Guidelines in Neurosurgery: a critical appraisal.

BACKGROUND: The process of grading and stratifying evidence in the extensive literature on neurosurgical guidelines has evolved significantly, ranging from high-quality standards to suggested options. However, the methodology for guideline development has become increasingly complex, leading to challenges in their application across various neurosurgical specialties and settings. This mini review aims to explore the practical implications of published suggestions for managing neurosurgical patients. METHODS: A critical and focused collection of published literature concerning guidelines in different neurosurgical topics, from Pubmed and other sources formed the basis of this non-systematic narrative review. Only guidelines produced by neurosurgeons in the era of evidence based medicine (after 1996) were included. RESULTS: Neurosurgical guidelines often rely on a limited number of Randomized Controlled Trials (RCTs) and Class I evidence, particularly in surgical and emergency contexts where randomization of patient treatments may conflict with established clinical practices. Challenges also include the timely update of guidelines, which sometimes lags behind rapid shifts in evidence, and varying methodologies in guideline production that can result in divergent recommendations. Geographical disparities in disease burden and literature production further influence guideline applicability, suggesting a need for greater inclusion of authors from Low- and Middle-Income Countries (LMICs) to enhance realism and global relevance. Consensus conferences and expert reviews may serve as viable alternatives to address these challenges. CONCLUSION: While Evidence-Based Medicine remains pivotal, critical appraisal and practical application of guidelines must consider these complexities to optimize patient care and outcomes.

Surgical management of congenital cervical spondylolytic spondylolisthesis: illustrative case.

BACKGROUND: Congenital cervical spondylolytic spondylolisthesis is a rare and complex disorder of the cervical spine. Surgical treatment is reserved for those symptomatic patients who do not improve with conservative management. OBSERVATIONS: A 34-year-old man presented with bilateral C7 radiculopathy for the past 6 months. Magnetic resonance imaging of the cervical spine revealed grade II C6-7 spondylolisthesis. Computed tomography showed the presence of spondyloarthritis, bilateral pedicle dysplasia, bilateral isthmic defect, and spinous process schisis. Dynamic radiographs showed no signs of vertebral instability. Dynamic magnetic resonance imaging showed kinking of the spinal cord over the fulcrum of C6-7 kyphosis during flexion, with no signs of myelopathy. The patient underwent C6-7 anterior fusion surgery. His symptoms improved postoperatively, with a 2-month computed tomography scan showing initial bony bridging. LESSONS: The absence of evident instability on radiography does not always correspond to the absence of actual functional compression of neurological structures. Spinal misalignment, muscle dysfunction, and kyphotic deformity with kinking of the spinal cord and stretching of the nerve roots may also contribute to the development of symptoms. In this setting, dynamic magnetic resonance imaging can be extremely useful. Single-level anterior fusion surgery without posterior fixation can achieve solid fusion and improve the clinical conditions of patients. https://thejns.org/doi/10.3171/CASE24174.

Aggressive giant dumbell-shaped thoracic vertebral hemangioma: illustrative case.

BACKGROUND: Vertebral hemangioma is the most common benign tumor of the spine, diagnosed incidentally in most cases. In 0.4% of patients, the lesion is considered aggressive, causing neurological deficits. This subtype of hemangioma is characterized by strong postcontrast enhancement, cortical lysis, and epidural extension causing myelopathy and/or radiculopathy. OBSERVATIONS: A 52-year-old man presented with myelopathy symptoms, namely lower-limb hypoesthesia up to the T4-5 sensory level, right leg hyposthenia, and urinary incontinence. Imaging studies revealed a giant dumbbell-shaped lesion causing spinal cord compression, associated with signal alteration of the T3 vertebral body. The diagnosis of schwannoma was not certain given the radiological features, so a biopsy was planned and confirmed the diagnosis of vertebral hemangioma. Preoperative embolization, spinal fusion, and gross-total resection of the extravertebral component of the lesion were performed. LESSONS: This report should raise awareness of the differential diagnosis of dumbbell-shaped spinal tumors and the therapeutic strategies available for aggressive vertebral hemangiomas, a rare lesion that should be managed in a multidisciplinary setting. https://thejns.org/doi/10.3171/CASE24190.

