal study.

BACKGROUND: Since osteopenia has been reported to potentially associated with the progression of scoliosis, bone mineral density (BMD) might have some influences on adolescent idiopathic scoliosis (AIS). However, little is known about longitudinal BMD changes in AIS patients. This study aimed to investigate whether osteopenia in preoperative AIS patients persist at bone maturity, and to evaluate the association between BMD and AIS severity. METHODS: We reviewed 61 AIS patients who underwent surgery when they were Risser grade 4 or below and less than 20 years old (16.6 ± 1.9 years), were followed until they were at least 18 years old and had a Risser grade of 5, and followed at least 2 years after the surgery (mean follow-up 4.9 ± 1.7 years). We evaluated radiographical parameters and proximal femur BMD before surgery and at the final follow-up. A BMD of less than the mean minus 1SD was considered as low BMD. Based on preoperative BMD, 37 patients were assigned to normal BMD (N) group (1.02 ± 0.08 g/cm2) and 24 patients to low BMD (L) group (0.82 ± 0.06 g/cm2). RESULTS: All patients in the N-group had normal BMD at the final follow-up. In the L group, 15 patients (62.5%) had low BMD at the final follow-up (L-L group; preoperative 0.79 ± 0.05 g/cm2 and final follow-up 0.78 ± 0.05 g/cm2). The mean preoperative Cobb angle was significantly larger in the L-L group (67.8 ± 11.2°) than in those with normal BMD at the final follow-up (L-N group, 55.6 ± 11.8°) or the N-N group (50.8 ± 7.6°). Preoperative BMD was significantly negative correlated with the preoperative Cobb angle. The age at surgery and mean preoperative BMI were similar in the L-N and L-L groups. CONCLUSIONS: Of AIS patients with low preoperative BMD, 62.5% still had low BMD after reaching bone maturity, and low BMD was associated with the severity of scoliosis.

Hidden blood loss in extreme lateral interbody fusion for adult spinal deformity.

BACKGROUND: Extreme lateral interbody fusion (XLIF) is often used with posterior spinal fixation (PSF) to treat adult spinal deformity (ASD). However, the amount of intraoperative blood loss (IBL) reported for XLIF may underestimate the total blood loss (TBL). The objective of this study was to determine the total perioperative blood loss in XLIF for ASD. METHODS: We assessed 30 consecutive ASD patients with Schwab-SRS type L (mean age: 68.7 ± 8.2 years; mean follow-up 2.0 ± 1.3 years) who were treated by multilevel XLIF (mean, 2.5 ± 0.6 levels) followed by PSF after 3-5 days. We calculated the TBL after XLIF by the Gross equation, by hemoglobin (Hb) balance, and by the Orthopedic Surgery Transfusion Hemoglobin European Overview (OSTHEO) formula. We defined hidden blood loss (HBL) as the difference between the TBL and IBL. Pearson correlation, Spearman correlation, and multiple logistic regression analysis were performed to investigate the risk factors related to HBL. RESULTS: Post-XLIF blood tests showed a significant decrease in the Hb (from 11.8 ± 1.1 mg/dl to 10.6 ± 1.1 mg/dl) and hematocrit (from 36.0 ± 3.2% to 32.5 ± 3.2%). Although the mean IBL was relatively small (33 ± 52 mL), we calculated the TBL as 291 ± 171 mL (Gross equation) and the HBL as 258 ± 168 mL by Gross equation, which was 8 times greater than the IBL on average. There was no difference in the results obtained using the three methods. Multiple logistic regression analysis indicated preoperative lumber lordosis was the risk factor of high HBL (Odds ratio = 1.085, 95%CI: 1.006-1.170, p = 0.035). CONCLUSIONS: The HBL in XLIF was 8 times greater than the IBL. During the perioperative course of correction and fusion surgery for ASD with XLIF, surgeons need to pay attention not to underestimate the TBL.

"Missing-piece" sign with dural arteriovenous fistula at craniocervical junction: A case report.

