Resection versus biopsy for management of primary central nervous system lymphoma: a meta-analysis.

The role of surgery in the management of primary central nervous system lymphomas (PCNSL) is currently confined to diagnosis. However, over recent years, an increasing number of papers have suggested a possible positive prognostic impact of surgery in selected cases. The present work aims to perform a meta-analysis of the available literature evidence. A meta-analysis with meta-regression on the role of surgical resection compared to biopsy in the management of PCNSL was conducted according to the PRISMA statement, searching MEDLINE via PubMed and Embase. The random effect model was used. The quality of evidence was assessed using the GRADE framework. After screening 1395 records, we included 11 papers in our analysis. Patients who underwent surgical resection harbored superficial and single-lesion tumors. At 1-, 2-, and 5-year follow-up, progression-free survival did not differ between the two groups, while overall survival favored resection, even if in a non-significant fashion. Meta-regression analysis showed that the overall survival rate at 2 years, but not at 1 or 5 years, was significantly influenced by tumor location. There were no differences in terms of age, sex, Karnofsky performance status, adjuvant therapy, or procedure-related complications. Overall, the quality of evidence is low. The results of the present meta-analysis do not change the current standard of care for PCNSL. However, surgery could be non-inferior to biopsy with an acceptable risk profile in selected patients harboring single and superficial lesions. The low quality of evidence prompts future randomized studies.

Timing and outcome of bystanders treatment in patients with subarachnoid hemorrhage associated with multiple aneurysms.

In case of subarachnoid hemorrhage (SAH) associated with multiple intracranial aneurysms (MIAs), the main goal of acute treatment is securing the source of bleeding (index aneurysm). Indications and timing of bystanders treatment are instead still debated as the risk of new SAHs in patients harboring MIAs is not yet established. However, even if technically feasible, a simultaneous management of all aneurysms remains questionable, especially for safety issues. We retrospectively reviewed our last 5-year experience with SAH patients harboring MIAs entered in a clinic-radiological monitoring for bystanders follow-up in order to evaluate the occurrence of morphological changes, bleeding events, and safety and efficacy of a delayed treatment. We included 39 patients with mean age of 59.5 ± 12.2 years who survived a SAH. Among them, 14 underwent treatment, whereas 25 continued follow-up. The mean time between index and bystanders treatment was 14.3 ± 19.2 months. Patients undergoing bystanders treatment were mainly female and in general younger than patients undergoing observation. No cases of growth or bleeding were observed among bystanders within the two groups during the follow-up, which was longer than 1 year for the intervention group, and almost 40 months for the observation group. No major complications and mRS modifications were observed after bystanders treatment. Our data seem to suggest that within the short follow-up, intervention and observation seem to be likewise safe for bystander aneurysms, showing at the same time that a delayed management presents a similar risk profile of treating unruptured aneurysms in patients with no previous history of SAH.

Intraventricular infusion test accuracy in predicting short- and long-term outcome of iNPH patients: a 10-year update of a three-decade experience at a single institution.

OBJECTIVE: In a previous work, we found that an Intracranial Elastance Index (IEI) ≥0.3 at ventricular infusion test had a high accuracy in predicting shunt response at 6 and 12 months in idiopathic normal pressure hydrocephalus (iNPH). The aim of this study was to verify the accuracy of IEI to predict response to shunt at both short- and long-term follow-up. METHODS: Retrospective evaluation of 64 patients undergoing ventriculo-peritoneal shunting for iNPH between 2006 and 2015 based on a positive ventricular infusion test (IEI≥0.3). Patients were classified according to Krauss scale and mRS preoperatively, at 1-year and at last follow-up. An improvement of at least one point at Krauss score or at mRS was considered as a good outcome; unchanged or worsened patients were grouped as poor outcome. RESULTS: Mean follow-up was 6.6 years. Improvement at Krauss scale was seen in 62.5% and 64.3% of patients at 1-year and last follow-up, respectively. Patients in good functional status (mRS≤2) increased from 25 in the preoperative period to 57% at both 1-year and last follow-up. IEI was significantly associated with Krauss (p=0.041) and mRS (p=0.036) outcome at last follow-up. Patients with worse preoperative Krauss and mRS had higher chance to improve but higher overall scores after treatment. At ROC curves, IEI showed a good long-term prediction of change in mRS from first year to last follow-up. CONCLUSIONS: IEI≥0.3 predicts outcomes at both short- and long-term, with more than 50% of patients being able to look after themselves after 6 years from treatment.

