Intramedullary Spinal Cord Tumors Research Articles

Non-dysraphic intramedullary spinal cord lipoma: A case report

Introduction: Intramedullary nondysraphic spinal lipomas are extremely rare among primary spinal cord tumors. These patients present with nonspecific sensory symptoms followed by deterioration of motor symptoms. As the safety margins for neurological preservation are thin, meticulously locating the extent of the tumor and choosing the resection modalities is essential. Case Report: We report a rare case of a 35-year-old male who presented with progressive difficulty in walking for six months associated with numbness and tingling sensation in the bilateral upper and lower limbs. He was diagnosed with nondysraphic intramedullary cervicothoracic lipoma and underwent subtotal resection of the tumor. Conclusion: Nondysraphic intramedullary spinal cord lipomas are rare and may present as nonspecific neurological symptoms. Hence, they should be considered differentials of intramedullary spinal cord tumors. Surgery appears to be the mainstay of treatment.

Reliability and Predictors of Intraoperative Neuromonitoring Changes During Intramedullary Tumor Resection: A Multicenter Experience

INTRODUCTION: Intraoperative neuromonitoring (IONM) is used in real-time to alert neurosurgeons of potential neurological changes when resecting intramedullary spinal cord tumors (IMSCTs). Previous studies have reported variable reliability of IONM. METHODS: A multicenter retrospective study was performed on patients undergoing IMSCTs surgery with neuromonitoring at the three Mayo Clinic sites between 2005 to 2022. Demographics, SSEP, MEP changes and postoperative outcomes were recorded. Specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Variables found significant on univariate analysis (p < 0.05) were applied to a multivariate model to identify predictors for IONM SSEP and MEP changes. RESULTS: 135 patients underwent surgical resection for IMSCTs using IONM. The mean age at diagnosis was 45 ± 17.9 years. Laminectomy was the most frequent index operation (96.3%). A total of 8.9% of patients presented with short-term improvement, while 70.4% presented long-term improvement on their baseline McCormick Scale. Sensitivity, specificity, PPV, NPV, accounted for 86.2%, 51%, 5.2%, 99.2% for MEP; 77.8%, 48.2%, 4.4%, 98.6% for SSEP. We found predictors of IONM changes: poorly defined MEP baseline (OR 3.004, 95% CI 1.22-7.397, p = 0.017), WHO grade II tumors (OR 2.334, 95% CI 1.043-5.223, p = 0.039), cervicomedullary junction location (OR 0.103, 95% CI 0.011-0.983, p = 0.048). Only WHO grade II tumors (OR 2.85, 95% CI 1.208-6.727, p = 0.017) was a predictor for SSEP changes. CONCLUSIONS: Our study represents the largest cohort describing sensitivity, specificity, and predictive factors for intraoperative changes and postoperative outcomes of resection of IMSCTs. A poorly defined baseline and cervicomedullary tumor location were predictors of IONM MEP changes, whiIe WHO grade II tumors were a predictor for both IONM SSEP and MEP changes.

Predictive Factors of Long-Term Neurologic Outcome and Progression-Free Survival in Intramedullary Spinal Cord Tumors: A 10-year Single-Center Cohort Study and Review of the Literature

Intramedullary spinal cord tumors (IMSCTs) are a rare subgroup of neoplasms, encompassing both benign, slow-growing masses, and malignant lesions; radical surgical excision represents the cornerstone of treatment for such pathologies regardless of histopathology, which, on the other hand, is a known predictor of survival and neurologic outcome postsurgery. The present study aims to investigate the relevance of other factors in predicting survival and long-term functional outcomes. We conducted a review of current literature on functional outcomes of IMSCTs, as well as a 10-years prospective analysis of a wide cohort of patients with diagnosis of IMSCTs who underwent surgical resection at our institution. Our series encompasses 60 patients with IMSCTS, among which 36 ependymomas, 6 cavernous angiomas, 5 hemangioblastomas, 6 WHO Grade I-IV astrocytomas, 3 intramedullary spinal metastases and 4 miscellaneous tumors. GTR was achieved in 76,67% of patients, with high preoperative McCormick grade, syringomyelia and changes at neurophysiologic monitoring being the strongest predictors at multivariate analysis (P= 0.0027, P= 0.0017 and P= 0.001 respectively). Consistently with literature, preoperative neurologic function is the most important factor predicting long-term functional outcome (0.17, CI 0.069-0.57 with P= 0.0018), advocating for early surgery in the management of IMSCTs, whereas late complications such as myelopathy and neuropathic pain were present regardless of preoperative function.

