Outcome after Intracerebral Haemorrhage and Decompressive Craniectomy in Older Adults.

OBJECTIVE: There is a relationship between the incidence of spontaneous intracerebral haemorrhage (ICH) and age. The incidence increases with age. This study aims to facilitate the decision-making process in the treatment of ICH. It therefore investigated the outcome after ICH and decompressive craniectomy (DC) in older adults (>65 years of age). METHODS: Retrospective, multicentre, descriptive observational study including only consecutive patients who received DC as the consequence of ICH. Additive evacuation of ICH was performed after the individual decision of the neurosurgeon. Besides demographic data, clinical outcomes both at discharge and 12 months after surgery were evaluated according to the Glasgow Outcome Scale (GOS). Patients were divided into age groups of ≤65 and >65 years and cohorts with favourable outcome (GOS IV-V) and unfavourable outcome (GOS I to III). RESULTS: 56 patients were treated. Mean age was 53.3 (SD: 16.13) years. There were 41 (73.2%) patients aged ≤65 years and 15 (26.8%) patients aged >65 years. During hospital stay, 10 (24.4%) patients in the group of younger (≤65 years) and 5 (33.3%) in the group of older patients (>65 years) died. Mean time between ictus and surgery was 44.4 (SD: 70.79) hours for younger and 27.9 (SD: 41.71) hours for older patients. A disturbance of the pupillary function on admission occurred in 21 (51.2%) younger and 2 (13.3%) older patients (p = 0.014). Mean arterial pressure was 99.9 (SD: 17.00) mmHg for younger and 112.9 (21.80) mmHg in older patients. After 12 months, there was no significant difference in outcome between younger patients (≤65 years) and older patients (>65 years) after ICH and DC (p = 0.243). Nevertheless, in the group of younger patients (≤65 years), 9% had a very good and 15% had a good outcome. There was no good recovery in the group of older patients (>65 years). CONCLUSION: Patients >65 years of age treated with microsurgical haematoma evacuation and DC after ICH are likely to have a poor outcome. Furthermore, in the long term, only a few older adults have a good functional outcome with independence in daily life activities.

Case report: Atypical neurofibromatous neoplasm with uncertain biological potential of the sciatic nerve and a widespread arteriovenous fistula mimicking a malignant peripheral nerve tumor in a young patient with neurofibromatosis type 1.

We report an unusual constellation of diseases in a 32-year-old woman with neurofibromatosis type 1 (NF1) diagnosed with the recently described precursor entity of malignant peripheral nerve sheath tumor (MPNST), the so-called atypical neurofibromatous neoplasm with unknown biological potential (ANNUBP) and a large symptomatic cervical arteriovenous fistula. An [18F] 2-Fluoro-2-deoxy-D-glucose PET/CT (FDG-PET/CT) was performed to detect and stage a conspicuous symptomatic cervical tumor. The FDG-PET/CT showed high FDG uptake in one of the multiple known tumorous lesions associated with peripheral nerves. However, no relevant FDP uptake was observed in this affected cervical area. After digital subtraction angiography, the cervical mass turned out to be a widespread arteriovenous fistula of the vertebral artery. This was successfully treated using endovascular embolization. Subsequently, magnet resonance imaging (MRI) of the FDG-positive tumor revealed a well-enhanced homogeneous mass of the sciatic nerve measuring 5.2×2.4×2.8 cm. Microsurgical gross total tumor resection was performed using ultrasound. The final histopathological diagnosis was ANNUBP transformed from neurofibroma. The patient benefited excellently from the surgery; no recurrence or metastasis has been observed since resection. According to imaging, ANNUBP can be characterized as a well-enhanced homogeneous mass on MRI, displaying high uptake on FDG-PET/CT and hypoechogenic in ultrasound.

Health-related quality of life in patients with peripheral nerve tumors: results from the German multicentric Peripheral Nerve Tumor Registry.

