Risk Of Postoperative Neurological Deficits Research Articles

Risk of Tumor Progression after Microsurgery for Parasellar Meningioma Invading the Cavernous Sinus.

Parasellar meningiomas, which may invade the cavernous sinus, pose a significant challenge to neurosurgeons due to the high risk of postoperative neurological deficits associated with aggressive resection of the intracavernous part of the tumour. Therefore, subtotal tumour removal followed by observation or radiotherapy for the residual meningioma in the cavernous sinus is recommended. This retrospective study aimed to identify prognostic factors influencing recurrence and progression-free survival (PFS) in parasellar meningiomas invading the cavernous sinus after incomplete surgical treatment. This study included adult patients diagnosed with benign parasellar meningioma (WHO Grade I) invading the cavernous sinus, treated at our institution between 2006 and 2020, and with a postsurgical follow-up of at least 3 years. Surgical treatment involved near-total resection (NTR) with an intracavernous residual tumour or subtotal resection (STR) with additional extracavernous tumour left in place. Kaplan-Meier analysis estimated PFS rates, and Cox regression tested survival time differences between groups. Among the 32 patients, the estimated median PFS was 11 years. Radiotherapy improved 5-year PFS only in patients with STR (p = 0.003). The univariate analysis identified preoperative tumour size, low preoperative Karnofsky Performance Score (KPS), and marked brain oedema as significant factors affecting meningioma progression after surgery. The multivariate analysis confirmed tumour size as an independent factor for progression (p = 0.012). For patients with parasellar meningioma invading the cavernous sinus, extracavernous tumour removal followed by close radiological surveillance of the residual intracavernous meningioma is a safe and appropriate strategy. When an extracavernous tumour component is left, adjuvant stereotactic radiotherapy or radiosurgery is recommended to control tumour growth.

Precise execution of personalized surgical planning using three-dimensional printed guide template in severe and complex adult spinal deformity patients requiring three-column osteotomy: a retrospective, comparative matched-cohort study

BackgroundThe surgical treatment of severe and complex adult spinal deformity (ASD) commonly required three-column osteotomy (3-CO), which was technically demanding with high risk of neurological deficit. Personalized three dimensional (3D)-printed guide template based on preoperative planning has been gradually applied in 3-CO procedure. The purpose of this study was to compare the efficacy, safety, and precision of 3D-printed osteotomy guide template and free-hand technique in the treatment of severe and complex ASD patients requiring 3-CO.MethodsThis was a single-centre retrospective comparative cohort study of patients with severe and complex ASD (Cobb angle of scoliosis > 80° with flexibility < 25% or focal kyphosis > 90°) who underwent posterior spinal fusion and 3-CO between January 2020 to January 2023, with a minimum 12 months follow-up. Personalized computer-assisted three-dimensional osteotomy simulation was performed for all recruited patients, who were further divided into template and non-template groups based on the application of 3D-printed osteotomy guide template according to the surgical planning. Patients in the two groups were age- and gender- propensity-matched. The radiographic parameters, postoperative neurological deficit, and precision of osteotomy execution were compared between groups.ResultsA total of 40 patients (age 36.53 ± 11.98 years) were retrospectively recruited, with 20 patients in each group. The preoperative focal kyphosis (FK) was 92.72° ± 36.77° in the template group and 93.47° ± 33.91° in the non-template group, with a main curve Cobb angle of 63.35° (15.00°, 92.25°) and 64.00° (20.25°, 99.20°), respectively. Following the correction surgery, there were no significant differences in postoperative FK, postoperative main curve Cobb angle, correction rate of FK (54.20% vs. 51.94%, P = 0.738), and correction rate of main curve Cobb angle (72.41% vs. 61.33%, P = 0.101) between the groups. However, the match ratio of execution to simulation osteotomy angle was significantly greater in the template group than the non-template group (coronal: 89.90% vs. 74.50%, P < 0.001; sagittal: 90.45% vs. 80.35%, P < 0.001). The operating time (ORT) was significantly shorter (359.25 ± 57.79 min vs. 398.90 ± 59.48 min, P = 0.039) and the incidence of postoperative neurological deficit (5.0% vs. 35.0%, P = 0.018) was significantly lower in the template group than the non-template group.ConclusionPerforming 3-CO with the assistance of personalized 3D-printed guide template could increase the precision of execution, decrease the risk of postoperative neurological deficit, and shorten the ORT in the correction surgery for severe and complex ASD. The personalized osteotomy guide had the advantages of 3D insight of the case-specific anatomy, identification of osteotomy location, and translation of the surgical planning or simulation to the real surgical site.

