Automated volumetric assessment of pituitary adenoma.

PURPOSE: Assessment of pituitary adenoma (PA) volume and extent of resection (EOR) through manual segmentation is time-consuming and likely suffers from poor interrater agreement, especially postoperatively. Automated tumor segmentation and volumetry by use of deep learning techniques may provide more objective and quick volumetry. METHODS: We developed an automated volumetry pipeline for pituitary adenoma. Preoperative and three-month postoperative T1-weighted, contrast-enhanced magnetic resonance imaging (MRI) with manual segmentations were used for model training. After adequate preprocessing, an ensemble of convolutional neural networks (CNNs) was trained and validated for preoperative and postoperative automated segmentation of tumor tissue. Generalization was evaluated on a separate holdout set. RESULTS: In total, 193 image sets were used for training and 20 were held out for validation. At validation using the holdout set, our models (preoperative / postoperative) demonstrated a median Dice score of 0.71 (0.27) / 0 (0), a mean Jaccard score of 0.53 ± 0.21/0.030 ± 0.085 and a mean 95th percentile Hausdorff distance of 3.89 ± 1.96./12.199 ± 6.684. Pearson's correlation coefficient for volume correlation was 0.85 / 0.22 and -0.14 for extent of resection. Gross total resection was detected with a sensitivity of 66.67% and specificity of 36.36%. CONCLUSIONS: Our volumetry pipeline demonstrated its ability to accurately segment pituitary adenomas. This is highly valuable for lesion detection and evaluation of progression of pituitary incidentalomas. Postoperatively, however, objective and precise detection of residual tumor remains less successful. Larger datasets, more diverse data, and more elaborate modeling could potentially improve performance.

Mixed Reality for Cranial Neurosurgical Planning: A Single-Center Applicability Study With the First 107 Subsequent Holograms.

BACKGROUND AND OBJECTIVES: Mixed reality (MxR) benefits neurosurgery by improving anatomic visualization, surgical planning and training. We aim to validate the usability of a dedicated certified system for this purpose. METHODS: All cases prepared with MxR in our center in 2022 were prospectively collected. Holographic rendering was achieved using an incorporated fully automatic algorithm in the MxR application, combined with contrast-based semiautomatic rendering and/or manual segmentation where necessary. Hologram segmentation times were documented. Visualization during surgical preparation (defined as the interval between finalized anesthesiological induction and sterile draping) was performed using MxR glasses and direct streaming to a side screen. Surgical preparation times were compared with a matched historical cohort of 2021. Modifications of the surgical approach after 3-dimensional (3D) visualization were noted. Usability was assessed by evaluating 7 neurosurgeons with more than 3 months of experience with the system using a Usefulness, Satisfaction and Ease of use (USE) questionnaire. RESULTS: One hundred-seven neurosurgical cases prepared with a 3D hologram were collected. Surgical indications were oncologic (63/107, 59%), cerebrovascular (27/107, 25%), and carotid endarterectomy (17/107, 16%). Mean hologram segmentation time was 39.4 ± 20.4 minutes. Average surgical preparation time was 48.0 ± 17.3 minutes for MxR cases vs 52 ± 17 minutes in the matched 2021 cohort without MxR (mean difference 4, 95% CI 1.7527-9.7527). Based on the 3D hologram, the surgical approach was modified in 3 cases. Good usability was found by 57% of the users. CONCLUSION: The perioperative use of 3D holograms improved direct anatomic visualization while not significantly increasing intraoperative surgical preparation time. Usability of the system was adequate. Further technological development is necessary to improve the automatic algorithms and reduce the preparation time by circumventing manual and semiautomatic segmentation. Future studies should focus on quantifying the potential benefits in teaching, training, and the impact on surgical and functional outcomes.

Incidence, therapy, and outcome in the management of chronic subdural hematoma in Switzerland: a population-based multicenter cohort study.

