[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.

Estimation of the number of feeding arteries of spinal arteriovenous malformations by using three-dimensional digital subtraction angiography.

PURPOSE: Spinal angiography is the gold standard for evaluation or diagnosis of spinal arteriovenous malformations (AVMs). However, some feeding arteries might be overlooked when multiple feeders exist. This study aimed to retrospectively review cases of spinal intra-dural AVMs, which were identified by three-dimensional digital subtraction angiography (3D-DSA), and attempted to estimate the number of feeding arteries. METHODS: We retrospectively reviewed patients with spinal intra-dural AVMs who underwent 3D-DSA at Hokkaido University Hospital from January 2005 to December 2016. We selected 9 patients in whom we could obtain data of multi-planar reconstruction of 3D-DSA. We measured the computed tomography (CT) values of feeding arteries and draining veins. The CT values represented the averages of maximum CT values of 5 continuous axial slices. The ratio of the CT value of feeders to that of drainers (F/D ratio) was calculated. The correlation between the F/D ratio and the number of feeders was examined with Pearson's correlation coefficient. RESULTS: The average number of feeders was 2.3 (1-4), and the number of feeders was significantly positively correlated with the F/D ratio (r = 0.855, P = .003). CONCLUSIONS: We conclude that the number of feeding arteries of spinal intra-dural AVMs can be estimated by using the F/D ratio obtained from 3D-DSA. These slides can be retrieved under Electronic Supplementary Material.

Health-related quality of life in patients with spinal dural arteriovenous fistulae.

Neurological improvement in patients with spinal dural arteriovenous fistulae (SDAVF) is often partial even after adequate treatment. While treatment outcomes have been evaluated primarily on the basis of the postoperative changes in neurological deficits, outcome measures should also reflect the patient-reported outcome (PRO). We conducted a health-related quality of life (HRQOL) survey in 52 SDAVF patients; 33 (63.5%) completed the short-form 36 Health Survey (SF-36) questionnaire. They were 25 males and 8 females ranging in age from 47 to 85 years (mean age 70.0 years). The mean follow-up period was 95.6 months. We analyzed the completed questionnaires and examined the clinical factors associated with their HRQOL. After treatment, gait- and micturition disturbances persisted in 31 (93.9%) and 31 (93.9%) of our patients; 26 (78.8%) reported chronic leg pain. The SF-36 scores of treated SDAVF patients were significantly lower than the national average of 50 for all 8 sub-items in the questionnaire. The scores for physical functioning (PF) and role-physical (RP) were particularly low. With the exception of bodily pain (BP), there was a significant negative correlation between the Aminoff-Logue scale (ALS) scores for gait- and micturition and the sub-item scores. The score for BP showed a significant positive correlation with the scores for the 7 other SF-36 sub-items. The HRQOL of treated SDAVF patients was lower than the national average with respect to both physical and mental aspects. Persistent post-treatment pain and gait- and micturition disturbances were responsible for their lower HRQOL.

Long-term outcomes after surgical and endovascular treatment of spinal dural arteriovenous fistulae.

PURPOSE: To examine the validity of our treatment strategy for spinal dural arteriovenous fistulae (SDAVF), based on the treatment results and the long-term outcome. METHODS: This study included 50 SDAVF patients (38 men, 12 women, mean age 63.2 years) with progressive myelopathy. The treatment strategy involved embolization as the initial management tool and surgery if embolization was considered unsuitable. Their medical records were evaluated to identify the treatment results and functional outcomes. The mean follow-up period was 81.2 months (range 27-184 months). RESULTS: Complete obliteration was achieved in 22 (71.0%) of 31 embolized patients and in 18 of 19 (94.7%) operated patients. The initial success rate was significantly lower in embolized than operated patients. At the last follow-up, 33 of the 50 patients (66%) manifested improved gait and 16 (32%) improved micturition. The activity of daily living (ADL) was improved in 33 (66%). When we compared the rates of functional improvement at the last follow-up, there was no significant difference between patients treated initially by embolization or surgery. CONCLUSIONS: The long-term outcomes in SDAVF patients treated by multidisciplinary management with first-line embolization were comparable to those in earlier surgical series. However, our results were unable to demonstrate the superiority of endovascular embolization to surgical treatment for SDAVF. For the purpose of justifying endovascular embolization as a first-line treatment for SDAVF, it will be necessary to show further improvement in both the initial treatment success and the complication rates.

Increased Blood Viscosity in Ischemic Stroke Patients with Small Artery Occlusion Measured by an Electromagnetic Spinning Sphere Viscometer.