The application value and improved warning criterion of D-wave monitoring in intramedullary spinal cord tumor surgery

BACKGROUND CONTEXTThe primary treatment method for intramedullary spinal cord tumor (IMSCT) is surgical resection, but this procedure carries a significant risk of neurological damage. Intraoperative neurophysiological monitoring (IONM) has become a necessary adjunctive tool for IMSCT resection. PURPOSEThe current study aimed to explore the application value of D-wave monitoring in IMSCT surgery, and tried to investigate a tailored criterion for its early warning. STUDY DESIGNA retrospective clinical study. PATIENT SAMPLEA retrospective analysis was conducted based on the data of patients who underwent IMSCT surgeries performed by the same neurosurgical team at our hospital. IONM was applied in all surgeries. According to inclusion and exclusion criteria, ultimately 90 patients were enrolled in the study. OUTCOME MEASURESThe McCormick Scale (MMS) was applied to assess the functional outcome through outpatient visits or telephone follow-up at one month and six months postoperatively. Patients with an MMS grade over II one month after surgery were considered to have newly developed postoperative motor dysfunction (PMD). If the MMS grade could be restored to I or II six months after surgery, it was defined as a short-term PMD. Otherwise, it was defined as a long-term PMD. METHODSThe predictive value of different IONM modalities, including somatosensory evoked potential (SEP), muscle motor evoked potential (MEP), and D-wave for PMD, was assessed with sensitivity, specificity, positive predictive value, negative predictive value, and subsequent logistic regression analysis. At last, the cut-off value of the D-wave amplitude reduction ratio for predicting PMD was obtained through the receiver operating characteristic (ROC) curve analysis. RESULTSSEP showed the worst performance in predicting short-term and long-term PMD. Significant MEP changes were indicated as an independent predictive factor for short-term PMD (OR 5.062, 95% CI 1.947–13.166, p=.001), while D-wave changes were demonstrated as an independent predictor for long-term PMD (OR 339.433, 95% CI 11.337–10770.311, p=.001). The optimum cut-off value of the D-wave amplitude reduction ratio for predicting long-term PMD was 42.18%, with a sensitivity of 100% and a specificity of 93.8% (AUC=0.981, p<.001). CONCLUSIONSD-wave monitoring showed extremely high specificity in predicting PMD compared to SEP and MEP monitoring. Moreover, the authors suggested that a D-wave amplitude reduction of over 40% during IMSCT surgery generally indicates long-term PMD for patients.

The Ribbon Sign as a Radiological Indicator of Intramedullary Spinal Cord Subependymomas

INTRODUCTION: Intramedullary spinal cord (IMSC) subependymomas are rare World Health Organization grade 1 ependymal tumors. The potential presence of functional neural tissue within the tumor and poorly demarcated planes presents a risk to resection. Recognition of an intramedullary subependymoma on preoperative imaging can assist in operative planning and factor into the decision-making for gross- or sub-total resection. However, no definitive pathognomonic features have been reported on magnetic resonance imaging (MRI). METHODS: We retrospectively reviewed preoperative MRIs of patients presenting with IMSC tumors at a large tertiary academic institution between April 2005 and January 2022. The diagnosis was confirmed histologically. The “ribbon sign” was defined as a ribbon-like structure of T2 isointense spinal cord tissue interwoven between regions of T2 hyperintense tumor. The ribbon sign was confirmed by an expert neuroradiologist. RESULTS: MRIs from 151 patients were reviewed, including 42 (28%) astrocytomas, 82 (54%) ependymomas, 8 (5.3%) gangliogliomas, and 19 (13%) hemangioblastomas. Of the 82 ependymomas, ten patients (12%) presented with intramedullary subependymomas. The ribbon sign was demonstrated on nine (90%) patients with histologically proven subependymomas. No other tumor types displayed the ribbon sign. CONCLUSIONS: The ribbon sign is a distinctive imaging feature of IMSC subependymomas and indicates the presence of spinal cord tissue between eccentrically located tumor. Recognition of the sign should prompt clinicians to consider a diagnosis of subependymoma. Unlike their intracranial counterparts, resection of these lesions can be technically difficult, particularly in cases with poor demarcation between cord and tumor. Therefore, the risks and benefits of gross- vs. sub-total resection should be carefully considered and discussed with patients.