Background: Chronic subdural hematoma (cSDH) is a disease affecting mainly elderly individuals. The reported incidence ranges from 2.0/100,000 to 58 per 100,000 person-years when only considering patients who are over 70 years old, with an overall incidence of 8.2-14.0 per 100,000 persons. Due to an estimated doubling of the population above 65 years old between 2000 and 2030, cSDH will become an even more significant concern. To gain an overview of cSDH hospital admission rates, treatment, and outcome, we performed this multicenter national cohort study of patients requiring surgical treatment of cSDH. Methods: A multicenter cohort study included patients treated in 2013 in a Swiss center accredited for residency. Demographics, medical history, symptoms, and medication were recorded. Imaging at admission was evaluated, and therapy was divided into burr hole craniostomy (BHC), twist drill craniostomy (TDC), and craniotomy. Patients' outcomes were dichotomized into good (mRS, 0-3) and poor (mRS, 4-6) outcomes. A two-sided t-test for unpaired variables was performed, while a chi-square test was performed for categorical variables, and a p-value of <0.05 was considered to be statistically significant. Results: A total of 663 patients were included. The median age was 76 years, and the overall incidence rate was 8.2/100,000. With age, the incidence rate increased to 64.2/100,000 in patients aged 80-89 years. The most prevalent symptoms were gait disturbance in 362 (58.6%) of patients, headache in 286 (46.4%), and focal neurological deficits in 252 (40.7%). CSDH distribution was unilateral in 478 (72.1%) patients, while 185 presented a bilateral hematoma with no difference in the outcome. BHC was the most performed procedure for 758 (97.3%) evacuations. CSDH recurrence was noted in 104 patients (20.1%). A good outcome was seen in almost 81% of patients. Factors associated with poor outcomes were age, GCS and mRS on admission, and the occurrence of multiple deficits present at the diagnosis of the cSDH. Conclusion: As the first multicenter national cohort-based study analyzing the disease burden of cSDH, our study reveals that the hospital admission rate of cSDH was 8.2/100,000, while with age, it rose to 64.2/100,000. A good outcome was seen in 81% of patients, who maintained the same quality of life as before the surgery. However, the mortality rate was 4%.

Prognostic assessment in patients operated for brain metastasis from systemic tumors.

BACKGROUND: Established models for prognostic assessment in patients with brain metastasis do not stratify for prior surgery. Here we tested the prognostic accuracy of the Graded Prognostic Assessment (GPA) score model in patients operated for BM and explored further prognostic factors. METHODS: We included 285 patients operated for brain metastasis at the University Hospital Zurich in the analysis. Information on patient characteristics, imaging, staging, peri- and postoperative complications and survival were extracted from the files and integrated into a multivariate Cox hazard model. RESULTS: The GPA score showed an association with outcome. We further identified residual tumor after surgery (p = 0.007, hazard ratio (HR) 1.6, 95% confidence interval (CI) 1.1-2.3) steroid use (p = 0.021, HR 1.7, 95% CI 1.1-2.6) and number of extracranial metastasis sites (p = 0.009, HR 1.4, 95% CI 1.1-1.6) at the time of surgery as independent prognostic factors. A trend was observed for postoperative infection of the subarachnoid space (p = 0.102, HR 3.5, 95% CI 0.8-15.7). CONCLUSIONS: We confirm the prognostic capacity of the GPA score in a cohort of operated patients with brain metastasis. However, extent of resection and steroid use provide additional aid for the prognostic assessment in these patients.

DeepEOR: automated perioperative volumetric assessment of variable grade gliomas using deep learning.

