Molecular insights and the role of 18F-FDG-PET/CT in the diagnosis of spinal gliomas.

BACKGROUND: In recent years, molecular findings on spinal gliomas have become increasingly important. This study aimed to investigate the role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in the diagnosis of spinal glioma. METHODS: This study included patients diagnosed with spinal cord glioma who underwent 18F-FDG-PET examination at the Department of Neurosurgery, Nagoya University Hospital between January 2016 and November 2023. The gliomas were divided into two groups, high-grade and low-grade, based on pathological and molecular studies. The maximum standardized uptake values (SUVmax) of the tumors were quantified and subsequently represented using receiver operating characteristic (ROC) curves. RESULTS: Eighteen participants were included in this study. Of the participants, seven had high-grade glioma with an SUVmax of 6.76 ± 0.72, and eleven had low-grade glioma with an SUVmax of 4.02 ± 1.78, and a statistically significant difference between the two groups. The ROC curve delineated an SUVmax cutoff value of 5.650, with an area under the curve (AUC) of approximately 0.909. Based on the cutoff value, the results of the diagnostic performance rendered a sensitivity and negative predictive value of 1.0, whereas the specificity and positive predictive value were 0.909 and 0.875, respectively. CONCLUSIONS: The present study shows that 18F-FDG-PET exhibits a markedly sensitive and negative predictive value in the assessment of spinal gliomas. Additionally, these findings have potential implications for the qualitative assessment of spinal gliomas using 18F-FDG-PET/CT. This imaging modality may be useful for making timely treatment decisions in situations where a detailed diagnosis by molecular analysis is not possible.

Re-irradiation spine stereotactic body radiotherapy following high-dose conventional radiotherapy for metastatic epidural spinal cord compression: a retrospective study.

PURPOSE:  We aimed to evaluate the efficacy and safety of re-irradiation stereotactic body radiation therapy (SBRT) in patients with metastatic epidural spinal cord compression (MESCC) following high-dose conventional radiotherapy. MATERIALS AND METHODS:  Twenty-one patients met the following eligibility criteria: with an irradiation history of 50 Gy2 equivalent dose in 2-Gy fractions (EQD2) or more, diagnosed MESCC in the cervical or thoracic spines, and treated with re-irradiation SBRT of 24 Gy in 2 fractions between April 2018 and March 2023. Prior treatment was radiotherapy alone, not including surgery. The primary endpoint was a 1-year local failure rate. Overall survival (OS) and treatment-related adverse events were assessed as the secondary endpoints. Since our cohort includes one treatment-related death (TRD) of esophageal perforation, the cumulative esophageal dose was evaluated to find the dose constraints related to severe toxicities. RESULTS:  The median age was 68, and 14 males were included. The primary tumor sites (esophagus/lung/head and neck/others) were 6/6/7/2, and the median initial radiotherapy dose was 60 Gy2 EQD2 (range: 50-105 Gy2, 60-70/ > 70 Gy2 were 11/4). Ten patients underwent surgery followed by SBRT and 11 SBRT alone. At the median follow-up time of 10.4 months, 17 patients died of systemic disease progression including one TRD. No radiation-induced myelopathy or nerve root injuries occurred. Local failure occurred in six patients, with a 1-year local failure rate of 29.3% and a 1-year OS of 55.0%. Other toxicities included five cases of vertebral compression fractures (23.8%) and one radiation pneumonitis. The cumulative esophageal dose was recommended as follows: Dmax < 203, D0.035 cc < 187, and D1cc < 167 (Gy3 in biological effective dose). CONCLUSION:  Re-irradiation spine SBRT may be effective for selected patients with cervical or thoracic MESCC, even with high-dose irradiation histories. The cumulative dose assessment across the original and re-irradiated esophagus was recommended to decrease the risk of severe esophageal toxicities.

Peptide Receptor Radionuclide Therapy for Recurrent Olfactory Neuroblastoma After Cranioplasty for Surgical Infection: A Case Report.

