Transcranial Corticospinal Motor-Evoked Potentials in Cases of Ventral and Ventrolateral Intradural Extramedullary Cervical Spinal Cord Tumors.

Background and Objectives: We studied the clinical significance of an amplitude decrement and disappearance alarm criteria in transcranial motor-evoked potential (MEP) monitoring during surgeries on extramedullary tumors at the cervical spine with reference to postoperative morbidity. Material and Methods: We diagnosed and surgically treated fourteen patients with intradural extramedullary ventral or ventrolateral lesions to the cervical spinal cord in the Clinic of Neurosurgery at the University Hospital St Ivan Rilski from January 2018 to July 2022. Eight cases were diagnosed with schwannoma, and the remaining six had meningiomas. The follow-up period for neurological assessment was six months. Results: A decrease in the intraoperative transcranial MEPs of 50% or more compared to baseline in two cases (14.3%) resulted in an immediate postoperative motor deficit. One patient demonstrated full neurological recovery within six months, while the other exhibited only partial improvement. In six cases (42.9%) with preoperative motor deficits, tumor resection and decompression of the cervical spinal cord led directly to an increment of the transcranial MEPs by more than 20%. Postoperatively and at the 6-month follow-up, these patients showed recovery from the preoperative deficits. In the remaining cases, MEPs were stable during surgery with no clinical deterioration of the motor function. Conclusions: The decremented MEP criteria corresponded to postoperative motor deficit, whereas the improvement of the same parameters after decompression implied future recovery of preoperative motor deficits. The combination of different MEP criteria is likely to be helpful when tailored to a specific case of ventral or ventrolateral extramedullary lesions in the cervical spine.

[Minimally invasive surgical treatment of extramedullary tumors at the level of craniovertebral junction: experience of the Burdenko Neurosurgical Center]. / Minimal'no invazivnoe khirurgicheskoe lechenie patsientov s ekstramedullyarnymi opukholyami na urovne kraniovertebral'nogo perekhoda: opyt NMITs neirokhirurgii im. akad. N.N. Burdenko.

OBJECTIVE: To describe own experience of treating patients with extramedullary tumors at the level of craniovertebral junction using minimally invasive surgical approaches. MATERIAL AND METHODS: The study included 29 patients who underwent minimally invasive microsurgical resection of extramedullary tumors at the level of craniovertebral junction. We analyzed the main clinical and surgical parameters. RESULTS: Gross total resection was achieved in most patients with high degree of safety. Two patients required redo surgery due to CSF leakage and soft tissue cyst. Mean length of hospital-stay was 7 days. VAS score of pain syndrome at discharge was 2 points and 0 points after 3 months. No significant differences in neurophysiological monitoring indicators were observed (p=0.76). CONCLUSION: Minimally invasive posterior approaches to extramedullary tumors at the level of craniovertebral junction can significantly reduce surgical trauma with equal extent of resection.

Malignant Spinal Tumors.

Malignant spinal tumors constitute around 22% of all primary spinal tumors. The most common location of metastases to the spinal region is the extradural compartment. The molecular and genetic characterization of these tumors was the basis for the updated WHO classification of CNS tumors in 2016, where many CNS tumors are now diagnosed according to their genetic profile rather than relying solely on the histopathological appearance. Magnetic resonance imaging (MRI) is the current gold standard for the initial evaluation and subsequent follow-up on intradural spinal cord tumors, and the imaging sequences must include T2-weighted images (WI), short time inversion recovery (STIR), and pre- and post-contrast T1-WI in the axial, sagittal, and coronal planes. The clinical presentation is highly variable and depends on the tumor size, growth rate, type, infiltrative, necrotic and hemorrhagic potential as well as the exact location within the spinal compartment. Surgical intervention remains the mainstay of management of symptomatic and radiographically enlarging spinal tumors, where the goal is to achieve maximal safe resection. Tumor recurrences are managed with repeat surgical resection (preferred whenever possible and safe), radiotherapy, chemotherapy, or any combination of these therapies.

Spinal Intradural Extramedullary Tumors: A Retrospective Analysis on Ten-Years' Experience of Minimally Invasive Surgery and a Comparison with the Open Approach.

