Publications by authors named "Luca Regli"

261 Publications

Leptomeningeal collateral activation indicates severely impaired cerebrovascular reserve capacity in patients with symptomatic unilateral carotid artery occlusion.

J Cereb Blood Flow Metab 2021 Jun 10:271678X211024373. Epub 2021 Jun 10.

Department of Neurosurgery, University Hospital Zurich, University of Zurich, Zurich, Switzerland.

For patients with symptomatic unilateral internal carotid artery (ICA) occlusion, impaired cerebrovascular reactivity (CVR) indicates increased stroke risk. Here, the role of collateral activation remains a matter of debate, whereas angio-anatomical collateral abundancy does not necessarily imply sufficient compensatory flow provided. We aimed to further elucidate the role of collateral activation in the presence of impaired CVR. From a prospective database, 62 patients with symptomatic unilateral ICA occlusion underwent blood oxygenation-level dependent (BOLD) fMRI CVR imaging and a transcranial Doppler (TCD) investigation for primary and secondary collateral activation. Descriptive statistic and multivariate analysis were used to evaluate the relationship between BOLD-CVR values and collateral activation. Patients with activated secondary collaterals exhibited more impaired BOLD-CVR values of the ipsilateral hemisphere (p = 0.02). Specifically, activation of leptomeningeal collaterals showed severely impaired ipsilateral hemisphere BOLD-CVR values when compared to activation of ophthalmic collaterals (0.05 ± 0.09 vs. 0.12 ± 0.04, p = 0.005). Moreover, the prediction analysis showed leptomeningeal collateral activation as a strong independent predictor for ipsilateral hemispheric BOLD-CVR. In our study, ipsilateral leptomeningeal collateral activation is the sole collateral pathway associated with severely impaired BOLD-CVR in patients with symptomatic unilateral ICA occlusion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/0271678X211024373DOI Listing
June 2021

Cerebrospinal fluid hemoglobin drives subarachnoid hemorrhage-related secondary brain injury.

J Cereb Blood Flow Metab 2021 Jun 8:271678X211020629. Epub 2021 Jun 8.

Division of Internal Medicine, Universitätsspital and University of Zurich; Zurich, Switzerland.

Secondary brain injury after aneurysmal subarachnoid hemorrhage (SAH-SBI) contributes to poor outcomes in patients after rupture of an intracranial aneurysm. The lack of diagnostic biomarkers and novel drug targets represent an unmet need. The aim of this study was to investigate the clinical and pathophysiological association between cerebrospinal fluid hemoglobin (CSF-Hb) and SAH-SBI. In a cohort of 47 patients, we collected daily CSF-samples within 14 days after aneurysm rupture. There was very strong evidence for a positive association between spectrophotometrically determined CSF-Hb and SAH-SBI. The accuracy of CSF-Hb to monitor for SAH-SBI markedly exceeded that of established methods (AUC: 0.89 [0.85-0.92]). Temporal proteome analysis revealed erythrolysis accompanied by an adaptive macrophage response as the two dominant biological processes in the CSF-space after aneurysm rupture. Ex-vivo experiments on the vasoconstrictive and oxidative potential of Hb revealed critical inflection points overlapping CSF-Hb thresholds in patients with SAH-SBI. Selective depletion and in-solution neutralization by haptoglobin or hemopexin efficiently attenuated the vasoconstrictive and lipid peroxidation activities of CSF-Hb. Collectively, the clinical association between high CSF-Hb levels and SAH-SBI, the underlying pathophysiological rationale, and the favorable effects of haptoglobin and hemopexin in ex-vivo experiments position CSF-Hb as a highly attractive biomarker and potential drug target.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/0271678X211020629DOI Listing
June 2021

Mapping Cerebrovascular Reactivity Impairment in Patients With Symptomatic Unilateral Carotid Artery Disease.

J Am Heart Assoc 2021 Jun 9;10(12):e020792. Epub 2021 Jun 9.

Department of Neurosurgery University Hospital ZurichUniversity of Zurich Switzerland.

Background Comprehensive hemodynamic impairment mapping using blood oxygenation-level dependent (BOLD) cerebrovascular reactivity (CVR) can be used to identify hemodynamically relevant symptomatic unilateral carotid artery disease. Methods and Results This prospective cohort study was conducted between February 2015 and July 2020 at the Clinical Neuroscience Center of the University Hospital Zurich, Zurich, Switzerland. One hundred two patients with newly diagnosed symptomatic unilateral internal carotid artery (ICA) occlusion or with 70% to 99% ICA stenosis were included. An age-matched healthy cohort of 12 subjects underwent an identical BOLD functional magnetic resonance imaging examination. Using BOLD functional magnetic resonance imaging with a standardized CO stimulus, CVR impairment was evaluated. Moreover, embolic versus hemodynamic ischemic patterns were evaluated on diffusion-weighted imaging. Sixty-seven patients had unilateral ICA occlusion and 35 patients unilateral 70% to 99% ICA stenosis. Patients with ICA occlusion exhibited lower whole-brain and ipsilateral hemisphere mean BOLD-CVR values as compared with healthy subjects (0.12±0.08 versus 0.19±0.04, =0.004 and 0.09±0.09 versus 0.18±0.04, <0.001) and ICA stenosis cohort (0.12±0.08 versus 0.16±0.05, =0.01 and 0.09±0.09 versus 0.15±0.05, =0.01); however, only 40 (58%) patients of the cohort showed significant BOLD-CVR impairment. Conversely, there was no difference in mean BOLD-CVR values between healthy patients and patients with ICA stenosis, although 5 (14%) patients with ICA stenosis showed a significant BOLD-CVR impairment. No significant BOLD-CVR difference was discernible between patients with hemodynamic ischemic infarcts versus those with embolic infarct distribution (0.11±0.08 versus 0.13±0.06, =0.12). Conclusions Comprehensive BOLD-CVR mapping allows for identification of hemodynamically relevant symptomatic unilateral carotid artery stenosis or occlusion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/JAHA.121.020792DOI Listing
June 2021

Hypermetabolism and impaired cerebrovascular reactivity beyond the standard MRI-identified tumor border indicate diffuse glioma extended tissue infiltration.

Neurooncol Adv 2021 Jan-Dec;3(1):vdab048. Epub 2021 Mar 30.

Department of Neurosurgery, University Hospital Zurich, University of Zurich, Zurich, Switzerland.

Background: Diffuse gliomas exhibit diffuse infiltrative growth, often beyond the magnetic resonance imaging (MRI)-detectable tumor lesion. Within this lesion, hypermetabolism and impaired cerebrovascular reactivity (CVR) are found, but its exact distribution pattern into the peritumoral environment is unknown. Our aim was to better characterize the extent of diffuse glioma tissue infiltration, beyond the visible lesion (ie, beyond the T1-contrast-enhancing lesion and/or T2/FLAIR-defined tumor border), with metabolic positron emission tomography (PET), and functional MRI CVR (blood oxygenation-level-dependent CVR [BOLD-CVR]) mapping.