Outcomes of non-contiguous two-level anterior cervical discectomy and fusion in patients with degenerative cervical myelopathy: a retrospective study.

BACKGROUND: Non-contiguous two-level Anterior Cervical Discectomy and Fusion (ACDF) may be a viable option for patients with degenerative cervical myelopathy and imaging-evident spine and radicular compression at two non-contiguous cervical levels. The risk of hastening degeneration and triggering Adjacent Segment Disease at the spine levels located between the fused levels is a putative adverse event, which was assessed in a few studies. The aim of this study is to investigate the clinical outcomes of patients undergoing non-contiguous two levels ACDF and to assess biomechanical modifications at non-fused segments. METHOD: We retrospectively reviewed all patients with noncontiguous two-level spine and radicular compression, who underwent simultaneous noncontiguous two-level ACDF at our center. We analyzed clinical and radiological outcomes and investigated the rate of adjacent segment disease. Radiographic parameters were calculated on pre- and postoperative images. RESULTS: Thirty-two patients underwent simultaneous noncontiguous two-level ACDF for cervical myelo-radiculopathy between 2015 and 2021 and were followed up for a mean period of 43.3 months. For all patients, the mJOA score significantly improved from 14.57 ± 2.3 to 16.5 ± 2.1 (p<0.01) and the NDI score significantly decreased from 21.45 ± 4.3 to 12.8 ± 2.3 (p<0.01) postoperatively. Cervical lordosis increased after surgery (from 9.65° ±9.47 to 15.12° ± 6.09); intermediate disc height decreased (5.68 mm ± 0.57 to 5.27 mm ±0.98); the ROMs of intermediate (from 12.45 ± 2.33 to 14.77 ± 1.98), cranial (from 14.63 ± 1.59 to 15.71 ± 1.02), and caudal (from 11.58 ± 2.32 to 13.33 ± 2.67) segments slightly increased. During follow-up assessment, in one patient the myelopathy worsened due to spine compression at the intermediate level. CONCLUSIONS: Simultaneous and non-contiguous two-level ACDF is a safe and effective procedure. The occurrence of postoperative adjacent and intermediate segment disease is rare.

Monocentric Retrospective Analysis of Clinical Outcomes, Complications, and Adjacent Segment Disease in 507 Patients Undergoing Anterior Cervical Discectomy and Fusion for Degenerative Cervical Myelopathy.

BACKGROUND: Degenerative cervical myelopathy (DCM) is a leading cause of nontraumatic spinal cord injury. Surgery aims to arrest neurological decline and improve conditions, but controversies surround risks and benefits in elderly patients, outcomes in mild myelopathy, and the risk of adjacent segment disease (ASD). METHODS: Retrospective data of patients who underwent anterior cervical discectomy and fusion for DCM in our hospital were collected. Patients were stratified by preoperative modified Japanese Orthopaedic Association (mJOA) (mild, moderate, severe) and age (under 70, over 70). Clinical outcomes, complications, and ASD rate were analyzed. We evaluated the relationship between mJOA recovery rate and the risk of complications and various preoperative parameters. RESULTS: Five hundred seven consecutive patients were included in the study, with a mean follow-up of 43.52 months (12-71). Improvement in all outcome variables was observed in mild, moderate, and severe myelopathy categories, with elderly patients showing a lower improvement. Except for age, no other variable correlated with mJOA recovery rate. We observed 45 complications (11.1% of patients), with 14 in the U70 group and 31 in the O70 group (P value < 0.001). Age, Charlson comorbidity index, and ASA score were found to be predictors of complications. Fourteen patients (2.8% of total), mean age 54.2, developed radiological and clinical ASD. Most had cranial-level ASD with Pfirmann grade ≥ 2 before index surgery. CONCLUSIONS: Most myelopathic patients improve after anterior cervical discectomy and fusion. Elderly patients show a lower improvement and higher complication rates than their younger counterparts. ASD rates are low, and younger patients with preexisting cranial level alterations are more susceptible.

From data to practice: brain meningioma treatment in elderly patients - a survey of the Italian Society of Neurosurgery (SINch®) and systematic review and meta-analysis.

