Long-term outcome in new onset refractory status epilepticus: a retrospective study.

BACKGROUND: New onset refractory status epilepticus (NORSE) is a neurologic emergency without an immediately identifiable cause. The complicated and long ICU stay of the patients can lead to perceiving a prolongation of therapies as futile. However, a recovery is possible even in severe cases. This retrospective study investigates ICU treatments, short- and long-term outcome and ethical decisions of a case series of patients with NORSE. METHODS: Overall, 283 adults were admitted with status epilepticus (SE) to the Neurocritical Care Unit of the University Hospital Zurich, Switzerland, between 01.2010 and 12.2022. Of them, 25 had a NORSE. We collected demographic, clinical, therapeutic and outcome data. Descriptive statistics was performed. RESULTS: Most patients were female (68%), previously healthy (Charlson comorbidity index 1 [0-4]) and relatively young (54 ± 17 years). 96% presented with super-refractory SE. Despite extensive workup, the majority (68%) of cases remained cryptogenic. Most patients had a long and complicated ICU stay. The in-hospital mortality was 36% (n = 9). The mortality at last available follow-up was 56% (n = 14) on average 30 months after ICU admission. The cause of in-hospital death for 89% (n = 8) of the patients was the withholding/withdrawing of therapies. Medical staff except for one patient triggered the decision. The end of life (EOL) decision was taken 29 [12-51] days after the ICU admission. Death occurred on day 6 [1-8.5] after the decision was taken. The functional outcome improved over time for 13/16 (81%) hospital survivors (median mRS at hospital discharge 4 [3.75-5] vs. median mRS at last available follow-up 2 [1.75-3], p < 0.001). CONCLUSIONS: Our data suggest that the long-term outcome can still be favorable in NORSE survivors, despite a prolonged and complicated ICU stay. Clinicians should be careful in taking EOL decisions to avoid the risk of a self-fulfilling prophecy. Our results encourage clinicians to continue treatment even in initially refractory cases.

Predicting outcome after aneurysmal subarachnoid hemorrhage by exploitation of signal complexity: a prospective two-center cohort study.

BACKGROUND: Signal complexity (i.e. entropy) describes the level of order within a system. Low physiological signal complexity predicts unfavorable outcome in a variety of diseases and is assumed to reflect increased rigidity of the cardio/cerebrovascular system leading to (or reflecting) autoregulation failure. Aneurysmal subarachnoid hemorrhage (aSAH) is followed by a cascade of complex systemic and cerebral sequelae. In aSAH, the value of entropy has not been established yet. METHODS: aSAH patients from 2 prospective cohorts (Zurich-derivation cohort, Aachen-validation cohort) were included. Multiscale Entropy (MSE) was estimated for arterial blood pressure, intracranial pressure, heart rate, and their derivatives, and compared to dichotomized (1-4 vs. 5-8) or ordinal outcome (GOSE-extended Glasgow Outcome Scale) at 12 months using uni- and multivariable (adjusted for age, World Federation of Neurological Surgeons grade, modified Fisher (mFisher) grade, delayed cerebral infarction), and ordinal methods (proportional odds logistic regression/sliding dichotomy). The multivariable logistic regression models were validated internally using bootstrapping and externally by assessing the calibration and discrimination. RESULTS: A total of 330 (derivation: 241, validation: 89) aSAH patients were analyzed. Decreasing MSE was associated with a higher likelihood of unfavorable outcome independent of covariates and analysis method. The multivariable adjusted logistic regression models were well calibrated and only showed a slight decrease in discrimination when assessed in the validation cohort. The ordinal analysis revealed its effect to be linear. MSE remained valid when adjusting the outcome definition against the initial severity. CONCLUSIONS: MSE metrics and thereby complexity of physiological signals are independent, internally and externally valid predictors of 12-month outcome. Incorporating high-frequency physiological data as part of clinical outcome prediction may enable precise, individualized outcome prediction. The results of this study warrant further investigation into the cause of the resulting complexity as well as its association to important and potentially preventable complications including vasospasm and delayed cerebral ischemia.