Methods: From a prospective glioma database, 18 subjects (19 datasets) with diffuse glioma ( = 2 with anaplastic astrocytoma, = 10 with anaplastic oligodendroglioma, and = 7 with glioblastoma) underwent a BOLD-CVR and metabolic PET study between February 2016 and September 2019, 7 of them at primary diagnosis and 12 at tumor recurrence. In addition, 19 matched healthy controls underwent an identical BOLD-CVR study. The tumor lesion was defined using high-resolution anatomical MRI. Volumes of interest starting from the tumor lesion outward up to 30 mm were created for a detailed peritumoral PET and BOLD-CVR tissue analysis. Student's test was used for statistical analysis.

Results: Patients with diffuse glioma exhibit impaired BOLD-CVR 12 mm beyond the tumor lesion ( = .02) with normalization of BOLD-CVR values after 24 mm. Metabolic PET shows a difference between the affected and contralateral hemisphere of 6 mm ( = .05) with PET values normalization after 12 mm.

Conclusion: We demonstrate hypermetabolism and impaired CVR beyond the standard MRI-defined tumor border, suggesting active tumor infiltration in the peritumoral environment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/noajnl/vdab048DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8156976PMC
March 2021

Assessment of the Minimum Clinically Important Difference in the Smartphone-Based 6-Minute Walking Test after Surgery for Lumbar Degenerative Disc Disease.

Spine (Phila Pa 1976) 2021 Feb 15. Epub 2021 Feb 15.

aDepartment of Neurosurgery, Kantonsspital St. Gallen, St. Gallen, Switzerland bDepartment of Neurosurgery, University Hospital Zurich & Clinical Neuroscience Center, University of Zurich, Zurich, Switzerland.

Study Design: Prospective cohort study.

Objective: The aim of this study was to determine the minimum clinically important difference (MCID) of the 6-minute walking test (6WT) after surgery for lumbar degenerative disc disease (DDD).

Summary Of Background Data: The smartphone-based 6WT is a valid and reliable tool to quantify objective functional impairment in patients with lumbar DDD. To date, the MCID of the 6WT has not be described in patients with DDD.

Methods: We assessed patients pre- and 6-weeks postoperatively, analysing both raw 6-minute walking distances (6WD; in meters) and standardized 6WT z-scores. Three methods were applied to compute MCID values using established patient-reported outcomes measures (PROMs) as anchors (VAS back/leg pain, Zurich Claudication Questionnaire (ZCQ), Core Outcome Measures Index (COMI)): (1) average change, (2) minimum detectable change, and (3) the change difference approach.

Results: We studied 49 patients (59% male) with a mean age of 55.5 ± 15.8 years. The computation methods revealed MCID values ranging from 81m (z-score of 0.9) based on the VAS back pain to 99m (z-score of 1.0) based on the ZCQ physical function scale. The average MCID of the 6WT was 92m (z-score of 1.0). Based on the average MCID of raw 6WD values or standardized z-scores, 53% or 49% of patients classified as 6-week responders to surgery for lumbar DDD, respectively.

Conclusion: The MCID for the 6WT in lumbar DDD patients is variable, depending on the calculation technique. We propose a MCID of 92m (z-score of 1.0), based on the average of all three methods. Using a z-score as MCID allows for the standardization of clinically meaningful change and attenuates age- and sex-related differences.

Level Of Evidence: 3.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/BRS.0000000000003991DOI Listing
February 2021

External Validation of the Minimum Clinically Important Difference in the Timed-Up-and-Go (TUG) Test after Surgery for Lumbar Degenerative Disc Disease.

Spine (Phila Pa 1976) 2021 May 24. Epub 2021 May 24.

Department of Neurosurgery, University Hospital Zurich and Clinical Neuroscience Center, University of Zurich, Zurich, Switzerland Department of Neurosurgery, Cantonal Hospital St.Gallen, St.Gallen, Switzerland Neuro- and Spine Center, Hirslanden Clinic St. Anna, Lucerne, Switzerland.

Study Design: Prospective observational cohort study.

Objective: To provide external validation of the minimum clinically important difference (MCID) of the Timed-Up-and-Go (TUG) test.

Summary Of Background Data: The TUG test is one of the best explored and most frequently applied objective task-based functional outcome measure in patients with lumbar degenerative disc disease (DDD). The increased use of the TUG test is based on its solid psychometric properties, however, an external validation of the originally determined MCID is lacking.

Methods: N = 49 patients with lumbar DDD, scheduled for elective spine surgery, were assessed pre- and 6-weeks (W6) postoperative. MCID values were calculate for raw TUG test times (in s) and standardized TUG z-scores using three different computation methods and the following established patient-reported outcome measures (PROMs) as anchors: Visual Analog Scales (VAS), Core Outcome Measures Index (COMI) Back, Zurich Claudication Questionnaire (ZCQ)).

Results: The three computation methods generated a range of MCID values, depending on the PROM used as anchor, from 0.9 s (z-score of 0.3) based on the VAS leg pain to 3.0 s (z-score of 2.7) based on the ZCQ physical function scale. The average MCID of the TUG test across all anchors and computation methods was 2.1 s (z-score of 1.5). According to the average MCID of raw TUG test values or TUG z-scores, 41% and 43% of patients classified as W6 responders to surgery, respectively.

Conclusion: This study confirms the ordinally reported TUG MCID values in patients undergoing surgery for lumbar. A TUG test time change of 2.1 s (or TUG z-score change of 1.5) indicates an objective and clinically meaningful change in functional status. This report facilitates the interpretation of TUG test results in clinical routine as well as in research.Level of Evidence: 3.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/BRS.0000000000004128DOI Listing
May 2021

Responsiveness of the self-measured 6-minute walking test and the Timed Up and Go test in patients with degenerative lumbar disorders.

J Neurosurg Spine 2021 May 7. Epub 2021 May 7.

Department of Neurosurgery, University Hospital Zurich and Clinical Neuroscience Center, University of Zurich.

Objective: The 6-minute walking test (6WT) and the Timed Up and Go (TUG) test are two of the most commonly applied standardized measures of objective functional impairment that help support clinical decision-making for patients undergoing surgery for degenerative lumbar disorders. This study correlates smartphone-app-based 6WT and TUG results to evaluate their responsiveness.

Methods: In a prospective study, 49 consecutive patients were assessed preoperatively and 6 weeks postoperatively using the 6WT, the TUG test, and commonly used patient-reported outcome measures. Raw values and standardized z-scores of both objective tests were correlated. An external criterion for treatment success was created based on the Zurich Claudication Questionnaire patient satisfaction subscale. Internal and external responsiveness for both functional tests was evaluated.

Results: The mean preoperative 6WT results improved from 401 m (SD 129 m), z-score -1.65 (SD 1.6) to 495 m (SD 129 m), z-score -0.71 (SD 1.6, p < 0.001). The mean preoperative TUG test results improved from 10.44 seconds (SD 4.37, z-score: -3.22) to 8.47 seconds (SD 3.38, z-score: -1.93, p < 0.001). The 6WT showed a strong negative correlation with TUG test results (r = -66, 95% CI 0.76-0.53, p < 0.001). The 6WT showed higher internal responsiveness (standardized responsive mean = 0.86) compared to the TUG test (standardized responsive mean = 0.67). Evaluation of external responsiveness revealed that the 6WT was capable of differentiating between patients who were satisfied and those who were unsatisfied with their treatment results (area under the curve = 0.70), whereas this was not evident for the TUG test ( area under the curve = 0.53).