The management of meningioma in elderly patients (MEP) presents a complex and evolving challenge. Data available offer conflicting information on treatment options and complications. This survey aimed to examine the current approach to MEP, comparing the national profile to data in the current literature. A survey addressing the treatments options and management of meningioma in elderly was designed on behalf of SINch® (Società Italiana di Neurochirurgia) and sent via email to all Chiefs of Neurosurgical Departments. The survey remained open for responses from May 5th, 2022, until November 21st, 2022. A search of the literature published between January 2000 and March 2023, in accordance to PRISMA guidelines, was included. A total of 51 Neurosurgical centers participated in the survey. The caseload profile of each center influences the choice of treatment selection (Stereotactic Radiosurgery versus open surgery) (p = 0.01) and the consolidated practice of discussing cases within a multidisciplinary group (p = 0.02). The pooled meta-analysis demonstrated a significant increased risk in the elderly group for permanent deficits (p < 0.00001), postoperative infections (p = 0.0004) and hemorrhage (p = 0.0001), perioperative mortality (p < 0.00001), and medical complications (p < 0.00001) as compared to the young population. This study presents the initial comprehensive analysis of the existing trends in the surgical management of MEP in Italy. The significant variation in practices primarily stems from the absence of standardized guidelines. While most centers have adopted an integrated approach, there is a need to promote a multidisciplinary care model. Prospective studies are needed to gather robust evidence in this clinical setting.

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

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

Proposal of a new score system (Cervical Surgical Score) for management of degenerative cervical myelopathy.

BACKGROUND: To date, no shared algorithms with the aim of guiding surgical strategy in complex cases of degenerative cervical myelopathy (DCM) exist. Our purpose is to present the Cervical Surgical Score (CSS) which could help in identifying complex DCM cases, suggesting a surgical strategy. METHODS: We created the CSS based on multidisciplinary and literature-focused discussions, based on eight parameters including number of levels of cervical pathology and myelopathy, type and predominance of compression and grade of clinical myelopathy. We prospectively enrolled surgical DCM patients in a 15-months period, collecting clinical and radiological data. During outpatient clinic a specific surgical indication was offered to DCM patients. To validate the score, each outpatient clinic surgical indication was compared a posteriori to the one that resulted from multidisciplinary CSS scoring, focusing on patients for which both an anterior and posterior approach were considered suitable. RESULTS: A total of 100 patients operated on for DCM at our Institution between December 2021 and February 2023 were prospectively enrolled. In 53% of patients the pathology was present at more than two levels. According to CSS calculation, 14% of patients resulted in the "grey zone", where both an anterior and posterior approach were deemed feasible. Among them, in 42.8% of cases the CSS allowed a modification of the originally planned surgery. Looking at outcome, an improvement of m-JOA score in 62% of patients was disclosed. CONCLUSIONS: This preliminary study showed the reliability and usefulness of CSS in detecting complex DCM cases, requiring further analysis by expert spine surgeons, suggesting a surgical strategy.

Quantification of cauda equina nerve root dispersion through radiomics features in weight-bearing MRI in normal subjects and spinal canal stenosis patients.