Objective: Peripheral nerve tumors (PNTs) are rare diseases. So far, no multicenter data on diagnostics, the efficacy of treatment, long-term outcomes, and health-related quality of life (HRQoL) exist. The establishment of the Peripheral Nerve Tumor Registry (PNTR) in 2015 allows for the systematic analysis of patients with tumors associated with peripheral nerves. The present study aims to investigate the impact of PNT on an individual's HRQoL and the effect of surgery. Methods: HRQoL was pre- and postoperatively assessed by the Euro-Qol-5D-5L (EQ-5D-5L) and Euro-Qol visual analog scale (EQ-VAS) survey in the retrospective and prospective study arm in three active participating study centers. An index was calculated based on the EQ-5D-5L for the quantification of health state (0: worst possible state of health, 1: best possible state of health). The EQ-VAS ranges from 0% (worst imaginable health status) to 100% (best possible health status). Patient characteristics (age, sex), as well as disease (histopathological entity) and treatment (pre- and postoperative symptoms, type of treatment)-specific data, were analyzed. Results: Data from 171 patients from three high-volume centers were included, with schwannoma (70.8%, n = 121) and neurofibroma (15.8%, n = 27) being the most prevalent histopathological diagnoses. Both the median health index value (preoperative: 0.887, n = 167; postoperative: 0.910, n = 166) and the median EQ-VAS (preoperative: 75%, n = 167; postoperative: 85%, n = 166) of the entire cohort regarding all histopathological diagnosis improved significantly after surgical therapy (p < 0.001). Preoperatively, 12.3% (n = 21) reached the highest index score of 1.0 in EQ-5D-5L and 100% in the EQ-VAS score in 5.3% (n = 9) of all patients. Postoperatively, the highest index score of 1.0 and 100% in the EQ-VAS score increased significantly and were achieved in 33.3% (n = 57) and 11.1% (n = 19) of the patients, respectively (p < 0.001). Conclusion: For the first time, our study presents multicenter data on life quality and the effect of surgery in primarily benign peripheral nerve tumors. Early surgery at a specialized center could improve neurological outcomes and, in conclusion, better QoL. In summary, surgical therapy significantly improved the entire cohort's QoL, VAS, and analgesia.

Mapping Motor Neuroplasticity after Successful Surgical Brachial Plexus Reconstruction Using Navigated Transcranial Magnetic Stimulation (nTMS).

Brachial plexus reconstruction (BPR) consists of the complex surgical restoration of nerve structures. To further understand the underlying motor cortex changes and evaluate neuroplasticity after a successful surgery, we performed a navigated transcranial magnetic stimulation (nTMS) study mapping the postoperative motor representation of the formerly plegic arm. We conducted a prospective nTMS study mapping the musculocutaneous nerve as a representative, prominent target of BPR including a patient (n = 8) and a control group (n = 10). Measurements like resting motor threshold (RMT), cortical motor area location, and size were taken. Mathematical analysis was performed using MATLAB 2022, statistical analysis was performed using SPSS 26, and nTMS mapping was performed using the Nexstim NBS 5.1 system. Mapping was feasible in seven out of eight patients. Median RMT on the affected hemisphere was 41% compared to 50% on the unaffected hemisphere and they were 37% and 36% on the left and right hemispheres of the control group. The motor area location showed a relocation of bicep brachii representation at the middle precentral gyrus of the corresponding contralateral hemisphere. Motor area size was increased compared to the control group and the patient's unaffected, ipsilateral hemisphere. Understanding cortical reorganization is important for potential future treatments like therapeutic nTMS. The issue of motor neuroplasticity in patients with brachial plexus lesions is worth exploring in further studies.

The impact of SARS-Covid-19 pandemic on peripheral nerve surgery - A single centre report.

OBJECTIVE: SARS-Cov-19 pandemic totally changed daily routine work in German hospitals. As hospital capacity was reduced, many surgeries were postponed or even cancelled. On March 25th 2020 the German Society of Neurosurgery (DGNC) published a statement in which urgent non-elective surgeries were defined for each neurosurgical domain, whereas elective interventions were deferred. The present work examines the impact of these Covid strategies focusing on patients with peripheral lesions who were conducted to our department during this period of time. METHODS: All patients who underwent any peripheral nerve surgery at our department from January 2018 until December 2022, were included. The complete range of surgeries including peripheral nerve lesions was examined encompassing compression syndromes, traumatic lesions of brachial plexus, traumatic lesions and tumors of single peripheral nerves. The numbers of surgical procedures were compared before, during and after pandemic. Pearson correlation coefficient was analysed. RESULTS: From 2018 to 2022 the total number of surgical procedures involving peripheral nerves included 2422 procedures. Compression syndromes made up the largest proportion (1433 operations, 59%), followed by peripheral nerve lesions (445 operations, 18%), peripheral nerve tumors (344 operations, 14%) and lesions of the brachial plexus (142 operations, 6%). The average was 40,5 interventions per month, the range was 7-63. Two declines in the number of peripheral nerve surgeries were noted during this period. The first was in April and May 2020 with an average drop of 65% and 41% respectively. In these months the average number of operations was 37. The second decrease was from October 2021 until January 2022, where number of surgeries was reduced by 16%, 36%, 83% and 18% with an average number of 50 operations. Both declines showed a significant and strong correlation with the lower number of compression syndrome treatments (r = 0.952, p < 0.001 and r = 0.968, p < 0.001), while no drop and no significant correlation was found in the treatment of traumatic peripheral nerve injuries (p = 0.769, r = 0.095 and p = 0.243, r = 0.366) and traumatic brachial plexus injuries (p = 0.787, r = 0.088 and p = 0.780, r = 0.09). A weak significant correlation was seen in the treatment numbers of peripheral nerve tumors (p = 0.017, r = 0.672 and p = 0.015, r = 0.67). CONCLUSION: Covid-19 pandemic lead to a significant decrease in the number of nerve decompressions, since, according to the German Society of Neurosurgery, those were considered as elective surgeries.