BACKGROUND: Peputide receptor radionuclide therapy with 177Lu for midgut neuroendocrine metastasis has been clinically approved as a safe treatment. Unresectable metastases of olfactory neuroblastoma have shorter survival due to insufficient effective systemic treatment. CASE REPORT: Herein, we report a patient treated with peputide receptor radionuclide therapy for unresectable recurrent olfactory neusroblastoma following a rare cranial metastasectomy infection. A 50-year-old female patient with olfactory neuroblastoma of Kadish C was initially treated by skull base surgery plus postoperative radiotherapy following chemotherapy. Recurrent disease with neck and intracranial metastases was treated by four salvage surgeries. Surgical site infection following intracranial metastasectomy was treated with debridement and delayed cranioplasty. Peputide receptor radionuclide therapy was performed for unresectable multiple metastases after cranioplasty. Successful therapy using four cycles of peputide receptor radionuclide had neither grade 3 nor grade 4 adverse events. The patient was followed at an outpatient clinic. CONCLUSION: Further case accrual of peputide receptor radionuclide therapy is required to develop a treatment for unresectable olfactory neuroblastoma.

Brain metastasis and intracranial leptomeningeal metastasis from malignant peripheral nerve sheath tumors: illustrative cases.

BACKGROUND: Malignant peripheral nerve sheath tumors (MPNSTs) are rare soft-tissue tumors. Intracranial metastasis from MPNSTs is quite rare. OBSERVATIONS: The authors report on a 73-year-old male whose MPNST metastasized to the brain and a 32-year-old male with leptomeningeal metastasis from MPNST and review 41 cases of MPNST that developed intracranial metastasis, as reported in the literature. LESSONS: Brain metastasis and leptomeningeal metastasis of MPNSTs show different clinical courses and require pathology-specific treatment.

Dosimetric analysis on computed tomography myelography based treatment planning in stereotactic body radiotherapy for spinal metastases.

This study aimed to quantitatively evaluate the influence of enhanced contrast on the CT myelography image of the spinal cord and/or cauda equina in addition to the target volume in spine SBRT treatment planning. In total, 19 patients who had previously undergone spine SBRT were randomly selected. The rigid image registration accuracy of CT myelography that aligned with the treatment planning CT was evaluated by calculating the normalized mutual information (NMI) and Pearson's correlation coefficient for the vertebral landmarks. At postregistration, the contrast-enhanced region of the CT myelography image was replaced with water-mass density, and the original treatment plan was recalculated on this image. For comparison, the dose was also recalculated on the contrast-enhanced CT myelography images. The NMI and Pearson's correlation coefficients for landmarks were 0.39 ± 0.12 and 0.97 ± 0.04, respectively. The mean D0.035cc of the spinal cord and/or cauda equina on the CT myelography image with the contrast-enhanced region replaced by water-mass density showed -0.37% ± 0.64% changes compared with that of the treatment planning CT. Conversely, the mean D0.035cc in contrast-enhanced CT myelography changed by -1.39% ± 0.51%. The percentage change in D98% for the planning target volume was confirmed to be small by replacing the contrast-enhanced region with water-mass density (p < 0.01). The dose calculation of the target volume, spinal cord, and/or cauda equina using the CT myelography image that replaced the contrast-enhanced region with water-mass density could be a more appropriate procedure with less dose calculation uncertainty.

Recent Molecular and Genetic Findings in Intramedullary Spinal Cord Tumors.

The study of genetic alterations and molecular biology in central nervous system (CNS) tumors has improved the accuracy of estimations of patient prognosis and tumor categorization. Therefore, the updated 2021 World Health Organization (WHO) classification includes various diagnostic genes, molecules, and pathways for diagnosis, as well as histological findings. These findings are expected both to have diagnostic applications and to facilitate new targeted therapies that target tumor-specific genetic changes and molecular biology. Intramedullary spinal cord tumors (IMSCTs) are rare CNS tumors that are difficult to treat because they occur in eloquent areas. Although the genetic underpinnings of IMSCTs remain unclear compared to their intracranial counterparts, the genetic characteristics of these tumors are gradually being revealed. Here, we describe the major changes in the new 2021 WHO classification and review the major types of IMSCTs, with an emphasis on their clinical features and genetic alterations.

Radiological Analysis of Minimally Invasive Microscopic Laminectomy for Lumbar Canal Stenosis with a Focus on Multilevel Stenosis and Spondylolisthesis.