Human-AI Teaming in Critical Care: A Comparative Analysis of Data Scientists' and Clinicians' Perspectives on AI Augmentation and Automation.

BACKGROUND: Artificial intelligence (AI) holds immense potential for enhancing clinical and administrative health care tasks. However, slow adoption and implementation challenges highlight the need to consider how humans can effectively collaborate with AI within broader socio-technical systems in health care. OBJECTIVE: In the example of intensive care units (ICUs), we compare data scientists' and clinicians' assessments of the optimal utilization of human and AI capabilities by determining suitable levels of human-AI teaming for safely and meaningfully augmenting or automating 6 core tasks. The goal is to provide actionable recommendations for policy makers and health care practitioners regarding AI design and implementation. METHODS: In this multimethod study, we combine a systematic task analysis across 6 ICUs with an international Delphi survey involving 19 health data scientists from the industry and academia and 61 ICU clinicians (25 physicians and 36 nurses) to define and assess optimal levels of human-AI teaming (level 1=no performance benefits; level 2=AI augments human performance; level 3=humans augment AI performance; level 4=AI performs without human input). Stakeholder groups also considered ethical and social implications. RESULTS: Both stakeholder groups chose level 2 and 3 human-AI teaming for 4 out of 6 core tasks in the ICU. For one task (monitoring), level 4 was the preferred design choice. For the task of patient interactions, both data scientists and clinicians agreed that AI should not be used regardless of technological feasibility due to the importance of the physician-patient and nurse-patient relationship and ethical concerns. Human-AI design choices rely on interpretability, predictability, and control over AI systems. If these conditions are not met and AI performs below human-level reliability, a reduction to level 1 or shifting accountability away from human end users is advised. If AI performs at or beyond human-level reliability and these conditions are not met, shifting to level 4 automation should be considered to ensure safe and efficient human-AI teaming. CONCLUSIONS: By considering the sociotechnical system and determining appropriate levels of human-AI teaming, our study showcases the potential for improving the safety and effectiveness of AI usage in ICUs and broader health care settings. Regulatory measures should prioritize interpretability, predictability, and control if clinicians hold full accountability. Ethical and social implications must be carefully evaluated to ensure effective collaboration between humans and AI, particularly considering the most recent advancements in generative AI.

Delirium in Neurocritical Care: Uncovering Undisclosed Psychotropic Substance and Medication Use and Stress Exposure by Hair Analysis.

OBJECTIVE: In intensive care, delirium is frequent, prolongs the stay, increases health care costs, and worsens patient outcome. Several substances and medications as well as stress can impact the risk of delirium; however, assessment of previous exposure to psychotropic agents and stress by self-reports or third-party information is not always reliable. Hair analysis can be used to objectively assess medication and substance use (including chronic alcohol consumption), and allows for the determination of stress-related long-term changes in steroid hormones and endocannabinoids. METHODS: Consecutive adult patients with acute brain injury admitted to the neurocritical care unit were included. Delirium was diagnosed using the Confusion Assessment Method for the Intensive Care Unit. Liquid chromatography coupled with tandem mass spectrometry was used to investigate psychoactive substances and medications, ethyl glucuronide, steroid hormones, and endocannabinoids in hair samples. Univariable and multivariable analyses were used to reveal any associations with the occurrence of delirium. RESULTS: Of 50 consecutive patients, 21 (42%) were diagnosed with delirium. Detection of antipsychotics or antidepressants in hair was more frequent in patients with delirium (antidepressants: 43% vs. 14%, p = 0.040; antipsychotics: 29% vs. 0%, p = 0.021). These patients also displayed higher ethyl glucuronide levels (p = 0.049). Anandamide (AEA) concentrations were higher in patients with delirium (p = 0.005), whereas oleoylethanolamide (p = 0.045) and palmitoylethanolamide (PEA) (p = 0.017) concentrations were lower in patients with delirium. Backward stepwise logistic regression analysis revealed antidepressants and AEA/PEA to be independent relevant predictors of delirium. CONCLUSIONS: Hair analysis provides crucial and otherwise unattainable information regarding chronic stress and the use of psychotropic substances and medications. Undisclosed antidepressant/antipsychotic use or intense chronic alcohol consumption is susceptible to treatment (continuation of medication or provision of low-dose benzodiazepines in case of alcohol). Chronic stress can be evaluated using stress markers and endocannabinoids in hair, potentially allowing for personalized delirium risk stratification and preventive measures.