Combined stent retriever angioplasty and continuous intra-arterial nimodipine infusion as salvage therapy for cerebral vasospasm and delayed cerebral ischemia after subarachnoid hemorrhage: illustrative case.

BACKGROUND: Delayed cerebral ischemia (DCI) and cerebral vasospasm (CV) are severe complications of spontaneous subarachnoid hemorrhage (SAH) contributing to an inferior outcome. Rescue therapies include intra-arterial balloon angioplasty and repetitive and finally continuous intra-arterial nimodipine infusion. OBSERVATIONS: In the presented case, a young female patient with fulminant refractory DCI and CV, despite induced hypertension and nimodipine application, was treated with three-vessel continuous intra-arterial infusion and additional repetitive angioplasty of the basilar and middle cerebral arteries using a stent retriever, leading to a good clinical outcome. Additional stent retriever dilatation to continuous intra-arterial nimodipine application in three vessel territories may represent a further escalation step in the rescue therapy for severe CV and DCI after SAH. Montreal Cognitive Assessment and SF-36 testing showed satisfactory results 3 months after initial treatment with intra-arterial nimodipine catheters in three vessel territory circulations and additional stent retriever vasodilation of severe CV. LESSONS: We report a unique rescue strategy involving implantation of an additional intra-arterial catheter into the vertebral artery and repetitive stent retriever dilatations of the middle cerebral and basilar arteries as an extra therapy for continuous intra-arterial nimodipine vaspospasmolytic therapy in three vessel territories, resulting in a very good clinical outcome.

Pituitary Stalk Morphology as a Predictor of New-Onset Adrenocortical Insufficiency and Arginine Vasopressin Deficiency after Transsphenoidal Resections of Pituitary Macroadenomas: A Retrospective Single-Center Study with a Focus on iMRI.

BACKGROUND: A new-onset adrenocortical insufficiency (NAI) is the most critical postoperative endocrinological complication after transsphenoidal surgery for macroadenomas. Because of increased mortality risk, arginine vasopressin deficiency (AVP-D) is also a relevant postoperative complication. This study aimed to identify easy-to-acquire magnet resonance imaging (MRI) aspects of the pituitary stalk to predict these insufficiencies after transsphenoidal surgery. METHODS: Pituitary stalk morphology was reviewed intraoperatively and three months postoperatively in the MRIs of 48 transsphenoidal surgeries for macroadenomas. NAI was validated in endocrinological follow-up controls 10-14 months post-surgery. RESULTS: Intraoperative pituitary stalk diameters were 0.5 mm larger in patients who developed NAI and AVP-D. The odds ratio was 29 for NAI and 6 for AVP-D in binary regression analysis. A value of 2.9 mm was identified as the optimal cut-off for the minimal pituitary stalk diameter regarding NAI, with a high specificity of 89%. There was no difference in pituitary stalk diameter regarding these insufficiencies three months post-surgery. CONCLUSIONS: We identified an increased pituitary stalk diameter in intraoperative MRIs as a predictive factor of NAI and AVP-D after transsphenoidal surgery. These findings might improve the early detection of NAI and, thus, optimal management. However, validating these retrospective findings in prospective studies is obligatory.

Augmented Reality-Assisted versus Freehand Ventriculostomy in a Head Model.