PURPOSE: Volumetric assessments, such as extent of resection (EOR) or residual tumor volume, are essential criterions in glioma resection surgery. Our goal is to develop and validate segmentation machine learning models for pre- and postoperative magnetic resonance imaging scans, allowing us to assess the percentagewise tumor reduction after intracranial surgery for gliomas. METHODS: For the development of the preoperative segmentation model (U-Net), MRI scans of 1053 patients from the Multimodal Brain Tumor Segmentation Challenge (BraTS) 2021 as well as from patients who underwent surgery at the University Hospital in Zurich were used. Subsequently, the model was evaluated on a holdout set containing 285 images from the same sources. The postoperative model was developed using 72 scans and validated on 45 scans obtained from the BraTS 2015 and Zurich dataset. Performance is evaluated using Dice Similarity score, Jaccard coefficient and Hausdorff 95%. RESULTS: We were able to achieve an overall mean Dice Similarity Score of 0.59 and 0.29 on the pre- and postoperative holdout sets, respectively. Our algorithm managed to determine correct EOR in 44.1%. CONCLUSION: Although our models are not suitable for clinical use at this point, the possible applications are vast, going from automated lesion detection to disease progression evaluation. Precise determination of EOR is a challenging task, but we managed to show that deep learning can provide fast and objective estimates.

Longitudinal neuropsychological assessment after aneurysmal subarachnoid hemorrhage and its relationship with delayed cerebral ischemia: a prospective Swiss multicenter study.

OBJECTIVE: While prior retrospective studies have suggested that delayed cerebral ischemia (DCI) is a predictor of neuropsychological deficits after aneurysmal subarachnoid hemorrhage (aSAH), all studies to date have shown a high risk of bias. This study was designed to determine the impact of DCI on the longitudinal neuropsychological outcome after aSAH, and importantly, it includes a baseline examination after aSAH but before DCI onset to reduce the risk of bias. METHODS: In a prospective, multicenter study (8 Swiss centers), 112 consecutive alert patients underwent serial neuropsychological assessments (Montreal Cognitive Assessment [MoCA]) before and after the DCI period (first assessment, < 72 hours after aSAH; second, 14 days after aSAH; third, 3 months after aSAH). The authors compared standardized MoCA scores and determined the likelihood for a clinically meaningful decline of ≥ 2 points from baseline in patients with DCI versus those without. RESULTS: The authors screened 519 patients, enrolled 128, and obtained complete data in 112 (87.5%; mean [± SD] age 53.9 ± 13.9 years; 66.1% female; 73% World Federation of Neurosurgical Societies [WFNS] grade I, 17% WFNS grade II, 10% WFNS grades III-V), of whom 30 (26.8%) developed DCI. MoCA z-scores were worse in the DCI group at baseline (-2.6 vs -1.4, p = 0.013) and 14 days (-3.4 vs -0.9, p < 0.001), and 3 months (-0.8 vs 0.0, p = 0.037) after aSAH. Patients with DCI were more likely to experience a decline of ≥ 2 points in MoCA score at 14 days after aSAH (adjusted OR [aOR] 3.02, 95% CI 1.07-8.54; p = 0.037), but the likelihood was similar to that in patients without DCI at 3 months after aSAH (aOR 1.58, 95% CI 0.28-8.89; p = 0.606). CONCLUSIONS: Aneurysmal SAH patients experiencing DCI have worse neuropsychological function before and until 3 months after the DCI period. DCI itself is responsible for a temporary and clinically meaningful decline in neuropsychological function, but its effect on the MoCA score could not be measured at the time of the 3-month follow-up in patients with low-grade aSAH with little or no impairment of consciousness. Whether these findings can be extrapolated to patients with high-grade aSAH remains unclear. Clinical trial registration no.: NCT03032471 (ClinicalTrials.gov).

Determining the impact of postoperative complications in neurosurgery based on simulated longitudinal smartphone app-based assessment.