OBJECTIVE: We retrospectively compared the radiological and clinical outcomes of two different surgical techniques (lumbar spinous process splitting laminectomy [LSPSL] and unilateral laminotomy for bilateral decompression [ULBD]) to treat lumbar spinal canal stenosis (LCS). METHODS: We performed a retrospective comparative study of 141 consecutive patients with an average age of 70.8 ± 9.4 years who had undergone LSPSL or ULBD for LCS between April 2015 and April 2019. None of the patients had developed remote fractures of the spinous processes using either technique. These cases were divided into 2 groups: group L, 73 patients who had undergone LSPSL from April 2015 to April 2017; and group U, 68 patients who had undergone ULBD from May 2017 to April 2019. The clinical and radiological outcomes and surgical complications at the 1-year postoperative follow-up period were evaluated. RESULTS: We found no significant differences in the operative time between the 2 groups. However, group U had had significantly less blood loss than group L. The facet joints were significantly well preserved in group U. We examined the multilevel and spondylolisthesis cases separately and found that both surgical procedures were equally effective and that the visual analog scale scores for back or leg pain and Japanese Orthopaedic Association scores had significantly improved postoperatively in each group. Group U showed better outcomes in terms of LCS recurrence, with 3 patients in the group L requiring repeat surgery. CONCLUSIONS: We found both ULBD and LSPSL to be safe and effective techniques for LCS, even for patients with spondylolisthesis and multilevel disease. ULBD was superior in terms of recurrence prevention, preservation of the facet joints, and less blood loss.

Piecemeal resection of aggressive vertebral hemangioma using real-time navigation-guided drilling technique.

Vertebral hemangiomas are the most common benign vertebral tumors and are usually asymptomatic. Aggressive subtypes of the tumor, called aggressive VHs (AVHs), can become symptomatic with extraosseous extensions and require surgical removal. We present a case of AVH in a 36-year-old man presenting with low back pain and right leg pain that persisted for three months. Imaging studies showed a Th12 vertebral tumor that extended into the spinal canal and was squeezing the spinal cord. Computed tomography (CT)-guided biopsy indicated vertebral hemangimoa. Following preoperative arterial embolization, piecemeal gross total resection was attained under navigation guidance. He was left with no neurological deficit and remained well at the 12-month postoperative folow-up. Since AVHs are benign tumor, piecemeal removal of the tumor can be selected. However, disadvantage of the approach include difficulty of making decision how much to remove the front part of the vertebral body close to thoracic descending aorta. Furthermore, when the tumor tissue is too hard to curett, manipulation in tight spaces near the spinal cord carries the risk of damaging it. Navigation-guided drill is highly helpful for real-time monitoring of ongoing tumor resection. It enables safely resection of the tumor especially in the anterior cortical surface of the vertebral body and easily resection even hard tumors. This method results in reducing residual tumor and maintaining safety resection.

Preoperative Embolization of Spinal Metastatic Tumor: The Use of Selective Computed Tomography Angiography for the Detection of Radiculomedullary Arteries.

INTRODUCTION: Preoperative embolization for metastatic spinal cord compression (MSCC) has a risk of spinal ischemia. This study aimed to assess the efficacy and safety of preoperative embolization in patients with MSCC and evaluate the use of computed tomography (CT) angiography for the detection of the radiculomedullary arteries (RMA). METHODS: This retrospective study included 20 patients (12 men and 8 women; median age, 66 years), who underwent preoperative embolization before a decompression surgery, which corresponded to 22 embolization procedures. The detection ability of RMA was evaluated using angiography and selective CT angiography. Surgical data including intraoperative blood loss and transfusion were also evaluated. RESULTS: Six RMAs were identified at the levels of affected vertebrae and one level above and below in the diagnostic spinal angiography. In addition to spinal angiography, adjunctive selective CT angiography allowed visualization of another five RMAs. Overall, 11 RMAs were identified in 9 patients. Preoperative embolization was successfully achieved in all patients. As regards complications related to embolization procedure, palsy exacerbated in one patient (4.5%), which improved postoperatively. During the surgical procedure, the mean intraoperative blood loss was 353.4±254.2 mL without intraoperative transfusion in all patients. CONCLUSIONS: The present study showed small amounts of intraoperative blood loss without any severe complications related to preoperative embolization. Selective CT angiography was a useful technique to detect RMAs and contributed to the safety of preoperative embolization.

