The "state of the art" of intraoperative neurophysiological monitoring: An Italian neurosurgical survey.

Introduction: Intraoperative Neurophysiological Monitoring (IOM) is widely used in neurosurgery but specific guidelines are lacking. Therefore, we can assume differences in IOM application between Neurosurgical centers. Research question: The section of Functional Neurosurgery of the Italian Society of Neurosurgery realized a survey aiming to obtain general data on the current practice of IOM in Italy. Materials and methods: A 22-item questionnaire was designed focusing on: volume procedures, indications, awake surgery, experience, organization and equipe. The questionnaire has been sent to Italian Neurosurgery centers. Results: A total of 54 centers completed the survey. The annual volume of surgeries range from 300 to 2000, and IOM is used in 10-20% of the procedures. In 46% of the cases is a neurologist or a neurophysiologist who performs IOM. For supra-tentorial pathology, almost all perform MEPs (94%) SSEPs (89%), direct cortical stimulation (85%). All centers perform IOM in spinal surgery and 95% in posterior fossa surgery. Among the 50% that perform peripheral nerve surgery, all use IOM. Awake surgery is performed by 70% of centers. The neurosurgeon is the only responsible for IOM in 35% of centers. In 83% of cases IOM implementation is adequate to the request. Discussion and conclusions: The Italian Neurosurgical centers perform IOM with high level of specialization, but differences exist in organization, techniques, and expertise. Our survey provides a snapshot of the state of the art in Italy and it could be a starting point to implement a consensus on the practice of IOM.

T1-Weighted Contrast Enhancement, Apparent Diffusion Coefficient, and Cerebral-Blood-Volume Changes after Glioblastoma Resection: MRI within 48 Hours vs. beyond 48 Hours.

BACKGROUND: The aim of the study is to identify the advantages, if any, of post-operative MRIs performed at 48 h compared to MRIs performed after 48 h in glioblastoma surgery. MATERIALS AND METHODS: To assess the presence of a residual tumor, the T1-weighted Contrast Enhancement (CE), Apparent Diffusion Coefficient (ADC), and Cerebral Blood Volume (rCBV) in the proximity of the surgical cavity were considered. The rCBV ratio was calculated by comparing the rCBV with the contralateral normal white matter. After the blind image examinations by the two radiologists, the patients were divided into two groups according to time window after surgery: ≤48 h (group 1) and >48 h (group 2). RESULTS: A total of 145 patients were enrolled; at the 6-month follow-up MRI, disease recurrence was 89.9% (125/139), with a mean patient survival of 8.5 months (SD 7.8). The mean ADC and rCBV ratio values presented statistical differences between the two groups (p < 0.05). Of these 40 patients in whom an ADC value was not obtained, the rCBV values could not be calculated in 52.5% (21/40) due to artifacts (p < 0.05). CONCLUSION: The study showed differences in CE, rCBV, and ADC values between the groups of patients undergoing MRIs before and after 48 h. An MRI performed within 48 h may increase the ability of detecting GBM by the perfusion technique with the calculation of the rCBV ratio.

Use of fluorescein sodium-assisted intraoperative sample validation to maximize the diagnostic yield of stereotactic brain biopsy: progress toward a new standard of care?