Sodium-fluorescein-guided awake surgery for cerebral metastases located in eloquent brain areas: technical notes and preliminary experiences.

Awake craniotomy (AC) maximizes the resection of lesions in eloquent brain areas while preserving functionality. Tumor delineation with intraoperative use of sodium fluorescein (NaFl) facilitates total resection. When used with AC, it may allow for safe resection without increasing the risk of postoperative neurologic deficits. This study investigated the efficacy and safety of the combined use of NaFl and AC for maximum safe resection in patients with brain metastases. Patients who underwent AC due to brain metastasis in the Department of Neurosurgery of Uludağ University's Faculty of Medicine between January 1, 2018 and August 1, 2022, were retrospectively analyzed. The study comprised 2 patient groups: plain AC (pAC) and NaFl-guided AC (NaFlg-AC). Surgical outcomes related to fluorescence intensity, degree of resection, perioperative complications, and postoperative neurological factors were evaluated. The pAC group included 16 patients (12 males, 4 females), and the NaFlg-AC group comprised 21 (13 males, 7 females). The mean patient ages for males and females were 61.4 years (61.4 ± 9.5 years) and 60.4 years (60.6 ± 12 years), respectively. The most common origin of the metastatic lesion was the lung in both the pAC and NaFlg-AC groups (n = 12 vs. n = 14, respectively). Gross total resection (GTR) was achieved in 85.7% of the patients in the NaFlg-AC group, whereas the GTR rate was 68.7% in the pAC group. There was no significant difference in GTR rates between the 2 groups (p = 0.254). The mean duration of the resection time was significantly shorter in the NaFlg-AC group (45.95 ± 7.00 min vs. 57.5 ± 12.51 min; p = 0.002). The patients' Karnofsky Performance Status (KPS) score did not reach statistical significance at 6-month follow-up in either group compared to their preoperative baseline scores (p = 0.374). KPS did not show a significant difference between the 2 groups at any time. Fluorescence-guided resection in AC for metastatic tumors in sensory, motor, and cognitive areas is a feasible, safe, and convenient technique that significantly increases GTR rates and shortens operative time compared to conventional white light surgery without fluorescence guidance. It also does not increase the incidence of postoperative complications. With the combined use of AC and NaFl, ensuring clear and visible tumor margins during surgery and controlling patients' neurological function in real-time are possible.

Utility of Decremental Triggered Electromyogram for Intraoperative Neuromonitoring to Identify Midline in Posterior Myelotomy for Spinal Cord Intramedullary Lesions: Technical Note of a Novel Method.

Intramedullary spinal cord lesions are eloquent lesions that are surgically resected via posterior midline myelotomy (PMM). This treatment method carries the risk of postoperative neurological deficits. Various intraoperative neuromonitoring techniques have been used to address this concern. Our study aimed to highlight a newly developed monitoring technique (decremental-triggered electromyogram [dtEMG]) as a novel method to identify the spinal cord midline during PMM. Seven patients in prone position underwent PMM for an intramedullary lesion using dtEMG for neuromonitoring. dtEMG was used to determine the threshold amplitude (ie, the lowest amplitude to elicit an EMG response) as well as a silent zone, which was determined to be the midline. The age range was 26-73 years. dtEMG detected a silent zone in 6/7 patients. The only patient in whom dtEMG was not useful was a patient with complete paraplegia and sensory loss before surgery. There were no motor evoked or somatosensory evoked potential changes related to PMM in these patients. Although the commonly used neuromonitoring techniques, including motor and sensory evoked potentials and free-run electromyograms are of utmost importance in spinal cord surgery, they lack the potential to identify midline in such cases. The currently available tools, including dorsal column mapping, are more cumbersome to use. The newly proposed dtEMG technique can safely and efficiently identify the midline when used as an intraoperative neuromonitoring technique in PMM for spinal cord intramedullary lesion resection.