BACKGROUND: Complications after neurosurgical operations can have severe impact on patient well-being, which is poorly reflected by current grading systems. The objective of this work was to develop and conduct a feasibility study of a new smartphone application that allows for the longitudinal assessment of postoperative well-being and complications. METHODS: We developed a smartphone application "Post OP Tracker" according to requirements from clinical experience and tested it on simulated patients. Participants received regular notifications through the app, inquiring them about their well-being and complications that had to be answered according to their assigned scenarios. After a 12-week period, subjects answered a questionnaire about the app's functionality, user-friendliness, and acceptability. RESULTS: A total of 13 participants (mean age 34.8, range 24-68 years, 4 (30.8%) female) volunteered in this feasibility study. Most of them had a professional background in either health care or software development. All participants downloaded, installed, and applied the app for an average of 12.9 weeks. On a scale of 1 (worst) to 4 (best), the app was rated on average 3.6 in overall satisfaction and 3.8 in acceptance. The design achieved a somewhat favorable score of 3.1. One participant (7.7%) reported major technical issues. The gathered patient data can be used to graphically display the simulated outcome and assess the impact of postoperative complications. CONCLUSIONS: This study suggests the feasibility to longitudinally gather postoperative data on subjective well-being through a smartphone application. Among potential patients, our application indicated to be functional, user-friendly, and well accepted. Using this app-based approach, further studies will enable us to classify postoperative complications according to their impact on the patient's well-being.

Machine learning-augmented objective functional testing in the degenerative spine: quantifying impairment using patient-specific five-repetition sit-to-stand assessment.

OBJECTIVE: What is considered "abnormal" in clinical testing is typically defined by simple thresholds derived from normative data. For instance, when testing using the five-repetition sit-to-stand (5R-STS) test, the upper limit of normal (ULN) from a population of spine-healthy volunteers (10.5 seconds) is used to identify objective functional impairment (OFI), but this fails to consider different properties of individuals (e.g., taller and shorter, older and younger). Therefore, the authors developed a personalized testing strategy to quantify patient-specific OFI using machine learning. METHODS: Patients with disc herniation, spinal stenosis, spondylolisthesis, or discogenic chronic low-back pain and a population of spine-healthy volunteers, from two prospective studies, were included. A machine learning model was trained on normative data to predict personalized "expected" test times and their confidence intervals and ULNs (99th percentiles) based on simple demographics. OFI was defined as a test time greater than the personalized ULN. OFI was categorized into types 1 to 3 based on a clustering algorithm. A web app was developed to deploy the model clinically. RESULTS: Overall, 288 patients and 129 spine-healthy individuals were included. The model predicted "expected" test times with a mean absolute error of 1.18 (95% CI 1.13-1.21) seconds and R2 of 0.37 (95% CI 0.34-0.41). Based on the implemented personalized testing strategy, 191 patients (66.3%) exhibited OFI. Type 1, 2, and 3 impairments were seen in 64 (33.5%), 91 (47.6%), and 36 (18.8%) patients, respectively. Increasing detected levels of OFI were associated with statistically significant increases in subjective functional impairment, extreme anxiety and depression symptoms, being bedridden, extreme pain or discomfort, inability to carry out activities of daily living, and a limited ability to work. CONCLUSIONS: In the era of "precision medicine," simple population-based thresholds may eventually not be adequate to monitor quality and safety in neurosurgery. Individualized assessment integrating machine learning techniques provides more detailed and objective clinical assessment. The personalized testing strategy demonstrated concurrent validity with quality-of-life measures, and the freely accessible web app (https://neurosurgery.shinyapps.io/5RSTS/) enabled clinical application.

Assessment of the Minimum Clinically Important Difference in the Smartphone-based 6-minute Walking Test After Surgery for Lumbar Degenerative Disc Disease.

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 been described in patients with DDD. METHODS: We assessed patients pre- and 6-weeks postoperatively, analyzing 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]): average change, minimum detectable change, and the change difference approach. RESULT: We studied 49 patients (59% male) with a mean age of 55.5 ±â€Š15.8 years. The computation methods revealed MCID values ranging from 81 m (z score of 0.9) based on the VAS back pain to 99 m (z score of 1.0) based on the ZCQ physical function scale. The average MCID of the 6WT was 92 m (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.

Intraoperative BOLD-fMRI Cerebrovascular Reactivity Assessment.

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.

Intraoperative Neurophysiologic Assessment in Deep Brain Stimulation Surgery and its Impact on Lead Placement.