Conclusions: Both tests adequately quantified functional impairment in surgical candidates with degenerative lumbar disorders. The 6WT demonstrated better internal and external responsiveness compared with the TUG test. Clinical trial registration no.: NCT03977961 (clinicaltrials.gov).

Abbreviations: AUC = area under the curve; COMI = Core Outcome Measures Index; DLDs = degenerative lumbar disorders; LDH = lumbar disc herniation; LSS = lumbar spinal stenosis; PROM = patient-reported outcome measure; ROC = receiver operating characteristic; SRM = standardized responsive mean; TUG = Timed Up and Go; VAS = visual analog scale; 6WD = 6-minute walking distance; 6WT = 6-minute walking test; ZCQ = Zurich Claudication Questionnaire.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.11.SPINE201621DOI Listing
May 2021

Intraoperative BOLD-fMRI Cerebrovascular Reactivity Assessment.

Acta Neurochir Suppl 2021 ;132:139-143

Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland.

Blood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) has gained attention in recent years as an effective way to investigate CVR, a measure of the hemodynamic state of the brain, with high spatial and temporal resolution. An association between impaired CVR and diverse pathologies has been observed, especially in ischemic cerebrovascular diseases and brain gliomas. The ability to obtain this information intraoperatively is novel and has not been widely tested. We report our first experience with this intraoperative technique in vascular and oncologic neurosurgical patients, discuss the results of its feasibility, and the possible developments of the intraoperative employment of BOLD-CVR.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/978-3-030-63453-7_20DOI Listing
January 2021

When Is Diagnostic Subtraction Angiography Indicated Before Clipping of Unruptured and Ruptured Intracranial Aneurysms? An International Survey of Current Practice.

Acta Neurochir Suppl 2021 ;132:9-17

Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland.

Introduction: The goal of this survey is to investigate the indications for preoperative digital subtraction angiography (DSA) before clipping of ruptured and unruptured intracranial aneurysms in an international panel of neurovascular specialists.

Methods: An anonymous survey of 23 multiple-choice questions relating to indications for DSA before clipping of an intracranial aneurysm was distributed to the international panel of attendees of the European-Japanese Cerebrovascular Congress (EJCVC), which took place in Milan, Italy on 7-9 June 2018. The survey was collected during the same conference. Descriptive statistics were used to analyze the data.

Results: A total of 93 surveys were distributed, and 67 (72%) completed surveys were returned by responders from 13 different countries. Eighty-five percent of all responders were neurosurgeons. For unruptured and ruptured middle cerebral artery (MCA) aneurysms without life-threatening hematoma, approximately 60% of responders perform surgery without preoperative DSA. For aneurysms in other locations than MCA, microsurgery is done without preoperative DSA in 68% of unruptured and in 73% of ruptured cases. In cases of ruptured MCA or ruptured non-MCA aneurysms with life-threatening hematoma, surgery is performed without DSA in 97% and 96% of patients, respectively. Factors which lead to preoperative DSA being performed were: aneurysmal shape (fusiform, dissecting), etiology (infectious), size (>25 mm), possible presence of perforators or efferent vessels arising from the aneurysm, intra-aneurysmal thrombus, previous treatment, location (posterior circulation and paraclinoid aneurysm) and flow-replacement bypass contemplated for final aneurysm treatment. These are all factors that qualify an aneurysm as a complex aneurysm.

Conclusion: There is still a high variability in the surgeons' preoperative workup regarding the indication for DSA before clipping of ruptured and unruptured intracranial aneurysms, except for ruptured aneurysms with life-threatening hematoma. There is a general consensus among cerebrovascular specialists that any angioanatomical feature indicating a complex aneurysm should lead to a more detailed workup including preoperative DSA.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/978-3-030-63453-7_2DOI Listing
January 2021

Enhanced Recovery After Surgery strategies for elective craniotomy: a systematic review.

J Neurosurg 2021 May 7:1-25. Epub 2021 May 7.

1Machine Intelligence in Clinical Neuroscience (MICN) Laboratory, Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Switzerland.

Objective: Enhanced Recovery After Surgery (ERAS) has led to a paradigm shift in perioperative care through multimodal interventions. Still, ERAS remains a relatively new concept in neurosurgery, and there is no summary of evidence on ERAS applications in cranial neurosurgery.

Methods: The authors systematically reviewed the literature using the PubMed/MEDLINE, Embase, Scopus, and Cochrane Library databases for ERAS protocols and elements. Studies had to assess at least one pre-, peri-, or postoperative ERAS element and evaluate at least one of the following outcomes: 1) length of hospital stay, 2) length of ICU stay, 3) postoperative pain, 4) direct and indirect healthcare cost, 5) complication rate, 6) readmission rate, or 7) patient satisfaction.

Results: A final 27 articles were included in the qualitative analysis, with mixed quality of evidence ranging from high in 3 cases to very low in 1 case. Seventeen studies reported a complete ERAS protocol. Preoperative ERAS elements include patient selection through multidisciplinary team discussion, patient counseling and education to adjust expectations of the postoperative period, and mental state assessment; antimicrobial, steroidal, and antiepileptic prophylaxes; nutritional assessment, as well as preoperative oral carbohydrate loading; and postoperative nausea and vomiting (PONV) prophylaxis. Anesthesiology interventions included local anesthesia for pin sites, regional field block or scalp block, avoidance or minimization of the duration of invasive monitoring, and limitation of intraoperative mannitol. Other intraoperative elements include absorbable skin sutures and avoidance of wound drains. Postoperatively, the authors identified early extubation, observation in a step-down unit instead of routine ICU admission, early mobilization, early fluid de-escalation, early intake of solid food and liquids, early removal of invasive monitoring, professional nutritional assessment, PONV management, nonopioid rescue analgesia, and early postoperative imaging. Other postoperative interventions included discharge criteria standardization and home visits or progress monitoring by a nurse.

Conclusions: A wide range of evidence-based interventions are available to improve recovery after elective craniotomy, although there are few published ERAS protocols. Patient-centered optimization of neurosurgical care spanning the pre-, intra-, and postoperative periods is feasible and has already provided positive results in terms of improved outcomes such as postoperative pain, patient satisfaction, reduced length of stay, and cost reduction with an excellent safety profile. Although fast-track recovery protocols and ERAS studies are gaining momentum for elective craniotomy, prospective trials are needed to provide stronger evidence.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.10.JNS203160DOI Listing
May 2021

Topographic volume-standardization atlas of the human brain.

Brain Struct Funct 2021 Jul 7;226(6):1699-1711. Epub 2021 May 7.

Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland.