Clinical and Radiological Clues of Traumatic Craniocervical Junction Injuries Requiring Occipitocervical Fusion to Early Diagnosis.

OBJECTIVE: The purpose of this study is to find the clinical and radiographic characteristics of traumatic craniocervical junction (CCJ) injuries requiring occipitocervical fusion (OC fusion) for early diagnosis and surgical intervention. METHODS: We retrospectively reviewed 12 patients with CCJ injuries presenting to St. Michaels Hospital in Toronto who underwent OC fusion and looked into the following variables; (1) initial trauma data on emergency room arrival, (2) associated injuries, (3) imaging characteristics of computed tomography (CT) scan and magnetic resonance imaging (MRI), (4) surgical procedures, surgical complications, and neurological outcome. RESULTS: All patients were treated as acute spinal injuries and underwent OC fusion on an emergency basis. Patients consisted of 10 males and 2 females with an average age of 47 years (range, 18-82 years). All patients sustained high-energy injuries. Three patients out of 6 patients with normal BAI (basion-axial interval) and BDI (basion-dens interval) values showed visible CCJ injuries on CT scans. However, the remaining 3 patients had no clear evidence of occipitoatlantal instability on CT scans. MRI clearly described several findings indicating occipitoatlantal instability. The 8 patients with normal values of ADI (atlantodens interval interval) demonstrated atlantoaxial instability on CT scan, however, all MRI more clearly and reliably demonstrated C1/2 facet injury and/or cruciate ligament injury. CONCLUSION: We advocate measures to help recognize CCJ injury at an early stage in the present study. Occipitoatlantal instability needs to be carefully investigated on MRI in addition to CT scan with special attention to facet joint and ligament integrity.

Preoperative Intracranial Dissemination of Spinal Myxopapillary Ependymoma Attributed to Tumor Hemorrhage.

BACKGROUND: Spinal myxopapillary ependymoma (SME), generally considered a benign entity, can exhibit brain and whole-spine metastases as well as local recurrence after surgery. However, the presence of preoperative retrograde intracranial dissemination at the time of diagnosis is very rare. CASE DESCRIPTION: We report a case of SME in a 22-year-old man who presented with acute exacerbation of chronic back pain shooting down both thighs and weakness in both legs. Magnetic resonance imaging of the brain and whole spine showed an enhancing mass occupying the majority of the spinal canal at the L1-L2 level and multiple foci dissemination, including in the right pons, lateral midbrain, and occipital lobe, and at the C7, Th6, L4, and S2 levels of the spinal canal at the time of diagnosis. On gross total removal of the dominant tumor located at the L1-L2 level, severe intradural arachnoiditis and syrinx filled with xanthochromic cerebrospinal fluid was noted, indicating the presence of previous tumor hemorrhage. Histopathologic analysis of the tumor supported SME diagnosis, and <1% of cells showed Ki-67 expression. We speculated that distant retrograde dissemination could have been attributed to metastatic spread through cerebrospinal fluid caused by tumor hemorrhage, which may explain distant dissemination despite low expression of Ki-67. CONCLUSIONS: Screening of the whole brain and spine at the time of diagnosis is imperative when tumor is detected at any level of the neuraxis. The present case of SME with a preoperative intracranial lesion is the fifth case documented in the medical literature.

Thoracic Disc Herniation Manifesting as Abdominal Pain Alone Associated with Thoracic Radiculopathy.

Symptomatic thoracic disc herniation (TDH) with thoracic radiculopathy alone is an extremely rare condition. Here, we report a rare case of TDH in a 52-year-old man who presented with medically refractory severe right flank pain. Based on pain distribution, pain intensity changes according to truncal position, ineffectiveness of intercostal nerve block, and radiological findings, his pain was determined to be caused by TDH at T9-10 level. Symptomatic TDH often requires invasive surgery. However, TDH with radiculopathy alone can be treated via a posterior approach without spinal cord manipulation or spinal fusion. We could eliminate the pain by removing TDH with hemilaminectomy and microdiscectomy using an O-arm-based navigation system.

Intraosseous Melanotic Schwannoma in the Sacrum Mimicking Primary Bone Tumor.