BACKGROUND: Ventriculostomy (VST) is a frequent neurosurgical procedure. Freehand catheter placement represents the standard current practice. However, multiple attempts are often required. We present augmented reality (AR) headset guided VST with in-house developed head models. We conducted a proof of concept study in which we tested AR-guided as well as freehand VST. Repeated AR punctures were conducted to investigate if a learning curve can be derived. METHODS: Five custom-made 3D-printed head models, each holding an anatomically different ventricular system, were filled with agarose gel. Eleven surgeons placed two AR-guided as well as two freehand ventricular drains per head. A subgroup of four surgeons did a total of three series of AR-guided punctures each to test for a learning curve. A Microsoft HoloLens served as the hardware platform. The marker-based tracking did not require rigid head fixation. Catheter tip position was evaluated in computed tomography scans. RESULTS: Marker-tracking, image segmentation, and holographic display worked satisfactorily. In freehand VST, a success rate of 72.7% was achieved, which was higher than under AR guidance (68.2%, difference not statistically significant). Repeated AR-guided punctures increased the success rate from 65 to 95%. We assume a steep learning curve as repeated AR-guided punctures led to an increase in successful attempts. Overall user experience showed positive feedback. CONCLUSIONS: We achieved promising results that encourage the continued development and technical improvement. However, several more developmental steps have to be taken before an application in humans can be considered. In the future, AR headset-based holograms have the potential to serve as a compact navigational help inside and outside the operating room.

Intraoperative MRI-Guided Resection Is Not Superior to 5-Aminolevulinic Acid Guidance in Newly Diagnosed Glioblastoma: A Prospective Controlled Multicenter Clinical Trial.

PURPOSE: Prospective data suggested a superiority of intraoperative MRI (iMRI) over 5-aminolevulinic acid (5-ALA) for achieving complete resections of contrast enhancement in glioblastoma surgery. We investigated this hypothesis in a prospective clinical trial and correlated residual disease volumes with clinical outcome in newly diagnosed glioblastoma. METHODS: This is a prospective controlled multicenter parallel-group trial with two center-specific treatment arms (5-ALA and iMRI) and blinded evaluation. The primary end point was complete resection of contrast enhancement on early postoperative MRI. We assessed resectability and extent of resection by an independent blinded centralized review of preoperative and postoperative MRI with 1-mm slices. Secondary end points included progression-free survival (PFS) and overall survival (OS), patient-reported quality of life, and clinical parameters. RESULTS: We recruited 314 patients with newly diagnosed glioblastomas at 11 German centers. A total of 127 patients in the 5-ALA and 150 in the iMRI arm were analyzed in the as-treated analysis. Complete resections, defined as a residual tumor ≤0.175 cm³, were achieved in 90 patients (78%) in the 5-ALA and 115 (81%) in the iMRI arm (P = .79). Incision-suture times (P < .001) were significantly longer in the iMRI arm (316 v 215 [5-ALA] minutes). Median PFS and OS were comparable in both arms. The lack of any residual contrast enhancing tumor (0 cm³) was a significant favorable prognostic factor for PFS (P < .001) and OS (P = .048), especially in methylguanine-DNA-methyltransferase unmethylated tumors (P = .006). CONCLUSION: We could not confirm superiority of iMRI over 5-ALA for achieving complete resections. Neurosurgical interventions in newly diagnosed glioblastoma shall aim for safe complete resections with 0 cm³ contrast-enhancing residual disease, as any other residual tumor volume is a negative predictor for PFS and OS.

Restoring musculocutaneous nerve function in 146 brachial plexus operations - A retrospective analysis.

