Compromised Accuracy of Stereotactic Target Delineation Associated with Computed Tomography-Based Frame Registration: A Comparative Analysis of Magnetic Resonance Imaging-Computed Tomography Fusion.

INTRODUCTION: Recent advancements in stereotactic neurosurgical techniques have become increasingly reliant on image-based target planning. We devised a case-phantom comparative analysis to evaluate the target registration errors arising during the magnetic resonance imaging (MRI)-computed tomography (CT) image fusion process. METHODS: For subjects whose preoperative MRI and CT images both contained fiducial frame localizers, we investigated discrepancies in target coordinates derived from frame registration based on either MRI or CT. We generated a phantom target through an image fusion process, merging the framed CT images with their corresponding reference MRIs after masking their fiducial indicators. This phantom target was then compared with the original during each instance of target planning. RESULTS: In our investigative study with 26 frame registrations, a systematic error in the y-axis was observed as -0.89 ± 0.42 mm across cases using either conventional CT and/or cone-beam CT (O-arm). For the z-axis, errors varied on a case-by-case basis, recording at +0.64 ± 1.09 mm with a predominant occurrence in those merged with cone-beam CT. Collectively, these errors resulted in an average Euclidean error of 1.33 ± 0.93 mm. CONCLUSION: Our findings suggest that the accuracy of frame-based stereotactic planning is potentially compromised during MRI-CT fusion process. Practitioners should recognize this issue, underscoring a pressing need for strategies and advancements to optimize the process.

Frailty is not an independent risk factor for worse clinical outcomes in lumbar spinal surgery: a prospective cohort study.

PURPOSE: Recently, many studies revealed that frailty affects unfavorably on postoperative outcomes in lumbar spinal diseases. This study aimed to investigate the relationship between frailty and clinical outcomes while identifying risk factors associated with worse clinical outcomes following lumbar spinal surgery. METHODS: From March 2019 to February 2021, we prospectively enrolled eligible patients with degenerative lumbar spinal diseases requiring surgery. Frailty was assessed preoperatively. To identify the impact of frailty on lumbar spinal diseases, clinical outcomes, which were measured with patient-reported outcomes (PROs) and postoperative complications, were compared according to the frailty. PROs were assessed preoperatively and one year postoperatively. In addition, risk factors for preoperative and postoperative worse clinical outcomes were investigated. RESULTS: PROs were constantly lower in the frail group than in the non-frail group before and after surgery, and the change of PROs between before and after surgery and postoperative complications were not different between the groups. In addition, frailty was a persistent risk factor for postoperative worse clinical outcome before and after surgery in lumbar spinal surgery. CONCLUSION: Frailty persistently affects the clinical outcome negatively before and after surgery in lumbar spinal surgery. However, as the change of the clinical outcome is not different between the frail group and the non-frail group, it is difficult to interpret whether the frail patients are vulnerable to the surgery. In conclusion, frailty is not an independent risk factor for worse clinical outcome in lumbar spinal surgery.

Effectiveness of intraoperative table modification for achieving lumbar lordosis in multilevel lumbar fusion surgery: a propensity score-matched study.

BACKGROUND: In multilevel posterior lumbar interbody fusion (PLIF) with posterior screw fixation, obtaining sufficient lumbar lordosis (LL) is difficult, especially in patients with osteoporosis. We performed intraoperative table modification (TM) using gravitational dropping of the patient's lumbar spine, to improve restoration of LL. METHODS: We retrospectively reviewed the medical records of patients who underwent three- or four-level PLIF between 2005 and 2019. One hundred eleven patients were enrolled, with 96 patients receiving non-TM-PLIF and 15 patients receiving TM-PLIF. Radiological parameters, including segmental lordosis (SL), LL, sacral slope (SS), pelvic incidence, and pelvic tilt, were measured. Clinical outcomes were measured using a visual analogue scale (VAS) for the back and leg preoperatively and at the last follow-up. Additionally, the correlation between the bone mineral density (BMD) and the radiological parameters was calculated for TM-PLIF. We performed propensity score matching between the groups to control the baseline difference. RESULTS: We found a statistically better correction between immediate and last follow-up postoperative SL (p = 0.04), as well as between preoperative and last follow-up SL (p < 0.01) in the TM-PLIF group compared to that in the non-TM-PLIF group. VAS for the back and leg were not significantly different between the two groups. Additionally, the efficacy of lordosis correction in the TM-PLIF group showed a statistically significant negative correlation between BMD and the SS change both before and after the surgery (rho = -0.60, p = 0.02). CONCLUSION: Whilst further study is required to conclusively establish its efficacy, TM-PLIF (table modification using gravitational dropping) shows potential advantages for restoring and maintaining LL in multilevel lumbar fusion, particularly in cases with low BMD.