Factors Affecting Functional Outcome In Operated Cases Of Intramedullary Spinal Cord Tumours : A Retrospective Study In Western India

Factors Affecting Functional Outcome In Operated Cases Of Intramedullary Spinal Cord Tumours : A Retrospective Study In Western India

Exploring disparities in surgical recommendations for patients with primary intramedullary spinal cord tumors: an analysis of the Surveillance, Epidemiology, and End Results database from 2000 to 2019.

Factors that may drive recommendations for operative intervention for patients with intramedullary spinal cord tumors (ISCTs) have yet to be extensively studied. The authors investigated racial and socioeconomic disparities in the management of patients with primary spinal cord ependymomas and nonependymal gliomas, with the aim of determining the associations between socioeconomic patient characteristics, survival, and recommendations for the resection of primary ISCTs. The Surveillance, Epidemiology, and End Results registry was queried to identify all patients > 18 years of age with ISCTs diagnosed between 2000 and 2019. Univariable and multivariable logistic regression analyses were used to calculate odds ratios for variables associated with receiving a surgical recommendation. Log-rank tests and multivariable Cox proportional hazards models were used to investigate overall survival (OS) and disease-specific survival (DSS). The authors identified 2325 patients (mean age 49 [SD 16] years; 48.8% female; 67.4% non-Hispanic White, 7.8% non-Hispanic Black, 16.2% Hispanic, 6.5% Asian/Pacific Islander, 0.6% Native American; 56.7% married; 64.4% with household income < $75,000; 73.8% with spinal ependymoma; and 26.2% with nonependymal spinal glioma). Eighty-seven percent of patients received a surgical recommendation. In multivariable models, marriage was associated with higher odds of receiving a surgical recommendation for ependymomas (OR 1.80, p = 0.005). In multivariable models for nonependymal spinal gliomas, older age (OR 0.98, p = 0.001) and increased number of tumors (OR 0.62, p = 0.015) were associated with decreased odds of receiving surgical recommendations. Among ependymomas, marriage (HR 0.59, p = 0.001), younger age (HR 0.93, p < 0.001), female sex (HR 0.43, p = 0.006), and decreased number of tumors (HR 0.56, p < 0.001) were associated with improved OS. Among nonependymal spinal gliomas, median household income ≥ $75,000 (HR 0.69, p = 0.020) and younger age (HR 0.98, p < 0.001) were associated with improved DSS, while Black race (HR 4.65, p = 0.027) and older age (HR 1.05, p < 0.001) were associated with worse OS. In patients with spinal ependymomas and nonependymal spinal gliomas, recommendations for surgery appear to be unaffected by patient sex, race, or income. Survival disparities appear to exist among unmarried, male, Black, and lower-income cohorts. Continued initiatives to identify drivers of disparities while improving health equity in this patient population are needed.

Definition, Frequency and Risk Factors for Intra-Operative Spinal Cord Injury: A Knowledge Synthesis.

Mixed-methods approach. Intra-operative spinal cord injury (ISCI) is a devastating complication of spinal surgery. Presently, a uniform definition for ISCI does not exist. Consequently, the reported frequency of ISCI and important risk factors vary in the existing literature. To address these gaps in knowledge, a mixed-methods knowledge synthesis was undertaken. A scoping review was conducted to review the definitions used for ISCI and to ascertain the frequency of ISCI. The definition of ISCI underwent formal review, revision and voting by the Guidelines Development Group (GDG). A systematic review of the literature was conducted to determine the risk factors for ISCI. Based on this systematic review and GDG input, a table was created to summarize the factors deemed to increase the risk for ISCI. All reviews were done according to PRISMA standards and were registered on PROSPERO. The frequency of ISCI ranged from 0 to 61%. Older age, male sex, cardiovascular disease including hypertension, severe myelopathy, blood loss, requirement for osteotomy, coronal deformity angular ratio, and curve magnitude were associated with an increased risk of ISCI. Better pre-operative neurological status and use of intra-operative neuromonitoring (IONM) were associated with a decreased risk of ISCI. The risk factors for ISCI included a rigid thoracic curve with high deformity angular ratio, revision congenital deformity with significant cord compression and myelopathy, extrinsic intradural or extradural lesions with cord compression and myelopathy, intramedullary spinal cord tumor, unstable spine fractures (bilateral facet dislocation and disc herniation), extension distraction injury with ankylosing spondylitis, ossification of posterior longitudinal ligament (OPLL) with severe cord compression, and moderate to severe myelopathy. ISCI has been defined as "a new or worsening neurological deficit attributable to spinal cord dysfunction during spine surgery that is diagnosed intra-operatively via neurophysiologic monitoring or by an intraoperative wake-up test, or immediately post-operatively based on clinical assessment". This paper defines clinical and imaging factors which increase the risk for ISCI and that could assist clinicians in decision making.