OBJECTIVES: Spinal dural arteriovenous fistula (sDAVF) is a rare and often underdiagnosed spinal disease. Early diagnosis is required because the deficits are reversible and delays in treatment cause permanent morbidity. Although the abnormal vascular flow void is a critical radiographic feature of sDAVF, they are not always present. A characteristic enhancement pattern of sDAVF has been recently reported as the "missing-piece" sign which can lead to the early and correct diagnosis. METHODS: We presented imaging findings, treatment decisions, and the outcome of a rare case of sDAVF, in which the "missing-piece" sign appeared atypical. RESULTS: A 60-year-old woman developed numbness and weakness in her extremities. Spinal MRI revealed longitudinal hyperintensity in the T2-weighted image, extending from the thoracic level to medulla oblongata. At first, myelopathy with inflammation or tumor was suspected because of the lack of flow voids and vascular abnormalities in CT-angiography and MR-DSA. However, we administered intravenous methylprednisolone and her symptom got worse with the appearance of the "missing-piece" sign. Then, we successfully diagnosed sDAVF by angiography. The "missing-piece" sign was considered to derive from inconsistency of the intrinsic venous system of spinal cord, with the abrupt segments without enhancement. The same etiology was considered in our case. CONCLUSIONS: Detecting the "missing-piece" sign can lead to the correct diagnosis of sDAVF, even if the sign appeared atypical.

A Review of Treatment Methods Focusing on Human Induced Pluripotent Stem Cell-Derived Neural Stem/Progenitor Cell Transplantation for Chronic Spinal Cord Injury.

Cell transplantation therapy using human induced pluripotent stem cell-derived neural stem/progenitor cells (hiPSC-NS/PCs) has attracted attention as a regenerative therapy for spinal cord injury (SCI), and its efficacy in treating the subacute phase of SCI has been reported in numerous studies. However, few studies have focused on treatment in the chronic phase, which accounts for many patients, suggesting that there are factors that are difficult to overcome in the treatment of chronic SCI. The search for therapeutic strategies that focus on chronic SCI is fraught with challenges, and the combination of different therapies is thought to be the key to a solution. In addition, many issues remain to be addressed, including the investigation of therapeutic approaches for more severe injury models of chronic SCI and the acquisition of practical motor function. This review summarizes the current progress in regenerative therapy for SCI and discusses the prospects for regenerative medicine, particularly in animal models of chronic SCI.

3D imaging of supraspinal inputs to the thoracic and lumbar spinal cord mapped by retrograde tracing and light-sheet microscopy.

The supraspinal inputs play a major role in tuning the hindlimb locomotion function. While most research on spinal cord injury (SCI) with rodents is based on thoracic segments, the difference in connectivity of the supraspinal centers to the thoracic and lumbar cord is still unknown. Here, we combined retrograde tracing and 3D imaging to map the connectivity of supraspinal neurons projecting to thoracic (T9-vertebral) and lumbar (T13-vertebral) spinal levels in adult female mice. We dissected the difference in connections of corticospinal neurons (CSNs), rubrospinal neurons, and reticulospinal neurons projecting to thoracic and lumbar cords. The ratio of double-labeled neurons is higher in T13-vertebral projection CSNs and parvocellular part of the red nucleus (RPC) than in T9-vertebral projection. Using the Cre-DIO system, we precisely targeted CSNs projecting to T9-vertebral or T13-vertebral. We found that abundant axon branches communicated with the red nucleus and reticular formation and distributed from cervical gray matter to the lumbar cord. Their collateral branches showed a distinct innervation pattern in thoracic and lumbar gray matters and a similar distribution pattern in the cervical spinal cord. These results revealed the difference in connectivity between the thoracic and lumbar projection supraspinal centers and clarified the collateralization of thoracic/lumbar projection CSNs throughout the brain and spinal cord. This study highlights brain-spinal cord neural networks and the complexity of the axon terminals of spinal projection CSNs, which could contribute to the development of targeted therapeutic strategies connecting CST fibers and hindlimb function recovery. Cover Image for this issue: https://doi.org/10.1111/jnc.15414.

Clinical outcomes and a therapeutic indication of intramedullary spinal cord astrocytoma.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Although intramedullary astrocytoma is associated with a high mortality rate, the optimal treatment has not reached a consensus. This study aimed at evaluating neurologic function and overall survival rate (OSR) in the treatment of this tumor. SETTING: The single institution in Japan. METHODS: This study enrolled 67 subjects who underwent surgical treatment for intramedullary astrocytoma. Demographic, imaging, and surgical information were collected from each participant. Tumors were histologically categorized using the World Health Organization classification, and subjects were divided into low-grade (I and II; n = 40) and high-grade (III and IV; n = 27) groups. Neurologic status was evaluated using the modified McCormick scale (MMS). OSR was assessed using Kaplan-Meier methods. RESULTS: The OSR decreased when the pathological grade increased (p < 0.01). Regarding the therapeutic efficacy for low-grade astrocytomas, subjects who underwent gross total resection (GTR) showed a higher OSR than those who did not (p = 0.02). GTR prevented worsening of MMS score, while non-GTR increased the MMS score (p < 0.01). In the high-grade group, 19 and 10 underwent radiation therapy and chemotherapy, respectively. However, both treatments did not improve OSR. Cordotomy was performed for subjects whose lesional area was at the thoracic level, but the OSR did not significantly increase. CONCLUSIONS: The most beneficial therapeutic strategy for low-grade astrocytomas was GTR, whereas that for the high-grade tumors was unclear. Further studies with a larger sample size are warranted to validate the effective treatment for malignant astrocytomas.