Comparison between VII-to-VII and XII-to-VII coaptation techniques for early facial nerve reanimation after surgical intra-cranial injuries: a systematic review and pooled analysis of the functional outcomes.

The surgical injury of the intracranial portion of the facial nerve (FN) is a severe complication of many skull base procedures, and it represents a relevant issue in terms of patients' discomfort, social interactions, risk for depression, and social costs. The aim of this study was to investigate the surgical and functional outcomes of the most common facial nerve rehabilitation techniques. The present study is a systematic review of the pertinent literature, according to the PRISMA guidelines. Two different online medical databases (PubMed, Scopus) were screened for studies reporting the functional outcome, measured by the House-Brackman (HB) scale, and complications, in FN early reanimation, following surgical injuries on its intracranial portion. Data on the VII-to-VII and XII-to-VII coaptation, the surgical technique, the use of a nerve graft, the duration of the deficit, and complications were collected and pooled. The XII-to-VII end-to-side coaptation seems to provide higher chances for functional restoration (HB 1-3) than the VII-to-VII (68.8% vs 60.6%), regardless of the duration of the palsy deficit, the use or not of a nerve graft, and the use of stitches or glues. However, its complication rate was as high as 28.6%, and a second procedure is then often needed. The XII-to-VII side-to-end coaptation is the most effective in providing a functional outcome (HB 1-3), even though it is associated to a higher complication rate. Further trials are needed to better investigate this relevant topic, in terms of health-related social costs and patients' quality of life.

Predicting meningioma consistency and brain-meningioma interface with intraoperative strain ultrasound elastography: a novel application to guide surgical strategy.

OBJECTIVE: Providing new tools to improve surgical planning is considered a main goal in meningioma treatment. In this context, two factors are crucial in determining operating strategy: meningioma-brain interface and meningioma consistency. The use of intraoperative ultrasound (ioUS) elastosonography, a real-time imaging technique, has been introduced in general surgery to evaluate similar features in other pathological settings such as thyroid and prostate cancer. The aim of the present study was to evaluate ioUS elastosonography in the intraoperative prediction of key intracranial meningioma features and to evaluate its application in guiding surgical strategy. METHODS: An institutional series of 36 meningiomas studied with ioUS elastosonography is reported. Elastographic data, intraoperative surgical findings, and corresponding preoperative MRI features were classified, applying a score from 0 to 2 to both meningioma consistency and meningioma-brain interface. Statistical analysis was performed to determine the degree of agreement between meningioma elastosonographic features and surgical findings, and whether intraoperative elastosonography was a better predictor than preoperative MRI in assessing meningioma consistency and slip-brain interface, using intraoperative findings as the gold standard. RESULTS: A significantly high degree of reliability and agreement between ioUS elastographic scores and surgical finding scores was reported (intraclass correlation coefficient = 0.848, F = 12.147, p < 0.001). When analyzing both consistency and brain-tumor interface, ioUS elastography proved to have a rather elevated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive (LR+) and negative likelihood ratio (LR-). This consideration was true especially for meningiomas with a hard consistency (sensitivity = 0.92, specificity = 0.96, PPV = 0.92, NPV = 0.96, LR+ = 22.00, LR- = 0.09) and for those presenting with an adherent slip-brain interface (sensitivity = 0.76, specificity = 0.95, PPV = 0.93, NPV = 0.82, LR+ = 14.3, LR- = 0.25). Furthermore, predictions derived from ioUS elastography were found to be more accurate than MRI-derived predictions, as demonstrated by McNemar's test results in both consistency (p < 0.001) and interface (p < 0.001). CONCLUSIONS: While external validation of the data is needed to transform ioUS elastography into a fully deployable clinical tool, this experience confirmed that it may be integrated into meningioma surgical planning, especially because of its rapidity and cost-effectiveness.