Sequencing of cerebrospinal fluid cell-free DNA facilitated early differential diagnosis of intramedullary spinal cord tumors

Pre-surgery differential diagnosis is valuable for personalized treatment planning in intramedullary spinal cord tumors. This study assessed the performance of sequencing cell-free DNA (cfDNA) in cerebrospinal fluid (CSF) for differential diagnosis of these tumors. Prospectively enrolling 45 patients with intramedullary spinal cord lesions, including diffuse midline glioma (DMG), H3K27-altered (14/45), glioblastoma (1/45), H3-wildtype-astrocytoma (10/45), ependymoma (11/45), and other lesions (9/45), CSF samples were collected via lumbar puncture (41/45), intraoperative extraction (3/45), and Ommaya reservoir (1/45). Then, these samples underwent targeted sequencing along with paired tissue DNA. DMG, H3K27-altered patients exhibited a higher ctDNA positivity (85.7%, 12/14) compared to patients with H3-wildtype-astrocytoma (0/8, P = 0.0003), ependymoma (2/10, P = 0.003), and glioneuronal tumor (0/3, P = 0.009). The histological-grade-IV (P = 0.0027), Ki-67 index ≥10% (P = 0.014), and tumor reaching spinal cord surface (P = 0.012) are also associated with higher ctDNA positivity. Interestingly, for patients with TERT promoter mutant tumors, TERT mutation was detectable in the CSF cfDNA of one DMG case, but not other five cases with histological-grade-II tumors. Shared copy number variants were exclusively observed in DMG, H3K27-altered, and showed a strong correlation (Correlation = 0.95) between CSF and tissue. Finally, H3K27M mutations in CSF exhibited high diagnostic efficiency for DMG, H3K27-altered (Sensitivity = 85.7%, Specificity = 100.0%, AUC = 0.929). Notably, H3K27M was detectable in CSF from patients with recurrent tumors, making it easily applicable for postoperative monitoring. In conclusion, the molecular profile from ctDNA released into CSF of malignant tumors was more frequently detected compared to relatively benign ones. Sequencing of ctDNA in CSF exhibited high efficiency for the differential diagnosis of DMG, H3K27-altered.

ROLE OF MAGNETIC RESONANCE IMAGING IN THE EVALUATION OF SPINAL CORD LESIONS IN A TERTIARY CARE HOSPITAL, HYDERABAD

Background: Using other imaging modalities, subtle bone marrow, soft tissue, and spinal cord abnormalities, which may not be apparent, can be readily detected on magnetic resonance imaging (MRI). Prompt and accurate diagnosis, expeditious management, and avoidance of unnecessary procedures are achieved by early detection. Aim: The aim is to study the role of MRI in diagnosing spinal cord lesions. Methods: This study was conducted during the period from November 2018 to November 2020 and it is a prospective descriptive study of 50 patients who were referred to the Department of Radiodiagnosis Osmania General Hospital and MNJ Institute of Oncology and Regional Cancer Centre, Hyderabad, Telangana. Results: In the present study of 50 cases, different spinal cord lesions were found. The most common spinal cord lesions were neoplastic (38%) followed by spinal cord trauma (28%), and congenital lesions (16%). The most common spinal lesions were found in the 20–29 age group (40%), with more male predilection of 72% in comparison to 28% female in the present study. Out of 19 neoplastic lesions, the most common type of intramedullary spinal cord tumor (IMSC) is ependymoma (31.5%). The second most common IMSC tumor is astrocytoma 15.7% of all neoplastic lesions in the present study and the most common tumor among children. The most common location of the lesion is the thoracic cord. Hemangioblastomas constitute 10.5% of all spinal cord tumors in the present study. Meningiomas which are intradural extramedullary lesions constituted 10.5%. Neurofibroma constituted 5.2% which are intradural extramedullary with extradural component noted in NF1. Spinal cord metastasis constituted 26.3%. Intradural intramedullary lesions constituted 48% followed by extradural lesions 40% followed by intradural extramedullary lesions 12%. Conclusion: MRI by virtue of non-invasiveness, lack of radiation hazard, and the ability to demonstrate structural changes is an investigation of choice for spinal cord pathologies. The ability to image the cord directly rather than indirectly as in myelography, the absence of bone artifacts as in computed tomography, and the multiplanar capabilities indicate that MRI is the procedure of choice in the examination of the spinal cord.