Comparison of surgical outcomes of posterior surgeries between cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVE: To compare the surgical outcomes and complications of posterior decompression between individuals with cervical spondylotic myelopathy (CSM) and those with ossification of the posterior longitudinal ligament (OPLL). SETTING: Seventeen medical institutions in Japan. METHODS: This study included 814 individuals with CSM (n = 636) and OPLL (n = 178) who underwent posterior decompression. Propensity score matching of the baseline characteristics was performed to compare surgical outcomes and perioperative complications between the CSM and OPLL groups. RESULTS: Before propensity score matching, the OPLL group had higher percentage of male individuals, body mass index, and number of stenosis levels and longer duration of symptoms (P < 0.01, P < 0.01, P < 0.01, and P < 0.01, respectively). After matching, the baseline characteristics were comparable between the CSM (n = 98) and OPLL (n = 98) groups. The postoperative Japanese Orthopaedic Association (JOA) scores, preoperative-to-postoperative changes in the JOA scores, and JOA score recovery rates were not significantly different between the groups (P = 0.42, P = 0.47, and P = 0.09, respectively). The postoperative visual analog scale (VAS) score for neck pain and preoperative-to-postoperative changes in the VAS score for neck pain were not significantly different between the groups (P = 0.25 and P = 0.50, respectively). The incidence of perioperative complications was comparable between groups. CONCLUSION: Neurological improvement and complication rates after surgery were comparable between individuals with CSM and those with OPLL, suggesting similar effectiveness and safety of posterior decompression for both conditions.

K-line (-) in the neck-flexed position negatively affects surgical outcome of expansive open-door laminoplasty for cervical spondylotic myelopathy.

BACKGROUND: The K-line in the neck-flexed position (FK-line) on radiography reflects dynamic factors and cervical alignment. Although the FK-line has been reported to affect the neurological recovery after muscle-preserving selective laminectomy for cervical spondylotic myelopathy (CSM), its influence on surgical outcomes after expansive open-door laminoplasty (ELAP) has not been investigated. METHODS: We reviewed the surgical outcomes in 81 patients with multilevel CSM who underwent C4-C6 ELAP combined with C3 and C7 partial laminectomy using a laminoplasty plate and were followed up for at least 2 years. We defined the K-line (-) as some portion of a bony spur or the vertebral body crossing the FK-line, whereas the FK-line (+) was defined as that never crossing the FK-line. Patients were divided into the FK-line (+) (n = 61) and FK-line (-) groups (n = 20), and the surgical outcomes were compared between the groups. A multivariate analysis was performed to identify the factors that influenced the neurological outcomes. RESULTS: The FK-line (-) group had a smaller C2-C7 angle, smaller C7 slope, greater postoperative increase in the C2-C7 sagittal vertical axis, greater kyphosis in cervical flexion and less lordosis in cervical extension, and higher incidence of postoperative residual spinal cord compression. The preoperative-to-postoperative changes in the Japanese Orthopedic Association (JOA) score and JOA score recovery rate (RR) were lower in the FK-line (-) group. The multiple linear regression analysis revealed that the K-line (-) (ß = -0.327, P = 0.011) and high signal intensity (SI) changes on T2-weighted imaging (WI) combined with the low SI changes on T1-WI in the spinal cord (ß = -0.320, P = 0.013) negatively affected the JOA score RR. CONCLUSIONS: The FK-line can be used for patients with CSM as a simple indicator of neurological outcomes after ELAP.

The characteristics of the young patients with cervical ossification of the posterior longitudinal ligament of the spine: A multicenter cross-sectional study.