Specific anatomical patterns are seen in various diseases affecting the brain. Clinical studies on the topography of pathologies are often limited by the absence of a normalization of the prevalence of pathologies to the relative volume of the affected anatomical structures. A comprehensive reference on the relative volumes of clinically relevant anatomical structures serving for such a normalization, is currently lacking. The analyses are based on anatomical high-resolution three-dimensional T1-weighted magnetic resonance imaging data of 30 healthy Caucasian volunteers, including 14 females (mean age 37.79 years, SD 13.04) and 16 males (mean age 38.31 years, SD 16.91). Semi-automated anatomical segmentation was used, guided by a neuroanatomical parcellation algorithm differentiating 96 structures. Relative volumes were derived by normalizing parenchymal structures to the total individual encephalic volume and ventricular segments to the total individual ventricular volume. The present investigation provides the absolute and relative volumes of 96 anatomical parcellation units of the human encephalon. A larger absolute volume in males than in females is found for almost all parcellation units. While parenchymal structures display a trend towards decreasing volumes with increasing age, a significant inverse effect is seen with the ventricular system. The variances in volumes as well as the effects of gender and age are given for each structure before and after normalization. The provided atlas constitutes an anatomically detailed and comprehensive analysis of the absolute and relative volumes of the human encephalic structures using a clinically oriented parcellation algorithm. It is intended to serve as a reference for volume-standardization in clinical studies on the topographic prevalence of pathologies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00429-021-02280-1DOI Listing
July 2021

Impact of intraoperative magnetic resonance imaging on gross total resection, extent of resection, and residual tumor volume in pituitary surgery: systematic review and meta-analysis.

Pituitary 2021 May 4. Epub 2021 May 4.

Machine Intelligence in Clinical Neuroscience (MICN) Laboratory, Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland.

Background: Residual tumor tissue after pituitary adenoma surgery, is linked with additional morbidity and mortality. Intraoperative magnetic resonance imaging (ioMRI) could improve resection. We aim to assess the improvement in gross total resection (GTR), extent of resection (EOR), and residual tumor volume (RV) achieved using ioMRI.

Methods: A systematic review was carried out on PubMed/MEDLINE to identify any studies reporting intra- and postoperative (1) GTR, (2) EOR, or (3) RV in patients who underwent resection of pituitary adenomas with ioMRI. Random effects meta-analysis of the rate of improvement after ioMRI for these three surgical outcomes was intended.

Results: Among 34 included studies (2130 patients), the proportion of patients with conversion to GTR (∆GTR) after ioMRI was 0.19 (95% CI 0.15-0.23). Mean ∆EOR was + 9.07% after ioMRI. Mean ∆RV was 0.784 cm. For endoscopically treated patients, ∆GTR was 0.17 (95% CI 0.09-0.25), while microscopic ∆GTR was 0.19 (95% CI 0.15-0.23). Low-field ioMRI studies demonstrated a ∆GTR of 0.19 (95% CI 0.11-0.28), while high-field and ultra-high-field ioMRI demonstrated a ∆GTR of 0.19 (95% CI 0.15-0.24) and 0.20 (95% CI 0.13-0.28), respectively.

Conclusions: Our meta-analysis demonstrates that around one fifth of patients undergoing pituitary adenoma resection convert from non-GTR to GTR after the use of ioMRI. EOR and RV can also be improved to a certain extent using ioMRI. Endoscopic versus microscopic technique or field strength does not appear to alter the impact of ioMRI. Statistical heterogeneity was high, indicating that the improvement in surgical results due to ioMRI varies considerably by center.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11102-021-01147-2DOI Listing
May 2021

Patients with Moyamoya Vasculopathy Evaluated at a Single-Center in The Netherlands; Clinical Presentation and Outcome.

J Clin Med 2021 Apr 27;10(9). Epub 2021 Apr 27.

Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, G03.129, P.O. Box 85500, 3508 GA Utrecht, The Netherlands.

Information on presentation and outcome of moyamoya vasculopathy (MMV) in European countries is limited. We investigated patient characteristics, treatment and outcome of patients with MMV. We retrieved patient characteristics and treatment information and determined functional outcome (modified Rankin Score (mRS); type of school/work) by structured telephone interviews. We performed uni- and multivariable logistic regression analysis to determine predictors of poor outcome. We included 64 patients with bilateral MMV. In children (31 patients), median age was 5 years (interquartile range (IQR) 2-11) and in adults (33 patients), it was 33 years (IQR 28-41). Predominant mode of presentation was ischemia (children 84%; adults 88%). Modified Rankin Scale (mRS) at presentation was ≤2 in 74%. Revascularization was performed in 42 patients (23 children). Median follow-up time was 46 months (IQR 26-90). During this period, 16 patients had recurrent stroke(s) and four patients died. In 73% of the patients (83% surgical group; 55% medically treated group), mRS was ≤2; 46% were able to return to regular school or work, of whom only 41% were on the same level. Univariable analysis revealed that surgical treatment was associated with lower odds of poor outcome ((mRS ≥ 3), OR 0.24; = 0.017). This association was no longer statistically significant (OR 3.47; = 0.067) in the multivariable model, including age and diagnosis (moyamoya disease or moyamoya syndrome). In this cohort of patients with MMV who presented in a single European center, a large proportion had good functional outcome. Nevertheless, less than half were able to attend regular school or were able to work at their previous level, indicating a large impact of the disease on their life.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/jcm10091898DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8124614PMC
April 2021

Distinct Cerebrovascular Reactivity Patterns for Brain Radiation Necrosis.

Cancers (Basel) 2021 Apr 13;13(8). Epub 2021 Apr 13.

Department of Neurosurgery, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland.

Current imaging-based discrimination between radiation necrosis versus recurrent glioblastoma contrast-enhancing lesions remains imprecise but is paramount for prognostic and therapeutic evaluation. We examined whether patients with radiation necrosis exhibit distinct patterns of blood oxygenation-level dependent fMRI cerebrovascular reactivity (BOLD-CVR) as the first step to better distinguishing patients with radiation necrosis from recurrent glioblastoma compared with patients with newly diagnosed glioblastoma before surgery and radiotherapy. Eight consecutive patients with primary and secondary brain tumors and a multidisciplinary clinical and radiological diagnosis of radiation necrosis, and fourteen patients with a first diagnosis of glioblastoma underwent BOLD-CVR mapping. For all these patients, the contrast-enhancing lesion was derived from high-resolution T1-weighted MRI and rendered the volume-of-interest (VOI). From this primary VOI, additional 3 mm concentric expanding VOIs up to 30 mm were created for a detailed perilesional BOLD-CVR tissue analysis between the two groups. Receiver operating characteristic curves assessed the discriminative properties of BOLD-CVR for both groups. Mean intralesional BOLD-CVR values were markedly lower in radiation necrosis than in glioblastoma contrast-enhancing lesions (0.001 ± 0.06 vs. 0.057 ± 0.05; = 0.04). Perilesionally, a characteristic BOLD-CVR pattern was observed for radiation necrosis and glioblastoma patients, with an improvement of BOLD-CVR values in the radiation necrosis group and persisting lower perilesional BOLD-CVR values in glioblastoma patients. The ROC analysis discriminated against both groups when these two parameters were analyzed together (area under the curve: 0.85, 95% CI: 0.65-1.00). : In this preliminary analysis, distinctive intralesional and perilesional BOLD-cerebrovascular reactivity patterns are found for radiation necrosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cancers13081840DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8069508PMC
April 2021

[Acute Traumatic Central Cord Syndrome: Etiology, Pathophysiology, Clinical Manifestation, and Treatment].