Awake craniotomy in epilepsy surgery includes previously inoperable patients with preserved efficiency and safety

Introduction: Whilst awake craniotomy has been widely used historically in epilepsy surgery, the safety and efficacy of this approach in epilepsy surgery has been sparsely investigated in controlled studies. The objective of this study is to investigate the safety and efficacy of awake resection in epilepsy surgery and focuses on the possibility to widen surgical indications with awake surgery. Methods: Fifteen patients operated with awake epilepsy surgery were compared to 30 matched controls undergoing conventional/asleep epilepsy surgery. The groups were compared with regard to neurological complications, seizure control and location of resection. Results: Regarding seizure control, 86% of patients in the awake group reached Engel grade 1–2 compared to 73% in the control group, operated with conventional/asleep surgery, not a statistically significant difference. Neither was there a statistical significant difference regarding postoperative neurological complications. However, there was a significant difference in location of the resection when comparing the two groups. Of the 15 patients operated with awake intraoperative mapping, four had previously been considered as non-operable by epilepsy surgery centres, due to vicinity to eloquent brain regions and predicted risk of post-operative neurological deficits. Discussion: The results show that awake epilepsy surgery yields similar level of seizure control when compared to conventional asleep surgery, with maintained safety in regard to neurological complications. Furthermore, the results indicate that awake craniotomy in epilepsy surgery is feasible and possible in patients otherwise regarded as inoperable with epileptigenic zone in proximity to eloquent brain structures.

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.

P15.07.B FUNCTIONAL BRAIN MAPPING DURING AWAKE TUMOR RESECTIONS USING ESM-FMRI CO-REGISTERED FUNCTIONAL ULTRASOUND (FUS)-IMAGING

Abstract BACKGROUND Neurosurgical resection of brain tumors resembles a balancing act between maximing extent of tumor resection (efficacy) and minimizing the risk of post-operative neurological deficits (safety). Given the difficulty of this trade-off, it is surprising how limited the neurosurgeon’s intra-operative tools are. To this day, neurosurgeons still resect brain tumors without any form of real-time volumetric functional imaging. Functional Ultrasound (fUS) shows great potential as a next-generation intra-operative functional imaging technique, combining submillimeter-subsecond spatiotemporal resolution, high-depth penetration and large fields of view. In previous work we have successfully shown fUS’ ability to map out hemodynamics-based functional brain activity during language and motor tasks during awake tumor resections. However, there has been no study comparing fUS-acquired functional maps and its gold standard counterpart of BOLD-fMRI imaging or Electrocortical Stimulation Mapping (ESM). Here we present our first results of concomitant ESM-, fMRI- and fUS-imaging in the same human subjects. MATERIAL AND METHODS In N = 3 patients undergoing awake surgery for tumor removal, we performed paired functional testing with pre-operative fMRI and intra-operative fUS and ESM. Using conventional linear ultrasound arrays (GE L8-18I-D (7.8 MHz) and GE 9L-D Logiq 9 (5.3 MHz)) interfaced with our experimental system (Vantage-256, Verasonics), we could acquire fUS-images up to 8 cm in depth with a PRF up to 800 Hz. Building on clinically available neuro-navigation software with optical tracking (Brainlab), we co-registered our intra-operative fUS-maps and ESM-hotspots to pre-operative MRI/CT-data in real-time to study spatiotemporal overlap. RESULTS In motor, language and visual tasks, we were able to demonstrate consistent spatial overlap between the fUS-based and ESM- and fMRI-based functional regions. Our fUS functional maps presented with unprecedented mesoscopic-scale precision (400 µm), even at depths of over &amp;gt; 5 cm. In contrast to fMRI and ESM, fUS was also able to concomitantly visualize the in-vivo microvascular morphology underlying the functional hemodynamics. The current results were only obtainable after we developed a powerful study pipeline including pre-operative fMRI-imaging and ROI-planning, intra-operative integration of experimental Doppler-data and co-registered functional analyses. CONCLUSION The work presented here is the first-ever, in-human comparison between ESM-, fMRI- and fUS-based functional data, serving as a significant milestone towards further clinical maturity of fUS as a new intra-operative tool to improve the safety and efficacy of neurosurgical brain tumor resections. Disclosure: This work was supported by the NWO-Groot grant of The Dutch Organization for Scientific Research (NWO) (Grant no. 108845).

Maximal safe resection of diffuse lower grade gliomas primarily within central lobe using cortical/subcortical direct electrical stimulation under awake craniotomy.

