Optimal catheter selection for acute stroke patients with type III aortic arch based on magnetic resonance angiography road mapping of the para-aortic trans-femoral access route before mechanical thrombectomy.

BACKGROUND: Although mechanical thrombectomy for acute ischemic stroke has a high recanalization rate, procedurally challenging lesions remain in approximately 10% of the cases. Type III aortic arches, due to their anatomical configuration, are a fundamental problem impacting this procedure. This study aimed to determine whether optimal catheter selection for type III aortic arches, using magnetic resonance angiography (MRA)-based road mapping of the para-aortic transfemoral access route, reduces the time required for mechanical thrombectomy. METHODS: We retrospectively evaluated 203 consecutive patients who underwent mechanical thrombectomy at multiple centers between April 2018 and July 2022. Twenty-three patients were diagnosed with a type III aortic arch using MRA-based road mapping performed to visualize the para-aortic access route before neuro-interventional procedures. Among the 23 patients with type III aortic arches, 10 received a Simmons-type catheter (initial Simmons group) and 13 received a JB-2-type catheter® (initial JB-2 group) as their first inner catheter. The time required for mechanical thrombectomy was compared between the groups. RESULTS: Compared with the initial JB-2 group, the initial Simmons group exhibited a significantly shorter "puncture-to-recanalization time" (105 vs. 53 min, p = 0.009) and "door-to-recanalization time" (164 vs. 129 min, p = 0.032). CONCLUSIONS: Optimal catheter selection by identifying the aortic arch before mechanical thrombectomy using MRA-based road mapping effectively reduced the mechanical thrombectomy time. This suggests that even in type III aorta cases, appropriate catheter selection may shorten the mechanical thrombectomy time and improve acute ischemic stroke prognosis.

Epidemiology and Comparative Analysis of Outcomes of Intramedullary Spinal Cord Tumor Between Pediatric and Adult Patients.

STUDY DESIGN: This was as clinical retrospective study. OBJECTIVES: We sought to evaluate the characteristics of Pediatric intramedullary spinal cord tumors (PISCTs) and to identify differences between pediatric and adult intramedullary spinal cord tumors. SUMMARY OF BACKGROUND DATA: PISCTs represent a rare clinical entity with limited evidence-base in the literature. METHODS: This study is a subanalysis of the retrospective multicenter observational study authorized by the Neurospinal Society of Japan, including consecutive patients with spinal intramedullary tumors treated surgically at 58 institutions between 2009 and 2020. Data on 1080 intramedullary spinal cord tumors were obtained, consisting of 91 pediatric and 939 adult patients. Survival was compared using Cox hazard regression while clinical differences were evaluated using multivariable logistic regression that controlled for confounders. RESULTS: Pediatric patients had a shorter overall, and progression-free, survival than adults. Pediatric patients with ISCTs were likely to have scoliosis [odds ratio (OR) = 6.49, 95% CI: 2.26-18.7], short preoperative symptom duration (OR = 0.99, 95% CI: 0.98-0.99), lower incidence of paresthesia (OR = 0.41, 95% CI: 0.22-0.77), higher incidence of paresis (OR = 2.10, 95% CI: 1.01-4.35), histopathology of astrocytoma (OR = 2.97, 95% CI: 1.19-7.43), and postoperative functional deterioration upon discharge (OR = 2.83, 95% CI: 1.43-5.58). Age was not a statistically significant prognostic factor of overall survival among the pediatric cohort. CONCLUSION: We found that the clinical characteristics of ISCTs differed between pediatric and adult patients. In terms of histopathological types, astrocytoma was most common in pediatric patients. ISCT occurring at an early age may not be an indicator for poor prognosis.

Shorter survival time of adolescents and young adult patients than older adults with spinal cord glioblastoma: a multicenter study.