OBJECTIVE: In patients with contraindication to open resection, histological diagnosis is obtained through a stereotactic biopsy (SB). Missed diagnoses and sampling errors are important limitations of SB; therefore, various ways have been proposed to increase the diagnostic yield (DY). Intraoperative histopathology can obtain a DY exceeding 98% but with several drawbacks, namely prolonged operative times and logistic concerns. The objective of this study was to evaluate whether intraoperative validation of samples with fluorescein sodium can obtain a high DY with the same ease of use as standard SB. METHODS: One hundred three consecutive cases of frameless neuronavigated SB performed at the authors' center from May 2013 to June 2021 were included. Two groups were compared: 46 patients underwent standard nonassisted SB (nSB), and 57 patients underwent fluorescein sodium-assisted SB (fSB). Data were collected retrospectively before 2017 and prospectively thereafter. DY, operative time, and rate of complications were compared between the two groups. The surgical technique for fSB was standardized, and a novel classification system for intraoperative fluorescence findings was developed. RESULTS: Statistically significant differences between the two groups were identified. The DY of the fSB group (100%, 95% CI 93.73%-100%) was significantly greater than that of the nSB group (89.13%, 95% CI 80.14%-98.13%) (p = 0.0157). No statistically significant differences were observed in terms of mean operative time (p = 0.7104), intraoperative complications (p = 0.999), or postoperative complications (p = 0.5083). CONCLUSIONS: Compared with standard nSB, fSB showed a significantly higher DY and similar surgical time and rate of complications. The ease of use, wide diagnostic spectrum, and low cost make fluorescein sodium preferable to other fluorophores. The present study strengthens the limited data in the literature indicating routine use of fSB. The proposed workflow suggests that fSB should be the standard of care for contrast-enhanced cases. Intraoperative histopathology should be limited to nonenhancing cases, and nSB should be avoided. Future prospective multicenter studies will be useful for further validation of our findings.

Preliminary Validation of FoRCaSco: A New Grading System for Cerebral and Cerebellar Cavernomas.

OBJECTIVE: Surgical indications for cerebral cavernous malformations (CCMs) remain significantly center- and surgeon-dependent; available grading systems are potentially limited, as they do not include epileptologic and radiologic data. Several experienced authors proposed a new grading system for CCM and the first group of patients capable of providing its statistical validation was analyzed. METHODS: A retrospective series of 289 CCMs diagnosed between 2008 and 2021 was collected in a shared anonymous database among 9 centers. The new grading system ranges from -1 to 10. For each patient with cortical and cerebellar cavernous malformations the grading system was applied, and a retrospective outcome analysis was performed. We proposed a score of 4 as a cutoff for surgical indication. RESULTS: Operated patients with a score ≥4 were grouped with non-operated patients with a score <4, as they constituted the group that received correct treatment according to the new grading system. Patients with a score ≥4, who underwent surgery and had an improved outcome, were compared to patients with a score ≥4 who were not operated (P = 0.04), and to patients with a score <4 who underwent surgery (P < 0.001). CONCLUSIONS: This preliminary statistical analysis demonstrated that this new grading would be applicable in surgical reality. The cutoff score of 4 correctly separated the patients who could benefit from surgical intervention from those who would not. The outcome analysis showed that the treated patients in whom the grading system has been correctly applied have a better outcome than those in whom the grading system has not been applied.

Dissecting Aneurysm of the L1 Radiculomedullary Artery Associated with Subarachnoid Hemorrhage: A Case Report.

BACKGROUND: Both spinal artery aneurysm and spinal subarachnoid hemorrhage represent a very rare event. METHODS: We report a case of a ruptured dissecting aneurysm of the right L1 radiculomedullary artery associated with subarachnoid hemorrhage and severe motor weakness. RESULTS: An urgent decompressive hemilaminectomy was performed due to worsening in motor deficit. A subsequent spinal angiography showed a dissection of radiculomedullary artery of L1 on the right side, treated conservatively. CONCLUSION: Nowadays, therapeutic strategies for this aneurysm remain controversial. Conservative strategy can represent a valid alternative.

Intraoperative Computed Tomography for C1-C2 Stabilization by Goel-Harms: Analysis of Clinical Efficacy and a Novel Classification of Screw Placement Accuracy.