Spinal intradural extramedullary (ID-EM) tumors are pathologies widely treated through a classical open approach. However, minimally invasive surgery is gaining traction as a comparable treatment option because it carries less morbidity and may reduce healthcare costs.This study aimed to compare the clinical and functional outcomes of open versus minimally invasive approaches for patients with ID-EM tumors. We performed a retrospective analysis on prospectively collected data from patients with ID-EM tumors submitted to surgery. Baseline features and operative variables were compared, including surgery duration and estimated blood loss (EBL). Postoperative data covered tumor histology, length of stay (LOS), complication(s), and neurological status (Medical Research Council (MRC) scale) at the last follow-up.In total, 46 patients were included: 30 (65.2%) operated through an open approach and 16 (34.8%) through a minimally invasive surgical (MIS) approach. The predominant histology type was schwannomas (43.5%). Lesions more frequently affected the lumbar spine (34.8%). The tumor dimensions were similar in both cohorts. The minimally invasive approach was on average 76.7 min faster and correlated positively with less EBL (140 mL less than that of the open approach). Patients in the MIS group had shorter LOSs (5.63 days vs. 17.27 days) and had fewer postoperative complications. No significant difference in functional outcome was found.MIS is as effective as the traditional approach in achieving comparable functional outcomes, with advantages such as shorter surgery durations, less blood loss, and shorter hospital LOSs.

Recurrent spinal meningeal melanocytoma at lumbar spine level: a case report.

INTRODUCTION: Spinal meningeal melanocytoma is an extremely rare tumour with an estimated annual incidence of 1 per 10 million people. It usually arises from the intradural extramedullary compartment at the cervical levels. Although these tumours are histologically benign, they may behave aggressively. Local recurrence could occur even after total tumour excision. CASE REPORT: We report a case of a 33-year-old Asian male who developed progressive weakness and numbness of the bilateral lower extremities as well as urinary retention five years after complete tumour resection of lumbar spinal meningeal melanocytoma. Magnetic resonance imaging of the lumbar spine revealed a mass with thecal sac compression which was hypointense on T2-weighted images and hyperintense on T1-weighted images. The patient underwent total tumour removal. Histologic examination was compatible with recurrent meningeal melanocytoma. After a 4-week inpatient rehabilitation programme, he was able to ambulate without assistance and to do clean intermittent catheterisation for micturition on a regular basis. DISCUSSION: This is the first reported case of intradural extramedullary meningeal melanocytoma located at the lumbar region. Clinicians should consider the possibility of these rare tumours at any level of the spine, and be aware of sphincter dysfunction in addition to motor and sensory deficits of extremities.

Intradural extramedullary tumor location in the axial view affects the alert timing of intraoperative neurophysiologic monitoring.

OBJECTIVE: Intraoperative neurophysiologic monitoring (IONM) reportedly helps prevent postoperative neurological complications following high-risk spinal cord surgeries. There are negative and positive reports about using IONM for intradural extramedullary (IDEM) tumors. We investigated factors affecting alerts of IONM in IDEM tumor surgery. METHODS: We analyzed 39 patients with IDEM tumors who underwent surgery using IONM at our hospital between January 2014 and March 2021. Neurological symptoms were evaluated pre- and postoperatively using the manual muscle test (MMT). All patients were evaluated to ascertain the tumor level and location in the axial view, the operative time, intraoperative bleeding volume, and histological type. Additionally, the intraoperative procedure associated with significant IONM changes in transcranial electrical stimulation muscle-evoked potential was investigated. RESULTS: There were 11 false-positive and 16 true-negative cases. There was one true-positive case and one false-negative case; the monitoring accuracy achieved a sensitivity of 50%, a specificity of 59%, a positive predictive value of 8%, and a negative predictive value of 94%. In the 22 alert cases, if the tumor was located anterolateral in the axial view, alerts were triggered with a significant difference (p = 0.02) during tumor resection. Alerts were generated for fifteen patients during tumor resection; nine (60%) showed waveform improvement by intervention and were classified as rescue cases. CONCLUSION: Alert is probably triggered during tumor resection for anterolaterally located tumors. Alerts during tumor resection procedures were more likely to be rescued than other procedures in IDEM tumor surgery.

Endoscopic surgical treatment for primary spinal lesions.