OBJECTIVE: Cancers in adolescents and young adults (AYAs) (age 15-39 years) often present with unique characteristics and poor outcomes. To date, spinal cord glioblastoma, a rare tumor, remains poorly understood across all age groups, including AYAs. This comparative study aimed to investigate the clinical characteristics and outcomes of spinal cord glioblastoma in AYAs and older adults (age 40-74 years), given the limited availability of studies focusing on AYAs. METHODS: Data from the Neurospinal Society of Japan's retrospective intramedullary tumor registry (2009-2020) were analyzed. Patients were dichotomized on the basis of age into AYAs and older adults. Univariate and multivariate Cox proportional hazards regression models were utilized to explore risk factors for overall survival (OS). RESULTS: A total of 32 patients were included in the study, with a median (range) age of 43 (15-74) years. Of these, 14 (43.8%) were AYAs and 18 (56.2%) were older adults. The median OS was 11.0 months in AYAs and 32.0 months in older adults, and the 1-year OS rates were 42.9% and 66.7%, respectively, with AYAs having a significantly worse prognosis (p = 0.017). AYAs had worse preoperative Karnofsky Performance Status (KPS) than older patients (p = 0.037). Furthermore, AYAs had larger intramedullary tumors on admission (p = 0.027) and a significantly higher frequency of intracranial dissemination during the clinical course (p = 0.048). However, there were no significant differences in the degrees of surgical removal or postoperative radiochemotherapy between groups. The Cox proportional hazards regression model showed that AYAs (HR 3.53, 95% CI 1.17-10.64), intracranial dissemination (HR 4.30, 95% CI 1.29-14.36), and no radiation therapy (HR 57.34, 95% CI 6.73-488.39) were risk factors for mortality for patients of all ages. Worse preoperative KPS did not predict mortality in AYAs but did in older adults. The high incidence of intracranial dissemination may play an important role in the poor prognosis of AYAs, but further studies are needed. CONCLUSIONS: The clinical characteristics of AYAs with spinal cord glioblastoma differ from those of older adults. The prognosis of AYAs was clearly worse than that of older adults. The devastating clinical course of spinal glioblastoma in AYAs was in line with those of other cancers in this age group.

The Impact of Adjuvant Radiotherapy on Clinical Performance Status in Patients With Grade II Spinal Cord Astrocytoma - A Nationwide Analysis by the Neurospinal Society of Japan.

OBJECTIVE: The impact of adjuvant radiotherapy on overall survival (OS) and progression-free survival (PFS) of patients with grade II spinal cord astrocytomas remains controversial. Additionally, the relationship between progression and clinical deterioration after radiotherapy has not been well investigated. METHODS: This study included 53 patients with grade II intramedullary spinal cord astrocytomas treated by either subtotal, partial resection or open biopsy. Their clinical performance status was assessed immediately before operation and 1, 6, 12, 24, and 60 months after surgery by Karnofsky Performance Scale (KPS). Patients with and without adjuvant radiotherapy were compared. RESULTS: The groups with and without radiation comprised 23 and 30 patients with a mean age of 50.3 ± 22.6 years (range, 2-88 years). The mean overall disease progression rate was 47.1% during a mean follow-up period of 48.4 ± 39.8 months (range, 2.5-144.5 months). In the radiation group, 11 patients (47.8%) presented with progressive disease, whereas 14 patients (46.7%) presented with progressive disease in the group without radiation. There were no significant differences in OS or PFS among patients with or without adjuvant radiotherapy. KPS in both groups, especially radiation group, gradually decreased after operation and deteriorated before the confirmation of disease progression. CONCLUSION: Adjuvant radiotherapy did not show effectiveness regarding PFS or OS in patients with grade II spinal cord astrocytoma according to classical classification based on pathohistological findings.

Impact of surgical treatment for intramedullary spinal cord metastasis on neurological function and survival: A multicenter retrospective study by the Neurospinal Society of Japan.