OBJECTIVES: While the efficacy of deep brain stimulation (DBS) to treat various neurological disorders is undisputed, the surgical methods differ widely and the importance of intraoperative microelectrode recording (MER) or macrostimulation (MS) remains controversially debated. The objective of this study is to evaluate the impact of MER and MS on intraoperative lead placement. PATIENTS AND METHODS: We included 101 patients who underwent awake bilateral implantation of electrodes in the subthalamic nucleus with MER and MS for Parkinson's disease from 2009 to 2017 in a retrospective observational study. We analyzed intraoperative motor outcomes between anatomically planned stimulation point (PSP) and definite stimulation point (DSP), lead adjustments and Unified Parkinson's Disease Rating Scale Item III (UPDRS-III), levodopa equivalent daily dose (LEDD), and adverse events (AE) after 6 months. RESULTS: We adjusted 65/202 leads in 47/101 patients. In adjusted leads, MS results improved significantly when comparing PSP and DSP (p < 0.001), resulting in a number needed to treat of 9.6. After DBS, UPDRS-III and LEDD improved significantly after 6 months in adjusted and nonadjusted patients (p < 0.001). In 87% of leads, the active contact at 6 months still covered the optimal stimulation point during surgery. In total, 15 AE occurred. CONCLUSION: MER and MS have a relevant impact on the intraoperative decision of final lead placement and prevent from a substantial rate of poor stimulation outcome. The optimal stimulation points during surgery and chronic stimulation strongly overlap. Follow-up UPDRS-III results, LEDD reductions, and DBS-related AE correspond well to previously published data.

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

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.

Response assessment and outcome of combining immunotherapy and radiosurgery for brain metastasis from malignant melanoma.

BACKGROUND: The optimal sequence of stereotactic radiotherapy (SRT) and immune checkpoint inhibition (ICI) and assessment of response in patients with brain metastases from melanoma remain challenging. METHODS: We reviewed clinical and neuroimaging data of 62 patients with melanoma, including 26 patients with BRAF-mutant tumours, with newly diagnosed brain metastases treated with ICI alone (n=10, group 1), SRT alone or in combination with other systemic therapies (n=20, group 2) or ICI plus SRT (n=32, group 3). Response was assessed retrospectively using response evaluation criteria in solid tumours (RECIST) V.1.1, response assessment in neuro-oncology (RANO) and immunotherapy RANO (iRANO) criteria. MRI follow-up from 43 patients was available for central review. RESULTS: Patients treated with ICI alone showed no objective responses and had worse outcome than patients treated with SRT without or with ICI. RECIST, RANO and iRANO criteria were concordant for complete response (CR) and partial response (PR). RANO called progression earlier than RECIST for clinical deterioration without MRI progression in some patients. Progression was called later when using iRANO criteria because of the need for a confirmatory scan. Pseudoprogression was documented in seven patients: three patients in group 2 and four patients in group 3. Radionecrosis was documented in seven patients: two patients in group 2 and five patients in group 3. Regression of non-irradiated lesions was seen neither in two patients treated with SRT alone nor in five patients treated with SRT plus ICI, providing no evidence for rare abscopal effects. CONCLUSIONS: Pseudoprogression is uncommon with ICI alone, suggesting that growing lesions in such patients should trigger an intervention. Pseudoprogression rates were similar after SRT alone or SRT in combination with ICI. Abscopal effects are rare or do not exist. Response assessment criteria should be considered carefully when designing clinical studies for patients with brain metastases who receive SRT.

Influence of the Intensive Care Unit Environment on the Reliability of the Montreal Cognitive Assessment.