INTRODUCTION: A brachial plexus lesion is a devastating injury often affecting young, male adults after traffic accidents. Therefore, surgical restoration of elbow flexion is critical for establishing antigravity movement of the upper extremity. We analyzed different methods for musculocutaneous reconstruction regarding outcome. METHODS: We conducted a retrospective analysis of 146 brachial plexus surgeries with musculocutaneous reconstruction performed at our department from 2013 to 2017. Demographic data, surgical method, donor and graft nerve characteristics, body mass index (BMI) as well as functional outcome of biceps muscle based on medical research council (MRC) strength grades before and after surgery were analyzed. Multivariate analysis was performed using SPSS. RESULTS: Oberlin reconstruction was the procedure performed most often (34.2%, n = 50). Nerve transfer and autologous repair showed no significant differences regarding outcome (p = 0.599, OR 0.644 CI95% 0.126-3.307). In case of nerve transfers, we found no significant difference whether reconstruction was performed with or without a nerve graft (e.g. sural nerve) (p = 0.277, OR 0.619 CI95% 0.261-1.469). Multivariate analysis identifies patient age as a strong predictor for outcome, univariate analysis indicates that nerve graft length > 15 cm and BMI of > 25 could lead to inferior outcome. When patients with early recovery (n = 19) are included into final evaluation after 24 months, the general success rate of reconstructions is 62,7% (52/83). CONCLUSION: Reconstruction of musculocutaneous nerve after brachial plexus injury results in a high rate of clinical improvement. Nerve transfer and autologous reconstruction both show similar results. Young age was confirmed as an independent predictor for better clinical outcome. Prospective multicenter studies are needed to further clarify.

Effectiveness and Safety of CT-Guided Facet Joint Cyst Rupture for Radicular Pain as First Choice Therapy: A Retrospective Analysis.

OBJECTIVE: To evaluate effectiveness and safety of computed tomography (CT)-guided cyst rupture with intraarticular contrast-enhanced injection of steroid and local anesthetic as first choice therapy in patients with facet joint cyst-induced radicular pain. DESIGN: Retrospective data set analysis. SETTING: University hospital. SUBJECTS: One hundred and twenty-one patients suffering from radicular pain attributable to facet joint cysts were included. METHODS: The rate of patients without following surgery was assessed and defined as surrogate to measure effectiveness. Patients' characteristics, procedure-associated complications, technical aspects, and imaging findings on magnetic resonance imaging (MRI) were analyzed. A subgroup of 65 patients (54%) underwent telephone interview to assess pain relief and clinical outcome measured by Numeric Rating Scale and Oswestry Disability Index. Analyses between the groups with and without surgery were performed by Fisher exact test and two-sample unpaired t-test, respectively. RESULTS: The effectiveness of CT-guided cyst rupture was found to be 66.1%. Procedure-induced pain yielded in premature abort in two cases (1.7%). The detection of epidural contrast agent was statistically significantly associated with no need for surgery (P = .010). The cyst level was associated with the status of following surgery (P = .026), that is, cysts at lower lumbar spine were easier to rupture than cysts at other locations (cervical, thoracic, or upper lumbar spine). No further significant association was found. CONCLUSIONS: CT-guided cyst rupture as the first-choice therapy in patients with cyst-induced radicular pain was safe and effective. Successful cyst rupture was associated with no need for surgery. Cysts at lower lumbar spine revealed the highest success rate.

Fight INflammation to Improve outcome after aneurysmal Subarachnoid HEmorRhage (FINISHER) trial: Study protocol for a randomized controlled trial.

RATIONALE: Aneurysmal subarachnoid hemorrhage (SAH) has high morbidity and mortality. While the primary injury results from the initial bleeding cannot currently be influenced, secondary injury through vasospasm and delayed cerebral ischemia worsens outcome and might be a target for interventions to improve outcome. To date, beside the aneurysm treatment to prevent re-bleeding and the administration of oral nimodipine, there is no therapy available, so novel treatment concepts are needed. Evidence suggests that inflammation contributes to delayed cerebral ischemia and poor outcome in SAH. Some studies suggest a beneficial effect of anti-inflammatory glucocorticoids, but there are no data from randomized controlled trials examining the efficacy of glucocorticoids. Therefore, current guidelines do not recommend the use of glucocorticoids in SAH. AIM: The Fight INflammation to Improve outcome after aneurysmal Subarachnoid HEmorRhage (FINISHER) trial aims to determine whether dexamethasone improves outcome in a clinically relevant endpoint in SAH patients. METHODS AND DESIGN: FINISHER is a multicenter, prospective, randomized, double-blinded, placebo-controlled clinical phase III trial which is testing the outcome and safety of anti-inflammatory treatment with dexamethasone in SAH patients. SAMPLE SIZE ESTIMATES: In all, 334 patients will be randomized to either dexamethasone or placebo within 48 h after SAH. The dexamethasone dose is 8 mg tds for days 1-7 and then 8 mg od for days 8-21. STUDY OUTCOME: The primary outcome is the modified Rankin Scale (mRS) at 6 months, which is dichotomized to favorable (mRS 0-3) versus unfavorable (mRS 4-6). DISCUSSION: The results of this study will provide the first phase III evidence as to whether dexamethasone improves outcome in SAH.