The risk factors of intracerebral hemorrhage in deep brain stimulation: does target matter?

BACKGROUND: Although deep brain stimulation (DBS) is a relatively safe and effective surgery compared with ablative surgeries, intracerebral hemorrhage (ICH) is a serious complication during DBS that could result in a fatal prognosis. We retrospectively investigated whether ICH incidence differed between patients who underwent DBS in the subthalamic nucleus (STN) and in the globus pallidus interna (GPi), together with previously identified risk factors for ICH. METHODS: We retrospectively reviewed the medical records of 275 patients (527 DBS targets) who received DBS for Parkinson's disease or dystonia from April 2001 to December 2020. In cases that developed intra- or postoperative ICH, patients were classified as asymptomatic, symptomatic with temporary neurological deficit or symptomatic with permanent neurological deficit, according to patient clinical status. RESULTS: ICH occurred in 12 procedures (2.3%) among the 527 DBS procedures (275 patients) evaluated. In multivariable logistic regression analysis, the risk factor for all cases of ICH was systolic blood pressure (BP) during surgery (cut-off value 129.4 mmHg) (OR = 1.05, 95% CI = 1.01-1.09, P = 0.023). In addition, for ICH with permanent neurological deficit, STN target site (P = 0.024) and systolic BP during surgery (cut-off value: 148.3 mmHg) (P = 0.004) were identified as risk factors in univariable analyses. CONCLUSION: Even though the risk factor for all ICH in DBS was BP during surgery, when focused on ICH evoking permanent neurological deficit, the target location as well as systolic BP during surgery proved to be related.

Clinically significant radiographic parameter for thoracic myelopathy caused by ossification of the ligamentum flavum.

PURPOSE: To investigate radiographic parameters to improve the accuracy of radiologic diagnosis for ossification of ligamentum flavum (OLF)-induced thoracic myelopathy and thereby establish a useful diagnostic method for identifying the responsible segment. METHODS: We classified 101 patients who underwent surgical treatment for OLF-induced thoracic myelopathy as the myelopathy group and 102 patients who had incidental OLF and were hospitalized with compression fracture as the non-myelopathy group between January 2009 and December 2016. We measured the thickness of OLF (TOLF), cross-sectional area of OLF (AOLF), anteroposterior canal diameter, and the ratio of each of these parameters. RESULTS: Most OLF cases with lateral-type axial morphology were in the non-myelopathy group and most with fused and tuberous type in the myelopathy group. Most grade-I and grade-II cases were also in the non-myelopathy group, whereas grade-IV cases were mostly observed in the myelopathy group. The AOLF ratio was found to be the best radiologic parameter. The optimal cutoff point of the AOLF ratio was 33.00%, with 87.1% sensitivity and 87.3% specificity. The AOLF ratio was significantly correlated with preoperative neurological status. CONCLUSIONS: An AOLF ratio greater than 33% is the most accurate diagnostic indicator of OLF-induced thoracic myelopathy. In cases of multiple-segment OLF, confirmation of cord signal change on MRI and an AOLF measurement will help determine the responsible segment. AOLF measurement will also improve the accuracy of diagnosis of OLF-induced thoracic myelopathy in cases of grade III or extended-type axial morphology. These slides can be retrieved under Electronic Supplementary Material.

New grading system for the clinical evaluation of patients with spinal vascular lesions.