Praxis (Bern 1994) 2021 Apr;110(6):324-335

Klinik für Neurochirurgie, Kantonsspital St. Gallen, St. Gallen.

Acute Traumatic Central Cord Syndrome: Etiology, Pathophysiology, Clinical Manifestation, and Treatment The acute traumatic central cord syndrome (ATCCS) represents an injury to the spinal cord with disproportionately greater motor impairment of the upper than the lower extremities, with bladder dysfunction and with varying degrees of sensory loss below the level of the respective lesion. The mechanism of ATCCS is most commonly a traumatic hyperextension injury of the cervical spine at the base of an underlying spondylosis and spinal stenosis. The mean age is 53 years, and segments C4 to Th1 are most frequently affected. In addition to medical history and clinical examination, the definitive diagnosis is made by magnetic resonance imaging, where T2-hyperintense lesions are typically observed in the affected spinal cord segment. Surgical decompression (and fusion) of the respective segment is recommended to prevent repetitive trauma to the spinal cord and to stop progression of clinical symptoms. Patients with diagnosed ATCCS and who are treated adequately usually have a good prognosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1024/1661-8157/a003659DOI Listing
April 2021

Improving intraoperative evoked potentials at short latency by a novel neuro-stimulation technology with delayed return discharge.

Clin Neurophysiol 2021 Jun 7;132(6):1195-1199. Epub 2021 Apr 7.

Department of Neurosurgery, University Hospital Zurich, University of Zurich, Switzerland; Klinisches Neurowissenschaften Zentrum, Universität Zürich, Switzerland.

Objective: The intraoperative monitoring of cranial nerve function records evoked responses at latencies of a few milliseconds. Unfortunately, these responses may be masked by the electrical artifact of the stimulation pulse. In electrical stimulation, the return discharge of the stimulation pulse significantly contributes to the width of the electrical artifact.

Methods: We have generated stimulation pulses with an ISIS Neurostimulator (inomed Medizintechnik GmbH) providing a novel stimulation artifact reduction technique. It delays the return discharge of the stimulating pulse beyond the latency of the expected physiological response. This delayed return discharge is controlled such that no unintended physiological response is evoked.

Results: In 21 neurosurgical interventions with motor evoked potentials of the facial nerve (FNMEP), the stimulation method generated a stimulation pulse artifact with reduced tail duration. Compared to conventional stimulation with immediate return discharge, the signal-to-noise ratio of the physiological response may improve with the novel stimulation method. In some surgeries, only the novel stimulation method generated clearly identifiable response signals.

Conclusions: The reduced width of the stimulation artifact extends the toolbox of intraoperative monitoring modalities by rendering the interpretation of cranial nerve evoked potentials more reliable.

Significance: The novel technique enhances the number of patients for whom intraoperative monitoring may aid in cranial neurosurgery.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.clinph.2021.02.396DOI Listing
June 2021

Adverse Events in Neurosurgery: The Novel Therapy-Disability-Neurology Grade.

Neurosurgery 2021 Apr 22. Epub 2021 Apr 22.

Department of Neurosurgery and Clinical Neuroscience Center, University Hospital and University of Zurich, Zurich, Switzerland.

Background: The most widely used classifications of adverse events (AEs) in neurosurgery define their severity according to the therapy used to treat them. This concept has substantial shortcomings because it does not reflect the severity of AEs that are not treated, such as new neurological deficits.

Objective: To present a novel multidimensional and patient-centered classification of the severity of AE in neurosurgery and evaluate its applicability.

Methods: The Therapy-Disability-Neurology (TDN) grading system classifies AEs depending on the associated therapy, disability, and neurological deficits. We conducted a 2-center retrospective observational study on 6071 interventions covering the whole neurosurgical spectrum with data prospectively recorded between 2013 and 2019 at 2 institutions from 2 countries.

Results: Using the first patient cohort (4680 interventions), a positive correlation was found between severity of AE and LOS as well as treatment cost. Each grade was associated with a greater deterioration of the Karnofsky Performance Status Scale (KPS) at discharge and at follow-up. When using the same methods on the external validation cohort (1391 interventions), correlations between the grades of AE, LOS, and KPS at discharge were even more pronounced.

Conclusion: Our results suggest that the TDN grade is consistent with clinical and economic repercussions of AE and thus reflects AE severity. It is easily interpreted and enables comparison between different medical centers. The standardized report of the severity of AE in the scientific literature could constitute an important step forward toward a more critical, patient-centered, and evidence-based decision-making in neurosurgery.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/neuros/nyab121DOI Listing
April 2021

Surgical revascularization of frontal areas in pediatric Moyamoya vasculopathy: a systematic review.

J Neurosurg Sci 2021 Apr 16. Epub 2021 Apr 16.

Department of Neurosurgery, University Hospital Zurich, Clinical Neuroscience Centre, Zurich, Switzerland -

Objective: To systematically review the literature on surgical revascularization techniques for flow-augmentation of the frontal areas and/or anterior cerebral artery (ACA) territory in children with Moyamoya vasculopathy (MMV), to elucidate the current surgical practice and describe the outcome associated to the different techniques.

Evidence Acquisition: The systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. MEDLINE, Web of Science and EMBASE were searched up to April 2020. Published techniques were systematically analyzed according to level of evidence, revascularization technique, opening of the interhemispheric fissure (IF), uni- or bilateral revascularization, clinical, neurocognitive, angiographic, perfusion and hemodynamic outcome.

Evidence Synthesis: Twenty-five studies were enrolled, including 829 patients: among these, 13 patients underwent direct revascularization of ACA territories, 570 indirect revascularization and 246 patients combined revascularization. One study reached a level of evidence II (grade of recommendation B), 8 studies were level III (grade B) and 16 studies were level IV (grade C). The surgical techniques proposed in the enrolled papers were systematically described.

Conclusions: Combined techniques (grade of recommendation B) and indirect techniques (grade of recommendation C) are considered effective for revascularizing the frontal areas and/or anterior cerebral artery (ACA) territory in children with MMV. While performing the revascularization, surgical risks can be reduced by avoiding the exposure of the superior sagittal sinus and opening of IF (recommendation grade C). There is not sufficient evidence to define which type of surgical technique should be preferred. Future studies are needed for a longitudinal assessment of comparable outcomes and to determine which revascularization technique for the frontal areas and/or ACA territory is optimal for this highly specific pediatric population.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.23736/S0390-5616.20.05172-3DOI Listing
April 2021

HLA Ligand Atlas: a benign reference of HLA-presented peptides to improve T-cell-based cancer immunotherapy.

J Immunother Cancer 2021 Apr;9(4)

Clinical Neuroscience Center and Department of Neurosurgery, University Hospital and University of Zurich, Zurich, Switzerland.