BACKGROUND: The introduction of intraoperative computed tomography (iCT) could improve the surgical results of C1-C2 stabilization by Goel-Harms, especially in patients with complex deformities. This study aims to investigate the impact of iCT on the accuracy of C1-C2 screw positioning and to develop a score based on multiparametric analysis of imaging data (Cervical Screw Placement Accuracy score [CSPAs]). METHODS: Twenty-one patients were retrospectively evaluated. The data obtained with the use of an iCT were compared with the incidence of cases of malpositioning in the literature. Multiparametric imaging criteria were developed: the 82 screw positions were evaluated using the CSPA criteria and 2 additional variables. The CSPAs was obtained from the aggregation of the CSPAs criteria: optimal (CSPAs ≥8), suboptimal (CSPAs = 6-7), malpositioned (CSPAs ≤5). RESULTS: The average incidence of malpositioning in C1-C2 arthrodesis decreased from 13% without iCT to 1.2% with the aid of iCT, considering a monoparametric value. The CSPAs analysis shows a greater discretion and higher number of well-defined categories of the accuracy of C1-C2 screw position: optimal, 80.3%; suboptimal, 17.1%; and malposition, 2.6%. A correlation was observed between the accuracy of the positioning of both right and left screws in C2. Furthermore, the anatomic site of C2 screws was found to be a predictor of cortical invasion. CONCLUSIONS: The results suggest that the introduction of the iCT is associated with a consistent improvement of the accuracy in the positioning of the screws. A multiparametric score (CSPAs) could improve the assessment of screw placement.

Flow diverter stents with hydrophilic polymer coating for the treatment of acutely ruptured aneurysms using single antiplatelet therapy: Preliminary experience.

BACKGROUND: The use of flow diverter stent (FDS) has limitations in cases of subarachnoid haemorrhage caused by ruptured aneurysm, due to the need for double antiplatelet therapy and the delay in the aneurysm occluding. The p48 MW and the p64 MW (Phenox) are available with Hydrophilic Polymer Coating (HPC), that reduces the risk of thrombus formation. Purpose of this study is to evaluate the safety and efficacy of p48 and p64 MW HPC with single antiplatelet therapy for the acute treatment of ruptured aneurysm. METHODS: We retrospectively evaluated all patients treated for acutely ruptured aneurysms with a p48 MW HPC or p64 MW HPC from October 2019 to April 2020 using single antiplatelet therapy. For each patient, we considered demographic and aneurysm-related data, clinical presentation, size and location of the implanted flow diverter stent, intra- and post-procedural complications, aneurysm occlusion. RESULTS: Seven patients were included. The ruptured aneurysms were four saccular, two blister-like and one dissecting, six in the anterior and one in posterior circulation. No intraprocedural stent thrombosis and rebleeding was observed. In two cases the aneurysm is completely excluded, in one patient it was found only neck perfusion, in three cases there were mild reduction of the sac and in one case there was a persistent perfusion. No patients needed retreatment in this series. CONCLUSION: In our experience, FDS HPC appears a potential treatment option in selected cases. Our study is limited by small population and short-term follow-up. We report our preliminary data, but further investigations are necessary.

Choroid Plexus Carcinoma in Adults: Literature Review and First Report of a Location into the Third Ventricle.

Choroid plexus carcinoma (CPC) is a rare intraventricular neoplasm originating from choroid plexus. CPC is the most aggressive choroid plexus tumor. Almost all the CPCs are detected in children, and the preferred location is the lateral ventricle. We reviewed the literature to evaluate the state of the art concerning the management of CPC in adults and report the first case described of the extremely rare localization into the third ventricle. A 38-year-old woman presented a medical history of Parinaud syndrome and occasional facial weakness. Brain magnetic resonance imaging revealed a mass lesion in the pineal region and posterior part of the third ventricle with obstructive hydrocephalus. She underwent subtotal resection through a supracerebellar infratentorial approach. After the histopathological diagnosis of CPC, the patient underwent a second surgery with gross total resection and adjuvant radiotherapy. CPC in adults, given its extreme rarity, does not have a standardized treatment. Gross total resection should be the first step of the treatment: however, according to the literature, gross total resection is achieved only in 40-75% of cases in CPC as opposed to 95% in choroid plexus papilloma, mainly due to the difficulty in managing a highly vascularized tumor in such a deep location. Chemotherapy has not an established role and adjuvant treatment is based on radiotherapy. In the case described hereby the gross total resection associated with surgical treatment of hydrocephalus and adjuvant radiotherapy has achieved a good clinical and radiological outcome.