Intraoperative Neurophysiologic Monitoring and Mapping During Surgery on Intramedullary Spinal Cord Tumors in Children and Adolescents.

Surgical resection of intramedullary spinal cord tumors carries significant risks of neurologic deficits, especially in cases of infiltrative tumors. In pediatric patients, this type of surgery may be associated with a high risk of poor neurologic outcome. Intraoperative neurophysiologic monitoring has been adopted as part of the clinical routine by many centers as a useful adjunct for intraoperative assessment of neurologic integrity. To what extent intraoperative neurophysiologic mapping strategies may further support intraoperative decision-making is still a matter of debate. Here, we report on a small cohort of five pediatric patients in whom mapping with the double-train paradigm was used to identify the dorsal column and corticospinal tract and to guide the surgical resection. We also discuss the possible benefits and challenges regarding the available literature.

Spinal Cord Neoplasms.

This article discusses the diagnostic approach to patients with suspected neoplasms of the spinal cord and reviews the most common primary and metastatic spinal neoplasms and their presentations. Neoplasms of the spinal cord are rare entities that can involve the spinal cord parenchyma, the dura and leptomeninges, or the extradural space. The most common intramedullary spinal cord neoplasms are primary spinal cord tumors, including ependymomas, pilocytic astrocytomas, and diffuse midline gliomas. The most common primary neoplasms of the spine are intradural extramedullary spinal meningiomas, whereas primary neoplasms of the leptomeninges are rare. Advances in molecular characterization of spinal cord tumors and recent clinical trials of these rare entities are expanding the repertoire of systemic therapy options for primary spinal cord neoplasms. Metastases to the spine most often affect the extradural space. Metastatic epidural spinal cord compression is a neurologic emergency that requires a rapid, multidisciplinary response to preserve neurologic function. Neurologists should understand the diagnostic approach to neoplasms of the spinal cord. Knowledge of the most common spinal cord neoplasms will allow for appropriate management and optimal patient care.

Intramedullary Spinal Cord Tumors: Whole-Genome Sequencing to Assist Management and Prognosis.

Intramedullary spinal cord tumors (IMSCTs) harbor unique genetic mutations which may play a role in prognostication and management. To this end, we present the largest cohort of IMSCTs with genetic characterization in the literature from our multi-site institutional registry. A total of 93 IMSCT patient records were reviewed from the years 1999 to 2020. Out of these, 61 complied with all inclusion criteria, 14 of these patients had undergone genetic studies with 8 undergoing whole-genomic sequencing. Univariate analyses were used to assess any factors associated with progression-free survival (PFS) using the Cox proportional hazards model. Firth's penalized likelihood approach was used to account for the low event rates. Fisher's exact test was performed to compare whole-genome analyses and specific gene mutations with progression. PFS (months) was given as a hazard ratio. Only the absence of copy neutral loss of heterozygosity (LOH) was shown to be significant (0.05, p = 0.008). Additionally, higher risk of recurrence/progression was associated with LOH (p = 0.0179). Our results suggest LOH as a genetic predictor of shorter progression-free survival, particularly within ependymoma and glioblastoma tumor types. Further genomic research with larger multi-institutional datasets should focus on these mutations as possible prognostic factors.