Background: The human leucocyte antigen (HLA) complex controls adaptive immunity by presenting defined fractions of the intracellular and extracellular protein content to immune cells. Understanding the benign HLA ligand repertoire is a prerequisite to define safe T-cell-based immunotherapies against cancer. Due to the poor availability of benign tissues, if available, normal tissue adjacent to the tumor has been used as a benign surrogate when defining tumor-associated antigens. However, this comparison has proven to be insufficient and even resulted in lethal outcomes. In order to match the tumor immunopeptidome with an equivalent counterpart, we created the HLA Ligand Atlas, the first extensive collection of paired HLA-I and HLA-II immunopeptidomes from 227 benign human tissue samples. This dataset facilitates a balanced comparison between tumor and benign tissues on HLA ligand level.

Methods: Human tissue samples were obtained from 16 subjects at autopsy, five thymus samples and two ovary samples originating from living donors. HLA ligands were isolated via immunoaffinity purification and analyzed in over 1200 liquid chromatography mass spectrometry runs. Experimentally and computationally reproducible protocols were employed for data acquisition and processing.

Results: The initial release covers 51 HLA-I and 86 HLA-II allotypes presenting 90,428 HLA-I- and 142,625 HLA-II ligands. The HLA allotypes are representative for the world population. We observe that immunopeptidomes differ considerably between tissues and individuals on source protein and HLA-ligand level. Moreover, we discover 1407 HLA-I ligands from non-canonical genomic regions. Such peptides were previously described in tumors, peripheral blood mononuclear cells (PBMCs), healthy lung tissues and cell lines. In a case study in glioblastoma, we show that potential on-target off-tumor adverse events in immunotherapy can be avoided by comparing tumor immunopeptidomes to the provided multi-tissue reference.

Conclusion: Given that T-cell-based immunotherapies, such as CAR-T cells, affinity-enhanced T cell transfer, cancer vaccines and immune checkpoint inhibition, have significant side effects, the HLA Ligand Atlas is the first step toward defining tumor-associated targets with an improved safety profile. The resource provides insights into basic and applied immune-associated questions in the context of cancer immunotherapy, infection, transplantation, allergy and autoimmunity. It is publicly available and can be browsed in an easy-to-use web interface at .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/jitc-2020-002071DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8054196PMC
April 2021

Neurosurgery and neurointerventions for ischemic stroke.

J Neurosurg Sci 2021 Mar 11. Epub 2021 Mar 11.

Department of Neurosurgery, University Hospital Zurich, Clinical Neuroscience Centre, Zurich, Switzerland.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.23736/S0390-5616.21.05306-6DOI Listing
March 2021

Increased Ipsilateral Posterior Cerebral Artery P2-Segment Flow Velocity Predicts Hemodynamic Impairment.

Stroke 2021 Apr 9;52(4):1469-1472. Epub 2021 Mar 9.

Department of Neurosurgery (C.H.B.v.N., M.S., GE, M.H., A.H., L.R., J.F.), University Hospital Zurich, University of Zurich, Switzerland.

Background And Purpose: Increased Transcranial Doppler flow velocity in the ipsilateral P2-segment of the posterior cerebral artery (PCA-P2: cm/second) is associated with recurrent cerebrovascular events in patients with unilateral internal carotid artery occlusion. However, its predictive value and correlation with hemodynamic impairment in an overall stroke patient cohort remains to be determined.

Methods: Transcranial doppler PCA-P2 flow velocity was measured in 88 patients with symptomatic unilateral steno-occlusive disease who also underwent blood oxygenation-level dependent cerebrovascular reactivity imaging (blood oxygenation-level dependent [BOLD]-cerebrovascular reactivity [CVR]). A multivariate linear regression was used to evaluate the independent correlation between the ipsilateral PCA-P2 flow velocity measurements and hemispheric BOLD-CVR. Follow-up BOLD-CVR imaging data, available in 25 patients, were used to evaluate the temporal evolution of the BOLD-CVR and PCA-P2 flow velocity association using a mixed-effect model. Furthermore, a transcranial doppler cutoff for hemodynamic failure stage 2 was determined.

Results: The ipsilateral systolic PCA-P2 flow velocity strongly correlated with hemispheric BOLD-CVR (R=0.79; R=0.61), which remained unchanged when evaluating the follow-up data. Using a PCA-P2 systolic flow velocity cutoff value of 85 cm/second, patients with BOLD-CVR based hemodynamic failure stage 2 were diagnosed with an area under the curve of 95.

Conclusions: In patients with symptomatic unilateral steno-occlusive disease, increased ipsilateral transcranial doppler PCA-P2 systolic flow velocity independently correlates with BOLD-CVR based hemodynamic failure. A cutoff value of 85 cm/second appears to indicate hemodynamic failure stage 2, but this finding needs to be validated in an independent patient cohort.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/STROKEAHA.120.032848DOI Listing
April 2021

Telomerase reverse transcriptase promoter mutation- and O-methylguanine DNA methyltransferase promoter methylation-mediated sensitivity to temozolomide in isocitrate dehydrogenase-wild-type glioblastoma: is there a link?

Eur J Cancer 2021 Apr 22;147:84-94. Epub 2021 Feb 22.

Institute of Neuropathology, Heinrich Heine University, Medical Faculty, Düsseldorf, Germany; German Cancer Consortium, Partner Site Essen/Düsseldorf, German Cancer Research Center (DKFZ), Heidelberg, Germany. Electronic address:

Aim Of The Study: Benefit from temozolomide (TMZ) chemotherapy in the treatment of isocitrate dehydrogenase (IDH)-wild-type glioblastoma is essentially limited to patients with O-methylguanine DNA methyltransferase (MGMT) promoter-methylated tumours. Recent studies suggested that telomerase reverse transcriptase (TERT) promoter hotspot mutations may have an impact on the prognostic role of the MGMT status in patients with glioblastoma.

Methods: MGMT promoter methylation and TERT promoter mutation status were retrospectively assessed in a prospective cohort of patients with IDH-wild-type glioblastoma of the German Glioma Network (GGN) (n = 298) and an independent retrospective cohort from Düsseldorf, Germany, and Zurich, Switzerland (n = 302).

Results: In the GGN cohort, but not in the Düsseldorf/Zurich cohort, TERT promoter mutation was moderately associated with inferior outcomes in patients with MGMT promoter-unmethylated tumours (hazard ratio 1.74; 95% confidence interval: 1.07-2.82; p = 0.026). TERT promoter mutations were not associated with better outcomes in patients with MGMT promoter-methylated tumours in either cohort. The two different TERT promoter hotspot mutations (C228T and C250T) were not linked to distinct outcomes.

Conclusions: Analysis of two independent cohorts of patients with glioblastoma did not confirm previous data, suggesting that TERT promoter mutations confer an enhanced benefit from TMZ in patients with MGMT promoter-methylated glioblastoma. Thus, diagnostic testing for TERT promoter mutations may not be required for prediction of TMZ sensitivity in patients with IDH-wild-type glioblastoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejca.2021.01.014DOI Listing
April 2021

Blood-brain barrier alterations in human brain tumors revealed by genome-wide transcriptomic profiling.