Posttraumatic Middle Meningeal Artery Pseudoaneurysm: Case Report and Review of the Literature.

BACKGROUND: Intracranial pseudoaneurysm is a rare entity, with few cases described in the literature, and is mostly associated with a history of traumatic brain injury. Traumatic aneurysms comprise <1% of all intracranial aneurysms. In particular, middle meningeal artery (MMA) aneurysms are uncommon and usually caused by a skull fracture in the temporal region. About 40 traumatic MMA aneurysms are reported in the literature, and only 28 nontraumatic aneurysms are reported, usually related to high-flow conditions. The behavior of these aneurysms is largely unknown: both spontaneous resolution and aneurysm growth, leading to subsequent rupture, have been reported. Surgical and endovascular management are feasible for MMA aneurysms; however, the criterion standard treatment is not defined. CASE DESCRIPTION: We report the case of a traumatic pseudoaneurysm of the right MMA treated with an endovascular approach and provide a review of the literature. CONCLUSIONS: Aneurysms of the MMA are a rare entity that must be taken into account in the setting of a traumatic brain injury or predisposing factors. The diagnosis and aggressive treatment are mandatory, preventing the devastating consequences of their rupture. Endovascular and surgical techniques are well defined and available, even though there is not a demonstrated superiority in any of them.

Rare Case of Dumbbell-Shaped Spinal Cavernous Hemangioma and Literature Review.

BACKGROUND: Spinal epidural cavernous hemangiomas are rare vascular malformations. Exceptionally, they present with dumbbell-shaped morphology. When they happen, it's mandatory to include their pathology in the differential diagnosis because of their similarity to schwannomas. CASE DESCRIPTION: We report the case of a 72-year-old woman with a dumbbell-shaped thoracic epidural cavernous hemangioma. A literature review of diagnostic features and current treatment options are also discussed. CONCLUSIONS: Surgery is safe and effective in both improving patient condition and preventing acute hemorrhage that can worsen the outcome, causing neurologic and potentially irreversible deficits. The favorable result we obtained in our patient suggests that surgery should be evaluated as the first option, even in patients with large epidural cavernous hemangiomas.

Translaminar Approach for Treatment of Hidden Zone Foraminal Lumbar Disc Herniations: Surgical Technique and Preoperative Selection of Patients with Long-Term Follow-Up.

BACKGROUND: Lumbar disc herniation is a common degenerative disease of the lumbar spine with a prevalence of 1%-3% in some population studies. In 10% of patients, there is a fragment migrated cranially in Macnab's "hidden zone." In selected cases, this fragment can be removed with a translaminar approach that was described in 1998. We provide a detailed description of the technical advantages and pitfalls of the translaminar approach in a consecutive series of 32 patients treated at our institution. METHODS: Patients were divided preoperatively and postoperatively into 5 classes based on the Oswestry Disability Index (ODI): class 1, ODI 0%-20% (minimal disability); class 2, 20%-40% (moderate disability); class 3, 40%-60% (severe disability); 60%-80% (crippled); 80%-100% (bedridden or disabling symptoms). RESULTS: Four (12.5%) patients were upgraded 1 ODI class after the operation; 6 (18.7%) patients were upgraded 2 classes, 8 (25%) patients were upgraded 3 classes, and 11 (34.4%) patients were upgraded 4 classes. In 3 (9.4%) patients, ODI class did not change after the operation. After surgery, 7 (21.9%) patients developed mild low back pain. Mean follow-up was 25 months. CONCLUSIONS: When performed by dedicated spinal neurosurgeons, the translaminar approach is safe and effective in patients with long-term follow-up. Most patients showed an improvement in ODI. Major pitfalls were related to surgical selection and the narrow working space.