PrImary decompressive Craniectomy in AneurySmal Subarachnoid hemOrrhage (PICASSO) trial: study protocol for a randomized controlled trial.

BACKGROUND: Poor-grade aneurysmal subarachnoid hemorrhage (SAH) is associated with poor neurological outcome and high mortality. A major factor influencing morbidity and mortality is brain swelling in the acute phase. Decompressive craniectomy (DC) is currently used as an option in order to reduce intractably elevated intracranial pressure (ICP). However, execution and optimal timing of DC remain unclear. METHODS: PICASSO resembles a multicentric, prospective, 1:1 randomized standard treatment-controlled trial which analyzes whether primary DC (pDC) performed within 24 h combined with the best medical treatment in patients with poor-grade SAH reduces mortality and severe disability in comparison to best medical treatment alone and secondary craniectomy as ultima ratio therapy for elevated ICP. Consecutive patients presenting with poor-grade SAH, defined as grade 4-5 according to the World Federation of Neurosurgical Societies (WFNS), will be screened for eligibility. Two hundred sixteen patients will be randomized to receive either pDC additional to best medical treatment or best medical treatment alone. The primary outcome is the clinical outcome according to the modified Rankin Scale (mRS) at 12 months, which is dichotomized to favorable (mRS 0-4) and unfavorable (mRS 5-6). Secondary outcomes include morbidity and mortality, time to death, length of intensive care unit (ICU) stay and hospital stay, quality of life, rate of secondary DC due to intractably elevated ICP, effect of size of DC on outcome, use of duraplasty, and complications of DC. DISCUSSION: This multicenter trial aims to generate the first confirmatory data in a controlled randomized fashion that pDC improves the outcome in a clinically relevant endpoint in poor-grade SAH patients. TRIAL REGISTRATION: DRKS DRKS00017650. Registered on 09 June 2019.

Resilience in Lower Grade Glioma Patients.

Current data show that resilience is an important factor in cancer patients' well-being. We aim to explore the resilience of patients with lower grade glioma (LGG) and the potentially influencing factors. We performed a cross-sectional assessment of adult patients with LGG who were enrolled in the LoG-Glio registry. By phone interview, we administered the following measures: Resilience Scale (RS-13), distress thermometer, Montreal Cognitive Assessment Test for visually impaired patients (MoCA-Blind), internalized stigmatization by brain tumor (ISBI), Eastern Cooperative Oncological Group performance status (ECOG), patients' perspective questionnaire (PPQ) and typical clinical parameters. We calculated correlations and multivariate regression models. Of 74 patients who were assessed, 38% of those showed a low level of resilience. Our results revealed significant correlations of resilience with distress (p < 0.001, −0.49), MOCA (p = 0.003, 0.342), ECOG (p < 0.001, −0.602), stigmatization (p < 0.001, −0.558), pain (p < 0.001, −0.524), and occupation (p = 0.007, 0.329). In multivariate analyses, resilience was negatively associated with elevated ECOG (p = 0.020, ß = −0.383) and stigmatization levels (p = 0.008, ß = −0.350). Occupation showed a tendency towards a significant association with resilience (p = 0.088, ß = −0.254). Overall, low resilience affected more than one third of our cohort. Low functional status is a specific risk factor for low resilience. The relevant influence of stigmatization on resilience is a novel finding for patients suffering from a glioma and should be routinely identified and targeted in clinical routine.

Evaluation of a Navigated 3D Ultrasound Integration for Brain Tumor Surgery: First Results of an Ongoing Prospective Study.

The aim of the study was to assess the quality, accuracy and benefit of navigated 2D and 3D ultrasound for intra-axial tumor surgery in a prospective study. Patients intended for gross total resection were consecutively enrolled. Intraoperatively, a 2D and 3D iUS-based resection was performed. During surgery, the image quality, clinical benefit and navigation accuracy were recorded based on a standardized protocol using Likert's scales. A total of 16 consecutive patients were included. Mean ratings of image quality in 2D iUS were significantly higher than in 3D iUS (p < 0.001). There was no relevant decrease in rating during the surgery in 2D and 3D iUS (p > 0.46). The benefit was rated 2.2 in 2D iUS and 2.6 in 3D iUS (p = 0.08). The benefit remained stable in 2D, while there was a slight decrease in the benefit in 3D after complete tumor resection (p = 0.09). The accuracy was similar in both (mean 2.2 p = 0.88). Seven patients had a small tumor remnant in intraoperative MRT (mean 0.98 cm3) that was not appreciated with iUS. Crucially, 3D iUS allows for an accurate intraoperative update of imaging with slightly lower image quality than 2D iUS. Our preliminary data suggest that the benefit and accuracy of 2D and 3D iUS navigation do not undergo significant variations during tumor resection.

