Convolutional neural network-based magnetic resonance image differentiation of filum terminale ependymomas from schwannomas.

PURPOSE: Preoperative diagnosis of filum terminale ependymomas (FTEs) versus schwannomas is difficult but essential for surgical planning and prognostic assessment. With the advancement of deep-learning approaches based on convolutional neural networks (CNNs), the aim of this study was to determine whether CNN-based interpretation of magnetic resonance (MR) images of these two tumours could be achieved. METHODS: Contrast-enhanced MRI data from 50 patients with primary FTE and 50 schwannomas in the lumbosacral spinal canal were retrospectively collected and used as training and internal validation datasets. The diagnostic accuracy of MRI was determined by consistency with postoperative histopathological examination. T1-weighted (T1-WI), T2-weighted (T2-WI) and contrast-enhanced T1-weighted (CE-T1) MR images of the sagittal plane containing the tumour mass were selected for analysis. For each sequence, patient MRI data were randomly allocated to 5 groups that further underwent fivefold cross-validation to evaluate the diagnostic efficacy of the CNN models. An additional 34 pairs of cases were used as an external test dataset to validate the CNN classifiers. RESULTS: After comparing multiple backbone CNN models, we developed a diagnostic system using Inception-v3. In the external test dataset, the per-examination combined sensitivities were 0.78 (0.71-0.84, 95% CI) based on T1-weighted images, 0.79 (0.72-0.84, 95% CI) for T2-weighted images, 0.88 (0.83-0.92, 95% CI) for CE-T1 images, and 0.88 (0.83-0.92, 95% CI) for all weighted images. The combined specificities were 0.72 based on T1-WI (0.66-0.78, 95% CI), 0.84 (0.78-0.89, 95% CI) based on T2-WI, 0.74 (0.67-0.80, 95% CI) for CE-T1, and 0.81 (0.76-0.86, 95% CI) for all weighted images. After all three MRI modalities were merged, the receiver operating characteristic (ROC) curve was calculated, and the area under the curve (AUC) was 0.93, with an accuracy of 0.87. CONCLUSIONS: CNN based MRI analysis has the potential to accurately differentiate ependymomas from schwannomas in the lumbar segment.

Percutaneous Full Endoscopic Management of Spinal Foraminal Schwannomas: Case Series.

BACKGROUND: Schwannoma, a benign peripheral nerve sheath tumor, is perhaps only secondary to degenerative pathology as the most common lesion at neural foramen. The surgical dilemma here is either risking nerve injury because of inadequate exposure or the need for internal fixation because of facet joint sacrifice. OBJECTIVE: To evaluate the feasibility and safety of management of foraminal schwannomas by percutaneous full-endoscopic technique. METHODS: A single-center retrospective review was conducted on patients who underwent full-endoscopic resection of neural foraminal schwannomas. Tumors were grouped into either medial type or lateral type based on relevant location to the neural foramen, and respective surgical approaches were adopted. Data including preoperative neurological status, tumor size, surgery time, the extension of resection, and clinical outcomes were collected. The learning curve was plotted as surgical time/tumor size against case number. RESULTS: A total of 25 patients were treated between May 2015 and March 2022. Gross total resection was achieved in 24 patients, and near-total resection in 1 case, with 1 patient experienced transient voiding difficulty. No tumor recurrence or spinal instability was detected in the short-term follow-up (median follow-up 22 months, range 3 months-6 years). Surgical efficiency improved with the number of cases operated on and remained stable after the initial 10 cases. CONCLUSION: Percutaneous full-endoscopic technique is a safe and minimally invasive technique for the resection of foraminal schwannomas.

Prognostic Factors and Treatments Efficacy in Spontaneous Spinal Epidural Hematoma: A Multicenter Retrospective Study.