Diffuse lower-grade glioma (DLGG) in the central lobe is a challenge for safe resection procedures. To improve the extent of resection and reduce the risk of postoperative neurological deficits, we performed an awake craniotomy with cortical-subcortical direct electrical stimulation (DES) mapping for patients with DLGG located primarily within the central lobe. We investigated the outcomes of cortical-subcortical brain mapping using DES in an awake craniotomy for central lobe DLGG resection. We performed a retrospective analysis of clinical data of a cohort of consecutively treated patients from February 2017 to August 2021 with diffuse lower-grade gliomas located primarily within the central lobe. All patients underwent awake craniotomy with DES for cortical and subcortical mapping of eloquent brain areas, neuronavigation, and/or ultrasound to identify tumor location. Tumors were removed according to functional boundaries. Maximum safe tumor resection was the surgical objective for all patients. Thirteen patients underwent 15 awake craniotomies with intraoperative mapping of eloquent cortices and subcortical fibers using DES. Maximum safe tumor resection was achieved according to functional boundaries in all patients. The pre-operative tumor volumes ranged from 4.3 cm3 to 137.3 cm3 (median 19.2 cm3). The mean extent of tumor resection was 94.6%, with eight cases (53.3%) achieving total resection, four (26.7%) subtotal and three (20.0%) partial. The mean tumor residue was 1.2 cm3. All patients experienced early postoperative neurological deficits or worsening conditions. Three patients (20.0%) experienced late postoperative neurological deficits at the 3-month follow-up, including one moderate and two mild neurological deficits. None of the patients experienced late onset severe neurological impairments post-operatively. Ten patients with 12 tumor resections (80.0%) had resumed activities of daily living at the 3-month follow-up. Among 14 patients with pre-operative epilepsy, 12 (85.7%) were seizure-free after treatment with antiepileptic drugs 7 days after surgery up to the last follow-up. DLGG located primarily in the central lobe deemed inoperable can be safely resected using awake craniotomy with intraoperative DES without severe permanent neurological sequelae. Patients experienced an improved quality of life in terms of seizure control.

506 Evaluating Traditional and Non-Traditional Eloquent Areas in Patients with Brain Tumors: Large-scale Network Analysis Using a Machine Learning-Based Platform

INTRODUCTION: Developing mapping tools that allow identification of traditional or non-traditional eloquent areas is necessary to minimize the risk of postoperative neurologic deficits. The objective of our study is to evaluate the use of a novel cloud-based platform that uses machine learning to identify cerebral networks in patients with brain tumors. METHODS: We retrospectively included all adult patients who underwent surgery for brain tumor resection or thermal ablation at our Institution between the 16th of February and the 15th of May of 2021. Pre and postoperative contrast-enhanced MRI with T1-weighted and high-resolution Diffusion Tensor Imaging (DTI) sequences were uploaded into the Quicktome platform. After processing the data, we categorized the integrity of seven large-scale brain networks: sensorimotor, visual, ventral attention, central executive, default mode, dorsal attention and limbic. Affected networks were correlated with pre and postoperative clinical data, including neurologic deficits. RESULTS: Thirty-five (35) patients were included in the study. The average age of the sample was 63.2 years, and 51.4% (n=18) were females. The most affected network was the central executive network (40%), followed by the dorsal attention and default mode networks (31.4%), while the least affected were the visual (11%) and ventral attention networks (17%). Patients with preoperative deficits showed a significantly higher number of altered networks before the surgery (p=0.021), compared to patients without deficits. In addition, we found that patients without neurologic deficits had an average of 2.06 large-scale networks affected, with 75% of them not being related to traditional eloquent areas as the sensorimotor, language or visual circuits. CONCLUSION: The Quicktome platform is a practical tool that allows automatic visualization of large-scale brain networks in patients with brain tumors. Although further studies are needed, it may assist in the surgical management of traditional and non-traditional eloquent areas.