PURPOSE: Neurointerventional approaches have improved myelopathy in patients with spinal vascular lesions by providing effective management, particularly when surgical approaches are difficult. However, there have been challenges in describing and comparing recovery status during the post-treatment period. METHODS: We evaluated 43 patients with venous congestive myelopathy (VCM) using Aminoff-Logue Disability Scale for gait (AL-G) and micturition (AL-M) scores. These results were compared with our new PSMS grading system that evaluates four categories (grades 0-3): pain, sensory symptoms, motor deficit, and sphincter change. Simple linear regression was used to identify the association or trend among the scales. We also calculated an overall area under the receiver operating characteristic curve to compare the predictive ability of the PSMS system with that of the previous grading system (AL-G and AL-M). RESULTS: Compared with other grading system, the PSMS system was more sensitively correlated with patient status and the results were easy to compare with previous clinical statuses during follow-up. The PSMS system also measured pain, which is commonly associated with spinal dural arteriovenous fistula and not precisely evaluated by other grading system. CONCLUSIONS: The new PSMS grading system for patients with VCM correlated well with the previously used systems and included pain evaluation. This new grading system is an easy tool for the evaluation and comparison of outcomes before and after endovascular treatment.

A Novel Animal Model of Parkinson's Disease Using Optogenetics: Representation of Various Disease Stages by Modulating the Illumination Parameter.

BACKGROUND: The classic animal model of Parkinson's disease (PD) using neurotoxin can only simulate fixed stages of the disease by causing irreversible damage to the nigrostriatal system. OBJECTIVES: To develop an optogenetic PD model that can modulate the severity of disease by optical stimulation by introducing the halorhodopsin (NpHR) gene into the substantia nigra compacta. METHODS: Fifteen rats received injections of engineered AAV with NpHR-YFP gene into the substantia nigra. They were then subjected to illumination of 590-nm light wavelengths with 3 optical stimulation conditions, i.e., frequency-width: 5 Hz-10 ms (n = 5), 5 Hz-100 ms (n = 5), and 50 Hz-10 ms (n = 5). Eleven rats received 6-hydroxydopamine injections to establish the conventional PD model. RESULTS: The optogenetic models showed characteristic PD manifestations, similar to those of the conventional models; the severity of forelimb akinesia correlated with the total illumination value (frequency × width). The group with a low illumination value (5 Hz-10 ms) was comparable to the conventional partial model whereas the groups with high illumination values (5 Hz-100 ms and 50 Hz-10 ms) were similar to the conventional complete model. CONCLUSIONS: An optogenetic PD model has the advantage of more appropriately representing various PD stages by controlling illumination parameters.

Importance of the preoperative cross-sectional area of the semispinalis cervicis as a risk factor for loss of lordosis after laminoplasty in patients with cervical spondylotic myelopathy.

PURPOSE: To investigate the effect of the preoperative cross-sectional area (CSA) of the semispinalis cervicis on postoperative loss of cervical lordosis (LCL) after laminoplasty. METHODS: A total of 144 patients who met the inclusion criteria between January 1999 and December 2015 were enrolled. Radiographic assessments were performed to evaluate the T1 slope, C2-7 sagittal vertical axis (SVA), cephalad vertebral level undergoing laminoplasty (CVLL), preoperative C2-7 Cobb angle, and preoperative CSA of the semispinalis cervicis. RESULTS: The T1 slope and the summation of the CSAs (SCSA) at each level of the semispinalis cervicis correlated with LCL, whereas the C2-7 SVA, CVLL, and preoperative C2-7 Cobb angle did not. Multiple regression analysis demonstrated that a high T1 slope and a low SCSA of the semispinalis cervicis were associated with LCL after laminoplasty in patients with cervical spondylotic myelopathy (CSM). The CSA of the semispinalis cervicis at the C6 level had the greatest association with LCL, which suddenly decreased with a LCL of 10°. The best cutoff point of the CSA of the semispinalis cervicis at the C6 level, which predicts LCL > 10°, was 154.5 mm2 (sensitivity 74.3%; specificity 71.6%; area under the curve 0.828; 95% confidence interval 0.761-0.895). CONCLUSION: Preoperative SCSA of the semispinalis cervicis was a risk factor for LCL after laminoplasty. Spine surgeons should evaluate semispinalis cervicis muscularity at the C6 level when planning laminoplasty for patients with CSM. These slides can be retrieved under Electronic Supplementary Material.

Analysis of the Risk Factors Associated with Prolonged Intubation or Reintubation after Anterior Cervical Spine Surgery.