BACKGROUND AND OBJECTIVES: Spontaneous spinal epidural hematoma (SSEH) is an uncommon but serious condition with a high morbidity rate. Although SSEH is related to numerous risk factors, its etiology remains unclear. There is a paucity of data on its prognostic factors. We aim to evaluate prognostic factors for SSEH in this study. METHOD: A retrospective study was performed on patients who were admitted for SSEH in 3 academic neurosurgical centers from January 2010 to June 2021. Clinical parameters, including clinical condition on admission, anticoagulants use, imaging modality, the timing and type of surgery performed, and outcomes, were collected. Prognostic factors were analyzed. The Frankel scale was used to assess the clinical condition. RESULTS: A total of 105 patients with SSEH were retrieved from medical records, with a mean age of 51.3 years. Eighty-three patients (79%) complained of acute onset of severe neck or back pain. Eighty-two patients (78%) suffered from moderate to severe neurologic deficits (Frankel scale A-C). Anticoagulation usage was found in 20% of cases. Lower thoracic spine (p = 0.046), use of anticoagulants (p = 0.019), sphincter function disfunction (p = 0.008), severe neurologic deficits at admission (p < 0.001), and rapid deterioration (<1 hour, p = 0.004) were found to be associated with poor outcomes. Surgical decompression was performed in 74 (70%) cases. The univariate and multivariate analysis revealed that preoperative severe neurologic deficits (p = 0.005) and extended paraplegia time (>12 hours, p = 0.004) were independent adverse prognostic factors. The univariate analysis revealed that lower thoracic spine location (p = 0.08) and rapid progression (<6 hours, p = 0.005) were correlated with poor prognosis, but the multivariate analysis failed to identify them as independent prognostic factors. DISCUSSION: Adverse prognostic factors for SSEH might include thoracic segment location, use of anticoagulation, severe neurologic deficits on admission, sphincter dysfunction, and rapid progression. Preoperative neurologic deficit and extended paraplegia time were strongly correlated with the prognosis in the subset of patients who underwent surgical decompression. Timely surgical decompression is recommended for patients with moderate/severe neurologic deficits or progressive neurologic deterioration.

Intradural osteomas: Report of two cases.

BACKGROUND: Intradural osteoma is very rarely located in the subdural or subarachnoid space. Unfortunately, intradural osteoma lacks specificity in clinical manifestations and imaging features and there is currently no consensus on its diagnosis method or treatment strategy. Moreover, the pathogenesis of osteoma without skull structure involvement remains unclear. CASE SUMMARY: We describe two cases of intradural osteomas located in the subdural and subarachnoid spaces, respectively. The first case involved a 47-year-old woman who presented with a 3-year history of intermittent headache and dizziness. Intraoperatively, a bony hard mass was found in the left frontal area, attached to the inner surface of the dura mater and compressing the underlying arachnoid membrane and brain. The second case involved a 56-year-old woman who had an intracranial high-density lesion isolated under the right greater wing of the sphenoid. Intraoperatively, an arachnoid-covered bony tumor was found in the sylvian fissure. The pathological diagnosis for both patients was osteoma. CONCLUSION: Surgery and pathological examination are required for diagnosis of intradural osteomas, and craniotomy is a safe and effective treatment.

Intracranial hypertension due to spinal cord tumor misdiagnosed as pseudotumor cerebri syndrome: case report.

BACKGROUND: Isolated onset of intracranial hypertension due to spinal cord tumor is rare, thus, easily leading to misdiagnosis and delay in effective treatment. CASE PRESENTATION: Herein, we describe a 45-year-old female patient who manifested isolated symptoms and signs of intracranial hypertension and whose condition was initially diagnosed as idiopathic intracranial hypertension and transverse sinus stenosis. The patient received a stent implantation; however, no improvements were observed. One year later her symptoms exacerbated, and during rehospitalization a spinal imaging examination revealed a lumbar tumor. Pathologic evaluation confirmed schwannoma, and tumor resection significantly improved her symptoms, except for poor vision. CONCLUSIONS: Space-occupying lesions of the spine should be considered in the differential diagnosis of idiopathic intracranial hypertension, even in the absence of spine-localized signs or symptoms.