CNTM-01. Evaluating Traditional and Non-Traditional Eloquent Areas in Patients with Brain Tumors: Large-scale Network Analysis Using a Machine Learning-Based Platform

Abstract BACKGROUND Developing mapping tools that allow identification of traditional or non-traditional eloquent areas is necessary to minimize the risk of postoperative neurologic deficits. The objective of our study is to evaluate the use of a novel cloud-based platform that uses machine learning to identify cerebral networks in patients with brain tumors. METHODS We retrospectively included all adult patients who underwent surgery for brain tumor resection or thermal ablation at our Institution between the 16th of February and the 15th of May of 2021. Pre and postoperative contrast-enhanced MRI with T1-weighted and high-resolution Diffusion Tensor Imaging (DTI) sequences were uploaded into the Quicktome platform. After processing the data, we categorized the integrity of seven large-scale brain networks: sensorimotor, visual, ventral attention, central executive, default mode, dorsal attention and limbic. Affected networks were correlated with pre and postoperative clinical data, including neurologic deficits. RESULTS Thirty-five (35) patients were included in the study. The average age of the sample was 63.2 years, and 51.4% (n=18) were females. The most affected network was the central executive network (40%), followed by the dorsal attention and default mode networks (31.4%), while the least affected were the visual (11%) and ventral attention networks (17%). Patients with preoperative deficits showed a significantly higher number of altered networks before the surgery (p=0.021), compared to patients without deficits. In addition, we found that patients without neurologic deficits had an average of 2.06 large-scale networks affected, with 75% of them not being related to traditional eloquent areas as the sensorimotor, language or visual circuits. CONCLUSIONS The Quicktome platform is a practical tool that allows automatic visualization of large-scale brain networks in patients with brain tumors. Although further studies are needed, it may assist in the surgical management of traditional and non-traditional eloquent areas.

Dexmedetomidine versus fentanyl in intraoperative neuromuscular monitoring using propofol based total intravenous anesthesia regimen in kyphoscoliosis correction surgery

BackgroundIntraoperative neuromuscular monitoring (IONM) is used to reduce the risk of postoperative neurological deficit in patients undergoing kyphoscoliosis correction surgery. Somatosensory evoked potentials (SSEPs) are among the several techniques developed by neurophysiologists to increase the sensitivity of intraoperative monitoring. We administered total intravenous anesthesia (TIVA) to 20 patients undergoing kyphoscoliosis deformity correction surgeries: group A: propofol and dexmedetomidine and group B: propofol and fentanyl. The primary objective of our study was to compare the effect of dexmedetomidine and fentanyl on intraoperative hemodynamic parameters and their interference with SSEP’s readings. The secondary objective was to assess the total intraoperative requirement of inhalational anesthetic agents, quality of surgical field, and the cost-effectiveness of either regimen.ResultsIntraoperative hemodynamic stability, analgesia, surgical field, and cost-effectiveness (due to reduced requirement of sevoflurane) were better with dexmedetomidine than fentanyl. SSEPs were successfully recorded with both the drugs while the requirement of inhalation anesthetic agents was significantly reduced in the dexmedetomidine group than in the fentanyl group. There were no injuries while recording SSEPs. The latency and amplitude of SSEPs were maintained throughout either group. No intraoperative awakening or awareness was noted (bispectral index was maintained in the range of 40 to 60). No postoperative neurological deficit was noted in any patient.ConclusionsBoth dexmedetomidine and fentanyl can be successfully used in propofol-based TIVA for SSEP monitoring in kyphoscoliosis correction surgeries, but the better analgesic profile, ease of maintaining stable hemodynamics with a significant reduction in inhalational agent requirement, and opioid-sparing effect by dexmedetomidine make it a more desirable agent to be used in propofol-based TIVA.

243. Should somatosensory evoked potentials and motor evoked potentials monitoring be routinely used in all posterior cervical operations for degenerative conditions of the cervical spine?