BACKGROUND: Standardized postoperative airway management is essential for patients undergoing anterior cervical spine surgery (ACSS). The paucity of clinical series evaluating these airway complications after ACSS has been resulted in a significant limitation in statistical analyses. METHODS: A retrospective cohort study was performed regarding airway distress (intubation for more than 24 hours or unplanned reintubation within 7 days of operation) developed after ACSS. If prevertebral soft tissue swelling was evident after the operation, patients were managed with prolonged intubation (longer than 24 hours). Preoperative and intraoperative patient data, and postoperative outcome (time to extubation and reintubation) were analyzed. RESULTS: Between 2008 and 2016, a total of 400 ACSS were performed. Of them, 389 patients (97.25%) extubated within 24 hours of surgery without airway complication, but 11 patients (2.75%) showed postoperative airway compromise; 7 patients (1.75%) needed prolonged intubation, while 4 patients (1.00%) required unplanned reintubation. The mean time for extubation were 2.75 hours (range: 0-23 hours) and 50.55 hours (range: 0-250 hours), respectively. Age (P = 0.015), diabetes mellitus (P = 0.003), operative time longer than 5 hours (P = 0.048), and estimated blood loss (EBL) greater than 300 mL (P = 0.042) were associated with prolonged intubation or reintubation. In prolonged intubation group, all patients showed no airway distress after extubation. CONCLUSION: In ACSS, postoperative airway compromise is related to both patients and operative factors. We recommend a prolonged intubation for patients who are exposed to these risk factors to perform a safe and effective extubation.

Practicality of using the figure-of-eight bandage to prevent fatal wound dehiscence after spinal tumor surgery for upper thoracic metastasis.

OBJECT: Serious postoperative wound problems can frequently develop after surgery with perioperative RT for upper thoracic metastatic lesions. The figure-of-eight bandage can restrict excessive shoulder motion, which could prevent wound dehiscence. The purpose of this study was to describe the efficacy of using the figure-of-eight bandage to prevent postoperative wound dehiscence. METHODS: Between February 2005 and July 2015, we retrospectively evaluated the medical records of cancer patients who underwent surgery with or without RT for spinal metastasis involving the upper thoracic spine. From January 2009, all patients received figure-of-eight bandaging immediately postoperatively, which was then maintained for 2 months. The outcome measures were the incidence and successful management of wound dehiscence following application of the figure-of-eight bandage. RESULTS: One hundred and fifteen patients (71 men and 44 women) were enrolled in the present study. A figure-of-eight bandage in conjunction with a thoracolumbosacral orthosis (TLSO) was applied to 78 patients, while only TLSO was applied to 37 patients. The overall rate of wound dehiscence was 4.34% and the mean duration before wound dehiscence was 27.0 days (range, 22-31 days) after surgery. In the TLSO-only group, wound dehiscence occurred in four patients (10.81%), meanwhile there was only one case (1.33%) of wound dehiscence in the group that had received the figure-of-eight bandage with TLSO. Three of four patients with wound dehiscence in the TLSO only group died from unresolved wound problems and another patient was treated with wound closure followed by the application of the figure-of-eight bandage. The only patient with wound dehiscence among the patients who received both the figure-of-eight bandage and TLSO was managed by primary wound closure without further complication. CONCLUSION: Current study suggests that the figure-of-eight bandage could prevent wound dehiscence and be used to treat wound problems easily.

Clinical analysis of C5 palsy after cervical decompression surgery: relationship between recovery duration and clinical and radiological factors.

BACKGROUND: Postoperative C5 palsy is a widely known complication of cervical decompression surgery. Many studies have focused on its etiology and factors affecting it. However, no study to date has evaluated the association between the clinical outcome and recovery duration of post-operative C5 palsy. We evaluated this in our current report. METHODS: A retrospective analysis was conducted for 710 consecutive degenerative cervical spine decompression surgeries performed in a single institution. We included all patients who underwent any type of surgical procedure for cervical spinal stenosis, ossification of posterior longitudinal ligament (OPLL), or cervical spondylotic myelopathy (CSM). Demographic, radiologic, clinical information was recorded. Finally, correlation analysis was conducted to identify demographic, radiologic, or clinical factors related with recovery duration (within or after 6 months). RESULTS: The incident rate of postoperative C5 palsy was 5.1 % (36/710 cases). Analysis of recovery duration revealed that 18 patients had recovered within 6 months and 33 (91.7 %) within 2 years, whilst 3 individuals (8.3 %) had not fully recovered within the follow-up period. Factors related to longer recovery (>6 months) included motor grade ≤2 (p < 0.001), presence of multi-segment paresis involving more than the C5 root (p = 0.002), loss of somatic sensation with pain (p = 0.008), and the degree of posterior spinal cord shifting (p = 0.040). Furthermore, multivariate analysis revealed that motor grade ≤2 (p = 0.010) had a significant effect on a recovery duration beyond 6 months. CONCLUSIONS: A motor grade ≤2, the presence of multi-segment paresis involving more than the C5 root, the loss of somatic sensation with pain, and the degree of posterior spinal cord shifting significantly influence whether the duration of recovery from postoperative C5 palsy will take longer than 6 months.