Acute subdural hematoma in the elderly: outcome analysis in a retrospective multicentric series of 213 patients.

OBJECTIVE: The objective of this study was to analyze the risk factors associated with the outcome of acute subdural hematoma (ASDH) in elderly patients treated either surgically or nonsurgically. METHODS: The authors performed a retrospective multicentric analysis of clinical and radiological data on patients aged ≥ 70 years who had been consecutively admitted to the neurosurgical department of 5 Italian hospitals for the management of posttraumatic ASDH in a 3-year period. Outcome was measured according to the Glasgow Outcome Scale (GOS) at discharge and at 6 months' follow-up. A GOS score of 1-3 was defined as a poor outcome and a GOS score of 4-5 as a good outcome. Univariate and multivariate statistics were used to determine outcome predictors in the entire study population and in the surgical group. RESULTS: Overall, 213 patients were admitted during the 3-year study period. Outcome was poor in 135 (63%) patients, as 65 (31%) died during their admission, 33 (15%) were in a vegetative state, and 37 (17%) had severe disability at discharge. Surgical patients had worse clinical and radiological findings on arrival or during their admission than the patients undergoing conservative treatment. Surgery was performed in 147 (69%) patients, and 114 (78%) of them had a poor outcome. In stratifying patients by their Glasgow Coma Scale (GCS) score, the authors found that surgery reduced mortality but not the frequency of a poor outcome in the patients with a moderate to severe GCS score. The GCS score and midline shift were the most significant predictors of outcome. Antiplatelet drugs were associated with better outcomes; however, patients taking such medications had a better GCS score and better radiological findings, which could have influenced the former finding. Patients with fixed pupils never had a good outcome. Age and Charlson Comorbidity Index were not associated with outcome. CONCLUSIONS: Traumatic ASDH in the elderly is a severe condition, with the GCS score and midline shift the stronger outcome predictors, while age per se and comorbidities were not associated with outcome. Antithrombotic drugs do not seem to negatively influence pretreatment status or posttreatment outcome. Surgery was performed in patients with a worse clinical and radiological status, reducing the rate of death but not the frequency of a poor outcome.

Minimally Invasive Decompression with Posterior Elements Preservation Versus Laminectomy and Fusion For Lumbar Degenerative Spondylolisthesis: A Systematic Review and Meta-Analysis of Surgical, Clinical and Radiological Outcomes.

INTRODUCTION: Chronic low back pain can be due to many different causes, including degenerative spondylolisthesis (DS). For patients who do not respond to conservative management, surgery remains the most effective treatment. Open laminectomy alone and laminectomy and fusion (LF) for DS have been widely investigated, however, no meta-analyses have compared minimally invasive decompression with posterior elements preservation (MID) techniques and LF. Minimally invasive techniques might provide specific advantages that were not recognized in previous studies that pooled different decompression strategies together. MATERIALS AND METHODS: This was a systematic review and meta-analysis, according to the PRISMA statement, of comparative studies reporting surgical, clinical and radiological outcomes of MID and LF for DS. RESULTS: A total of 3202 papers were screened and 7 were finally included in the meta-analysis. MID is associated with a shorter surgical duration and hospitalization stay, and a lower intraoperative blood loss and residual low back pain; however, the residual disability grade was lower in the LF group. Complication rates were similar between the two groups. The rate of adjacent segment degeneration was lower in the MID group, whereas data on radiological outcomes were heterogeneous and not suitable for data-pooling. CONCLUSIONS: This meta-analysis suggests that MID might be considered as an effective alternative to LF for DS. Further clinical trials will be needed to confirm our results, better investigate radiological outcomes, and identify patient subgroups that may benefit the most from specific techniques.