<h3>BACKGROUND CONTEXT</h3> Posterior decompression with or without instrumented fusion (PCF) are some of the most common procedures undertaken by spine surgeon. PCF can be the preferred approach for treating patients with cervical spinal traumatic fractures, degenerative spondylosis, deformity tumors, infection and vascular malformations. Intraoperative monitoring is helpful during cases where direct or indirect manipulation of the cord is expected. However, whether neuromonitoring is necessary in routine PCF surgery for degenerative cervical spine conditions remains unknown. <h3>PURPOSE</h3> Here we evaluate the utility of somatosensory evoked potential (SSEP) and motor evoked potential (MEP) monitoring as a tool for predicting postoperative neurologic deficits during PCF for degenerative cervical spine conditions. <h3>STUDY DESIGN/SETTING</h3> Retrospective review of prospectively collected clinical data. <h3>PATIENT SAMPLE</h3> This study included 498 patients who underwent posterior cervical operations for degenerative conditions of the cervical spine, excluding indications such as tumor, trauma, deformity, vascular lesions, and infection. <h3>OUTCOME MEASURES</h3> Sensory and motor neurologic deficit postoperatively. <h3>METHODS</h3> We retrospectively reviewed cases in which PCF was performed for a variety of cervical spine conditions at our institute over a 5-year period. SSEP monitoring was performed in all patients with MEP monitoring performed in only a subset of patients. Patients who had neurologic deficits postoperatively were then identified and detailed analysis was performed to ascertain whether SSEP or MEP monitoring accurately predicted onset of postoperative deficits. The sensitivity, specificity and predictive value of each monitoring paradigm was then determined. <h3>RESULTS</h3> We retrospectively evaluated clinical outcomes and intraoperative monitoring data in 757 patient and identified 498 patients who underwent posterior cervical operations for degenerative conditions of the cervical spine, excluding indications such as tumor, trauma, deformity, vascular lesions, and infection. Forty percent were female, 60% were male with ages ranging from 22 to 93 years-old (mean 67 years-old). SSEP were monitored for all 498 patients during surgery (121 patients [24.3%] had both MEP and SSEP monitoring). Twenty-one patients (4.2%) had neurological deficits after surgery in this cohort. SSEP monitoring had a higher specificity and sensitivity than MEP monitoring for detecting neurologic compromise intraoperatively in PCF cases (91% vs 79% and 60% vs 20% respectively). The positive (PPV) and negative predictive values (NPV) of SSEP monitoring in picking up intraoperative changes that translated to postoperative neurologic deficit were 30% and 97% respectively whereas PPV and NPV of MEP monitoring were 6% and 96% respectively. <h3>CONCLUSIONS</h3> Taken together, these data suggest that intraoperative SSEP and MEP monitoring during PCF is not reliable at predicting postoperative neurologic deficits. With their relatively high NPV, however, MEP and more so SSEP are useful to provide peace of mind intraoperatively when no abnormalities are detected. Thus, use of SSEP and MEP monitoring in PCF should only be limited to cases where the risk of postoperative neurologic deficit is high. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Perspective: Correlation Between Intracranial Pressure and Venous Sinus Pressures in Idiopathic Intracranial Hypertension

Resection of intramedullary spinal ependymomas carries great risk of postoperative neurological deficits. The objective of this study was to describe our experience using co-neurosurgeon teams to address intramedullary ependymomas to determine if the use of 2 experienced attending neurosurgeons with expertise in both neurosurgical oncology and spine pathology can improve outcomes for intramedullary ependymoma resections.We retrospectively compared surgical and disease control outcomes in intramedullary ependymoma cases performed by co-neurosurgeon (one neurosurgical oncologist and one neurosurgeon trained in spinal surgery) and single-neurosurgeon teams over a 13-year period at a single institution.Co-neurosurgeons performed resections in 34 (47.9%) patients, and a single neurosurgeon performed resections in 37 (52.1%) patients. There were no significant differences in the frequency of gross total resection in the co-neurosurgeon versus single-neurosurgeon group (85.7% vs. 78.4%, P = 0.45). Posterior spinal fusion was more common in the co-neurosurgeon group (35.3%) compared with the single-neurosurgeon group (8.1%) (P = 0.01). Two (5.9%) patients in the co-neurosurgeon group and 5 (13.5%) patients in the single-neurosurgeon group had complications requiring surgical revision (P = 0.28). Recurrence rates were similar in both groups (5.9% vs. 10.8%, P = 0.50). At last follow-up, 76% of patients who presented with mild or no deficits remained functionally independent.Resection of intramedullary ependymomas by co-neurosurgeon teams resulted in similar rates of gross total resection, postoperative complications, and recurrence compared with surgeries performed by a single neurosurgeon. Functional neurological outcomes were not impacted by co-neurosurgeons performing ependymoma resections.

The PROGRAM study: awake mapping versus asleep mapping versus no mapping for high-grade glioma resections: study protocol for an international multicenter prospective three-arm cohort study

IntroductionThe main surgical dilemma during glioma resections is the surgeon’s inability to accurately identify eloquent areas when the patient is under general anaesthesia without mapping techniques. Intraoperative stimulation mapping (ISM)...