BACKGROUND: Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by heterotopic bone formation in the posterior longitudinal ligament of the spine. Although the patients with OPLL are more common in the 60s and 70s, we know that there are markedly young patients (e.g., early 40s). However, to the best of our knowledge, there is few reports characterize young patients with cervical OPLL in terms of the imaging features, subjective symptoms, and ADL problems. METHODS: This is the multicenter cross-sectional study. Two hundred and thirty-seven Japanese symptomatic patients with cervical OPLL confirmed by standard X-rays collected from 16 institutions belonging to the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament formed by the Japanese Ministry of Health, Labor and Welfare were recruited. Whole spine CT data as well as demographic data such as age, gender, patients-based evaluations, and the 36-item Short Form Health Survey (SF-36) were evaluated. RESULTS: Young group (≦ 45 years old) consisted of 23 patients (8 females and 15 males), accounting for 9.7% of the total. Their characteristics were high body mass index (BMI), significant involvement of trauma in the onset and deterioration of symptoms, and the predominance of thoracic OPLL. The patient-based evaluations did not show a significant difference between the young and non-young groups, or between the genders in the young group except for bodily pain (BP) of SF-36. Female patients in young group had significantly lower BP score of SF-36 than that of male in young group. CONCLUSIONS: Characteristics of young patients with cervical OPLL were high BMI, significant involvement of trauma in the onset and deterioration of symptoms, lower BP score of SF-36 in female, and the predominance of thoracic OPLL.

Long Preservation of AAV-Transduced Fluorescence by a Modified Organic Solvent-Based Clearing Method.

The development of tissue clearing technologies allows 3D imaging of whole tissues and organs, especially in studies of the central nervous system innervated throughout the body. Although the three-dimensional imaging of solvent-cleared organs (3DISCO) method provides a powerful clearing capacity and high transparency, the rapid quenching of endogenous fluorescence and peroxide removal process decreases its practicability. This study provides a modified method named tDISCO to solve these limitations. The tDISCO protocol can preserve AAV-transduced endogenous EGFP fluorescence for months and achieve high transparency in a fast and simple clearing process. In addition to the brain, tDISCO was applied to other organs and even hard bone tissue. tDISCO also enabled us to visualize the long projection neurons and axons with high resolution. This method provides a fast and simple clearing protocol for 3D visualization of the AAV- transduced long projection neurons throughout the brain and spinal cord.

Baseline severity of myelopathy predicts neurological outcomes after posterior decompression surgery for cervical spondylotic myelopathy: a retrospective study.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: To identify the usefulness of the baseline severity of myelopathy for predicting surgical outcomes for cervical spondylotic myelopathy (CSM). SETTING: Seventeen institutions in Japan. METHODS: This study included 675 persons with CSM who underwent posterior decompression. According to baseline severity, the individuals were divided into the mild (Japanese Orthopaedic Association [JOA] score ≥ 14.5), moderate (JOA score = 10.5-14), and severe (JOA score ≤ 10) groups. Surgical outcomes and clinical variables were compared between the groups. Logistic regression analysis was used to develop a prediction model for unsatisfactory symptom state (postoperative JOA score ≤ 14, residual moderate or severe myelopathy). RESULTS: The mean (±standard deviation) age was 67 ± 12 years. The participants in the severe group were older than those in the mild group. Postoperative JOA scores were higher in the mild group than in the severe group. According to multivariate logistic regression analysis, the prediction model included preoperative JOA scores (odds ratio [OR] 0.60; 95% confidence interval [CI] 0.55-0.67) and age (OR 1.06, 95% CI 1.04-1.08). On the basis of the model, a representative combination of the thresholds to maximize the value of "sensitivity - (1 - specificity)" demonstrated a preoperative JOA score of 11.5 as a predictor of postoperative unsatisfactory symptom state in people around the mean age of the study cohort (67 years). CONCLUSIONS: The combination of the baseline severity of myelopathy and age can predict postoperative symptom states after posterior decompression surgery for CSM.

A systematic review and meta-analysis comparing anterior decompression with fusion and posterior laminoplasty for cervical spondylotic myelopathy.