Neuro Oncol 2021 Feb 9. Epub 2021 Feb 9.

Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zürich, Zürich University, Zürich, Switzerland.

Background: Brain tumors, whether primary or secondary, have limited therapeutic options despite advances in understanding driver gene mutations and heterogeneity within tumor cells. The cellular and molecular composition of brain tumor stroma, an important modifier of tumor growth, has been less investigated to date. Only few studies have focused on the vasculature of human brain tumors despite the fact that the blood-brain barrier (BBB) represents the major obstacle for efficient drug delivery.

Methods: In this study, we employed RNA sequencing to characterize transcriptional alterations of endothelial cells isolated from primary and secondary human brain tumors. We used an immunoprecipitation approach to enrich for endothelial cells from normal brain, glioblastoma (GBM) and lung cancer brain metastasis (BM).

Results: Analysis of the endothelial transcriptome showed deregulation of genes implicated in cell proliferation, angiogenesis and deposition of extracellular matrix (ECM) in the vasculature of GBM and BM. Deregulation of genes defining the BBB dysfunction module were found in both tumor types. We identified deregulated expression of genes in vessel-associated fibroblasts in GBM.

Conclusion: We characterize alterations in BBB genes in GBM and BM vasculature and identify proteins that might be exploited for developing drug delivery platforms. In addition, our analysis on vessel-associated fibroblasts in GBM shows that the cellular composition of brain tumor stroma merits further investigation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/neuonc/noab022DOI Listing
February 2021

Systematic review of brain arteriovenous malformation grading systems evaluating microsurgical treatment recommendation.

Neurosurg Rev 2021 Jan 27. Epub 2021 Jan 27.

Department of Neurosurgery, University Hospital Zurich, University of Zurich, Frauenklinikstrasse, 10, 8091, Zurich, Switzerland.

When evaluating brain arteriovenous malformations (bAVMs) for microsurgical resection, the natural history of bAVM rupture must be balanced against the perioperative risks. It is therefore adamant to have a reliable surgical grading system, balancing these important factors. This study systematically reviews the literature in order to identify and assess the quality of grading systems with regard to microsurgical bAVM treatment. A systematic literature review was performed to provide an overview of all available bAVM grading systems relevant for microsurgical treatment evaluation and to assess the most comprehensive grading system specifically for each subgroup of bAVM (i.e., unruptured, ruptured, and posterior fossa). Screening of 865 papers revealed thirteen grading systems for bAVM microsurgical risk stratification. Among them, two systems were specifically developed for ruptured bAVM and one specifically for posterior fossa bAVM. With one system being fundamentally different for supratentorial bAVM, the remaining nine systems used the same parameters: "size," "eloquence," "venous drainage," "arterial feeders," "age," "nidus compactness," and "hemorrhagic presentation". This study provides a comprehensive overview of all available bAVM grading systems relevant for surgical risk stratification. Furthermore, in the absence of a universal system appropriate to score all bAVMs, a workflow for selection of the best applicable scoring system in accordance with bAVM subgroups is presented.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10143-020-01464-3DOI Listing
January 2021

Traumatic Distal Anterior Cerebral Artery Aneurysms - Pathomechanism and Revascularisation Strategies.

J Stroke Cerebrovasc Dis 2021 Mar 2;30(3):105578. Epub 2021 Jan 2.

Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, Zurich, Switzerland; University of Zurich, Zurich, Switzerland;. Electronic address:

Traumatic intracranial aneurysms (TICA) of the distal anterior cerebral artery (dACA) are exceptionally rare and display therapeutic challenges due to their angioanatomical characteristics. The objective of this work was to discuss the mechanisms of TICA formation of the dACA and to elucidate the best treatment and revascularization strategies in these patients based on two illustrative cases. Case 1: 20-year-old patient with a traumatic, partially thrombosed 14 × 10 mm aneurysm of the right pericallosal artery (rPericA), distal to the origin of the right callosomarginal artery (rCMA). Complete trapping of the right dissection A3 aneurysm and flow replacement extra-to-intracranial (EC-IC) bypass (STA - radial artery - A4) was performed. Case 2: 16-year-old patient with a traumatic polylobulated, partially thrombosed 16 × 10 mm aneurysm of the rPericA. Microsurgical excision of the A3- segment harboring the aneurysm and flow replacement intra-to-intracranial (IC-IC) bypass via reimplantation of the right remaining PericA on the contralateral PericA (end-to-side anastomosis) was performed (in situ bypass). TICA of the dACA are exceptionally rare. Mechanical vessel wall injury and aneurysm formation of the dACA in blunt head trauma is very likely due to the proximity of the dACA with the rigid free edge of the falx. Given their nature as dissecting (complex) aneurysm, trapping and revascularization is a very important strategy. The interhemispheric cistern offers multiple revascularization options with its numerous donor vessels. The IC-IC bypass is often the simplest revascularization construct.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2020.105578DOI Listing
March 2021

Topographic brain tumor anatomy drives seizure risk and enables machine learning based prediction.

Neuroimage Clin 2020 19;28:102506. Epub 2020 Nov 19.

Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland; Division of Pediatric Neurosurgery, University Children's Hospital, Zurich, Switzerland.

Objective: The aim of this study was to identify relevant risk factors for epileptic seizures upon initial diagnosis of a brain tumor and to develop and validate a machine learning based prediction to allow for a tailored risk-based antiepileptic therapy.

Methods: Clinical, electrophysiological and high-resolution imaging data was obtained from a consecutive cohort of 1051 patients with newly diagnosed brain tumors. Factor-associated seizure risk difference allowed to determine the relevance of specific topographic, demographic and histopathologic variables available at the time of diagnosis for seizure risk. The data was divided in a 70/30 ratio into a training and test set. Different machine learning based predictive models were evaluated before a generalized additive model (GAM) was selected considering its traceability while maintaining high performance. Based on a clinical stratification of the risk factors, three different GAM were trained and internally validated.

Results: A total of 923 patients had full data and were included. Specific topographic anatomical patterns that drive seizure risk could be identified. The involvement of allopallial, mesopallial or primary motor/somatosensory neopallial structures by brain tumors results in a significant and clinically relevant increase in seizure risk. While topographic input was most relevant for the GAM, the best prediction was achieved by a combination of topographic, demographic and histopathologic information (Validation: AUC: 0.79, Accuracy: 0.72, Sensitivity: 0.81, Specificity: 0.66).

Conclusions: This study identifies specific phylogenetic anatomical patterns as epileptic drivers. A GAM allowed the prediction of seizure risk using topographic, demographic and histopathologic data achieving fair performance while maintaining transparency.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.nicl.2020.102506DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7711280PMC
November 2020

Patients undergoing surgery for lumbar degenerative spinal disorders favor smartphone-based objective self-assessment over paper-based patient-reported outcome measures.

Spine J 2021 Apr 17;21(4):610-617. Epub 2020 Dec 17.

Department of Neurosurgery, Kantonsspital St.Gallen, St. Gallen, Switzerland; Department of Neurosurgery, University Hospital Zurich & Clinical Neuroscience Center, University of Zurich, Zurich, Switzerland.