Oncology and Spinal Neurosurgeons Performing Resections of Intramedullary Ependymomas Compared with Single Neurosurgeons: A 13-Year Experience at a Single Institution

Resection of intramedullary spinal ependymomas carries great risk of postoperative neurological deficits. The objective of this study was to describe our experience using co-neurosurgeon teams to address intramedullary ependymomas to determine if the use of 2 experienced attending neurosurgeons with expertise in both neurosurgical oncology and spine pathology can improve outcomes for intramedullary ependymoma resections. We retrospectively compared surgical and disease control outcomes in intramedullary ependymoma cases performed by co-neurosurgeon (one neurosurgical oncologist and one neurosurgeon trained in spinal surgery) and single-neurosurgeon teams over a 13-year period at a single institution. Co-neurosurgeons performed resections in 34 (47.9%) patients, and a single neurosurgeon performed resections in 37 (52.1%) patients. There were no significant differences in the frequency of gross total resection in the co-neurosurgeon versus single-neurosurgeon group (85.7% vs. 78.4%, P= 0.45). Posterior spinal fusion was more common in the co-neurosurgeon group (35.3%) compared with the single-neurosurgeon group (8.1%) (P= 0.01). Two (5.9%) patients in the co-neurosurgeon group and 5 (13.5%) patients in the single-neurosurgeon group had complications requiring surgical revision (P= 0.28). Recurrence rates were similar in both groups (5.9% vs. 10.8%, P= 0.50). At last follow-up, 76% of patients who presented with mild or no deficits remained functionally independent. Resection of intramedullary ependymomas by co-neurosurgeon teams resulted in similar rates of gross total resection, postoperative complications, and recurrence compared with surgeries performed by a single neurosurgeon. Functional neurological outcomes were not impacted by co-neurosurgeons performing ependymoma resections.

The evolution of eloquent located low-grade gliomas surgical approaches, their natural history and molecular classification

Low-grade glioma is characterized by slow growth, infiltrative pattern through white matter tracts and progression to a malignant tumour type. The traditional classification is newly replaced by molecular stratification. This reorganisation gathers glioma with similar prognosis and treatment protocols. The preferential location of that tumour in eloquent areas constituted, over time, a real challenge regarding the best surgical approach. Because of the high risk of postoperative neurological deficits initially a more conservative management was adopted. Once with the development of preoperative and intraoperative functional assessment techniques, a higher degree of resection was possible in the limits of cortico-subcortical eloquence, being well known that this is a statistically significant factor for survival. We present in this paper the natural evolution of low-grade glioma, their new molecular classification, prognostic factors and the various approach proposed for eloquent ones.

Mapping of the Motor Cortex.

The resection of brain tumors located within or near the eloquent tissue has a higher risk of postoperative neurological deficits. The primary concerns include loss of sensory and motor functions in the contralateral face, upper and lower extremities, as well as speech deficits. Intraoperative neurophysiological monitoring (IONM) techniques are performed routinely for the identification and preservation of the functional integrity of the eloquent brain areas during neurosurgical procedures. The IONM modalities involve sensory, motor, and language mapping, which helps in the identification of the boundaries of these areas during surgical resection. Cortical motor Mapping (CmM) technique is considered as a gold-standard technique for mapping of the brain. We present the intraoperative CmM technique, including anesthesia recommendations, types of electrodes, as well as stimulation and recording parameters for successful monitoring.

Neurosurgical anatomy of the insula and Sylvian fissure in gliomas: literature data and own experience. The first report. Arteries

Insular gliomas account for 25 % of all low-grade and 10 % of all high-grade gliomas. This complex neural and vascular anatomy of the insula and subinsular areas and the attendant risk of postoperative neurological deficit render resection of insular gliomas challenging. Postoperative morbidity can result from injury to these arteries. The cortex and adjacent subcortical structures of the insula are supplied with blood from the cortical insular perforating arteries and lenticulostriate arteries. The source of both types of arteries is the middle cerebral artery. To preserve these vessels, it is necessary to take into account their location while performing approach and tumor debulking.The presurgical planning is extremely important for insular glioma surgery, which allows predicting the extent of removal and to assess the risk of postoperative morbidity. The digital subtractive angiography, CT angiography, MRI angiography make a full picture of the tumor relationship with the lenticulostriate arteries while it is almost impossible to identify the tumor involvement of the insular arteries.The aim of insular glioma surgery is to achieve total removal while preserving critical arteries. This goal is complicated both by a small diameter of lenticulostriate and insular arteries, which intraoperatively complicates their identification and their involvement in tumor tissue. The intraoperative neuroimaging, neuronavigation, intraoperative neuromonitoring can help guide the extent of resection and prevent or minimize postoperative morbidity. However, these advanced technologies are often insufficient without a comprehensive understanding of the insular functional and vascular anatomy.