Flexible endoscope visualization to assist in the removal of a string of 10 schwannomas at the cauda equina: technical case report.

Bead-like schwannomas at the cauda equina are rare but benign intraspinal tumors. They can involve multiple nerve roots and spread within the spinal canal, and open resection would cause significant trauma. The authors have successfully applied a novel minimally invasive technique for the total removal of such schwannomas. A 68-year-old woman presented with a 1-month history of left waist and leg pain. MRI demonstrated multiple intraspinal lesions located from L1 to S1. The diagnosis was bead-like schwannomas at the cauda equina. Two incisions were made at the T12 and L5 levels. A flexible endoscope was introduced into the spinal canal following hemisemilaminectomy under a microscope to identify the relationship between the tumors and the carrying nerves. After dissecting both cranial and caudal ends of the carrying nerve, the string of bead-like tumors was gently pulled out from the caudal end as a whole. The endoscope was reintroduced into the spinal canal to ensure complete tumor removal. The patient recovered quickly, and no tumor residual was found at postoperative MRI. Flexible endoscope-assisted visualization plus microscopic hemisemilaminectomy via 2 incisions is a feasible minimally invasive approach for selected patients with bead-like schwannomas at the cauda equina.

Stimulator of IFN genes mediates neuroinflammatory injury by suppressing AMPK signal in experimental subarachnoid hemorrhage.

BACKGROUND: Neuroinflammation is closely associated with the poor prognosis in subarachnoid hemorrhage (SAH) patients. This study was aimed to determine the role of stimulator of IFN genes (STING), an essential regulator to innate immunity, in the context of SAH. METHODS: A total of 344 male C57BL/6 J mice were subjected to endovascular perforation to develop a model of SAH. Selective STING antagonist C-176 and STING agonist CMA were administered at 30 min or 1 h post-modeling separately. To investigate the underlying mechanism, the AMPK inhibitor compound C was administered intracerebroventricularly at 30 min before surgery. Post-SAH assessments included SAH grade, neurological test, brain water content, western blotting, RT-PCR, and immunofluorescence. Oxygenated hemoglobin was introduced into BV2 cells to establish a SAH model in vitro. RESULTS: STING was mainly distributed in microglia, and microglial STING expression was significantly increased after SAH. Administration of C-176 substantially attenuated SAH-induced brain edema and neuronal injury. More importantly, C-176 significantly alleviated both short-term and persistent neurological dysfunction after SAH. Meanwhile, STING agonist CMA remarkably exacerbated neuronal injury and deteriorated neurological impairments. Mechanically, STING activation aggravated neuroinflammation via promoting microglial activation and polarizing into M1 phenotype, evidenced by microglial morphological changes, as well as the increased level of microglial M1 markers including IL-1ß, iNOS, IL-6, TNF-α, MCP-1, and NLRP3 inflammasome, while C-176 conferred a robust anti-inflammatory effect. However, all the mentioned beneficial effects of C-176 including alleviated neuroinflammation, attenuated neuronal injury and the improved neurological function were reversed by AMPK inhibitor compound C. Meanwhile, the critical role of AMPK signal in C-176 mediated anti-inflammatory effect was also confirmed in vitro. CONCLUSION: Microglial STING yielded neuroinflammation after SAH, while pharmacologic inhibition of STING could attenuate SAH-induced inflammatory injury at least partly by activating AMPK signal. These data supported the notion that STING might be a potential therapeutic target for SAH.

Utilizing real-time contrast medium to detect the fistula of giant spinal arachnoid cyst and treat with minimal invasive surgery.