Primary spinal cord tumours are infrequently encountered CNS neoplasms and can be broadly classified into intradural intramedullary and intradural extramedullary lesions. Resection of these lesions was traditionally done via open surgical access almost always with microscope assistance. With the advent of minimally invasive surgical techniques, endoscopic excision of these lesions has been attempted for selected tumours. Available literature mainly deals with retrospective reviews on small number of patients; therefore, extensive research is required to establish safety and efficacy of endoscopic approach for excision of primary spinal tumours.

Surgical treatment of solitary intradural extramedullary spinal cord metastases from solid cancers of non-neurogenic origin. A multicenter study.

PURPOSE: Intradural extramedullary spinal metastases (IESM) represent an extremely rare manifestation of systemic cancer. We evaluated the surgical indications, complications and outcome in a series of 43 patients with solitary intradural extramedullary metastases originating from solid cancer of non-neurogenic origin. METHODS: Patients' age, histopathological diagnoses of primary cancer, tumor size, spinal location, and extramedullary tumor dissemination were collected. Preoperative functional status, pre- and post-operative neurological status, extent of the tumor resection were also analyzed. RESULTS: The majority of IEMS occurred in the thoracic area, with the most common presenting symptoms ranging from motor (76.7%) to sensory (72%) deficits. Gross total resection was achieved in 55.8% of cases, while In 44.2% of patients a subtotal resection was performed due to strong adherence between the tumor and neural tissue. After surgery, 72.1% of patients exhibited improvement of symptoms in terms of pain relief and partial recovery of motor and/or sensory deficits, while neurologic functional status was severely affected postoperatively in 3 patients. CONCLUSION: Although there was no statistical significance between the different parameters and overall survival, KPS and the presence of other metastases were the strongest prognostic factors for overall survival and postoperative neurologic outcome.

A transpedicular approach to complex ventrally situated thoracic intradural extramedullary tumors: technique, indications, and multiinstitutional case series.

OBJECTIVE: Ventrally situated thoracic intradural extramedullary tumors are surgically challenging and difficult to access, and they may be complicated by extensive adhesions and calcifications. Selecting an approach for adequate ventral access is key to complete resection and optimization of outcomes. The authors present a case series of patients who underwent resection of ventral thoracic intradural extramedullary tumors and discuss indications and considerations for this technique. Additionally, they describe the use of a posterolateral transpedicular approach for resection of ventral thoracic intradural extramedullary tumors compared with other techniques, and they summarize the literature supporting its application. METHODS: From May 2017 to August 2020, 5 patients with ventral thoracic intradural extramedullary tumors underwent resection at one of the two academic institutions. RESULTS: Patient ages ranged from 47 to 75 (mean 63.4) years. All tumors were diagnosed as meningiomas or schwannomas by histological examination. Three of the 5 patients had evidence of partial or extensive tumor calcification. Four of the 5 patients underwent an initial posterolateral transpedicular approach for resection, with positive radiographic and clinical outcomes from surgery. One patient initially underwent an unsuccessful traditional direct posterior approach and required additional resection 2 years later after interval disease progression. There were no postoperative wound infections, CSF leaks, or other complications related to the transpedicular approach. CONCLUSIONS: Posterolateral transpedicular tumor resection is a safe technique for the treatment of complex ventrally situated thoracic intradural extramedullary tumors compared with the direct posterior approach. Anecdotally, this approach appears to be particularly beneficial in patients with calcified tumors.

Clinical characteristics and long-term outcomes for patients who undergo cytoreductive surgery for thoracic meningiomas: a retrospective analysis.