Craniocerebral disproportion after decompressive craniectomy in infants: The hidden enemy of cranial repair?

INTRODUCTION: Cranioplasty aims at restoring the physiological integrity and volume of the skull. Any disproportion between the intracranial content and the volume of the container may favor the occurrence of complications. A classification of volume mismatches is proposed. A negative mismatch, consisting of intracranial content minor to skull volume, is well represented by the sinking flap. On the other side, a positive mismatch, consisting of intracranial content higher than skull volume, usually depends on CSF collection or hydrocephalus once the brain edema is regressed. Though, in children, this condition may result from physiological brain growth after decompressive craniectomy. Treatment algorithm based on this classification is presented. ILLUSTRATIVE CASE: A 1-year-old boy with a severe traumatic brain injury underwent right decompressive craniectomy, evacuation of subdural hematoma, and dural expansion at another institution. After failure of autologous bone-assisted cranioplasty for infection, a helmet was recommended in order to postpone the cranial repair. Patient was admitted to our institution 3 years later. CT scan showed brain herniation through the cranial defect, associated to a condition of acquired craniocerebral disproportion, due to the condition of "open skull". Augmented hydroxyapatite cranioplasty (CustomBone, Finceramica, Faenza, Italy) was performed in order to manage this rare condition of positive volume mismatch. Subsequent course was uneventful and no complication was recorded at 30-month follow-up. CONCLUSIONS: This illustrative case highlights the possible occurrence of a positive structural mismatch between the skull and the intracranial content after decompressive craniectomy, thus configuring a condition of acquired craniocerebral disproportion, aside of other brain or CSF complications. We firstly recognize this condition in the literature and propose it as a possible factor affecting the outcome of cranioplasty in infants and young children.

The role of non-rigid cervical collar in pain relief and functional restoration after whiplash injury: a systematic review and a pooled analysis of randomized controlled trials.

PURPOSE: Whiplash injury (WI) represents a common diagnosis at every emergency department. Several investigations have been conducted to compare the different medical managements for non-surgical cases. However, the role of the immobilization with a non-rigid cervical collar (nRCC) for pain management and range of motion (RoM) preservation has not been completely clarified. METHODS: We performed a systematic review of the randomized control trials (RCTs) and a pooled analysis in order to investigate the role of the nRCC for pain management, scored through the visual analogue scale (VAS) and the RoM, by comparing the use of a nRCC (for 1-2 weeks) with a non-immobilization protocols, regardless of the association with physical therapy (PhT). Only patients with whiplash-associated disorders grade I-II were included. Due to a certain heterogeneity across the RCTs, follow-up period time range resetting was necessary in order to pool the data. RESULTS: A total of 141 papers were reviewed; 6 of them matched the inclusion criteria and were admitted to the final study. Pooled analysis showed that nRCC does not improve the outcome in terms of VAS score and RoM trends along the follow-up. Moreover, VAS and RoM trends seem to further improve at long-term follow-up in non-immobilization associated with PhT group. CONCLUSIONS: This pooled analysis of the available RCTs shows the absence of an advantage of the immobilization protocol with a nRCC after a WI. On the contrary, non-immobilization protocols show an overall better trend of pain relief and neck mobility recovery, regardless of the association of PhT. These slides can be retrieved under Electronic Supplementary Material.

Incidental intraoperative diagnosis of Mycobacterium abscessus meningeal infection: a case report and review of the literature.