Background: Neuropsychological screening becomes increasingly important for the evaluation of subarachnoid hemorrhage (SAH) and stroke patients. It is often performed during the surveillance period on the intensive (ICU), while it remains unknown, whether the distraction in this environment influences the results. We aimed to study the reliability of the Montreal Cognitive Assessment (MoCA) in the ICU environment. Methods: Consecutive stable patients with recent brain injury (tumor, trauma, stroke, etc.) were evaluated twice within 36 h using official parallel versions of the MoCA (ΔMoCA). The sequence of assessment was randomized into (a) busy ICU first or (b) quiet office first with subsequent crossover. For repeated MoCA, we determined sequence, period, location effects, and the intraclass correlation coefficient (ICC). Results: N = 50 patients were studied [n = 30 (60%) male], with a mean age of 57 years. The assessment's sequence ["ICU first" mean ΔMoCA -1.14 (SD 2.34) vs. "Office first" -0.73 (SD 1.52)] did not influence the MoCA (p = 0.47). On the 2nd period, participants scored 0.96 points worse (SD 2.01; p = 0.001), indicating no MoCA learning effect but a possible difference in parallel versions. There was no location effect (p = 0.31) with ΔMoCA between locations (Office minus ICU) of -0.32 (SD 2.21). The ICC for repeated MoCA was 0.87 (95% CI 0.79-0.92). Conclusions: The reliability of the MoCA was excellent, independent from the testing environment being ICU or office. This finding is helpful for patient care and studies investigating the effect of a therapeutic intervention on the neuropsychological outcome after SAH, stroke or traumatic brain injury.

Objective functional assessment using the "Timed Up and Go" test in patients with lumbar spinal stenosis.

OBJECTIVEPatient-reported outcome measures (PROMs) are standard of care for the assessment of functional impairment. Subjective outcome measures are increasingly complemented by objective ones, such as the "Timed Up and Go" (TUG) test. Currently, only a few studies report pre- and postoperative TUG test assessments in patients with lumbar spinal stenosis (LSS).METHODSA prospective two-center database was reviewed to identify patients with LSS who underwent lumbar decompression with or without fusion. The subjective functional status was estimated using PROMs for pain (visual analog scale [VAS]), disability (Roland-Morris Disability Index [RMDI] and Oswestry Disability Index [ODI]), and health-related quality of life (HRQoL; 12-Item Short-Form Physical Component Summary [SF-12 PCS] and the EQ-5D) preoperatively, as well as on postoperative day 3 (D3) and week 6 (W6). Objective functional impairment (OFI) was measured using age- and sex-standardized TUG test results.RESULTSSixty-four patients (n = 32 [50%] male, mean age 66.8 ± 11.7 years) were included. Preoperatively, they reported a mean VAS back pain score of 4.1 ± 2.7, VAS leg pain score of 5.4 ± 2.7, RMDI of 10.4 ± 5.3, ODI of 41.9 ± 16.2, SF-12 PCS score of 32.7 ± 8.3, and an EQ-5D index of 0.517 ± 0.226. The preoperative rates of severe, moderate, and mild OFI were 4.7% (n = 3), 12.5% (n = 8), and 7.8% (n = 5), respectively, and the mean OFI T-score was 116.3 ± 23.7. At W6, 60 (93.8%) of 64 patients had a TUG test result within the normal population range (no OFI); 3 patients (4.7%) had mild and 1 patient (1.6%) severe OFI. The mean W6 OFI T-score was significantly decreased (103.1 ± 13.6; p < 0.001). Correspondingly, the PROMs showed a decrease in subjective VAS back pain (1.6 ± 1.7, p < 0.001) and leg pain (1.0 ± 1.8, p < 0.001) scores, disability (RMDI 5.3 ± 4.7, p < 0.001; ODI 21.3 ± 16.1, p < 0.001), and increase in HRQoL (SF-12 PCS 40.1 ± 8.3, p < 0.001; EQ-5D 0.737 ± 0.192, p < 0.001) at W6. The W6 responder status (clinically meaningful improvement) ranged between 81.3% (VAS leg pain) and 29.7% (EQ-5D index) of patients.CONCLUSIONSThe TUG test is a quick and easily applicable tool that reliably measures OFI in patients with LSS. Objective tests incorporating longer walking time should be considered if OFI is suspected but fails to be proven by the TUG test, taking into account that neurogenic claudication may not clinically manifest during the brief TUG examination. Objective tests do not replace the subjective PROM-based assessment, but add valuable information to a comprehensive patient evaluation.

Standardized assessment of outcome and complications in chronic subdural hematoma: results from a large case series.