Background Context: Smartphone-based applications enable new prospects to monitor symptoms and assess functional outcome in patients with lumbar degenerative spinal disorders. However, little is known regarding patient acceptance and preference towards new modes of digital objective outcome assessment.

Purpose: To assess patient preference of an objective smartphone-based outcome measure compared to conventional paper-based subjective methods of outcome assessment.

Study Design: Prospective observational cohort study.

Patient Sample: Fourty-nine consecutive patients undergoing surgery for lumbar degenerative spinal disorder.

Outcome Measures: Patients completed a preference survey to assess different methods of outcome assessment. A 5-level Likert scale ranged from strong disagreement (2 points) over neutral (6 points) to strong agreement (10 points) was used.

Methods: Patients self-determined their objective functional impairment using the 6-minute Walking Test application (6WT-app) and completed a set of paper-based patient-reported outcome measures (PROMs) before and 6 weeks after surgery. Patients were then asked to rate the methods of outcome assessment in terms of suitability, convenience, and responsiveness to their symptoms.

Results: The majority of patients considered the 6WT-app a suitable instrument (median 8.0, interquartile range [IQR] 4.0). Patients found the 6WT more convenient (median 10.0, IQR 2.0) than the Zurich Claudication Questionnaire (ZCQ; median 8.0, IQR 4.0, p=.019) and Core Outcome Measure Index (COMI; median 8.0, IQR 4.0, p=.007). There was good agreement that the 6WT-app detects change in physical performance (8.0, IQR 4.0). 78 % of patients considered the 6WT superior in detecting differences in symptoms (vs. 22% for PROMs). Seventy-six percent of patients would select the 6WT over the other, 18% the ZCQ and 6% the COMI. Eighty-two percent of patients indicated their preference to use a smartphone app for the assessment and monitoring of their spine-related symptoms in the future.

Conclusions: Patients included in this study favored the smartphone-based evaluation of objective functional impairment over paper-based PROMs. Involving patients more actively by means of digital technology may increase patient compliance and satisfaction as well as diagnostic accuracy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.spinee.2020.11.013DOI Listing
April 2021

Flow-augmentation bypass in the treatment of acute ischemic stroke.

J Neurosurg Sci 2020 Dec 9. Epub 2020 Dec 9.

Department of Neurosurgery, University Hospital Zurich, Clinical Neuroscience Centre, Zurich, Switzerland -

Introduction: Results of 2 randomized trials did not show benefit of revascularization with extracranial-intracranial (EC-IC) flow augmentation bypass in patients with symptomatic occlusion of internal carotid artery (ICA). However, patients with acute stroke were not included in these studies. Herein, we systematically analyze and discuss the literature about flow augmentation bypass for treatment of acute ischemic stroke.

Evidence Acquisition: This systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. MEDLINE, Web of Science and EMBASE were independently searched by two reviewers for published series to identify literature relating to EC-IC bypass in the surgical management of acute ischemic stroke up to June 2020. Studies were categorized according to their level of evidence.

Evidence Synthesis: Nineteen studies met the inclusion criteria for the systematic literature review, including 16 level IV studies (10 case-series and 6 case reports) and 3 level III studies (retrospective cohort case-control studies). Occurrence of fatal or non-fatal ischemic or hemorrhagic postoperative stroke, as well as clinical functional outcome at follow-up were considered as primary and secondary endpoints, respectively.

Conclusions: The literature about flow augmentation bypass for treatment of acute ischemic stroke is scarce and heterogenous, with only 19 studies. The results of the present systematic review encourage further study to explore and validate the use of EC-IC bypass in the treatment of anterior circulation acute ischemic stroke in highly selected patients (symptomatic and with persistent penumbra despite best medical/endovascular treatment).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.23736/S0390-5616.20.05110-3DOI Listing
December 2020

Incidence and Outcome of Aneurysmal Subarachnoid Hemorrhage: The Swiss Study on Subarachnoid Hemorrhage (Swiss SOS).

Stroke 2021 01 4;52(1):344-347. Epub 2020 Dec 4.

Neuroradiology (L.R., M.D.), Kantonsspital Aarau Switzerland.

Background And Purpose: The purpose of this study was to assess nationwide incidence and outcomes of aneurysmal subarachnoid hemorrhage (aSAH). The Swiss SOS (Swiss Study on Subarachnoid Hemorrhage) was established in 2008 and offers the unique opportunity to provide this data from the point of care on a nationwide level.

Methods: All patients with confirmed aneurysmal subarachnoid hemorrhage admitted between January 1, 2009 and December 31, 2014, within Switzerland were recorded in a prospective registry. Incidence rates were calculated based on time-matched population data. Admission parameters and outcomes at discharge and at 1 year were recorded.

Results: We recorded data of 1787 consecutive patients. The incidence of aneurysmal subarachnoid hemorrhage in Switzerland was 3.7 per 100 000 persons/y. The number of female patients was 1170 (65.5%). With a follow-up rate of 91.3% at 1 year, 1042 patients (58.8%) led an independent life according to the modified Rankin Scale (0-2). About 1 in 10 patients survived in a dependent state (modified Rankin Scale, 3-5; n=185; 10.4%). Case fatality was 20.1% (n=356) at discharge and 22.1% (n=391) after 1 year.

Conclusions: The current incidence of aneurysmal subarachnoid hemorrhage in Switzerland is lower than expected and an indication of a global trend toward decreasing admissions for ruptured intracranial aneurysms. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03245866.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/STROKEAHA.120.029538DOI Listing
January 2021

Global adoption of robotic technology into neurosurgical practice and research.

Neurosurg Rev 2020 Nov 30. Epub 2020 Nov 30.

Machine Intelligence in Clinical Neuroscience (MICN) Lab, Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland.

Recent technological advancements have led to the development and implementation of robotic surgery in several specialties, including neurosurgery. Our aim was to carry out a worldwide survey among neurosurgeons to assess the adoption of and attitude toward robotic technology in the neurosurgical operating room and to identify factors associated with use of robotic technology. The online survey was made up of nine or ten compulsory questions and was distributed via the European Association of the Neurosurgical Societies (EANS) and the Congress of Neurological Surgeons (CNS) in February and March 2018. From a total of 7280 neurosurgeons who were sent the survey, we received 406 answers, corresponding to a response rate of 5.6%, mostly from Europe and North America. Overall, 197 neurosurgeons (48.5%) reported having used robotic technology in clinical practice. The highest rates of adoption of robotics were observed for Europe (54%) and North America (51%). Apart from geographical region, only age under 30, female gender, and absence of a non-academic setting were significantly associated with clinical use of robotics. The Mazor family (32%) and ROSA (26%) robots were most commonly reported among robot users. Our study provides a worldwide overview of neurosurgical adoption of robotic technology. Almost half of the surveyed neurosurgeons reported having clinical experience with at least one robotic system. Ongoing and future trials should aim to clarify superiority or non-inferiority of neurosurgical robotic applications and balance these potential benefits with considerations on acquisition and maintenance costs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10143-020-01445-6DOI Listing
November 2020