PURPOSE: Mycobacterium abscessus, and rapidly growing mycobacteria in general, are rare but increasing causes of central nervous system (CNS) infections. The aim of this study is to highlight the importance of considering these microorganism in the differential diagnosis of CNS infections, obtaining a prompt diagnosis, and improving clinical outcomes. METHODS: Case report and literature review. RESULTS: We report a case of meningeal infection in a patient who underwent decompressive craniectomy after a craniofacial trauma. The diagnosis was made analyzing a sample obtained during a second operation of cranioplasty. A regimen of amikacin, clarithromycin, and imipenem/cilastatin was started. In the following days, the patient experienced a variety of side effects. So, first clarithromycin was replaced with linezolid, then amikacin was stopped and cefoxitin added to the therapy and at the end all the antibiotics were withdrawn. The patient was discharged in good conditions and a clinical interdisciplinary follow-up was started. After 12 months, the patient is still doing well. After a literature analysis, 15 cases of M. abscessus CNS infections were identified. Various modes of acquisition, underlying disease and therapeutic schemes were evident. CONCLUSIONS: Considering the results of the literature analysis and the increasing incidence of M. abscessus, all specialists involved in the management of CNS infection should be aware of the importance of atypical microorganisms in differential diagnosis.

Minimally invasive decompression in patients with degenerative spondylolisthesis associated with lumbar spinal stenosis. Report of a surgical series and review of the literature.

We reported the results of minimally invasive spinal decompression (MISD) in patients with degenerative spondylolisthesis (DS) associated with lumbar spinal stenosis (LSS) and performed a literature review in order to evaluate the clinical and radiological outcomes, the complications and reoperation rate of MISD procedures in these patients. Data of 28 patients submitted to MISD for DS associated to LSS were reviewed. We evaluated the Visual Analogue Scale (VAS) both for low back pain (LBP) and legs pain, the Oswestry Disability Index (ODI) and the degree of the slippage. A PubMed search of the English literature was conducted. Only papers with more than 10 patients and reporting explicitly data of patients with DS were included in the analysis. We found a statistically significant improvement of LBP, legs pain and ODI in our series. The degree of slippage was stable at follow-up (FU) with no need of reoperation. No major complications occurred. In our literature review, we were able to analyze the differences in ODI in 156 patients and the differences in Japanese Orthopedic Association (JOA) score in 218 patients. We observed a statistically significant improvement of ODI and JOA score at FU compared to pre-operative. The percentage of slippage, evaluated in 283 patients, was unchanged at FU compared to pre-operative. The overall complication rate was 1.6%. The overall reoperation rate was 4.5%. MISD procedures are safe and effective in patients with DS associated to LSS and are associated to low morbidity and significant improvement of disability without progression of slippage.

Neuralgic Amyotrophy and Hourglass Nerve Constriction/Nerve Torsion: Two Sides of the Same Coin? A Clinical Review.

Neuralgic amyotrophy, also called Parsonage-Turner syndrome, in its classic presentation is a brachial plexopathy or a multifocal neuropathy, involving mainly motor nerves of the upper limb with a monophasic course. Recently, a new radiological entity was described, the hourglass constriction, which is characterized by a very focal constriction of a nerve, or part of it, usually associated with nerve thickening proximally and distally to the constriction. Another condition, which is similar from a radiological point of view to hourglass constriction, is nerve torsion. The pathophysiology of neuralgic amyotrophy, hourglass constriction and nerve torsion is still poorly understood, and a generic role of inflammation is proposed for all these conditions. It is now widely accepted that nerve imaging is necessary in identifying hourglass constrictions/nerve torsion pre-surgically in patients with an acute mononeuropathy/plexopathy. Ultrasound and MRI are useful tools for diagnosis, and they are consistent with intraoperative findings. The prognosis is generally favorable after surgery, with a high rate of good motor recovery.

Neurologic and Neuropsychological Outcomes for Treatment of Unruptured Middle Cerebral Artery Aneurysms: Standard Pterional Versus Minipterional Approach in a Retrospective Single-Center Analysis.