Diffuse Midline H3 K27-Altered Gliomas in the Spinal Cord: A Systematic Review

Background: Gliomas account for 80-90% of all intramedullary spinal cord tumors (IMSCTs). Though rare compared to brain tumors, spinal cord gliomas can cause significant morbidity and mortality. Diffuse midline gliomas (DMGs) with H3 K27M-mutation, first introduced in the 2016 WHO classification, are high-grade tumors with aggressive behavior and poor prognosis. The 2021 updated WHO classification renamed them "diffuse midline glioma, H3 K27-altered" to include other molecular changes. Limited single-institution data on spinal cord DMGs (DMGSCs) hinder comprehensive understanding and optimal treatment protocols. In this review, we summarize clinical and molecular features, management strategies, and survival impact in patients with DMG-SCs.&#x0D; Project Methods: A systematic review was performed following the (PRISMA) guidelines. PubMed, Ovid EMBASE, Scopus, and Web of Science were searched. Clinical characteristics, treatment protocols, and outcomes were analyzed.&#x0D; Results: A total of 26 studies with 259 patients were included. Most patients were male (63%), diagnosed at a mean age of 32 years (range, 4-72), and tumors were predominately located in the cervical (32%) or thoracic (43%) regions of the spinal cord. Primary management included surgical resection (97%), radiotherapy (78%), and chemotherapy (62%). Most common combination of treatment included surgical resection, radiotherapy, and chemotherapy (47%). The mean overall and progression free survival were 25 (range, 0.1-48) and 14 (range, 0.1-25) months, respectively. Gene alterations included p53 mutation (61%), loss of ATRX (46%), Olig- 2 positive (100%), and GFAP positive (80%). The mean Ki-67/MIB-1 was 23% (12-40%).&#x0D; Conclusion/Impact: DMG-SCs affect mostly the adult population and appear to resemble adult DMGs in terms of molecular features, management, and prognosis.

Multimodal Intraoperative Neurophysiological Monitoring in Intramedullary Spinal Cord Tumors: A 10-Year Single Center Experience.

The study aimed at evaluating the efficacy and the ability of D-wave monitoring combined with somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) to predict functional outcomes in intramedullary spinal cord tumor (IMSCT) surgery. Between December 2011 and December 2020, all patients harboring IMSCT who underwent surgery at our institution were prospectively collected in a surgical spinal registry and retrospectively analyzed. Patient charts and surgical and histological reports were analyzed. The multimodal IONM included SSEPs, MEPs, and-whenever possible-D-waves. All patients were evaluated using the modified McCormick and Frankel grade at admission and 3, 6, and 12 months of follow-up. Sixty-four patients were enrolled in the study. SSEP and MEP monitoring was performed in all patients. The D-wave was not recordable in seven patients (11%). Significant IONM changes (at least one evoked potential modality) were registered in 26 (41%) of the 64 patients. In five cases (8%) where the SSEPs and MEPs lost and the D-wave permanently dropped by about 50%, patients experienced a permanent deterioration of their neurological status. Multimodal IONM (SSEP, MEP, and D-wave neuromonitoring) significantly predicted postoperative deficits (p = 0.0001), with a sensitivity of 100.00% and a specificity of 95.65%. However, D-waves demonstrated significantly higher sensitivity (100%) than MEPs (62.5%) and SSEPs (71.42%) alone. These tests' specificities were 85.10%, 13.89%, and 17.39%, respectively. Comparing the area under ROC curves (AUCs) of these evoked potentials in 53 patients (where all three modalities of IONM were registered) using the pairwise t-test, D-wave monitoring appeared to have higher accuracy and ability to predict postoperative deficits with strong statistical significance compared with MEP and SSEP alone (0.992 vs. 0.798 vs. 0.542; p = 0.018 and p < 0.001). The use of multimodal IONM showed a statistically significant greater ability to predict postoperative deficits compared with SSEP, MEP, and D-wave monitoring alone. D-wave recording significantly increased the accuracy and clinical value of neurophysiological monitoring in IMSCT tumor resection.