OBJECTIVE: Primary spinal meningiomas represent a rare indolent neoplasm usually situated in the intradural-extramedullary compartment. They have a predilection for afflicting the thoracic spine and most frequently present with sensory and/or motor symptoms. Resection is the first-line treatment for symptomatic tumors, whereas other clinical factors will determine the need for adjuvant therapy. In this study, the authors aimed to elucidate clinical presentation, functional outcomes, and long-term outcomes in this population in order to better equip clinicians with the tools to counsel their patients. METHODS: This is a retrospective analysis of patients treated at the authors' institution between 1998 and 2018. All patients with thoracic meningiomas who underwent resection and completed at least one follow-up appointment were included. Multiple preoperative clinical variables, hospitalization details, and long-term outcomes were collected for the cohort. RESULTS: Forty-six patients who underwent resection for thoracic meningiomas were included. The average age of the cohort was 59 years, and the median follow-up was 53 months. Persistent sensory and motor symptoms were present in 29 patients (63%). Fifteen lesions were ventrally positioned. There were 43 WHO grade I tumors, 2 WHO grade II tumors, and 1 WHO grade III tumor; the grade III tumor was the only case of recurrence. The median length of hospitalization was 4 days. Seventeen patients (37%) were discharged to rehabilitation facilities. Thirty patients (65.2%) experienced resolution or improvement of symptoms, and there were no deaths within 30 days of surgery. Only 1 patient developed painful kyphosis and was managed medically. Ventral tumor position, new postoperative deficits, and length of stay did not correlate with disposition to a facility. Age, ventral position, blood loss, and increasing WHO grade did not correlate with length of stay. CONCLUSIONS: Outcomes are overall favorable for patients who undergo resection of thoracic meningiomas. Symptomatic patients often experience improvement, and patients generally do not require significant future operations. Tumors located ventrally, while anatomically challenging, do not necessarily herald a significantly worse prognosis or limit the extent of resection.

O-arm Navigation-Guided Surgical Resection and Posterior Fixation for a Large Sacral Schwannoma.

Sacral schwannoma is a rare tumor with relatively few symptoms; it thus tends to be large at diagnosis and is challenging to treat surgically. We present the case of a 12-year-old girl with a large sacral schwannoma that was successfully surgically resected using O-arm navigation in a two-stage operation. First, we performed tumor resection from the posterior aspect with assisted O-arm navigation. One week later, resection from the anterior aspect was conducted with posterior spinopelvic fixation and fibula graft. We performed partial resection of the tumor from the anterior and posterior aspects as much as possible. O-arm navigation contributed to precise and safe tumor resection and implant insertion.

Pediatric Spinal Subdural Abscesses: A Report of Three Consecutive Patients.

BACKGROUND: Despite technological advances in medical treatment, the prognosis of the rarely reported spinal subdural abscesses (SSAs) has remained a serious entity largely unaffected, especially when they are diagnosed late. In this study, the authors aimed to present the surgical outcomes of 3 consecutive pediatric patients with SSA. MATERIALS AND METHODS: We retrospectively reviewed the medical records of pediatric patients with spinal lesions who underwent surgery at 2 neurosurgical centers spanning 7 years, from 2012 to 2019. All pediatric patients who were diagnosed with SSA (n = 3) were selected as the core sample for this study. RESULTS: Three pediatric patients (2 females and 1 male) with SSA were surgically treated. Holocord SSA was observed in 1 patient. The mean age was 7.1 ± 7.7 years. The most common presenting symptoms were gait disturbance and weakness of lower extremities (100%). The mean preoperative course was 5.7 ± 4.0 weeks. The causative pathogens were Escherichia coli (E. coli) and M. tuberculosis. In the 2nd case, the pathogen was non-tuberculosis mycobacterium in the extramedullary abscess. In the 44th postoperative month, she underwent surgery for intramedullary abscess. The causative pathogen was E. coli. Except for 1 male adolescent who presented with severe clinical status (paraplegic), the improvement was observed in all patients at their last follow-up after 50.3 ± 43.5 months of average. CONCLUSIONS: Drainage followed by appropriate antibiotics is the optimal treatment for SSAs. Early diagnosis and urgent surgical treatment are essential for a good prognosis. All surgically treated SSA patients with neurological deficits were rehabilitated with physical therapy postoperatively.

Extensive craniospinal disseminated metastasis after the resection of intradural extramedullary ependymoma in the craniocervical junction: a case report and literature review.