Machine Learning Models for Classifying High- and Low-Grade Gliomas: A Systematic Review and Quality of Reporting Analysis.

Objectives: To systematically review, assess the reporting quality of, and discuss improvement opportunities for studies describing machine learning (ML) models for glioma grade prediction. Methods: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy (PRISMA-DTA) statement. A systematic search was performed in September 2020, and repeated in January 2021, on four databases: Embase, Medline, CENTRAL, and Web of Science Core Collection. Publications were screened in Covidence, and reporting quality was measured against the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) Statement. Descriptive statistics were calculated using GraphPad Prism 9. Results: The search identified 11,727 candidate articles with 1,135 articles undergoing full text review and 85 included in analysis. 67 (79%) articles were published between 2018-2021. The mean prediction accuracy of the best performing model in each study was 0.89 ± 0.09. The most common algorithm for conventional machine learning studies was Support Vector Machine (mean accuracy: 0.90 ± 0.07) and for deep learning studies was Convolutional Neural Network (mean accuracy: 0.91 ± 0.10). Only one study used both a large training dataset (n>200) and external validation (accuracy: 0.72) for their model. The mean adherence rate to TRIPOD was 44.5% ± 11.1%, with poor reporting adherence for model performance (0%), abstracts (0%), and titles (0%). Conclusions: The application of ML to glioma grade prediction has grown substantially, with ML model studies reporting high predictive accuracies but lacking essential metrics and characteristics for assessing model performance. Several domains, including generalizability and reproducibility, warrant further attention to enable translation into clinical practice. Systematic Review Registration: PROSPERO, identifier CRD42020209938.

Eloquent Lower Grade Gliomas, a Highly Vulnerable Cohort: Assessment of Patients' Functional Outcome After Surgery Based on the LoG-Glio Registry.

Majority of lower grade glioma (LGG) are located eloquently rendering surgical resection challenging. Aim of our study was to assess rate of permanent deficits and its predisposing risk factors. We retrieved 83 patients harboring an eloquently located LGGs from the prospective LoG-Glio Database. Patients without surgery or incomplete postoperative data were excluded. Sign rank test, explorative correlations by Spearman ρ and multivariable regression for new postoperative deficits were calculated. Eloquent region involved predominantly motor (45%) and language (40%). At first follow up after 3 months permanent neuro-logical deficits (NDs) were noted in 39%. Mild deficits remained in 29% and severe deficits in 10%. Complete tumor removal (CTR) was successfully in 62% of intended cases. Postoperative and 3-month follow up National Institute of Health Stroke Score (NIHSS) showed significantly lower values than preoperatively (p<0.001). 38% cases showed a decreased NIHSS at 3-month, while occurrence was only 14% at 9-12-month follow up. 6/7 patients with mild aphasia recovered after 9-12 months, while motor deficits present at 3-month follow up were persistent in majority of patients. Eastern oncology group functional status (ECOG) significantly decreased by surgery (p < 0.001) in 31% of cases. Between 3-month and 9-12-months follow up no significant improvement was seen. In the multivariable model CTR (p=0.019, OR 31.9), and ECOG>0 (p=0.021, OR 8.5) were independent predictors for permanent postoperative deficit according to NIHSS at 3-month according to multivariable regression model. Patients harboring eloquently located LGG are highly vulnerable for permanent deficits. Almost one third of patients have a permanent reduction of their functional status based on ECOG. Risk of an extended resection has to be balanced with the respective oncological benefit. Especially, patients with impaired pre-operative status are at risk for new permanent deficits. There is a relevant improvement of neurological symptoms in the first year after surgery, especially for patients with slight aphasia.

The Value of APTw CEST MRI in Routine Clinical Assessment of Human Brain Tumor Patients at 3T.