BACKGROUND: This retrospective multicenter study aimed to analyze the characteristics and surgical outcomes of intramedullary spinal cord metastasis (ISCM) and to discuss the controversy regarding its surgical indications. METHODS: This study included 29 ISCM patients who underwent surgery between 2009 and 2020. Biopsy cases were excluded from analysis. For functional and neurological functional assessments, Karnofsky Performance Status (KPS, %) and modified McCormick Scale (MMS, 5-grade scale) scores were determined before and after surgery. Patients were divided into two groups: a mild-to-moderate disability group with preoperative MMS grades 1 to 3, and a severe disability group with preoperative MMS grades 4 to 5. RESULTS: The mean preoperative KPS was 45.9, and the mean duration from symptom onset to surgical intervention was 1 month. The ISCM was located in the cervical spine in 10 cases and the thoracic spine in 19 cases. The access route (myelotomy) for ISCM removal was via the posterior median sulcus in 9 cases and via the posterior lateral sulcus in 11 cases, while others were not recorded. The degree of removal was gross total resection in 20 patients (69%), subtotal resection in 0 patients, and partial removal in 9 patients (31%). No significant complications related to the surgical procedures were recorded. Postoperative adjuvant therapy included radiotherapy in 17 patients (58.6%) and chemotherapy or molecular targeted therapy in 13 patients (44.8%). Pathological findings of ISCM showed that colorectal cancer was the most common in 9 cases, followed by lung cancer in 7, renal cell carcinoma in 5, and breast cancer in 2. Twenty-one of the 29 patients (72.4%) were confirmed to have survived 6 months after surgery: 8 of the 10 patients (80%) in the mild-to-moderate disability group and 13 of the 19 patients (68.4%) in the severe disability group. At 6 months after surgery, 3 of the 8 patients (38%) in the mild-to-moderate group were able to maintain or improve their function. Eleven of the 13 patients (85%) in the severe disability group maintained their function despite being severely disabled. CONCLUSIONS: This study suggests that surgical treatment can maintain or improve neurological function in a limited number of patients with ISCM, although it had minimal impact on improving the survival rate after surgery.

Comparison of Access Route for Endovascular Treatment by Time-Spatial Labeling Inversion Pulse (Time-SLIP) MRA and Contrast-Enhanced MRA.

Objective: In endovascular treatment, it is important to evaluate the access route for placing a catheter into the common carotid artery (CCA) promptly and safely prior to the procedure. We examined whether non-contrast MRA using time-spatial labeling inversion pulse (Time-SLIP) can be used in patients prior to endovascular thrombectomy for acute ischemic stroke. We compared Time-SLIP MRA to contrast-enhanced (CE) MRA and evaluated the efficacy in the evaluation of access routes. Methods: We retrospectively reviewed 31 patients admitted between October 2018 and December 2018 for cerebral infarction at our hospital. Blood vessels were imaged from the aortic arch to the CCA. A radiologist blindly evaluated quality score, stenosis, shape of the aorta, and degree of tortuosity. Results: There were no "non-diagnostic" images. The sensitivity, specificity, positive predictive value, and negative predictive value for stenosis were 83%, 96%, 83%, and 96%, respectively. The sensitivity for the aorta type classification was 100%. The sensitivity for mild tortuosity was 93%, for moderate was 100%, and for severe was 100%. Conclusion: Time-SLIP MRA can be an alternative to CE MRA in access route assessment for patients with cerebral infarction who are not eligible for acute thrombectomy therapy.

Outcomes of Intramedullary Spinal Cord Tumor Surgery in Older Versus Younger Adults: A Multicenter Subanalysis Study by the Neurospinal Society of Japan.

OBJECTIVE: Intramedullary spinal cord tumors (IMSCTs) are uncommon and difficult to treat. Studies examining the efficacy of rare IMSCT surgery in the elderly are limited. We conducted a subanalysis using multicenter retrospective-historical data provided by the Japan Neurospinal Society to compare surgical outcomes between older and younger adults with IMSCTs. METHODS: We classified patients with IMSCTs into younger (aged 18-64 years) or older ( ≥ 65 years) groups. The primary outcomes of "improved" or "worsened" from the preoperative period to 6 months after surgery were evaluated using the modified McCormick scale (mMCs). A favorable outcome was defined as an mMCs grade of I/II at 6 months. RESULTS: Among 841 patients registered, there were 658 younger (78.2%) and 183 older patients (21.8%) evaluated using mMCs at 6 months. Median preoperative mMCs grades were significantly worse in older patients than in younger patients. Neither the "improved" nor "worsened" rate differed significantly between the groups (28.1% vs. 25.1%; crude odds ratio [cOR], 0.86; 95% confidence interval [CI], 0.59-1.25; adjusted OR [aOR], 0.84; 95% CI, 0.55-1.28; 16.9% vs. 23.0%; cOR, 1.47; 95% CI, 0.98-2.20; aOR, 1.28; 95% CI, 0.83-1.97). Favorable outcomes were significantly less common among older adults in the univariate analysis but were not significant in the multivariate analysis (66.4% vs. 53.0%; cOR, 0.57; 95% CI, 0.41-0.80; aOR, 0.77; 95% CI, 0.50-1.19). In both younger and older patients, preoperative mMCs accurately predicted favorable outcomes. CONCLUSION: Age alone is not a sufficient reason to prohibit surgery for IMSCTs.