BACKGROUND: Spinal arachnoid cysts are rare and have varied clinical manifestations depending on the affected spinal region and nerve roots. A complete cyst excision with fistula closure is the first choice of treatment. However, it might be difficult to localize the specific position of the fistula because previous images have no enhancements or the fistula is too tiny to be detected. CASE PRESENTATION: This case is a giant lumbar extradural arachnoid cyst. We administered a lumbar injection with contrast medium into subarachnoid space under digital subtraction angiography (DSA) and disclosed the fistula. Confirming the location of fistula enabled us to perform minimally invasive surgery to ligate the fistula. Surgical intervention for a spinal arachnoid cyst might encounter the problem of the formation of a postoperative cerebrospinal fluid (CSF) fistula. We propose the option of detecting the fistula preoperatively for minimal invasive surgery. Recurrence depends on the long-term follow-up, and more cases are needed to further evaluate our technique. CONCLUSIONS: The real-time contrast medium technique for spinal arachnoid cysts contributes to the complete ligation with minimally invasive surgery.

Percutaneous Endoscopic Removal of Cervical Foraminal Schwannoma via Interlaminar Approach: A Case Report.

BACKGROUND AND IMPORTANCE: Cervical foraminal schwannomas commonly originate from spinal nerves that pass through the intervertebral foramen of the cervical vertebrae. Because of the proximity of this type of tumor to the vertebral artery and spinal nerves, surgical management remains a major challenge. Conventional open spine surgery usually requires the removal of the articular process and is supplemented by a simultaneous posterolateral spine fusion surgery. To decrease the associated risks of surgical complications by further reducing invasiveness, percutaneous spinal endoscopy may be used for resection of foraminal spinal neoplasm. CLINICAL PRESENTATION: A 52-yr-old female who presented with neck pains with duration of 1 yr was admitted to our hospital. Physical examination revealed moderate rigidity in the neck and grade 5 muscle strength in both upper and lower limbs. Preoperative magnetic resonance imaging (MRI) scans demonstrated a left-sided lesion at the C3-C4 intervertebral foraminal area. Under C-arm fluoroscopy navigation and neuromonitoring, the endoscope was properly positioned on the same side of the tumor, and a small part of the left C3 inferior and C4 superior lamina were first removed by an endoscopic drill to enlarge the interlaminar space. Next, through an endoscopic working canal, the left intervertebral ligamentum flavum was removed to fully expose the tumor. The tumor mass was finally resected in a piecemeal approach. Postoperative MRI confirmed complete tumor resection. CONCLUSION: This is the first case report of a total removal of a cervical foraminal schwannoma with a percutaneous spinal endoscopic procedure.

Percutaneous Endoscopic Removal of a Lumbar Epidural Angiolipoma via Interlaminar Approach: A Technical Report.

BACKGROUND: Although percutaneous endoscopic technique has been routinely used in the treatment of disk herniation, there are few reports on its application in the management of intraspinal tumors. We present a case report of lumbar epidural angiolipoma that was totally removed by percutaneous endoscopic technique. CASE DESCRIPTION: A 63-year-old man presented with a 4-month history of progressively worsening low back pain. No abnormal neurologic finding was noted on physical examination, and magnetic resonance imaging demonstrated a dorsally located L2-3 epidural lesion, suggestive of a noninfiltrating angiolipoma. During the operation, an 8-mm skin incision was made, and a dilator was bluntly inserted toward the interlaminar space, followed by insertion of a working cannula onto the ligamentum flavum and placement of the endoscope. The interlaminar space was enlarged by resection of part of the lower rim of the right L2 vertebral laminae, and the right side of the interlaminar ligamentum flavum was removed to expose the tumor. The tumor was totally removed piecemeal under endoscopic guidance, and pathologic examination confirmed the diagnosis of angiolipoma. CONCLUSIONS: This report supports the application of percutaneous endoscopic technique in the surgical resection of noninfiltrating extradural lumbar angiolipoma.

Microscope-assisted endoscopic interlaminar ligation of spinal arteriovenous fistulas: technical note.