BACKGROUND: In accordance with technique advancement and minimal invasiveness surgical approaches, the minipterional has progressively replaced the standard pterional approach for treatment of unruptured middle cerebral artery (MCA) aneurysms. Nowadays, multimodal intraoperative resources including microDoppler and microflow probes, indocyanine green videoangiography, and neurophysiologic monitoring constitute a fundamental prerequisite for increasing the safety of the clipping procedure. Our study investigated and compared in a single-center experience the effect of the evolution of a minimally invasive and multimodal approach in unruptured MCA aneurysm surgery by measuring postoperative complication rate, recovery time, and long-term neuropsychological and functional outcomes. METHODS: One hundred and thirty-one patients who underwent surgical treatment for unruptured MCA aneurysms at our institution were evaluated retrospectively. Patients' clinical, radiologic, and surgical reports were collected. Cognitive evaluation and quality of life were assessed through validated tests in telephone interviews. Patients who met the inclusion criteria were divided into 2 groups: "PT (pterional)" and "MPT (minipterional)." RESULTS: Ninety-two patients were included in the analysis. A significant reduction of postoperative complication rates and new-onset postoperative seizures was recorded in the MPT group (P value = 0.006). Severe cognitive deficits were lower in the MPT group, although without a clear statistical correlation. CONCLUSIONS: Decreased complication rates, faster recovery time, and a trend toward better cognitive and functional performances were documented for the MPT group of patients. In our experience, the minipterional approach with multimodality-assisted microsurgery reduced neurologic complications and recovery time and improved long-term cognitive outcome and quality of life.

Enhancing the Reliability of Intraoperative Ultrasound in Pediatric Space-Occupying Brain Lesions.

INTRODUCTION: Intraoperative ultrasound (IOUS) may aid the resection of space-occupying brain lesions, though technical limits may hinder its reliability. METHODS: IOUS (MyLabTwice®, Esaote, Italy) with a microconvex probe was utilized in 45 consecutive cases of children with supratentorial space-occupying lesions aiming to localize the lesion (pre-IOUS) and evaluate the extent of resection (EOR, post-IOUS). Technical limits were carefully assessed, and strategies to enhance the reliability of real-time imaging were accordingly proposed. RESULTS: Pre-IOUS allowed us to localize the lesion accurately in all of the cases (16 low-grade gliomas, 12 high-grade gliomas, eight gangliogliomas, seven dysembryoplastic neuroepithelial tumors, five cavernomas, and five other lesions, namely two focal cortical dysplasias, one meningioma, one subependymal giant cell astrocytoma, and one histiocytosis). In 10 deeply located lesions, IOUS with hyperechoic marker, eventually coupled with neuronavigation, was useful to plan the surgical route. In seven cases, the administration of contrast ensured a better definition of the vascular pattern of the tumor. Post-IOUS allowed the evaluation of EOR reliably in small lesions (<2 cm). In large lesions (>2 cm) assessing EOR is hindered by the collapsed surgical cavity, especially when the ventricular system is opened, and by artifacts that may simulate or hide residual tumors. The main strategies to overcome the former limit are inflation of the surgical cavity through pressure irrigation while insonating, and closure of the ventricular opening with Gelfoam before insonating. The strategies to overcome the latter are avoiding the use of hemostatic agents before IOUS and insonating through normal adjacent brain instead of corticotomy. These technical nuances enhanced the reliability of post-IOUS, with a total concordance to postoperative MRI. Indeed, the surgical plan was changed in about 30% of cases, as IOUS showed a residual tumor that was left behind. CONCLUSION: IOUS ensures reliable real-time imaging in the surgery of space-occupying brain lesions. Limits may be overcome with technical nuances and proper training.

The use of mixed reality for the treatment planning of unruptured intracranial aneurysms.