What Factors Predict the Development of Neurologic Deficits Following Resection of Intramedullary Spinal Cord Tumors: A Multi-Center Study

Intramedullary spinal cord tumors are challenging to resect, and their postoperative neurological outcomes are often difficult to predict, with few studies assessing this outcome. We reviewed the medical records of all patients surgically treated for Intramedullary spinal cord tumors at our multisite tertiary care institution (Mayo Clinic Arizona, Mayo Clinic Florida, Mayo Clinic Rochester) between June 2002 and May 2020. Variables that were significant in the univariate analyses were included in a multivariate logistic regression. "MissForest" operating on the Random Forest algorithm, was used for data imputation, and K-prototype was used for data clustering. Heatmaps were added to show correlations between postoperative neurological deficit and all other included variables. Shapley Additive exPlanations were implemented to understand each feature's importance. Our query resulted in 315 patients, with 160 meeting the inclusion criteria. There were 53 patients with astrocytoma, 66 with ependymoma, and 41 with hemangioblastoma. The mean age (standard deviation) was 42.3 (17.5), and 48.1% of patients were women (n= 77/160). Multivariate analysis revealed that pathologic grade >3 (OR=1.55; CI=[0.67, 3.58], P= 0.046 predicted a new neurological deficit. Random Forest algorithm (supervised machine learning) found age, use of neuromonitoring, histology of the tumor, performing a midline myelotomy, and tumor location to be the most important predictors of new postoperative neurological deficits. Tumor grade/histology, age, use of neuromonitoring, and myelotomy type appeared to be most predictive of postoperative neurological deficits. These results can be used to better inform patients of perioperative risk.

Surgical Outcomes and Medical Costs Associated with Spinal Cord Tumors: Comparison of Extramedullary and Intramedullary Tumors

This study aimed to clarify the differences in the perioperative data of patients with extramedullary and intramedullary tumors and estimate the impact of surgery on medical costs. This single-center retrospective study included consecutive patients who underwent spinal tumor resection between September 2020 and December 2022. The perioperative medical information and medical costs for individual patients were obtained from their medical records. Thirty-two patients with extramedullary spinal cord tumors and 18 with intramedullary spinal cord tumors were included in the study. The 2 groups had no difference in surgery-related or major systemic complications. However, the operation time and the length of hospital stay were significantly longer and activities of daily living at discharge tended to worsen in the intramedullary tumor group compared to those in the extramedullary tumor group. As a result, the discharge outcome was significantly different between the 2 groups. The total medical costs for intramedullary tumors were approximately 1.43 times higher than those for extramedullary tumors. Further, a better functional outcome at discharge can save medical costs, regardless of extramedullary or intramedullary tumors. Surgery for intramedullary tumors can be performed with similar perioperative risks as for extramedullary tumors. However, intramedullary tumors are associated with concerns, such as prolonged hospitalization and worsening of activities of daily living at discharge, which ultimately result in higher medical costs.

Effectiveness of intraoperative monitoring of the bulbocavernosus reflex for predicting postoperative pelvic disorders in the surgical treatment of distal spine tumors

The study evaluated the diagnostic effectiveness of changes in the parameters of the bulbocavernous reflex during intraoperative neurophysiological monitoring in the surgical treatment of caudal spinal cord tumors. The study was performed during examinations and neurosurgical treatment of 58 patients suffering from intradural extramedullary and intramedullary tumors of the caudal spinal cord. In 23 (39.7%) patients, the tumors were localized at the level of the lower thoraciclumbar spine (Th11L1), and in 35 (60.3%) patients, they were at the level of the lumbosacral spine (L2S2). Pelvic organ dysfunction was assessed based on the extent of neurogenic bladder symptoms before surgery, 1014 days after surgery, and a year later. The bulbocavernous reflex was recorded in response to genital nerve stimulation, with a series of three pulses lasting 0.5 ms each, and the repetition rate of the series was 2 Hz. The intensity of the stimulation current was 75% of the maximum intensity. The bulbocavernous reflex was registered from the external anal sphincter muscles. During intraoperative monitoring, the bulbocavernous reflex remained stable in 49 patients. In this group, pelvic dysfunction was not observed immediately or 12 months after surgery. Persistent changes in motor response parameters were registered in nine patients; seven and eight cases of dysuric disorders were observed immediately after surgery and 12 months after surgery, respectively. Persistent changes in the bulbocavernous reflex during intraoperative monitoring were significantly more often associated with pelvic organ dysfunction immediately after surgery (2 = 36,323; p 0.001) and 12 months after surgery (2 = 32,284; p 0.001). The sensitivity and specificity of intraoperative monitoring of the bulbocavernous reflex in assessing the risk of pelvic dysfunction in the postoperative period were 96.1% and 100%, respectively. In general, postoperative pelvic organ dysfunction is a frequent cause of neurological complications following surgical treatment of caudal spine tumors. Therefore, during surgery, neurophysiological monitoring is implemented to control pelvic organ functions, including the registration of the bulbocavernous reflex.