Enhanced axonal regeneration by transplanted Wnt3a-secreting human mesenchymal stem cells in a rat model of spinal cord injury.

BACKGROUND: While pure mesenchymal stem cell (MSC) treatment for spinal cord injury (SCI) is known to be safe, its efficacy is insufficient. Therefore, gene-modified stem cells are being developed to enhance the effect of pure MSCs. We investigated the effect of stem cell therapy through the transfection of a Wnt3a-producing gene that stimulates axonal regeneration. METHOD: MSCs obtained from the human umbilical cord blood (hMSCs) were multiplied, cultivated, and transfected with the pLenti-Wnt3a-GFP viral vector to produce Wnt3a-secreting hMSCs. A total of 50 rats were injured with an Infinite Horizon impactor at the level of the T7-8 vertebrae. Rats were divided into five groups according to the transplanted material: (1) phosphate-buffered saline injection group (sham group, n = 10); (Pertz et al. Proc Natl Acad Sci USA 105:1931-1936, 39) Wnt3a protein injection group (Wnt3a protein group, n = 10); (3) hMSC transplantation group (MSC group, n = 10); (4) hMSCs transfected with the pLenti vector transplantation group (pLenti-MSC group, n = 10); (5) hMSCs transfected with the pLenti+Wnt3a vector transplantation group (Wnt3a-MSC group, n = 10). Behavioral tests were performed daily for the first 3 days after injury and then weekly for 8 weeks. The injured spinal cords were extracted, and axonal regeneration markers including choline acetyltransferase (ChAT), growth-associated protein 43 (GAP43), and microtubule-associated protein 2 (MAP2) were investigated by immunofluorescence, RT-PCR, and western blotting. RESULTS: Seven weeks after the transplantation (8 weeks after SCI), rats in the Wnt3a-MSC group achieved significantly higher average scores in the motor behavior tests than those in the other groups (p < 0.05). Immunofluorescent stains showed greater immunoreactivity of ChAT, GAP43, and MAP2 in the Wnt3a-MSC group than in the other groups. RT-PCR and western blots revealed greater expression of these proteins in the Wnt3a-MSC group than in the other groups (p < 0.05). CONCLUSIONS: Wnt3a-secreting hMSC transplantation considerably improved neurological recovery and axonal regeneration in a rat SCI model.

Prognostic factor analysis after surgical decompression and stabilization for cervical spinal-cord injury.

INTRODUCTION: Several studies have demonstrated the role of decompression surgery in preventing secondary injury and improving the neurological outcome after spinal cord injury (SCI). We retrospectively analyzed the prognostic factors affecting the outcomes of decompression surgery in patients with SCI. METHODS: We performed one-level decompression and fusion surgery on 73 patients with cervical SCI. We classified all patients based on their interval to decompression, sex, age, surgical level, presence of high signal intensity, American Spinal Injury Association Impairment scale (AIS) before surgery, blood pressure at admission, the amount of cord compression, surgical time, estimated blood loss during surgery, and steroid use. We considered an improvement to have occurred if the patient showed an AIS improvement of ≥1 grade. RESULTS: Among the 73 patients with SCI we analyzed, 27 and 35 showed ≥1 grade of AIS improvement immediately and 3 months after surgery, respectively. Using multivariate analysis, the mean arterial blood pressure (MAP) was a significant prognostic factor affecting recovery in the SCI patients during the immediate post-operative period. In the late recovery period at 3 months after surgery, the AIS before surgery and the MAP were significant prognostic factors affecting recovery. CONCLUSIONS: Prognostic factors for AIS improvement include the initial neurological status before surgery and hemodynamic MAP at admission. The interval between decompression surgery and trauma does not affect the neurological outcome.

Optogenetic Inhibition of the Subthalamic Nucleus Reduces Levodopa-Induced Dyskinesias in a Rat Model of Parkinson's Disease.