INTRODUCTION: Chronic subdural hematomas (cSDH) are commonly deemed to have a benign prognosis. However, detailed and standardized data describing outcome and complications in a large prospective patient cohort is lacking. METHODS: Retrospective analysis of prospectively collected data in our institutional patient registry on consecutive patients undergoing surgery for cSDH from 2013 to 2017. Complications were assessed according to the Clavien-Dindo grading system (CDG). The outcome was measured with respect to two endpoints: occurrence of a complication with CDG 3-5 and lack of improvement in Karnofsky Performance Status (KPS) at the last follow-up. RESULTS: Out of 435 operations, 166 (38.3%) presented a complication until 3 months postoperative (CDG 1, 23 (5.3%); CDG 2, 62 (14.3%); CDG 3a, 7 (1.6%); CDG 3b, 64 (14.7%); CDG 4a, 2 (0.5%); and CDG 5, 8 (1.8%)). Higher CDG correlated with a lower KPS (rs = - 0.27, p < 0.001). A lack of improvement in KPS was associated with a Charlson Comorbidity Index (CCI) > 1 and the iso- or hypodense appearance of the cSDH. CONCLUSIONS: This study provides a reliable estimate of the rate of medical and surgical complications in cSDH surgery. Complications that required a surgical intervention turned out to be rare. Recording complications in a standardized and prospective fashion can therefore serve as a basis for assessing patient outcome and quality control within the department.

Validating a therapy-oriented complication grading system in lumbar spine surgery: a prospective population-based study.

The aim of the present study was to validate a therapy-oriented complication grading system in a well-defined neurosurgical patient population in which complications may entrain neurological deficits, which are severe but not treated. The prospective patient registry of the Department of Neurosurgery, University of Zurich provides extensive population-based data. In this study we focused on complications after lumbar spine surgeries and rated their severity by Clavien-Dindo grade (CDG). Analyzing 138 consecutive surgeries we noted 44 complications. As to treatment, CDG correlated with the length of hospital stay and treatment cost. As to patient outcome, CDG correlated with performance and outcome (McCormick). The present study demonstrates the correlation between outcome scales and the CDG. While the high correlation of CDG with costs seems self-evident, the present study shows this correlation for the first time. Furthermore, the study validates the CDG for a surgical subspecialty. As a further advantage, CDG registers any deviation from the normal postoperative course and allows comparison between surgical specialties.

Blood oxygen-level dependent functional assessment of cerebrovascular reactivity: Feasibility for intraoperative 3 Tesla MRI.

PURPOSE: To assess the feasibility of functional blood oxygen-level dependent (BOLD) MRI to evaluate intraoperative cerebrovascular reactivity (CVR) at 3 Tesla field strength. METHODS: Ten consecutive neurosurgical subjects scheduled for a clinical intraoperative MRI examination were enrolled in this study. In addition to the clinical protocol a BOLD sequence was implemented with three cycles of 44 s apnea to calculate CVR values on a voxel-by-voxel basis throughout the brain. The CVR range was then color-coded and superimposed on an anatomical volume to create high spatial resolution CVR maps. RESULTS: Ten subjects (mean age 34.8 ± 13.4; 2 females) uneventfully underwent the intraoperative BOLD protocol, with no complications occurring. Whole-brain CVR for all subjects was (mean ± SD) 0.69 ± 0.42, whereas CVR was markedly higher for tumor subjects as compared to vascular subjects, 0.81 ± 0.44 versus 0.33 ± 0.10, respectively. Furthermore, color-coded functional maps could be robustly interpreted for a whole-brain assessment of CVR. CONCLUSION: We demonstrate that intraoperative BOLD MRI is feasible in creating functional maps to assess cerebrovascular reactivity throughout the brain in subjects undergoing a neurosurgical procedure. Magn Reson Med 77:806-813, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Pituitary surgery and volumetric assessment of extent of resection: a paradigm shift in the use of intraoperative magnetic resonance imaging.