Spinal Cord Subependymoma: A Subanalysis of the Neurospinal Society of Japan's Multicenter Study of Intramedullary Spinal Cord Tumors.

OBJECTIVE: This study aimed to analyze the clinical characteristics, treatment strategies, and surgical outcomes of subependymoma patients from the 2022 Neurospinal Society of Japan multicenter intramedullary spinal cord tumor study. METHODS: Twenty-six patients with spinal cord subependymoma who were included in the index study of 1,033 patients were retrospectively analyzed. RESULTS: Mean patient age was 49.4 years. Seventeen patients were men and 9 were women. Sensory disturbance was reported in 22 patients and motor weakness in 18. Median duration of symptoms was 24 months. The tumor was eccentrically located in 19 patients (73.1%) and unilateral in 17 (65.4%). Gross total resection was achieved in 6 patients (23.1%). The same rate for ependymoma patients in the index study was significantly higher (74.8%). Median follow-up was 40.5 months (interquartile range, 18-68 months). In 2 patients who underwent only partial resection, reoperation was required owing to progression 68 and 90 months after surgery, respectively. No recurrence occurred in patients who underwent gross total resection. Five patients experienced neurological worsening after surgery. CONCLUSION: Although spinal cord subependymoma can be difficult to distinguish from other intramedullary spinal cord lesions before surgery, it is characterized by an indolent clinical course and eccentric location. Surgical treatment should prioritize functional preservation because the prognosis is good even after subtotal resection.

Comparison of the Recurrence and Surgical Outcome of Spinal Hemangioblastoma in Sporadic and Von Hippel-Lindau Diseases: A Subanalysis of a Nationwide Study by the Neurospinal Society of Japan.

OBJECTIVE: This study aimed to clarify the relationship between recurrence and the extent of resection in surgery for intramedullary spinal hemangioblastoma (sHB) and its impact on von Hippel-Lindau (vHL) disease. METHODS: Data on sHB cases followed up for at least 6 months after surgery were extracted from a nationwide registry of 1,033 consecutive spinal intramedullary tumors surgically treated between 2009 and 2020, and were retrospectively categorized into a sporadic or vHL group. The diagnosis of vHL disease was made at each institution based on clinical findings. RESULTS: A total of 168 patients (sporadic group, 101; vHL group, 67) were included in the study. Compared with the sporadic group, the vHL group had a younger onset (45.4 ± 16.8 years vs. 39.6 ± 14.1 years, p = 0.02), more preoperative motor (47.5% vs. 68.7%, p < 0.01) and gait (37.6% vs. 61.2%, p < 0.01) impairments, and more patients with worsening neurological symptoms at discharge (p = 0.02). The gross total resection (GTR) rates and the recurrence rates were not statistically different between the sporadic and the vHL groups. GTR significantly improved recurrence-free survival compared to non-GTR in all patient analysis (p < 0.01) but this trend was not observed in the sporadic group. Physical functional improvement from discharge to 6 months after surgery was observed in the sporadic group (p < 0.01) but not in the vHL group. CONCLUSION: A high GTR rate may sufficiently decrease susceptibility to recurrence, especially in patients with sHB with vHL. In sporadic sHB, postoperative functional improvement can be expected, and the long-term functional prognosis is favorable.

Intramedullary Schwannoma of the Spinal Cord: A Nationwide Analysis by the Neurospinal Society of Japan.

OBJECTIVE: This study was aimed to report the clinical characteristics of intramedullary schwannomas and discuss imaging findings and treatment strategies. METHODS: The inclusion criterion was consecutive patients with intramedullary schwannomas who were surgically treated at 8 centers between 2009 and 2020. Clinical characteristics included age, sex, clinical presentation, disease duration, and follow-up period. The modified McCormick scale was used to compare the preoperative and postoperative conditions. Pre- and postoperative magnetic resonance images (MRI) of each case were analyzed. RESULTS: The mean age of the total 11 patients at the operation was 50.2 years. The mean duration of the symptoms was 23 months, with limb paresthesia being the most common clinical presentation. The cervical spine was the most common localization level of the tumor in 6 cases. The mean follow-up duration was 49.4 months. Gross total resection (GTR) and subtotal resection (STR) was achieved in 9 and 2 cases, respectively. According to the modified McCormick scale at 6 months postoperatively, 7 cases (63.6%) had improved and 4 cases (36.3%) had unchanged grades. Typical MRI findings of the intramedullary schwannoma included ring-like enhancement, syringomyelia, cystic formation, intramedullary edema, and hemosiderin deposition. Gadolinium enhancement was homogenous in 8 cases (72.7%). The tumor margins were well demarcated in all cases. CONCLUSION: Intramedullary schwannoma should be considered when sharp margins and well-enhanced tumors are present at the cervical spine level and the initial symptoms are relatively mild, such as dysesthesia. When GTR cannot be achieved, STR for tumor decompression is recommended.