BACKGROUND AND PURPOSE: High blood viscosity causes blood stagnation and subsequent pathological thrombotic events, resulting in the development of ischemic stroke. We hypothesize that the contribution of blood viscosity may differ among ischemic stroke subtypes based on specific pathological conditions. We tried to verify this hypothesis by measuring blood viscosity in acute ischemic stroke patients using a newly developed electromagnetic spinning sphere (EMS) viscometer. METHODS: Measurements in acute ischemic stroke patients were performed 4 times during admission and data were compared with those obtained from 100 healthy outpatient volunteers. RESULTS: We enrolled 92 patients (cardioembolism: 25, large artery atherosclerosis: 42, and small artery occlusion [SAO]: 25) in this study. Comparisons of blood viscosity between the ischemic stroke subgroups and control group revealed that blood viscosity at the date of admission was significantly higher in the SAO group (5.37 ± 1.11 mPa⋅s) than in the control group (4.66 ± .72 mPa⋅s) (P < .01). Among all subtype groups showing a reduction in blood viscosity after 2 weeks, the SAO group showed the highest and most significant reduction, indicating that SAO patients had the most concentrated blood at the onset. CONCLUSIONS: Blood viscosity was significantly increased in the SAO group at the date of admission, which indicated the contribution of dehydration to the onset of ischemic stroke. The importance of dehydration needs to be emphasized more in the pathogenesis of SAO. The clinical application of the EMS viscometer is promising for understanding and differentiating the pathogenesis of ischemic stroke.

[A Dumbbell-Type Thoracic Spinal Lipoma: A Case Report].

Spinal lipomas are rare, accounting for less than 1% of all spinal tumors. Most are associated with spinal dysraphism. Spinal lipomas without spinal dysraphism are uncommon;they are typically subpial tumors. Some tumors are located both inside and outside the dura mater (so-called "dumbbell-type"). Herein, we report a patient with a dumbbell-type thoracic spinal lipoma. A man in his 50's complained of progressive gait disturbance, dysesthesia in his left leg, and hyperesthesia in his right leg. His symptoms were worsened by exercise. CT and MRI revealed a thoracic spinal lipoma extending from the spinal cord to the intervertebral foramen at the Th 6-8 level. He underwent partial tumor removal and untethering. Postoperatively he reported gradual symptom abatement. Dumbbell-type spinal lipomas are very rare. Besides partial removal of the tumor, untethering should be considered when symptoms are associated with tethering of the spinal cord.

[Intradural arachnoid cyst associated with syringomyelia: a case report].

An intradural arachnoid cyst is a relatively rare condition, occurring within the spinal subarachnoid space. We present the even-more rare case of an intradural arachnoid cyst associated with syringomyelia at the same spinal level. The patient was a 66-year-old man who presented with bilateral leg numbness and gait disturbance. Magnetic resonance imaging (MRI) revealed an intradural arachnoid cyst located dorsal to, and compressing, the thoracic spinal cord at the level of the 7th thoracic vertebra (Th 7). In addition, syringomyelia existed at the level of Th 8, slightly caudal to the intradural arachnoid cyst. We dissected the cyst but did not perform any surgical procedures for the syringomyelia. Post-operative MRI showed that the cyst had disappeared and the syringomyelia had spontaneously shrunk. The patient was discharged with improvement in his numbness and gait disturbance. There are a few case reports of intradural arachnoid cysts associated with syringomyelia, but recent evidence suggests that its occurrence is more common than previously thought. A combination of these two diseases is thought to be caused by blockage of cerebrospinal fluid (CSF) flow, which is also thought to cause adhesive arachnoiditis. For this reason, resection of the arachnoid cyst could improve the CSF flow and contribute to the shrinkage of syringomyelia. Furthermore, early treatment may correlate with improvement in radiological findings and neurological symptoms.

Preoperative predictors of foramen magnum decompression with dural splitting for amelioration of syringomyelia associated with Chiari type 1 malformation.