PURPOSE/AIM: Intradural extramedullary (IDEM) ependymomas are very rare, and IDEM ependymomas with craniospinal disseminated metastasis are exceptionally rare; only 2 preoperative cases have been confirmed, and postoperative cases have not been reported. CASE REPORT: We present a case of a 21-year-old female with an IDEM ependymoma of the craniocervical junction who experienced head and neck pain for more than 1 month. Magnetic resonance imaging (MRI) of the cervical spine revealed a large IDEM cystic lesion located in the medulla oblongata and the upper cervical spinal cord. The patient underwent surgery without complications, and the tumor was completely removed. Histopathological examination revealed a diagnosis of aplastic ependymoma, World Health Organization (WHO) grade III. The patient failed to follow-up with radiotherapy for one month after discharge. Nearly three months after surgery, craniospinal disseminated metastasis was found in the patient; subsequently, chemoradiotherapy was administered to prolong the survival time of the patient. Unfortunately, the patient underwent radiotherapy and chemotherapy for only 7 days; then, the patient gave up treatment and died 5 months later. CONCLUSIONS: To the best of our knowledge, no other cases of craniocervical junction anaplastic ependymomas with craniospinal disseminated metastasis have been reported in the literature. Total resection does not completely prevent recurrence and metastasis, and MRI of the entire neuraxis and timely postoperative craniospinal radiotherapy are necessary for the treatment of this disease.

Spinal paraganglioma presenting with raised intracranial pressure: a note on the diagnosis and post-operative management.

BACKGROUND: Spinal paragangliomas are tumors of neuroendocrine origin that present with symptoms of mass effect or neurosecretion but rarely involve the central nervous system. Raised intracranial pressure and papilledema are therefore unusual presentations of a spinal paraganglioma. METHODS: We review the case of a 54-year-old man who presented with headache and visual disturbance. Fundoscopy confirmed papilledema with normal intracranial imaging. Neuraxis imaging revealed a lumbar intradural extramedullary tumor and pathological analysis confirmed a WHO Grade I spinal paraganglioma. The tumor was resected and post operatively his vison improved with resolution of optic disc swelling. CONCLUSIONS: Raised intracranial pressure and papilledema are unusual clinical manifestations of spinal tumors and imaging the entire neuraxis can be valuable.

[Synchronous schwannoma and ependymoma of the cauda equina]. / Sochetanie shvannomy i ependimomy konskogo khvosta spinnogo mozga.

The article presents a case of surgical treatment of primary multiple benign tumors of the cauda equine of different histological origin: spinal nerve root schwannoma and ependymoma of the filum terminale.

Intradural extramedullary spinal metastasis of renal cell carcinoma: illustrative case report and comprehensive review of the literature.

STUDY DESIGN: Literature review. OBJECTIVES: Intradural metastasis of renal cell carcinoma (RCC) has rarely been reported. We describe a case of an intradural extramedullary spinal metastasis to the cervical spine in a 68-year-old male treated for RCC 22 years prior. Additionally, we review the known reports of both intradural extramedullary and intramedullary of RCC. METHODS: Case report and literature review. RESULTS: A 68-year-old male with a history of right-sided nephrectomy for RCC preformed 22 years prior now presents with a MRI of the cervical spine showing a 1.5 cm contrast enhancing intradural extramedullary lesion at the level of C3-C4. Surgical resection of the lesion was performed. The tumor's histological and immunohistochemical profile was consistent with metastatic RCC. There are 18 reported cases of intradural extramedullary metastases of sporadic RCC. The average age at diagnosis was 61.6 ± 14.3 years. The interval from diagnosis of primary RCC to diagnosis metastasis ranged from 0 to 264 months (mean 46.8 ± 74.0 months). Sixteen cases of intramedullary renal cell carcinoma metastasis are reported. The average age at time of diagnosis was 53.6 ± 10.2 years. The interval from diagnosis of primary RCC to diagnosis of metastasis ranged from 0 to 180 months (mean 20.9 ± 53.4 months). CONCLUSION: The 22-year interval from diagnosis of primary RCC to intradural metastasis is the longest latency reported in the literature. Intramedullary metastases tend to have a younger age at diagnosis and shorter interval from diagnosis of primary RCC compared to extramedullary lesions.

[Comparison of the safety and outcomes between keyhole surgery and total laminectomy for resection of intradural extramedullary spinal cord tumors].