Predictors of Progression-Free Survival in Patients With Spinal Intramedullary Ependymoma: A Multicenter Retrospective Study by the Neurospinal Society of Japan.

BACKGROUND AND OBJECTIVES: Ependymoma is the most common spinal intramedullary tumor. Although clinical outcomes have been described in the literature, most of the reports were based on limited numbers of cases or been confined to institutional experience. The objective of this study was to analyze more detailed characteristics of spinal intramedullary ependymoma (SIE) and provide clinical factors associated with progression-free survival (PFS). METHODS: This retrospective observational multicenter study included consecutive patients with SIE in the cervical or thoracic spine treated surgically at a total of 58 institutions between 2009 and 2020. The results of pathological diagnosis at each institute were confirmed, and patients with myxopapillary ependymoma, subependymoma, or unverified histopathology were strictly excluded from this study. Outcome measures included surgical data, surgery-related complications, postoperative systemic adverse events, postoperative adjuvant treatment, postoperative functional condition, and presence of recurrence. RESULTS: This study included 324 cases of World Health Organization grade II (96.4%) and 12 cases of World Health Organization grade III (3.6%). Gross total resection (GTR) was achieved in 76.5% of cases. Radiation therapy (RT) was applied after surgery in 16 cases (4.8%), all of which received local RT and 5 of which underwent chemotherapy in combination. Functional outcomes were significantly affected by preoperative neurological symptoms, tumor location, extent of tumor resection, and recurrence. Multivariate regression analysis suggested that limited extent of tumor resection or recurrence resulted in poor functional outcomes. Multiple comparisons among the groups undergoing GTR, subtotal resection and biopsy, or partial resection of the tumor showed that the probability of PFS differed significantly between GTR and other extents of resection. CONCLUSION: When GTR can be safely obtained in the surgery for SIE, functional maintenance and longer PFS can be expected.

Safety and Validity of Anterior Cervical Disc Replacement for Single-level Cervical Disc Disease: Initial Two-year Follow-up of the Prospective Observational Post-marketing Surveillance Study for Japanese Patients.

Anterior cervical disc replacement (ACDR) using cervical artificial disc (CAD) has the advantage of maintaining the range of motion (ROM) at the surgical level, subsequently reducing the postoperative risk of adjacent disc disease. Following the approval for the clinical use in Japan, a post-marketing surveillance (PMS) study was conducted for two different types of CAD, namely, Mobi-C (metal-on-plastic design) and Prestige LP (metal-on-metal design). The objective of this prospective observational multicenter study was to analyze the first 2-year surgical results of the PMS study of 1-level ACDR in Japan. A total of 54 patients were registered (Mobi-C, n = 24, MC group; Prestige LP, n = 30, PLP group). Preoperative neurological assessment revealed radiculopathy in 31 patients (57.4%) and myelopathy in 15 patients (27.8%). Preoperative radiological assessment classified the disease category as disc herniation in 15 patients (27.8%), osteophyte in 6 patients (11.1%), and both in 33 patients (61.1%). The postoperative follow-up rates at 6 weeks, 6 months, 1 year, and 2 years after ACDR were 92.6%, 87.0%, 83.3%, and 79.6%, respectively. In both groups, patients' neurological condition improved significantly after surgery. Radiographic assessment revealed loss of mobility at the surgical level in 9.5% of patients in the MC group and in 9.1% of patients in the PLP group. No secondary surgeries at the initial surgical level and no serious adverse events were observed in either group. The present results suggest that 1-level ACDR is safe, although medium- to long-term follow-up is mandatory to further verify the validity of ACDR for Japanese patients.