Primary tumors of sacrum are rarely seen, and the differential diagnosis is extensive, such as chordomas, giant cell tumors, and schwannomas. Sacral intraosseous schwannomas (IOSs) are very rare and encompass approximately 1%-5% of all spinal schwannomas. Melanotic schwannomas (MSs) are categorized as an unusual variant of benign schwannomas; however, they sometimes follow a malignant course. The authors present a case of MS with intraosseous extension into sacrum in a 48-year-old male arising from the left S2 nerve root. Magnetic resonance imaging (MRI) and computed tomography (CT) scan demonstrated a destructive mass in the sacrum. He was made a diagnosis with MS by 18F-fluoro-deoxy-glucose positron-emission-tomography (18F-FDG PET) and open biopsy. The tumor was blackish-colored and vascular-rich fragile tumor covered by fibrous capsule. The floor of the tumor was not encapsulated and invading into the sacral bone. Total removal of the tumor together with the left S2 nerve of origin via posterior approach was achieved. The patient made dramatic recovery of neurological symptoms and tumor recurrence is not seen for 6-month follow-up period. MS is a benign tumor with potential for aggressive behavior and capacity to metastasize. Therefore, total removal of the tumor and careful postoperative follow-up are recommended. Postoperative spinopelvic stability also needs to be taken into consideration. The authors discuss our successful management with a focus on diagnostic process, surgical planning, and histological consideration to provide the most up-to-date guidance on managing this challenging tumor.

Surgical treatment of a thoracic ventral intradural arachnoid cyst associated with syringomyelia: case report.

The pathogenesis of thoracic ventral intradural spinal arachnoid cyst (ISAC) is unknown due to its extremely low incidence. In addition, its surgical treatment is complicated because of the ventral location, large craniocaudal extension, and frequent coexistence of syringomyelia. The optimal surgical strategy for thoracic ventral ISAC remains unclear and continues to be a matter of debate. In this report, the authors describe an extremely rare case presenting with a compressive thoracic ventral ISAC associated with syringomyelia that was successfully treated with a simple cyst-pleural shunt. The patient's medical history revealed bacterial spinal meningitis along with an extensive spinal epidural abscess, suggesting the incidence of extensive adhesive arachnoiditis (AA) to be a plausible cause for this pathology. Thoracic ventral ISAC reportedly occurs secondary to AA and is commonly associated with syringomyelia. Placement of a cyst-pleural shunt is an effective, safe, and uncomplicated surgical strategy, which can provide sufficient cyst drainage regardless of the coexistence of AA, and thus should be considered as primary surgical treatment. Syrinx drainage could be reserved for a later attempt in case the cyst-pleural shunt fails to reduce the extent of syringomyelia.

Reduction in surgical site infection with suprafascial intrawound application of vancomycin powder in instrumented posterior spinal fusion: a retrospective case-control study.

OBJECTIVE Recent studies have demonstrated the efficacy of subfascial intrawound application of vancomycin powder in spine surgery in reducing the rate of surgical site infections (SSIs). However, to date no study has evaluated the efficacy and safety of suprafascial application of vancomycin powder in spine surgery. The purpose of this study was to quantify the rate of SSIs after open instrumented posterior spinal fusion with and without application of suprafascial vancomycin powder and to evaluate the rate of vancomycin powder-related local adverse effects. METHODS The authors conducted a single-center retrospective case-control study of adult patients undergoing open instrumented posterior fusion of the cervical, thoracic, or lumbar spine performed by a single surgeon from January 2010 through December 2016. In March 2013, routine application of 1 g of suprafascial vancomycin powder was started for all cases in addition to standard systemic antibiotic prophylaxis. Baseline demographics and operative data as well as the SSI rates were compared between the study groups. The incidence of vancomycin powder-related adverse effects was analyzed. RESULTS A total of 515 patients (268 in the untreated group and 247 in the treated group) were included in the study. The mean age was significantly higher in the treated group than in the untreated group (58.4 vs 54.4 years, p < 0.01). Operative variables were similar between the study groups. Patients receiving vancomycin powder had a significantly lower infection rate (5.6% in the untreated group vs 0% in the treated group, p < 0.001). No vancomycin powder-related adverse effects were identified in the treated group. CONCLUSIONS Routine application of suprafascial intrawound vancomycin powder in addition to systemic antibiotic prophylaxis is an easy-to-use, safe, and effective strategy for preventing SSIs after instrumented posterior spinal fusion. Suprafascial application of vancomycin powder could be a valuable alternative to previously reported subfascial distribution, minimizing the risk of local adverse drug reactions.