BACKGROUND: A thorough comprehension of topographic neuroanatomy is paramount in neurosurgery. In recent years, great attention has been raised towards extended reality, which comprises virtual, augmented, and mixed reality (MR) as an aid for surgery. In this paper, we describe our preliminary experience with the use of a new MR platform, aiming to assess its reliability and usefulness in the planning of surgical treatment of unruptured intracranial aneurysms. METHODS: We prospectively enrolled 5 patients, harboring a total of 8 intracranial unruptured aneurysms, undergoing elective surgical clipping. A wearable mixed-reality device (HoloLens; Microsoft Corp., Redmond, WA, USA) was used to display and interact with a holographic model during surgical planning. Afterward, a total of 10 among surgeons and residents filled in a 5-point Likert-Scale evaluation questionnaire. RESULTS: According to the participants' feedback, the main MR platform advantages were considered the educational value, its utility during patients positioning and craniotomy planning, as well as the anatomical and imaging interpretation during surgery. The graphic performance was also deemed very satisfactory. On the other hand, the device was evaluated as not easy to use and pretty uncomfortable when worn for a long time. CONCLUSIONS: We demonstrated that MR could play important role in planning the surgical treatment of intracranial aneurysms by enhancing the visualization and understanding of the patient-specific anatomy.

A Study on the Role of Intraoperative Corticobulbar Motor Evoked Potentials for Improving Safety of Cerebellopontine Angle Surgery in Elderly Patients.

Preservation of facial nerve function (FNF) during neurosurgery for cerebellopontine angle (CPA) tumors is paramount in elderly patients. Corticobulbar facial motor evoked potentials (FMEPs) allow assessment intraoperatively of the functional integrity of facial motor pathways, thus improving safety. We aimed to evaluate the significance of intraoperative FMEPs in patients 65 years and older. A retrospective cohort of 35 patients undergoing CPA tumors resection was reported; outcomes of patients aged 65-69 years vs. ≥70 years were compared. FMEPs were registered both from upper and lower face muscles, and amplitude ratios (minimum-to-baseline, MBR; final-to-baseline, FBR; and recovery value, FBR minus MBR) were calculated. Overall, 78.8% of patients had a good late (at 1 year) FNF, with no differences between age groups. In patients aged ≥70 years, MBR significantly correlated with late FNF. At receiver operating characteristics (ROC) analysis, in patients aged 65-69 years, FBR (with 50% cut-off value) could reliably predict late FNF. By contrast, in patients aged ≥70 years, the most accurate predictor of late FNF was MBR, with 12.5% cut-off. Thus, FMEPs are a valuable tool for improving safety in CPA surgery in elderly patients as well. Considering literature data, we noticed higher cut-off values for FBR and a role for MBR, which suggests an increased vulnerability of facial nerves in elderly patients compared to younger ones.

Predictive value of intraoperative vagus nerve corticobulbar motor evoked potentials to assess the risk of dysphagia in fourth ventricle surgery.

OBJECTIVE: Dysphagia is a significant complication in fourth ventricle surgery. Corticobulbar motor evoked potentials (CB-MEPs) of the lower cranial nerves may provide real-time information possibly correlating with postoperative swallowing dysfunction, and the vagus nerves may prove ideal for this purpose. However, the literature is heterogeneous, non-systematic, and inconclusive on this topic. The object of this retrospective study was to evaluate the correlation between CB-MEPs of the vagus nerve and postoperative worsening or new-onset swallowing deficits in intraaxial fourth ventricle surgery. METHODS: In 21 consecutive patients undergoing surgery for fourth ventricle intraaxial tumors between February 2018 and October 2022, endotracheal tubes with two applied electrodes contacting the vocal cords were used to record vagus nerve MEPs including values at baseline, the end of surgery, and the minimum value during the operation. From the mean value of right and left vagus nerve MEP amplitudes, the minimum-to-baseline amplitude ratio (MBR) and final-to-baseline amplitude ratio (FBR) were calculated. These indexes were correlated with postoperative swallowing function. RESULTS: Given their clinical significance, receiver operating characteristic curves were obtained to evaluate the performance of these indexes in predicting postoperative swallowing function. The area under the curve (AUC) was 0.850 (p < 0.001) and the best cutoff for FBR was 67.55% for the worsening of swallowing in the postoperative period. The AUC was 0.750 (p = 0.026) and the best cutoff was 46.37% in MBR for the absence of a swallowing disorder at the late follow-up. CONCLUSIONS: This study confirmed that vagus nerve MEPs are reliable predictors of postoperative swallowing function in fourth ventricle surgery and can be feasibly used as an intraoperative monitoring technique.