Current Trends in the Surgical Management of Intramedullary Tumors: A Multicenter Study of 1,033 Patients by the Neurospinal Society of Japan.

OBJECTIVE: We performed a retrospective observational study to demonstrate the surgical risks and long-term prognoses of intramedullary tumors in Japan using a multicenter registry authorized by the Neurospinal Society of Japan. METHODS: Data from 1,033 consecutive patients with intramedullary tumors, treated between 2009 and 2020, were collected from 58 centers. Patients with spinal lipomas or myxopapillary ependymomas were excluded. Patient characteristics, clinical presentations, imaging characteristics, treatments, and outcomes were analyzed. The modified McCormick scale was used to classify functional status. Survival was described using Kaplan-Meier curves, and multivariable logistic regression analyses were performed. RESULTS: The mean age of the patients was 48.4 years. Data of 361 ependymomas, 196 hemangioblastomas, 168 astrocytic tumors, 160 cavernous malformations, and the remaining 126 cases including subependymomas, metastases, schwannomas, capillary hemangiomas, and intravascular B-cell lymphomas were analyzed. Twenty-two patients were undiagnosed. The mean follow-up duration was 46.1 ± 38.5 months. Gross total tumor removal was achieved in 672 tumors (65.1%). On the modified McCormick scale, 234 patients (22.7%) had worse postoperative grades at the time of discharge. However, neurological status gradually improved. At 6 months postoperatively, 251 (27.5%), 500 (54.9%), and 160 patients (17.6%) had improved, unchanged, and worsened grades, respectively. Preoperative functional status, gross total tumor removal, and histopathological type were significantly associated with mortality and functional outcomes. CONCLUSION: Our findings demonstrate better postoperative functional outcomes in patients with fewer preoperative neurological deficits. Degree of resection, postoperative treatments, and prognoses are closely related to the histology of intramedullary tumors.

Efficacy of the MRA-Based Road Mapping of the Para-Aortic Access Route before Mechanical Thrombectomy in Patients with Acute Ischemic Stroke.

INTRODUCTION: The aim of this study was to clarify whether magnetic resonance angiography (MRA)-based road mapping of the para-aortic transfemoral access route can reduce the procedural time of mechanical thrombectomy in patients with acute ischemic stroke. We further investigated the role of pre-procedural MRA-based road mapping in optimal initial catheter selection for rapid mechanical thrombectomy. MATERIALS AND METHODS: We retrospectively reviewed 57 consecutive patients with acute ischemic stroke who underwent mechanical thrombectomy at our hospital between April 2018 and May 2021. Twenty-nine patients underwent MRA-based road mapping to visualize the para-aortic access route, whereas 28 patients only underwent routine head magnetic resonance imaging/angiography without MRA-based road mapping before neuro-interventional procedures. We then compared the basic procedural times required for mechanical thrombectomy, such as the time from femoral artery puncture to recanalization ("puncture to recanalization time") and the time from the admission to recanalization ("door to recanalization time"), between the groups. RESULTS: MRA-based road mapping significantly reduced the "puncture to recanalization time" (52.0 min vs. 70.0 min; p = 0.019) and the "door to recanalization time" (146 min vs. 183 min; p = 0.013). CONCLUSION: MRA-based road mapping of the para-aortic access route is useful to reduce the procedural time of mechanical thrombectomy in acute stroke patients, possibly by enabling optimal initial catheter selection during the procedure.

Efficacy of Two-Stage Surgery for Spinal Cord Ependymomas.

STUDY DESIGN: Retrospective cohort study. PURPOSE: This study aimed to elucidate cases for which staged surgeries are effective by a retrospective review of previous operative cases of spinal ependymomas. OVERVIEW OF LITERATURE: Patients with spinal ependymomas are expected to have a good prognosis following total resection. However, forcible dissection of spinal ependymomas will lead to neurological deterioration. Moreover, resection is sometimes difficult when the tumor is large. We have performed two-stage surgeries for large spinal ependymomas, but the indication of staged surgery is unclear. METHODS: We retrospectively reviewed patients diagnosed with spinal ependymomas who underwent tumor resection in our institution. We obtained data regarding patients' clinical characteristics, tumoral radiological characteristics, and surgical factors and compared them to clear prognostic factors. Two-stage surgery was performed in 11 patients (36.7%), and single surgery was performed in 19 patients (63.3%). RESULTS: Thirty patients were included in the analyses and divided into two groups: single surgery and two-stage surgery groups. In the single surgery group, high tumor-cord ratio (TCR) and intraoperative motor evoked potential (MEP) reduction were significantly correlated with unfavorable outcomes, which were defined as deterioration of the modified McCormick scale grades 2 months and 1 year postoperatively. Alternatively, these factors were not significantly correlated with postoperative unfavorable outcomes in the two-stage surgery group. Receiver operating characteristic curves indicated that TCR of 0.866 yielded 85.7% sensitivity and 83.3% specificity 2 months postoperatively. CONCLUSIONS: The results suggested that high TCR might be an indication of two-stage surgery and that its cutoff value is 0.866. Moreover, switching from single surgery to two-stage surgery may prevent postoperative neurological deterioration when intraoperative MEP is decreasing.