BACKGROUND: The inhibition of neuronal activity by electrical deep brain stimulation is one of the mechanisms explaining the amelioration of levodopa-induced dyskinesia. However, electrical deep brain stimulation cannot specifically activate or inactivate selected types of neurons. OBJECTIVES: We applied optogenetics as an alternative treatment to deep brain stimulation for levodopa-induced dyskinesia, and also to confirm that the mechanism of levodopa-induced dyskinesia amelioration by subthalamic nucleus deep brain stimulation is mediated through neuronal inhibition. METHODS: 6-hydroxydopamine-induced hemiparkinsonian rats received injections of hSynapsin1-NpHR-YFP adeno-associated virus (AAV) or hSynapsin1-YFP AAV. Two weeks after viral injections, all rats were treated with daily injections of levodopa. Then, the optic fiber was implanted into the ipsilateral subthalamic nucleus. We performed various behavioral tests to evaluate the changes in levodopa-induced dyskinesias after optogenetic expression and illumination in the subthalamic nucleus. RESULTS: The behavioral tests revealed that optical inhibition of the subthalamic nucleus significantly ameliorated levodopa-induced dyskinesia by reducing the duration of the dyskinesias as well as the severity of axial dyskinesia. CONCLUSIONS: These findings will provide a useful foundation for the future development of optogenetic modulation systems that could be considered as an approach to dyskinesia therapy.

Neuralgias of the Head: Occipital Neuralgia.

Occipital neuralgia is defined by the International Headache Society as paroxysmal shooting or stabbing pain in the dermatomes of the greater or lesser occipital nerve. Various treatment methods exist, from medical treatment to open surgical procedures. Local injection with corticosteroid can improve symptoms, though generally only temporarily. More invasive procedures can be considered for cases that do not respond adequately to medical therapies or repeated injections. Radiofrequency lesioning of the greater occipital nerve can relieve symptoms, but there is a tendency for the pain to recur during follow-up. There also remains a substantial group of intractable patients that do not benefit from local injections and conventional procedures. Moreover, treatment of occipital neuralgia is sometimes challenging. More invasive procedures, such as C2 gangliotomy, C2 ganglionectomy, C2 to C3 rhizotomy, C2 to C3 root decompression, neurectomy, and neurolysis with or without sectioning of the inferior oblique muscle, are now rarely performed for medically refractory patients. Recently, a few reports have described positive results following peripheral nerve stimulation of the greater or lesser occipital nerve. Although this procedure is less invasive, the significance of the results is hampered by the small sample size and the lack of long-term data. Clinicians should always remember that destructive procedures carry grave risks: once an anatomic structure is destroyed, it cannot be easily recovered, if at all, and with any destructive procedure there is always the risk of the development of painful neuroma or causalgia, conditions that may be even harder to control than the original complaint.

Cauda equina lymphoma mimicking non-neoplastic hypertrophic neuropathy of the cauda equina: A case report.

Spinal cauda equina lymphoma (CEL) is very rare, with only about 14 cases reported in the English medical literature. Magnetic resonance image findings and the gross appearance of CEL at surgery are similar to those of non-neoplastic hypertrophic neuropathy of the cauda equina (HNCE); however, their prognosis and treatment are very different. We report a case of CEL and discuss the differences from non-neoplastic HNCE.

Which one is a valuable surrogate for predicting survival between Tomita and Tokuhashi scores in patients with spinal metastases? A meta-analysis for diagnostic test accuracy and individual participant data analysis.