Hybrid Method of Transvertebral Foraminotomy Combined with Anterior Cervical Decompression and Fusion for Multilevel Cervical Disease.

Transvertebral foraminotomy (TVF) combined with anterior cervical decompression and fusion (ACDF) can be used to treat multilevel cervical spondylotic myelopathy and radiculopathy; however, the radiological outcomes and effectiveness of this hybrid procedure are unknown. We retrospectively assessed 22 consecutive patients treated with combined TVF and ACDF between January 2007 and May 2016. The Japanese Orthopedic Association (JOA) score and Odom's criteria were analyzed. Radiological assessment included the C2-7 sagittal Cobb angle (CA) and range of motion (ROM). The tilting angle (TA), TA ROM, and disc height (DH) of segments adjacent to the ACDF were also measured. Adjacent segment degeneration, which includes disc degeneration, was evaluated. The mean postoperative follow-up was 41.7 months. All surgeries were performed at two adjacent segments, with ACDF and TVF of the upper and lower segments, respectively. The JOA scores significantly improved. There were no significant differences in the C2-7 CA, C2-7 ROM, TA, and TA ROM, but there was a statistically significant decrease in DH of the lower adjacent segment to ACDF. Progression of disc degeneration was identified in two patients, with no progression in the criterion of adjacent segment degeneration over the follow-up. The TVF combined with ACDF produced excellent clinical results and maintained spinal alignment, albeit with a reduction in DH. TVF was safely performed at the lower segment adjacent to the ACDF, although this might result in earlier degeneration. In conclusion, this hybrid method is less invasive and beneficial for reduction of the number of fused levels.

Clinical and Radiological Outcomes of Microscopic Lumbar Foraminal Decompression: A Pilot Analysis of Possible Risk Factors for Restenosis.

A single-center retrospective comparative study was designed to identify the risk factors for restenosis of lumbar foraminal stenosis (LFS) after microscopic foraminal decompression (MFD). 21 consecutive patients who underwent single-level MFD with an average of 19-month follow-up were divided into two study groups based on clinical outcomes; group 1 (7 patients with poor outcomes requiring revision surgery), group 2 (14 patients with good outcomes with no revision surgery required). Changes of lumbar spinal alignment on plain standing radiographs were compared and analyzed between two study groups to investigate the pathology and risk factors associated with restenosis after MFD. Preoperative disc wedging (DW) angle was significantly larger in group 1 than in group 2 (3.5 ± 1.0° vs 1.1 ± 0.2°, P < 0.01). Postoperatively, disc height (DH) and foraminal height (FH) decreased (P < 0.05), and DW deteriorated (P < 0.01) significantly in group 1, while there were no significant changes in group 2. Lumbar lordosis (LL) remarkably improved postoperatively in group 2 (24.7 ± 8.0 to 32.0 ± 7.0, P < 0.001), contrary to limited improvement in group 1 (25.1 ± 9.2 to 27.0 ± 12.0, P = 0.45). Postoperative LL is a predictive factor for restenosis after MFD. Decrease in DH or progression of DW was contributing to restenosis. LFS presenting with large DW and lumbar degenerative kyphosis should be excluded from surgical indications for MFD without instrumented fusion, considering the high recurrence rate.

Surgical Treatment of Rotational Vertebral Artery Syndrome Induced by Spinal Tumor: A Case Report and Literature Review.