OBJECTIVE: To quantify the distribution of cauda equina nerve roots in supine and upright positions using manual measurements and radiomics features both in normal subjects and in lumbar spinal canal stenosis (LSCS) patients. METHODS: We retrospectively recruited patients who underwent weight-bearing MRI in supine and upright positions for back pain. 3D T2-weighted isotropic acquisition (3D-HYCE) sequences were used to develop a 3D convolutional neural network for identification and segmentation of lumbar vertebrae. Para-axial reformatted images perpendicular to the spinal canal and parallel to each vertebral endplate were automatically extracted. From each level, we computed the maximum antero-posterior (AP) and latero-lateral (LL) dispersion of nerve roots; further, radiomics features were extracted to quantify standardized metrics of nerve root distribution. RESULTS: We included 16 patients with LSCS and 20 normal subjects. In normal subjects, nerve root AP dispersion significantly increased from supine to upright position (p < 0.001, L2-L5 levels), and radiomics features showed an increase in non-uniformity. In LSCS subjects, in the upright position AP dispersion of nerve roots and entropy-related features increased caudally to the stenosis level (p < 0.001) and decreased cranially (p < 0.001). Moreover, entropy-related radiomics features negatively correlated with pre-operative Pain Numerical Rating Scale. Comparison between normal subjects and LSCS patients showed a difference in AP dispersion and increase of variance cranially to the stenosis level (p < 0.001) in the upright position. CONCLUSIONS: Nerve root distribution inside the dural sac changed between supine and upright positions, and radiomics features were able to quantify the differences between normal and LSCS subjects. CLINICAL RELEVANCE STATEMENT: The distribution of cauda equina nerve roots and the redundant nerve root sign significantly varies between supine and upright positions in normal subjects and spinal canal stenosis patients, respectively. Radiomics features quantify nerve root dispersion and correlates with pain severity. KEY POINTS: • Weight-bearing MRI depicts spatial distribution of the cauda equina in both supine and upright positions in normal subjects and spinal stenosis patients. • Radiomics features can quantify the effects of spinal stenosis on the dispersion of the cauda equina in the dural sac. • In the orthostatic position, dispersion of nerve roots is different in lumbar spinal stenosis patients compared to that in normal subjects; entropy-related features negatively correlated with pre-operative Pain Numerical Rating Scale.

The lumbar adjacent-level syndrome: analysis of clinical, radiological, and surgical parameters in a large single-center series.

OBJECTIVE: The development of specific clinical and neurological symptoms and radiological degeneration affecting the segment adjacent to a spinal arthrodesis comprise the framework of adjacent-level syndrome. Through the analysis of a large surgical series, this study aimed to identify possible demographic, clinical, radiological, and surgical risk factors involved in the development of adjacent-level syndrome. METHODS: A single-center retrospective analysis of adult patients undergoing lumbar fusion procedures between January 2014 and December 2018 was performed. Clinical, demographic, radiological, and surgical data were collected. Patients who underwent surgery for adjacent-segment disease (ASD) were classified as the ASD group. All patients were evaluated 1 month after the surgical procedure clinically and radiologically (with lumbar radiographs) and 3 months afterward with CT scans. The last follow-up was performed by telephone interview. The median follow-up for patients included in the analysis was 67.2 months (range 39-98 months). RESULTS: A total of 902 patients were included in this study. Forty-nine (5.4%) patients required reoperation for ASD. A significantly higher BMI value was observed in the ASD group (p < 0.001). Microdiscectomy and microdecompression procedures performed at the upper or lower level of an arthrodesis without fusion extension have a statistically significant impact on the development of ASD (p = 0.001). Postoperative pelvic tilt in the ASD group was higher than in the non-ASD group. Numeric rating scale, Core Outcome Measures Index, and Oswestry Disability Index scores at the last follow-up were significantly higher in patients in the ASD group and in patients younger than 65 years. CONCLUSIONS: Identifying risk factors for the development of adjacent-level syndrome allows the implementation of a prevention strategy in patients undergoing lumbar arthrodesis surgery. Age older than 65 years, high BMI, preexisting disc degeneration at the adjacent level, and high postoperative pelvic tilt are the most relevant factors. In addition, patients older than 65 years achieve higher levels of clinical improvement and postsurgical satisfaction than do younger patients.

CT-based radiomics can identify physiological modifications of bone structure related to subjects' age and sex.