Description of the Diversity in Surgical Indication and Surgical Strategies for Primary Spinal Cord Tumors: A Nationwide Survey by the Neurospinal Society of Japan.

OBJECTIVE: To assess the current management of primary spinal cord tumors (PSCTs) and determine whether and to what extent there are differences in surgical strategies for PSCTs. METHODS: The Neurospinal Society of Japan conducted a survey between April 1 and 30, 2021. Certified spine surgeons were requested for information on the frequency of surgeries in 2020 and the surgical strategies adopted for each PSCTs. The following tumor histologies were focused: schwannoma, meningioma, and cauda equina tumor as extramedullary tumors; and ependymoma, hemangioblastoma, astrocytoma, and cavernoma as intramedullary tumors. The participants were divided according to their response as follows: experts, who had experienced ≥ 100 surgeries for PSCTs, and nonexperts. RESULTS: Among 308 participants (63%), 35 (11%) were experts. The total number of PSCTs in 2020 was 802 of which 564 tumors were extramedullary and 223 were intramedullary. Schwannoma accounted for 53% of the extramedullary tumors, and ependymoma accounted for 39% of the intramedullary tumors. Surgical strategies significantly differed among both the experts and nonexperts groups. Some discrepancies in the adopted surgical strategies were observed between groups. Some of the nonexperts, and none of the experts, ruled out surgery for schwannomas (Eden type 4), astrocytomas, or cavernomas. Five nonexperts (2.2%), and none of the experts, resected the entire dura for meningiomas. CONCLUSION: A nationwide survey revealed that a sufficient consensus did not exist regarding surgical strategies for PSCTs. A disease-specific registry for PSCTs is necessary in academic societies.

Prognostic role of H3K27M mutation, histone H3K27 methylation status, and EZH2 expression in diffuse spinal cord gliomas.

The objective of this study is to clarify clinical significance of the H3F3A K27M mutation (H3K27M) and analyze the correlation between H3K27M, H3K27me3 status, and EZH2 expression and prognosis in spinal cord gliomas. Patients with spinal cord diffuse glioma regardless of World Health Organization (WHO) grade underwent genetic analysis for H3F3A, HIST1H3B, TERT promoter, IDH1/2, and BRAF. H3K27me3 status and EZH2 expression were analyzed through immunohistochemistry. Thereafter, the association between H3K27M, H3K27me3 status, and EZH2 expression and prognosis was retrospectively analyzed using the log-rank test. A total of 26 cases, 5 with WHO grade 4, 9 with grade 3, and 12 with grade 2 glioma, were analyzed. Although WHO grade 2 cases tended to present favorable overall survival, the difference was not statistically significant. H3K27M, which was detected in four grade 4 cases (80%) and three grade 3 cases (33%), was not associated with prognosis among grade 3 and 4 cases. Among WHO grade 2-4 cases, the combination of retained H3K27me3 and negative EZH2 expression was correlated with favorable overall survival (p = 0.03). The combination of H3K27me3 status and EZH2 expression was considered as a potential prognostic marker in WHO grade 2-4 diffuse spinal cord gliomas.

[Successful Total Resection with Preceding Arterial Coil Embolization of Intradural Extramedullary Tumor at Craniovertebral Junction Encasing Dominant-side Vertebral Artery].