OBJECTIVE: The aim of this study was to quantitatively assess the role of intraoperative high-field 3-T MRI (3T-iMRI) in improving the gross-total resection (GTR) rate and the extent of resection (EOR) in endoscopic transsphenoidal surgery (TSS) for pituitary adenomas. METHODS: Radiological and clinical data from a prospective database were retrospectively analyzed. Volumetric measurements of adenoma volumes pre-, intraoperatively, and 3 months postoperatively were performed in a consecutive series of patients who had undergone endoscopic TSS. The quantitative contribution of 3T-iMRI was measured as a percentage of the additional rate of GTR and of the EOR achieved after 3T-iMRI. RESULTS: The cohort consisted of 50 patients (51 operations) harboring 33 nonfunctioning and 18 functioning pituitary adenomas. Mean adenoma diameter and volume were 21.1 mm (range 5-47 mm) and 5.23 cm(3) (range 0.09-22.14 cm(3)), respectively. According to Knosp's classification, 10 cases were Grade 0; 8, Grade 1; 17, Grade 2; 12, Grade 3; and 4, Grade 4. Gross-total resection was the surgical goal (targeted [t]GTR) in 34 of 51 operations and was initially achieved in 16 (47%) of 34 at 3T-iMRI and in 30 (88%) of 34 cases after further resection. In this subgroup, the EOR increased from 91% at 3T-iMRI to 99% at the 3-month MRI (p < 0.05). In the 17 cases in which subtotal resection (STR) had been planned (tSTR), the EOR increased from 79% to 86% (p < 0.05) and GTR could be achieved in 1 case. Intrasellar remnants were present in 20 of 51 procedures at 3T-iMRI and in only 5 (10%) of 51 procedures after further resection (median volume 0.15 cm(3)). Overall, the use of 3T-iMRI led to further resection in 27 (53%) of 51 procedures and permitted GTR in 15 (56%) of these 27 procedures; thus, the GTR rate in the entire cohort increased from 31% (16 of 51) to 61% (31 of 51) and the EOR increased from 87% to 95% (p < 0.05). CONCLUSIONS: The use of high-definition 3T-iMRI allowed precise visualization and quantification of adenoma remnant volume. It helped to increase GTR and EOR rates in both tGTR and tSTR patient groups. Moreover, it helped to achieve low rates of intrasellar remnants. These data support the use of 3T-iMRI to achieve maximal, safe adenoma resection.

Call for uniform neuropsychological assessment after aneurysmal subarachnoid hemorrhage: Swiss recommendations.

BACKGROUND: In a high proportion of patients with favorable outcome after aneurysmal subarachnoid hemorrhage (aSAH), neuropsychological deficits, depression, anxiety, and fatigue are responsible for the inability to return to their regular premorbid life and pursue their professional careers. These problems often remain unrecognized, as no recommendations concerning a standardized comprehensive assessment have yet found entry into clinical routines. METHODS: To establish a nationwide standard concerning a comprehensive assessment after aSAH, representatives of all neuropsychological and neurosurgical departments of those eight Swiss centers treating acute aSAH have agreed on a common protocol. In addition, a battery of questionnaires and neuropsychological tests was selected, optimally suited to the deficits found most prevalent in aSAH patients that was available in different languages and standardized. RESULTS: We propose a baseline inpatient neuropsychological screening using the Montreal Cognitive Assessment (MoCA) between days 14 and 28 after aSAH. In an outpatient setting at 3 and 12 months after bleeding, we recommend a neuropsychological examination, testing all relevant domains including attention, speed of information processing, executive functions, verbal and visual learning/memory, language, visuo-perceptual abilities, and premorbid intelligence. In addition, a detailed assessment capturing anxiety, depression, fatigue, symptoms of frontal lobe affection, and quality of life should be performed. CONCLUSIONS: This standardized neuropsychological assessment will lead to a more comprehensive assessment of the patient, facilitate the detection and subsequent treatment of previously unrecognized but relevant impairments, and help to determine the incidence, characteristics, modifiable risk factors, and the clinical course of these impairments after aSAH.