Treatment of intramedullary spinal cord tumors: a modified Delphi technique of the North American Spine Society Section of Spine Oncology.

Intramedullary spinal cord tumors (IMSCTs) are rare tumors with heterogeneous presentations and natural histories that complicate their management. Standardized guidelines are lacking on when to surgically intervene and the appropriate aggressiveness of resection, especially given the risk of new neurological deficits following resection of infiltrative tumors. Here, the authors present the results of a modified Delphi method using input from surgeons experienced with IMSCT removal to construct a framework for the operative management of IMSCTs based on the clinical, radiographic, and tumor-specific characteristics. A modified Delphi technique was conducted using a group of 14 neurosurgeons experienced in IMSCT resection. Three rounds of written correspondence, surveys, and videoconferencing were carried out. Participants were queried about clinical and radiographic criteria used to determine operative candidacy and guide decision-making. Members then completed a final survey indicating their choice of observation or surgery, choice of resection strategy, and decision to perform duraplasty, in response to a set of patient- and tumor-specific characteristics. Consensus was defined as ≥ 80% agreement, while responses with 70%-79% agreement were defined as agreement. Thirty-six total characteristics were assessed. There was consensus favoring surgical intervention for patients with new-onset myelopathy (86% agreement), chronic myelopathy (86%), or progression from mild to disabling numbness (86%), but disagreement for patients with mild numbness or chronic paraplegia. Age was not a determinant of operative candidacy except among frail patients, who were deemed more suitable for observation (93%). Well-circumscribed (93%) or posteriorly located tumors reaching the surface (86%) were consensus surgical lesions, and participants agreed that the presence of syringomyelia (71%) and peritumoral T2 signal change (79%) were favorable indications for surgery. There was consensus that complete loss of transcranial motor evoked potentials with a 50% decrease in the D-wave amplitude should halt further resection (93%). Preoperative symptoms seldom influenced choice of resection strategy, while a distinct cleavage plane (100%) or visible tumor-cord margins (100%) strongly favored gross-total resection. The authors present a modified Delphi technique highlighting areas of consensus and agreement regarding surgical management of IMSCTs. Although not intended as a substitute for individual clinical decision-making, the results can help guide care of these patients. Additionally, areas of controversy meriting further investigation are highlighted.

Neurological Outcome and Respiratory Insufficiency in Intramedullary Tumors of the Upper Cervical Spine.

Background and Objectives: Intramedullary spinal cord tumors (IMSCT) are rare entities. A location in the upper cervical spine as a highly eloquent region carries the risk of postoperative neurological deficits, such as tetraparesis or respiratory dysfunction. Evidence for respiratory dysfunction is scarce. This study aimed to describe these highly eloquent tumors' early and late postoperative clinical course. Materials and Methods: This is a single-center retrospective cohort study. We included 35 patients with IMSCT at levels of the craniocervical junction to C4 who underwent surgical treatment between 2008 and 2022. The authors analyzed the patients' preoperative status, tumor- and surgery-specific characteristics, and follow-up functional status. Results: The study cohort included twenty-two patients with grade II ependymoma (62.9%), two low-grade astrocytomas (5.7%), two glioblastomas (5.7%), six hemangioblastomas (17.1%), two metastases (5.7%), and one patient with partially intramedullary schwannoma (2.9%). Gross total resection was achieved in 76% of patients. Early dorsal column-related symptoms (gait ataxia and sensory loss) and motor deterioration occurred in 64% and 44% of patients. At a follow-up of 3.27 ± 3.83 years, 43% and 33% of patients still exhibited postoperative sensory and motor deterioration, respectively. The median McCormick Scale grade was 2 in the preoperative and late postoperative periods, respectively. Only three patients (8.6%) developed respiratory dysfunction, of whom, two patients, both with malignant IMSCT, required prolonged invasive ventilation. Conclusions: More than 60% of the patients with IMSCT in the upper cervical cord developed new neurological deficits in the immediate postoperative period, and more than 40% are permanent. However, these deficits are not disabling in most cases since most patients maintain functional independence as observed by unchanged low McCormick scores. The rate of respiratory insufficiency is relatively low and seems to be influenced by the rapid neurological deterioration in high-grade tumors.