PURPOSE: Radiomics of vertebral bone structure is a promising technique for identification of osteoporosis. We aimed at assessing the accuracy of machine learning in identifying physiological changes related to subjects' sex and age through analysis of radiomics features from CT images of lumbar vertebrae, and define its generalizability across different scanners. MATERIALS AND METHODS: We annotated spherical volumes-of-interest (VOIs) in the center of the vertebral body for each lumbar vertebra in 233 subjects who had undergone lumbar CT for back pain on 3 different scanners, and we evaluated radiomics features from each VOI. Subjects with history of bone metabolism disorders, cancer, and vertebral fractures were excluded. We performed machine learning classification and regression models to identify subjects' sex and age respectively, and we computed a voting model which combined predictions. RESULTS: The model was trained on 173 subjects and tested on an internal validation dataset of 60. Radiomics was able to identify subjects' sex within single CT scanner (ROC AUC: up to 0.9714), with lower performance on the combined dataset of the 3 scanners (ROC AUC: 0.5545). Higher consistency among different scanners was found in identification of subjects' age (R2 0.568 on all scanners, MAD 7.232 years), with highest results on a single CT scanner (R2 0.667, MAD 3.296 years). CONCLUSION: Radiomics features are able to extract biometric data from lumbar trabecular bone, and determine bone modifications related to subjects' sex and age with great accuracy. However, acquisition from different CT scanners reduces the accuracy of the analysis.

Towards a common language in neurosurgical outcome evaluation: the NEON (NEurosurgical Outcome Network) proposal.

BACKGROUND: The aim of this study was to achieve a consensus on the minimum set of outcome measures and predictors to be used in the neurosurgical practice and on the timing of outcome assessment. METHODS: A consensus building approach was employed. All neurosurgical departments in Lombardy (Italy) were invited to participate by the Carlo Besta Neurologic Institute IRCCS Foundation. Three workshops were organized during which a multidisciplinary group called Neurosurgical Outcome Network (NEON) was created and the methodology to select outcome measures, predictors, and timing of outcome assessment was established. Eight working groups were created for the different neurosurgical diseases (neuro-oncological, skull base, vascular, traumatic, spinal, peripheral nervous system, malformation, functional) and 8 workshops were organized to identify the outcome measures and predictors specific for each of the neurosurgical diseases based on the experts' clinical practice and the existing literature. RESULTS: A total of 20 neurosurgical departments participated in this study. Specific outcome measures, predictors and the timing of outcome assessment were identified for each of the 8 neurosurgical diseases. Moreover, a list of variables common to all pathologies were identified by the NEON group as further data to be collected. CONCLUSIONS: A consensus on the minimum set of outcome measures and predictors and the timing of outcome assessments for 8 neurosurgical diseases was achieved by a group of neurosurgeons of the Lombardy region, called NEON. These sets could be used in future studies for a more homogeneous data collection and as a starting point to reach further agreement also at national and international level.

Minimally invasive microsurgical decompression of the lumbar spine using a novel robotised digital microscope: A preliminary experience.

BACKGROUND: The operative microscope (OM) represents, to date, the standard for neurosurgical procedures. However, new technologies have been proposed during the latest years to overcome its limitations, from high-quality exoscopes to complex robotised visualisation systems. We report our preliminary experience with a novel digital robotised microscope, the BHS RoboticScope (RS), for minimally invasive spinal surgery. METHODS: We employed the RS in five consecutive patients who underwent bilateral lumbar spine decompression through a monolateral approach. Patient outcomes, device technical characteristics and the surgeon's personal perspectives have been evaluated. RESULTS: No complications occurred. All procedures were concluded without switching to the microscope. Image quality, lightning, depth perception and freedom of movement were judged satisfactory as compared to the standard microscope. CONCLUSION: The easy maneuverability and the high quality of pictures provided by the RS device improve the surgeon's comfort in deep fields, representing an effective option for minimally invasive spinal procedures.

Single-Stage Posterior Transpedicular Corpectomy and 360-Degree Reconstruction for Thoracic and Lumbar Burst Fractures: Technical Nuances and Outcomes.