BACKGROUND: The optimal surgical procedure for the treatment of cervical spondylotic myelopathy (CSM) remains controversial because there are few comprehensive studies that have investigated the surgical methods. Therefore, we conducted a systematic review and meta-analysis to evaluate evidence in the literature and to compare the surgical outcomes between anterior decompression with fusion (ADF) and laminoplasty, which are representative procedures for CSM. METHODS: An extensive literature search was performed using PubMed, Embase, and the Cochrane Library to identify comparative studies of ADF and laminoplasty for CSM. The language was restricted to English, and the publication period was from January 2001 to July 2019. We only included studies of CSM and excluded studies that involved patients with ossification of the posterior longitudinal ligament and treatments with posterior instrumented fusion. We extracted outcomes from the studies, such as preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, cervical alignment, surgical complications and reoperation rates. Then, a meta-analysis was performed on these surgical outcomes. RESULTS: Nine studies were obtained, and the quality of the studies was acceptable. In the meta-analysis, the preoperative JOA score was similar between the ADF and laminoplasty groups. The postoperative JOA scores and neurological recovery rates were not different between the ADF and laminoplasty groups. ADF exhibited more favorable results than laminoplasty in terms of postoperative cervical alignment. In contrast, overall complications were more frequently observed in the ADF group than in the laminoplasty group, leading to higher rates of reoperation. However, postoperative neck pain was more frequently observed in the laminoplasty group than in the ADF group. CONCLUSIONS: This systematic review and meta-analysis showed both the merits and shortcomings of ADF and laminoplasty. ADF and laminoplasty showed similar results in terms of neurological recovery. Postoperative cervical lordosis was better preserved with ADF than with laminoplasty. However, ADF was associated with a higher incidence of surgical complications than laminoplasty.

The effectiveness of chemonucleolysis with condoliase for treatment of painful lumbar disc herniation.

BACKGROUND: Chemonucleolysis with condoliase, which degrades chondroitin sulfate, could be a new, minimally invasive therapeutic option for patients with lumbar disc herniation (LDH). The purpose of this study was to analyze prognostic factors for clinical outcomes in LDH patients subjected to chemonucleolysis with condoliase. METHODS: Inclusion criteria for this procedure were 1) 18-70 years of age; 2) unilateral leg pain and positive straight leg raise (SLR) (<70°) or femoral nerve stretching test; 3) subligamentous extrusion verified on magnetic resonance imaging; 4) neurological symptoms consistent with a compressed nerve root on magnetic resonance imaging (MRI) images; and 5) minimum six months of follow-up. In total, 82 patients (55 men, 27 women; mean age, 47.2 ± 15.5 years; mean follow-up, 9.1 ± 3.0 months) who underwent chemonucleolysis with condoliase for painful LDH were included. An improvement of 50% or more in the Visual analogue scale (VAS) of leg pain was classified as effective. RESULTS: Seventy patients (85.4%) were classified into the effective (E) group and 12 patients (14.6%) into the less-effective (L) group. Surgical treatment was required in four patients. No severe adverse complications were reported; 41.3% of the patients developed disc degeneration of Pfirrmann grade 1 or more at the injected disc level. Univariate analysis revealed that young age (p = 0.036), without history of epidural or nerve root block (p = 0.024), and injection into the central portion of the intervertebral disc (p = 0.014) were significantly associated with clinical effectiveness. A logistic regression analysis revealed that injection into the central portion of the intervertebral disc (p = 0.049; odds ratio, 4.913; 95% confidence interval, 1.006-26.204) was significantly associated with clinical effectiveness. CONCLUSIONS: Chemonucleolysis with condoliase is a safe and effective treatment for painful LDH; 85.4% of the patients showed improvement after the treatment without severe adverse events. To obtain the best outcome, condoliase should be injected into the center of the intervertebral disc.

Risk predictors of perioperative complications for the palliative surgical treatment of spinal metastasis.

BACKGROUND: The complication rate for palliative surgery in spinal metastasis is relatively high, and major complications can impair the patient's activities of daily living. However, surgical indications are determined based primarily on the prognosis of the cancer, with the risk of complications not truly considered. We aimed to identify the risk predictors for perioperative complications in palliative surgery for spinal metastasis. METHODS: A multicentered, retrospective review of 195 consecutive patients with spinal metastasis who underwent palliative surgeries with posterior procedures from 2001 to 2016 was performed. We evaluated the type and incidence of perioperative complications within 14 days after surgery. Patients were categorized into either the complication group (C) or no-complication group (NC). Univariate and multivariate analyses were used to identify potential predictors for perioperative complications. RESULTS: Thirty patients (15%) experienced one or more complications within 14 days of surgery. The most frequent complications were surgical site infection (4%) and motor weakness (3%). A history of diabetes mellitus (C; 37%, NC; 9%: p < 0.01) and surgical time over 300 min (C; 27%, NC; 12%: p < 0.05) were significantly associated with complications according to univariate analysis. Increased blood loss and non-ambulatory status were determined to be potential risk factors. Of these factors, multivariate logistic regression revealed that a history of diabetes mellitus (OR: 6.6, p < 0.001) and blood loss over 1 L (OR: 2.7, p < 0.05) were the independent risk factors for perioperative complications. There was no difference in glycated hemoglobin A1c between the diabetes patients with and without perioperative complications. CONCLUSIONS: Diabetes mellitus should be used for the risk stratification of surgical candidates regardless of the treatment status, and strict prevention of bleeding is needed in palliative surgeries with posterior procedures to mitigate the risk of perioperative complications.