Vertebrobasilar insufficiency (VBI) provoked by physiological head rotation is known as rotational vertebral artery syndrome (RVAS) or Bow Hunter syndrome. RVAS most often occurs at C1-2 level with head rotation and presents with symptoms of VBI. Several previously published studies have reported RVAS at subaxial sites (V2 segment), however, tumor-induced RVAS has never been reported. The authors report the first case of RVAS at V2 segment due to compression from a spinal tumor. A 71-year-old man presented with symptoms of dizziness provoked by head rotation or neck extension. computed tomography (CT) angiography and dynamic cerebral angiography revealed circumferential stenosis with neutral neck position and complete occlusion of the left dominant vertebral artery (VA) at C5 level with his neck extended or rotated to the left. Complete neurological recovery was achieved after removal of a spinal osteochondroma and surgical decompression of the left VA via an anterior approach. Spinal tumors should be included in the differential diagnosis in cases of RVAS. Spinal degenerations or sarcomatous transformation of the tumor could lead to clinical manifestations of RVAS in cases with spinal osteochondroma. Complete removal of the tumor with or without spinal fusion would be the treatment of choice, in addition to medical treatment in the cases of acute stroke.

Chiari Type 1 Malformation-induced Intracranial Hypertension with Diffuse Brain Edema Treated with Foramen Magnum Decompression: A Case Report.

Chiari type 1 malformation (CM1) rarely causes papilloedema, which is indicative of high intracranial pressure with or without ventricular dilatation. Furthermore, concomitant brain parenchymal abnormalities have not been reported to date. In this paper, the authors report on a young woman of CM1-induced intracranial hypertension (ICH) with diffuse brain edema with a focus on venous sinus assessment, and discuss the surgical strategy. A 24-year-old woman presented to Nagoya University Hospital complaining of 4-year history of severe occipital headache and blurry vision with slowly progressive worsening. Head and whole spine MRI showed a CM1 with diffuse white matter hyperintensities (WMH) on T2-weighted imaging and narrowed brain sulci without hydrocephalus. Lumbar puncture revealed extremely high opening pressure. Detailed blood examination and other radiographical imaging studies denied the presence of tumor, collagen disease, encephalitis and other entities. Head magnetic resonance venography and angiography demonstrated severe transverse sinus stenosis on both sides. Foramen magnum decompression was performed to alleviate the ICH by restoration of cerebrospinal fluid (CSF) stagnation at the foramen magnum with successful outcome. The patient completely recovered from preoperative symptoms immediately after surgery. The diffuse WMH and narrowing brain sulci have been resolving. The most feasible explanation for this complicated pathophysiology was ICH induced by CM1 led to transverse sinus collapse, resulting in diffuse WMH as a result of venous hypertension. This case report is the first illustration of successful surgical treatment of CM1 with diffuse brain edema with a focus on venous sinus assessment.

Biomechanical Analysis of a Pedicle Screw-Rod System with a Novel Cross-Link Configuration.

STUDY DESIGN: The strength effects of a pedicle screw-rod system supplemented with a novel cross-link configuration were biomechanically evaluated in porcine spines. PURPOSE: To assess the biomechanical differences between a conventional cross-link pedicle screw-rod system versus a novel cross-link instrumentation, and to determine the effect of the cross-links. OVERVIEW OF LITERATURE: Transverse cross-link systems affect torsional rigidity, but are thought to have little impact on the sagittal motion of spinal constructs. We tested the strength effects in pullout and flexion-compression tests of novel cross-link pedicle screw constructs using porcine thoracic and lumbar vertebrae. METHODS: Five matched thoracic and lumbar vertebral segments from 15 porcine spines were instrumented with 5.0-mm pedicle screws, which were then connected with 6.0-mm rods after partial corpectomy in the middle vertebral body. The forces required for construct failure in pullout and flexion-compression tests were examined in a randomized manner for three different cross-link configurations: un-cross-link control, conventional cross-link, and cross-link passing through the base of the spinous process. Statistical comparisons of strength data were analyzed using Student's t-tests. RESULTS: The spinous process group required a significantly greater pullout force for construct failure than the control group (p=0.036). No difference was found between the control and cross-link groups, or the cross-link and spinous process groups in pullout testing. In flexion-compression testing, the spinous processes group required significantly greater forces for construct failure than the control and cross-link groups (p<0.001 and p=0.003, respectively). However, there was no difference between the control and cross-link groups. CONCLUSIONS: A novel cross-link configuration that features cross-link devices passing through the base of the spinous processes increased the mechanical resistance in pullout and flexion-compression testing compared to un-cross-link constructs. This configuration provided more resistance to middle-column damage under flexion-compression testing than conventional cross-link configuration.