BACKGROUND: We evaluate the feasibility of a single-stage posterior corpectomy and circumferential arthrodesis with the aid of spinal navigation for the treatment of traumatic thoracolumbar burst fractures. METHODS: This was a single-center, retrospective study. Demographics, clinical, and radiologic data of 19 patients who underwent surgery at our institution for thoracolumbar burst fractures between 2016 and 2019 were collected. All patients enrolled in the present study underwent surgery by means of posterior fixation and transpedicular corpectomy with the aid of an intraoperative image-guided neuronavigation system. RESULTS: Postoperative correction of the vertebral height ratio was achieved in all cases, with an average increase of 23.6% (p = 0.0005). No statistical differences (p = 0.9) were found comparing 1- and 3-month postoperative CT scans, in relation to vertebral height ratio. A statistically significant difference was found between the pre- and postoperative kyphotic angles for the thoracolumbar and lumbar segments (p = 0.0018 and 0.005, respectively), but no difference was found between kyphotic angles at the 3-month follow-up. A unilateral approach was performed on 15 patients (79%), while 4 cases (21%) required a bilateral laminectomy. We did not observe any significant intraoperative complication. CONCLUSION: Single-stage posterior corpectomy and fixation is a safe and effective approach for thoracic and lumbar burst fractures. It provides excellent 360-degree reconstruction in a single surgical stage with satisfactory results in terms of kyphosis reduction, biomechanical stability, and reduced invasiveness. Spinal navigation represents a fundamental tool to overcome some anatomical limits of the presented technique.

Lumbar adjacent segment degeneration after spinal fusion surgery: a systematic review and meta-analysis.

INTRODUCTION: Adjacent segment degeneration is among the most recognized long-term complications of lumbar surgery for degenerative spine pathologies with a relevant impact in spine surgical and clinical practice. It is reported a incidence of clinical adjacent segment disease between 5-30% of patients undergoing spinal fusion. We aimed to evaluate the main clinical and surgical risk factors for developing adjacent segment disease. EVIDENCE ACQUISITION: A systematic review and meta-analysis of the pertinent literature was performed, according to PRISMA and PICO guidelines, focusing on clinical and radiological adjacent segment disease. We exclusively included studies reporting demographic and clinical data, and surgical details published from 30 September 2015 to 30 September 2020. The effect of considered risk factors on the presence of adjacent segment disease was explored with a random-effects model. EVIDENCE SYNTHESIS: A total of 15 scientific publications, corresponding to 6253 patients, met the inclusion criteria for the qualitative and quantitative analysis. 720 of the patients developed a clinical and/or radiological adjacent syndrome disease, and 473 have been surgically managed. Ten articles qualified for the comparative geographical analysis. Advanced age and obesity are relevant risk factors for developing lumbar adjacent segment degeneration. Our data also reported a higher prevalence of adjacent segment degeneration in Western populations than in Eastern populations. The interbody fusion has a protective role toward lumbar adjacent segment degeneration. CONCLUSIONS: This study highlighted multifactorial issues regarding adjacent segment disease: clinical, anatomical, biomechanical, and radiological features. In view of increasing life expectancy and spinal surgery procedures, extensive multicenter studies will be needed to define the correct management of the adjacent segment disease.

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

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

Tentorial Notch Meningiomas: Innovative Preoperative Management and Literature Review.

Background: Tentorial meningiomas account for only 3-6% of all intracranial meningiomas. Among them, tentorial incisura (notch) location must be considered as a subgroup with specific surgical anatomy and indications, morbidity, and mortality. In this study, we propose an update on preoperative management in order to reduce postoperative deficits. Methods: We retrospectively collected adult patients treated for incisural meningioma between January 1992 and December 2016 in two different neurosurgical departments. Demographic, clinical, and neuroradiological preoperative and postoperative data were analyzed. In the most recent subgroup of tumors, a preoperative digital simulation was performed to define a volumetric digital quantification of the tumor resection. A review of the pertinent literature has been also done. Results: We included 26 patients. The median age was 58.4 years. Onset neurological signs were cranial nerve deficit in 9 patients, hemiparesis in 7, gait disturbance in 3, and intracranial hypertension in 3 patients. Simpson grade I removal was achieved in 12 patients, II in 10, III in 3, and IV in 1 patient. An overall rate of 23% postoperative complications was observed. The average follow-up duration was 68.5 months. Residual tumor was reported in 8 patients. Five patients underwent gamma knife radiosurgery. In 34.6% of patients, the surgical approach was chosen with preoperative digital planning estimating the potential volume of postoperative residual tumor, the target for radiosurgical treatment. Conclusions: A multidisciplinary approach to plan incisural meningiomas management is important. To lower postoperative morbidity and mortality, a careful preoperative case analysis is useful. A planned residual tumor, supported by preoperative simulation imaging, could be safely treated with radiosurgery.