Concise Review: Laying the Groundwork for a First-In-Human Study of an Induced Pluripotent Stem Cell-Based Intervention for Spinal Cord Injury.

There have been numerous attempts to develop stem cell transplantation approaches to promote the regeneration of spinal cord injury (SCI). Our multicenter team is currently planning to launch a first-in-human clinical study of an induced pluripotent stem cell (iPSC)-based cell transplant intervention for subacute SCI. This trial was conducted as class I regenerative medicine protocol as provided for under Japan's Act on the Safety of Regenerative Medicine, using neural stem/progenitor cells derived from a clinical-grade, integration-free human "iPSC stock" generated by the Kyoto University Center for iPS Cell Research and Application. In the present article, we describe how we are preparing to initiate this clinical study, including addressing the issues of safety and tumorigenesis as well as practical problems that must be overcome to enable the development of therapeutic interventions for patients with chronic SCI. Stem Cells 2019;37:6-13.

Gait ability required to achieve therapeutic effect in gait and balance function with the voluntary driven exoskeleton in patients with chronic spinal cord injury: a clinical study.

STUDY DESIGN: A non-randomized open-label single-arm clinical trial. OBJECTIVES: To analyze the effect of body weight supported treadmill training (BWSTT) with the voluntary driven exoskeleton (VDE) in persons with differing levels and completeness of spinal cord injury (SCI) and differing walking abilities. SETTING: Keio University Hospital, Tokyo, Japan. METHODS: Twenty individuals with chronic SCI (age, 43 ± 17 years) classified as American Spinal Injury Association Impairment Scale grade A (n = 2), B (n = 4), C (n = 8), or D (n = 6) who had reached a plateau in recovery. Participants underwent twenty 60 min sessions of BWSTT with the hybrid assisted limb. The speed, distance, and duration walked in every 60 min training session were recorded. The Walking Index for SCI Scale II (WISCI-II), 10 meters walk test (10MWT), 2 min walk test, timed up and go (TUG) test, Berg Balance Scale (BBS), lower extremity motor score (LEMS), Barthel Index, and Functional Independence Measure were evaluated at pre and post intervention. RESULTS: There was a significant improvement in 10MWT, TUG, and BBS after the intervention. Walking ability significantly improved in participants with high walking ability at baseline (WISCI-II score 6-20; n = 12) but not in participants with low walking ability (WISCI-II score 0-3; n = 8). Significant improvement of BBS was also shown in participants with high walking ability at baseline. CONCLUSIONS: Patients with high walking ability at baseline responded better to the training than those with low walking ability.

Characteristic cerebral structural changes identified using voxel-based morphometry in patients with post-surgical chronic myelopathic pain.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: Patients who undergo intramedullary spinal surgery occasionally experience post-surgical chronic pain; however, the underlying mechanisms are not yet completely understood. Therefore, this study aimed to identify the cerebral structural changes in patients with post-surgical chronic myelopathic pain using voxel-based morphometry. SETTING: Single university hospital in Tokyo, Japan. METHODS: Forty-nine patients who had undergone intramedullary spinal surgery between January 2002 and April 2014 participated in this study. Participants were classified into two groups based on their post-surgical chronic pain intensity: control (numeric rating scale score of <3) and pain (numeric rating scale score of ≥3) groups. We compared pain questionnaire and brain MRI between two groups. Brain MRI data of each participants was analyzed using voxel-based morphometry. RESULTS: Voxel-based morphometry revealed that the gray matter volume in the left supplementary motor area, left primary motor area, and left posterior cingulate cortex was higher in the pain group than that in the control group. In addition, the numeric rating scale score was significantly correlated with increased gray matter volume in the left primary motor area, left posterior cingulate cortex, and right superior parietal lobule. CONCLUSION: Present study elucidates the characteristic cerebral structural changes after an intramedullary spinal surgery using voxel-based morphometry and indicates that the structural changes in specific cerebral areas are associated with post-surgical chronic myelopathic pain.