Single-Level Cervical Arthroplasty with a Keel-less Prosthesis: Results in a Series of 35 Patients Operated on for Soft Disk Herniation with a Minimum of 3 Years of Follow-Up.

BACKGROUND: Cervical arthroplasty with artificial cervical disks has gained popularity as an alternative to anterior discectomy and fusion. The main advantages of disk arthroplasty include maintenance of the range of movement, restitution of disk height and spinal alignment, and reduction of adjacent segment degeneration (ASD). In this article, we aimed to assess the outcomes of the use of a keel-less prosthesis. MATERIAL AND METHODS: We included all the patients who underwent single-level cervical arthroplasties with the Discocerv Cervidisc Evolution for "soft" disk herniation. Clinical assessment included Neck Disability Index (NDI) and visual analog scale (VAS) for neck and arm pain. Radiologic studies investigated the occurrence of ASD and system failure or subsidence. The reoperation rate was also recorded. RESULTS: The study included 35 patients (14 men and 21 women; mean age: 42.5 years; mean follow-up: 57.8 months). There was a significant decrease in VAS neck and VAS arm scores, which went from 7.2 and 6.9 preoperatively to 2.2 and 1.7 postoperatively, 2.2 and 1.6 at 6 months, 2.0 and 1.8 at 1 year, and 2.1 and 1.3 at the last follow-up, respectively. The mean NDI score was 58.0 preoperatively, 19.4 postoperatively, 17.0 at 6 months, 16.1 at 1 year, and 16.2 at the last follow-up. Radiologic studies revealed a preserved range of motion in 33 of 35 patients. No ASD occurred and no reoperation was required. CONCLUSIONS: Cervical disk arthroplasty with a keel-less prosthesis can be a safe and effective alternative to fusion for degenerative disk disease in selected patients, with a possible reduction of ASD.

Intraoperative Corticobulbar Motor Evoked Potential in Cerebellopontine Angle Surgery: A Clinically Meaningful Tool to Predict Early and Late Facial Nerve Recovery.

BACKGROUND: Intraoperative neuromonitoring is crucial for facial nerve preservation in cerebellopontine angle (CPA) surgery. Among the available techniques, the role of intraoperative corticobulbar facial motor evoked potentials (FMEPs) is unclear. OBJECTIVE: To evaluate the significance of intraoperative FMEPs as indicators for early and late postoperative facial nerve function (FNF) in CPA tumor resection and the feasibility of their integration with standard monitoring techniques. METHODS: An institutional series of 83 patients who underwent surgery under intraoperative monitoring for CPA extra-axial tumor resection was reported. A pair of needle electrodes was used to record FMEP from orbicularis oculi (OOc) and orbicularis oris (OOr) muscles at baseline, at the end of surgery and minimum values recorded. From FMEP amplitudes, minimum-to-baseline amplitude ratio (MBR), final-to-baseline amplitude ratio (FBR), and recovery value, intended as FBR minus MBR, were calculated. These indices were correlated with early and late postoperative FNF. RESULTS: Our analysis demonstrated that higher FBR (both from OOc and OOr) and MBR (from OOr only) were associated with a good early and late FNF; a higher MBR from OOc was significantly associated with a good late FNF. The most accurate index in predicting early FNF was FBR measured from OOr with a cutoff of 35.56%, whereas the most accurate index in predicting late FNF was FBR as measured from OOc with a cutoff of 14.29%. CONCLUSION: Our study confirmed that FMEPs are reliable predictors of early and late postoperative FNF in CPA surgery and could be easily integrated with standard intraoperative neuromonitoring techniques.