This study is to estimate the diagnostic accuracy of Tokuhashi and Tomita scores that assures 6-month predicting survival regarded as a standard of surgical treatment. We searched PubMed, EMBASE, European PubMed central, and the Cochrane library for papers about the sensitivities and specificities of the Tokuhashi and/or Tomita scores to estimate predicting survival. Studies with cut-off values of ≥9 for Tokuhashi and ≤7 for Tomita scores based on prior studies were enrolled. Sensitivity, specificity, diagnostic odds ratio (DOR), area under the curve (AUC), and the best cut-off value were calculated via meta-analysis and individual participant data analysis. Finally, 22 studies were enrolled in the meta-analysis, and 1095 patients from 8 studies were included in the individual data analysis. In the meta-analysis, the pooled sensitivity/specificity/DOR for 6-month survival were 57.7 %/76.6 %/4.70 for the Tokuhashi score and 81.8 %/47.8 %/4.93 for Tomita score. The AUC of summary receiver operating characteristic plots was 0.748 for the Tokuhashi score and 0.714 for the Tomita score. Although Tokuhashi score was more accurate than Tomita score slightly, both showed low accuracy to predict 6 months residual survival. Moreover, the best cut-off values of Tokuhashi and Tomita scores were 8 and 6, not 9 and 7, for predicting 6-month survival, respectively. Estimation of 6-month predicting survival to decide surgery in patients with spinal metastasis is quite limited by using Tokuhashi and Tomita scores alone. Tokuhashi and Tomita scores could be incorporated as part of a multidisciplinary approach or perhaps interpreted in the context of a multidisciplinary approach.

Intraoperative direct puncture and embolization (IOPE) using a glue material for spinal cord arteriovenous fistula: a case report.

INTRODUCTION: Spinal arteriovenous fistula (AVF) is treated by embolization or surgery. However, transarterial embolization or surgery is difficult in rare cases when the fistula site is very complicated to access especially as in fistular nidus supplied by posterior and anterior spinal artery. We present the case which was treated with intraoperative direct puncture and embolization (IOPE) using glue material, since the usual transarterial or transvenous neurointerventional approach was difficult to embolize the AVF. METHODS: A 36-year-old woman presented with progressive leg weakness and pain after a 20-year history of lower back pain. She had pelvic and spinal AVF combined with arteriovenous malformation (AVM). Despite prior treatment of the pelvic lesion with radiotherapy and coil embolization, the spinal lesion persisted and caused repeated subarachnoid hemorrhages. A spinal angiogram revealed a tortuous and long feeder of the AVF which had growing venous sac, as well as AVM. Two embolization trials failed because of the long tortuosity and associated anterior spinal artery. Four months later, drastic leg weakness and pain occurred, and IOPE was performed using a glue material. RESULTS: The subsequent recovery of the patient was rapid. One month later, the use of a strong opioid could be discontinued, and the patient could walk with aid. A follow-up spinal angiogram revealed that the venous sac of the AVF had disappeared. CONCLUSION: In spinal AVF which is not feasible to access by usual intervention approach and to dissect surgically, IOPE with glue material can be considered for the treatment.

Symptomatic adjacent segment degeneration at the L3-4 level after fusion surgery at the L4-5 level: evaluation of the risk factors and 10-year incidence.

PURPOSE: There have been few studies on revision surgery for clinically symptomatic adjacent segment degeneration (CASD). We aimed to find the incidence of revision surgery due to CASD and to analyze the factors that affected CASD at the L3-4 level after L4-5 or L4-5-S1 level fusion surgery over a long-term follow-up period. METHODS: Between January 2001 and October 2009, fusion surgeries were performed on 401 patients with spondylolisthesis at the L4-5 or L4-5-S1 level; 378 patients were followed up for a minimum of 2 years. We assessed CASD-free survival using Kaplan-Meier survival analysis. We also analyzed factors affecting the development of CASD, including sex, age, pelvic incidence, overall lordosis, segmental lordosis, lamina inclination angle, facet tropism, and the extent of disc and facet degeneration. Isthmic spondylolisthesis treated using total laminectomy or degenerative spondylolisthesis treated using subtotal laminectomy and interbody fusion (IBF) or posterolateral fusion (PLF) were also included in the risk factor analysis. The difference in disc height before and after initial surgery was also analyzed, as was inclusion of the sacrum in the fusion level. RESULTS: Fusion extension surgery was performed on 33 of these patients due to CASD at the L3-4 level during the follow-up period. Kaplan-Meier survival analysis indicated 3-, 5-, and 10-year disease-free survival rates of 99.20, 96.71, and 76.93 %. Statistically significant factors affecting CASD included old age, low overall lordosis, low segmental lordosis, progression of facet degeneration, total laminectomy-treated isthmic spondylolisthesis, and PLF-alone rather than IBF alone or IBF + PLF. CONCLUSION: We determined six significant factors affecting CASD development. Among these risk factors, facet degeneration, isthmic-type spondylolisthesis, and the type of fusion show higher hazard ratios and seem to be clinically more relevant than the other three factors (age, overall lordosis, and segmental lordosis).