Postoperative Neurological Complications Following Revision Spine Surgery: A State Inpatient Database Analysis.

Postoperative neurological complications after spine surgery can result in increased mortality and morbidity. Despite the introduction of new spinal implants and surgical technology, reoperation rates have remained stable over recent years. Understanding the reasons for revision (refusion) surgery and the risk of neurological complications can assist in developing more effective screening protocols for repeat surgeries and early detection of potential neurological complications. This study was designed and conducted as a retrospective cohort study. The primary objective of this study was to evaluate whether revision spine surgery increased the risk of postoperative neurological deficits. A secondary objective of the study was to analyze whether deficits following repeat spine surgery increased morbidity and mortality. Data on revision spine procedures were extracted from the California State Inpatient Database for years 2008 to 2011. Patients who developed postoperative neurological deficits were then subdivided into causative procedure: revision anterior cervical discectomy and fusion, revision posterior cervical fusion, and revision thoracolumbar fusion. These data were then used to calculate the total incidence of postoperative neurological deficits following each type of procedure. The impact of neurological deficits on in-hospital morbidity following revision procedures was also calculated. Revision procedures accounted for 5.84% of all spine procedures in a total of 7645 patients. Among these patients, 67 patients (0.88%) developed a postoperative neurological deficit with an adjusted odds ratio of 1.56 (95% CI, 1.20-2.00, P < .05). When using individuals with no neurological deficit as the reference group, the odds of morbidity were 5.3 (95% CI, 3.15-9.00, P < .05) in those who sustained neurological deficit following revision procedure. This study exposes the increased risk of postoperative neurological complications in revision spine surgeries. In response, further studies are needed to evaluate the use of intraoperative neurophysiological monitoring to reduce this risk.

Use of Virtual Reality Platforms in the Preoperative Planning and Intraoperative Navigation of Deep-Seated Cavernomas

Abstract INTRODUCTION Cavernous malformations in deep-seated eloquent cortex pose significant management challenges. Surgical resection, when indicated, carries a high risk of postoperative neurologic deficit. Obtaining safe surgical access is highly dependent upon location and the patient's clinical status. Three-dimensional (3D) virtual reality platforms, neuronavigation, and advanced neuroimaging can be used as adjuncts to determine and perform the safest surgical approach. METHODS Five patients who underwent surgical resection of deep seated cavernomas in eloquent cortex were included. 3D images were created from Diffusion Tensor MR Imaging (DTI) using a 360 Virtual Reality planning software (Surgical Theater SRP, Version7.4.0, Cleveland, Ohio). The Surgical Theater system was integrated with the neuronavigation system (Brainlab AG Version 3.0.5, Feldkirchen, Germany) to allow for real time evaluation of the 3D tractography. The 360°VR model was used to assess the location of the cavernoma and relevant anatomy, map multiple trajectories, and compare the advantages and disadvantages of each. SRP and Brainlab projections were used to determine the limits of the cavernoma, guide the placement of the tubular retractor, and confirm the approach vector intraoperatively. RESULTS Locations of the cavernomas included left caudate head, right superior colliculus, right posteroinferior thalamus, right insula, and left medulla. All patients underwent craniotomy and microsurgical resection. Two patients who presented with a neurologic deficit partially improved after prolonged rehabilitation. Three patients who were neurologically intact on presentation remained so post-op. Gross-total resection was obtained in all patients. CONCLUSION Virtual segmentation allows for better understanding of complex anatomic relationships between the lesion and surrounding critical structures. Advanced planning familiarizes surgeons to the patient in the context of the surgical field, increasing spatial and positional orientation. 3D virtual reality planning platforms in conjunction with neuronavigation and DTI can assist in choosing the optimal surgical corridor to achieve gross-total resection of deep-seated cavernomas while minimizing neurologic risk.