OBJECTIVE: Among several procedures for syringomyelia associated with Chiari type 1 malformation (CM-1), foramen magnum decompression (FMD) with dural splitting is one of the treatment choices with low complication rates. However, some meta-analyses have suggested that FMD with dural splitting may be inferior to FMD with duraplasty based on clinical outcomes; therefore, a predictor of a good surgical outcome with dural splitting is essential. This study aimed to clarify the preoperative parameters for good outcomes in patients with FMD with dural splitting, including the volumetric perspective. METHODS: We reviewed the cases of patients diagnosed with CM-1 and syringomyelia who underwent FMD with dural splitting at our institution. We included patients who underwent magnetic resonance imaging (MRI) from 6 months to 1 year after surgery, and measured radiological parameters using preoperative computed tomography and preoperative/follow-up MRI. RESULTS: Thirty-one patients were enrolled. Among all radiological parameters, the volume of the herniated tonsils (Vtonsil) and the difference between the expected volume-increment and Vtonsil (Vincr-Vtonsil) in improved groups were significantly smaller than those in non-improved groups. To predict the improvement of the syrinx, Vincr-Vtonsil of 0.77 mL was the optimal cutoff value, and yielded 100% sensitivity and 48.0% specificity. CONCLUSIONS: Vtonsil and Vincr-Vtonsil, which are novel predictors based on the volumetric perspective, might be the optimal predictors for improvement of the syrinx associated with CM-1 by 1 year after surgery.

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.

Optimal Catheter Selection for Patients with Acute Stroke with Type III Aortic Arch Based on Magnetic Resonance Angiography Road Mapping of the Para-Aortic Transfemoral 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. 23 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 minutes, P = 0.009) and "door-to-recanalization time" (164 vs. 129 minutes, 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.

Optimal treatment strategy for low-grade spinal cord astrocytoma: a retrospective, multicenter analysis by the Neurospinal Society of Japan.

OBJECTIVE: Primary spinal cord gliomas are rare, and among these astrocytomas (WHO grade II) are much rarer. The optimal treatment strategy thus remains unclear. The authors conducted a multicenter study led by the Neurospinal Society of Japan (NSJ) to analyze treatment policies and outcomes. The aim was to present optimal treatment methods for spinal cord astrocytoma and to identify predictors of better outcomes. METHODS: Among 1033 consecutive cases of spinal cord intramedullary tumors treated surgically at 58 centers affiliated with the NSJ, 57 patients were diagnosed with diffuse astrocytoma (WHO grade II) and were enrolled in the present study. Among these 57 patients, treatment methods, outcomes, and tumor proliferation rate as evaluated by the MIB-1 staining index (SI) were analyzed, and the optimal treatment method for spinal cord astrocytomas (grade II) was determined. In addition, the authors searched for factors predicting better treatment outcomes. RESULTS: Treatment for spinal cord astrocytoma comprised three methods: surgery alone in 30 patients, adjuvant radiation therapy in 13 patients, and adjuvant chemoradiotherapy in 13 patients. One patient who did not undergo surgery was excluded from survival analysis. Treatment with surgery alone or surgery with radiotherapy was associated with significantly longer overall and progression-free survivals than that with adjuvant chemoradiotherapy. Patients treated with radiation therapy had a higher MIB-1 SI than those treated with surgery alone. The extent of tumor resection tended to correlate with longer survival. In contrast, postoperative neurological worsening showed the inverse order. Adjuvant chemoradiotherapy was associated with the shortest survival in both total cases and recurrent cases. The optimal cutoff value of MIB-1 SI for predicting longer survival by surgery alone was less than 4.0%. CONCLUSIONS: The optimal treatment for spinal cord astrocytoma is maximal tumor resection without neurological impairment. When some tumor remains in patients with an MIB-1 SI less than 4.0%, a wait-and-see approach is optimal. If the MIB-1 SI is higher than 4.0%, local radiation therapy is recommended. Adjuvant chemotherapy is not recommended for the treatment of grade II spinal cord astrocytoma.

Thoracolumbar intramedullary subependymoma with multiple cystic formation: a case report and review.

BACKGROUND: An intramedullary subependymoma is rare, particularly in the thoracolumbar region. Moreover, a radiographical obvious cystic formation of subependymoma of spinal cord rarely occurs in comparison to ependymoma. CASE REPORT: A 57-year-old woman presented with paraparesis. MRI revealed a multinodular and multicystic lesion in the spinal cord that was difficult to diagnose correctly. Intraoperative observation via midline myelotomy revealed a grayish, gelatinous solid mass with an eccentric localization. In addition, DREZtomy on the caudal side of the tumor revealed cystic formation. The cyst was punctured and xanthochromic fluid was collected. Attenuation of motor evoked potential (MEP) resulted in the partial removal of tumor. A pathological examination revealed the mass to be a subependymoma. The patient experienced transient worsening of symptoms, but improved gradually. No adjuvant radiosurgery was administered. Follow-up estimation 30 months after surgery revealed no evidences of regrowth. CONCLUSIONS: This report presents this rare case, a review of the literature associated with thoracolumbar subependymomas, and a discussion of the clinical and radiographical characteristics.

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.

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.

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.

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.

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.

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.