Spinal dural arteriovenous fistulas (SDAVFs) are the most common type of spinal arteriovenous malformations, and microsurgical ligation is the treatment modality most frequently used for these lesions. Developments in endoscopic techniques have made endoscopy an even less invasive alternative to routine microsurgical approaches in spine surgery, but endoscopic management of SDAVF or other intradural spinal lesions has not been reported to date. The authors describe the use of a microscope-assisted endoscopic interlaminar approach for the ligation of the proximal draining vein of an L-1 SDAVF in a 58-year-old man. A complete cure was confirmed by postoperative angiography. The postoperative course was uneventful, and short-term follow-up showed improvements in the patient's neurological function. The authors conclude that the endoscopic interlaminar approach with microscope assistance is a safe, minimally invasive, innovative technique for the surgical management of SDAVFs in selected patients.

[Surgical treatment of anterior circulation aneurysms via lateral supraorbital approach].

OBJECTIVE: To evaluate the efficacy of the surgery with lateral supraorbital approach for clipping anterior circulation aneurysms. METHODS: The clinical data of 99 patients with anterior circulation aneurysms who underwent a clipping via lateral supraorbital approach from October 2012 to September 2014 and 75 patients, who underwent a clipping via pterional approach from January 2010 to December 2011 in the second Affiliated Hospital, Zhejiang University School of Medicine were reviewed. The operative duration, prognosis, residual rate and rupture rate during surgery were compared between two groups. RESULTS: The patients by lateral supraorbital approach had a shorter operative duration, namely 37~61 min less than that in the patients by pterional approach. No difference were found in residual rate and rupture rate between two groups. The Glasgow Outcome Scale (GOS) at 3 months after surgery showed no significant difference between two groups. CONCLUSION: The lateral supraorbital approach can be used safely and effectively with shorter operative duration and less tissue damage for treatment of patients with anterior circulation aneurysms.

Minimally invasive removal of lumbar intradural extramedullary lesions using the interlaminar approach.

OBJECT Posterior midline laminectomy or hemilaminectomy has been successfully applied as the standard microsurgical technique for the treatment of spinal intradural pathologies. However, the associated risks of postoperative spinal instability increase the need for subsequent fusion surgery to prevent potential long-term spinal deformity. Continuous efforts have been made to minimize injuries to the surrounding tissue resulting from surgical manipulations. The authors report here their experiences with a novel minimally invasive surgical approach, namely the interlaminar approach, for the treatment of lumbar intraspinal tumors. METHODS A retrospective review was conducted of patients at the Second Affiliated Hospital of Zhejiang University School of Medicine who underwent minimally invasive resection of lumbar intradural-extramedullary tumors. By using an operative microscope, in addition to an endoscope when necessary, the authors were able to treat all patients with a unilateral, paramedian, bone-sparing interlaminar technique. Data including preoperative neurological status, tumor location, size, pathological diagnosis, extension of resections, intraoperative blood loss, length of hospital stay, and clinical outcomes were obtained through clinical and radiological examinations. RESULTS Eighteen patients diagnosed with lumbar intradural-extramedullary tumors were treated from October 2013 to March 2015 by this interlaminar technique. A microscope was used in 15 cases, and the remaining 3 cases were treated using a microscope as well as an endoscope. There were 14 schwannomas, 2 ependymomas, 1 epidermoid cyst, and 1 enterogenous cyst. Postoperative radiological follow-up revealed complete removal of all the lesions and no signs of bone defects in the lamina. At clinical follow-up, 14 of the 18 patients had less pain, and patients' motor/sensory functions improved or remained normal in all cases except 1. CONClUSIONS When meeting certain selection criteria, intradural-extramedullary lumbar tumors, especially schwannomas, can be completely and safely resected through a less-invasive interlaminar approach using a microscope, or a microscope in addition to an endoscope when necessary. This approach was advantageous because it caused even less bone destruction, resulting in better postoperative spinal stability, no need for facetectomy and fusion, and quicker functional recovery for the patients. Individualized surgical planning according to preoperative radiological findings is key to a successful microsurgical resection of these lesions through the interlaminar space.