OBJECTIVE: The surgical resection of craniovertebral junction(CVJ)meningioma is challenging because of the neighboring brainstem, lower cranial nerves, and vertebral artery(VA). Moreover, encasement of the VA by the tumor can raise the risk of complications and require cautious manipulation during surgery. CASE: A 46-year-old woman presented with a one-year history of neck pain. She had temporal hemiplegia and numbness on her left side. Magnetic resonance imaging(MRI)showed a CVJ meningioma pushing the brainstem from the right vertebral side and encasing the right VA. Digital subtraction angiography(DSA)showed two feeding arteries arising from the right VA and a sunburst sign. The right VA was the dominant side but did not have the right posterior inferior cerebellar artery(PICA). The anterior spinal artery(ASA)was dominant in the left VA. We performed a balloon test occlusion(BTO)for 20 min and it did not cause any complications;therefore, we occluded the VA using endovascular coils. After 4 days, we removed the meningioma in the prone position, using a far-lateral approach and C1-laminectomy. The laterally located meningioma pushed the brainstem. After detaching the tumor from the dura, we cut the encased VA and the tumor was resected safely(Simpson grade II). Postoperatively, she developed temporal thermal hypoalgesia on the left side of her body. Magnetic resonance imaging showed a microinfarction in the medulla. CONCLUSION: If the VA test occlusion provides a clear result, pre-operative endovascular sacrifice of the VA encased by CVJ meningioma is a feasible treatment strategy.

Spinal rosette-forming glioneuronal tumor: A case report.

RATIONALE: Rosette-forming glioneuronal tumor (RGNT) is a rare tumor which has been first reported as the fourth ventricle tumor by Komori et al and is classified as a distinct clinicopathological entity by the WHO Classification of Tumors of the Central Nervous System as in 2007. Although RGNTs were reported to occur in both supratentorial and inflatentorial sites, only 4 case reports of spinal RGNT have been demonstrated. PATIENT CONCERNS: A 37-year-old female presenting with slowly progressing right-sided clumsiness. Cervical magnetic resonance imaging revealed a spinal intramedullary tumor between the C2 and C5 levels. DIAGNOSES: Pathological analysis showed unique biphasic cellular architecture consisting of perivascular pseudorosettes dominantly with few neurocytic rosettes and diffuse astrocytoma component. The tumor cells composed of perivascular pseudorosettes showed positivity for both synaptophysin and glial markers such as GFAP and Olig2. Therefore, the diagnosis of RGNT was made. INTERVENTIONS: Gross total resection of the tumor was achieved. No adjuvant chemotherapy nor radiotherapy was conducted after operation. OUTCOMES: At 2 years after the operation, no recurrence was observed. LESSONS: Although RGNT arising from the spinal cord is extremely rare, we need to consider the tumor as a differential diagnosis for intramedullary spinal cord tumors.

Investigation of the Neuropathic Pain Caused by Syringomyelia Associated with Chiari I Malformation.

Study Design: Retrospective cohort study. Purpose: To investigate the correlation between the syrinx morphology and neuropathic pain caused by syringomyelia associated with Chiari I malformation. Overview of Literature: Neuropathic pain caused by syringomyelia is refractory and markedly impairs the patient. Methods: We examined 24 patients with neuropathic pain caused by syringomyelia associated with Chiari I malformation. We statistically analyzed the illness duration and age at surgery between patients with and without neuropathic pain. Additionally, we classified the morphology of the syringes into deviated (D), enlarged (E), central (C), and bulkhead (B) types using T2-weighted axial imaging. Moreover, we investigated the correlation between syrinx morphology and neuropathic pain. A Mann-Whitney U-test was performed to compare between the presence or absence of neuropathic pain and the presence or absence of type D syringes. Results: The median age at surgery was 27.5 years, and the median illness duration was 24 months. Among the 24 patients, 11 had preoperative neuropathic pain, one of which was free of neuropathic pain during the final follow-up period. Among patients with neuropathic pain, the syringes' preoperative morphology was type D in nine patients and types E and C in one patient each. No patient exhibited type B morphology. Among patients without neuropathic pain, the preoperative morphology of the syringes was type D in three patients, type E in seven patients, and types C and B in two patients each. For types D and E, a correlation between neuropathic pain and syrinx morphology was observed. Moreover, type D was associated with significant neuropathic pain in both preoperative and postoperative states. Conclusions: This study showed a correlation between the morphological features of the syringes and the occurrence of neuropathic pain in patients with syringomyelia associated with Chiari I malformation.