BACKGROUND: With fast-growing evidence in literature for clinical applications of chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI), this prospective study aimed at applying amide proton transfer-weighted (APTw) CEST imaging in a clinical setting to assess its diagnostic potential in differentiation of intracranial tumors at 3 tesla (T). METHODS: Using the asymmetry magnetization transfer ratio (MTRasym) analysis, CEST signals were quantitatively investigated in the tumor areas and in a similar sized region of the normal-appearing white matter (NAWM) on the contralateral hemisphere of 27 patients with intracranial tumors. Area under curve (AUC) analyses were used and results were compared to perfusion-weighted imaging (PWI). RESULTS: Using APTw CEST, contrast-enhancing tumor areas showed significantly higher APTw CEST metrics than contralateral NAWM (AUC = 0.82; p < 0.01). In subgroup analyses of each tumor entity vs. NAWM, statistically significant effects were yielded for glioblastomas (AUC = 0.96; p < 0.01) and for meningiomas (AUC = 1.0; p < 0.01) but not for lymphomas as well as metastases (p > 0.05). PWI showed results comparable to APTw CEST in glioblastoma (p < 0.01). CONCLUSIONS: This prospective study confirmed the high diagnostic potential of APTw CEST imaging in a routine clinical setting to differentiate brain tumors.

The Benefit of Intraoperative Magnetic Resonance Imaging in Endoscopic and Microscopic Transsphenoidal Resection of Recurrent Pituitary Adenomas.

The surgical treatment of recurrent adenomas can be challenging. Intraoperative magnetic resonance imaging (iMRI) can improve the orientation and increase the safe extent of resection. We conducted a quantitative and qualitative retrospective analysis of recurrent adenomas treated by endoscopic or microscopic iMRI-assisted transsphenoidal surgery. A total number of 59 resections were selected. Detailed volumetric measurements, tumor characteristics, and MRI features of intraoperative remnants were evaluated. Intraoperative MRI increased the gross total resection (GTR) rate from 33.9% to 49.2%. Common locations of tumor remnants after iMRI were the clivus, the wall of the cavernous sinus or the perforation of the diaphragm. Increasing tumor volume and the microscopic technique were significantly associated with further resection after iMRI in the univariate analysis (p = 0.004, OR 1.6; p = 0.009, OR 4.4). Only the increasing tumor volume was an independent predictor for further resection (p = 0.007, OR 1.5). A significantly higher proportion of GTRs was achieved with the endoscopic technique (p = 0.001). Patients with a large recurrent pituitary adenoma who underwent microscopic transsphenoidal resection were the most likely to benefit from iMRI regarding the extent of resection. Occult invasions of the cavernous sinus and/or the clivus were the most common findings leading to further resection of tumor remnants after iMRI.

Perineurioma: A Rare Entity of Peripheral Nerve Sheath Tumors.

OBJECTIVE: Intraneural perineurioma is a rare tumor entity. It is a benign, very slow growing peripheral nerve sheath tumor that typically occurs in children and young adults. Motor deficits and muscle atrophy are classic presenting symptoms, while sensory deficits are rare at the onset of the disease. Recommended treatment strategies are lacking. We have evaluated the clinical follow-up and our experience with treatment of this rare entity. METHODS: A total of 30 patients with intraneural perineuriomas were assessed retrospectively. Demographic data, clinical symptoms, diagnostic examinations, therapy strategies, and clinical outcome were analyzed. Descriptive statistical methods were used for evaluation. RESULTS: The mean age was 22 years. Eleven women and 19 men were affected. The lesion occurred in the area of the upper extremity in 16 patients and in the area of the lower extremity in 14 patients. The most frequently affected nerve was the sciatic nerve, followed by the radial nerve. All patients showed a motor deficit to some extent. Seventy percent (n = 21) revealed atrophy, 43.3% (n = 13) had sensitive deficits, and 17% (n = 5) suffered of pain. Fascicle biopsies were performed in 26 patients (87%). In four patients (13%), the tumor was completely resected and then reconstructed via nerve grafts. Seventy percent of the patients (n = 21) received a magnetic resonance imaging (MRI) within 5 years postoperatively, in which no progress was shown. CONCLUSIONS: To diagnose perineurioma, it is essential to take a biopsy of an enlarged, nonfunctional fascicle. Furthermore, a long-distance epineuriotomy to decompress the hypertrophic fascicle is reasonable. To preserve the nerves' residual function, a complete resection is not recommended. Results after grafting are poor. One reason for this might be residual tumor cells along the nerve that cannot be visualized. Malignant transformation is not yet reported and tumor growth is stable for years.