Objective: To compare the safety and outcomes between keyhole surgery and total laminectomy for resection of intradural extramedullary spinal cord tumors. Methods: Retrospectively collected the clinical data of 102 patients with intradural extramedullary spinal cord tumors(≤3 cm) treated by surgery in Department of Orthopedics in Fujian Provincial Hospital from January 2014 to January 2017. Fifty cases underwent the keyhole surgery and the other 52 received total laminectomy. The operation time, volume of intraoperative bleeding, the leaving bed time, the length of postoperative hospital stay, drainage, postoperative complications, intraoperative neuroelectrophysiological monitoring (IONM), preoperative and postoperative visual analogue score (VAS), neck disability index (NDI), Oswestry disability index (ODI), McCormick spinal cord function grading were analyzed and compared between the two groups to evaluate the safety and clinical outcomes. The data of two groups were compared by t, χ(2) or rank sum test. Results: The keyhole group was followed up for (30±15) months and the total laminectomy group was followed up for (45±15) months. All the tumors were completely resected. All the incision healed well and no cerebrospinal fluid leakage occurred. There was no statistically significant differences in baseline data, operation time, the results of IONM, preoperative and 3 months, 6 months, 12 months postoperative VAS, NDI (cervical tumors), ODI (thoracic and lumbar tumors), McCormick spinal cord function grading, tumor recurrence between the two groups (all P>0.05). The keyhole group had less intraoperative bleeding than that in the total laminectomy group ((73±24) ml vs (136±26) ml, t=-12.610, P<0.05), earlier postoperative leaving bed time ((1.4±0.6) d vs (6.5±1.0) d, t=-31.822, P<0.05), and the postoperative hospital stay was shorter ((4.3±0.8) d vs (11.2±2.0) d, t=-22.319, P<0.05), and it was more advantageous in terms of drainage. The VAS, NDI and ODI in the keyhole group improved significantly compared with those in the total laminectomy group 2 weeks post operation (all P<0.05). Conclusion: Compared with the total laminectomy, keyhole surgery is suitable for the treatment of intradural extramedullary spinal cord tumors with small size and limited location, and it is equivalently safe with faster functional recovery.

MYCN amplification drives an aggressive form of spinal ependymoma.

Spinal ependymal tumors form a histologically and molecularly heterogeneous group of tumors with generally good prognosis. However, their treatment can be challenging if infiltration of the spinal cord or dissemination throughout the central nervous system (CNS) occurs and, in these cases, clinical outcome remains poor. Here, we describe a new and relatively rare subgroup of spinal ependymal tumors identified using DNA methylation profiling that is distinct from other molecular subgroups of ependymoma. Copy number variation plots derived from DNA methylation arrays showed MYCN amplification as a characteristic genetic alteration in all cases of our cohort (n = 13), which was subsequently validated using fluorescence in situ hybridization. The histological diagnosis was anaplastic ependymoma (WHO Grade III) in ten cases and classic ependymoma (WHO Grade II) in three cases. Histological re-evaluation in five primary tumors and seven relapses showed characteristic histological features of ependymoma, namely pseudorosettes, GFAP- and EMA positivity. Electron microscopy revealed cilia, complex intercellular junctions and intermediate filaments in a representative sample. Taking these findings into account, we suggest to designate this molecular subgroup spinal ependymoma with MYCN amplification, SP-EPN-MYCN. SP-EPN-MYCN tumors showed distinct growth patterns with intradural, extramedullary localization mostly within the thoracic and cervical spine, diffuse leptomeningeal spread throughout the whole CNS and infiltrative invasion of the spinal cord. Dissemination was observed in 100% of cases. Despite high-intensity treatment, SP-EPN-MYCN showed significantly worse median progression free survival (PFS) (17 months) and median overall survival (OS) (87 months) than all other previously described molecular spinal ependymoma subgroups. OS and PFS were similar to supratentorial ependymoma with RELA-fusion (ST-EPN-RELA) and posterior fossa ependymoma A (PF-EPN-A), further highlighting the aggressiveness of this distinct new subgroup. We, therefore, propose to establish SP-EPN-MYCN as a new molecular subgroup in ependymoma and advocate for testing newly diagnosed spinal ependymal tumors for MYCN amplification.

Spinal intradural extramedullary cavernous hemangioma.

Spinal intradural extramedullary cavernous hemangiomas are very rare. Mixed intensities on T1- andT2-weighted images due to repeated hemorrhages and poor to absent contrast-enhancement are the most common imaging features of the disease allowing accurate differentiation from the far more frequent meningiomas and schwannomas of similar location.