The role of neuronal antibodies in cryptogenic new onset refractory status epilepticus.

Most cases with new onset refractory status epilepticus (NORSE) remain cryptogenic despite extensive diagnostic workup. The aim of this study was to analyze the etiology and clinical features of NORSE and investigate known or potentially novel autoantibodies in cryptogenic NORSE (cNORSE). We retrospectively assessed the medical records of adults with status epilepticus at a Swiss tertiary referral center between 2010 and 2021. Demographic, diagnostic, therapeutic, and outcome parameters were characterized. We performed post hoc screening for known or potentially novel autoantibodies including immunohistochemistry (IHC) on rat brain with cerebrospinal fluid (CSF) and serum samples of cNORSE. Twenty patients with NORSE were identified. Etiologies included infections (n = 4), Creutzfeldt-Jakob disease (n = 1), CASPR2 autoimmune encephalitis (n = 1), and carotid artery stenosis with recurrent perfusion deficit (n = 1). Thirteen cases (65%) were cryptogenic despite detailed evaluation. A posteriori IHC for neuronal autoantibodies yielded negative results in all available serum (n = 11) and CSF (n = 9) samples of cNORSE. Our results suggest that neuronal antibodies are unlikely to play a major role in the pathogenesis of cNORSE. Future studies should rather focus on other-especially T-cell- and cytokine-mediated-mechanisms of autoinflammation in this devastating disease, which is far too poorly understood so far.

Thrombocyte transfusion and rebleeding rate in patients using antiplatelet agents before aneurysmal subarachnoid hemorrhage.

OBJECTIVE: The reason for a rebleed after an initial hemorrhage in patients with aneurysmal subarachnoid hemorrhage (aSAH) is considered multifactorial. Antiplatelet use is one of the factors that has been related to early rebleed and worse outcome after aSAH. Thrombocyte transfusion overcomes the inhibitory effects of antiplatelet agents by increasing the number of functional thrombocytes, but its impact on the rebleed rate and clinical outcome remains unknown. The aim of this study was to assess the effect of thrombocyte transfusion on rebleeding and clinical outcome in patients with aSAH and prehemorrhage antiplatelet use, considering confounding factors. METHODS: Data were prospectively collected at a single tertiary reference center for aSAH in Zurich, Switzerland. Patients with aSAH and prehemorrhage antiplatelet use were divided into "thrombocyte transfusion" and "nontransfusion" groups based on whether they did or did not receive any thrombocyte transfusion in the acute stage of aSAH after hospital admission and before the exclusion of the bleeding source. Using multivariate logistic regression analysis, the impact of thrombocyte transfusion on the rebleed rate and on clinical outcome (defined as Glasgow Outcome Scale score 1-3) was calculated. RESULTS: One hundred fifty-seven patients were included, 87 (55.4%) of whom received thrombocyte transfusion. Eighteen (11.5%) of 157 patients had a rebleed during the hospital stay. The rebleed risk was 6.9% in the thrombocyte transfusion group and 17.1% in the nontransfusion group. After adjusting for confounders, thrombocyte transfusion showed evidence for a reduction in the rebleed rate (adjusted OR [aOR] 0.29, 95% CI 0.10-0.87). Fifty-seven patients (36.3%) achieved a poor outcome at 6 months' follow-up. Among those 57 patients, 31 (54.4%) underwent at least one thrombocyte transfusion. Thrombocyte transfusion was not associated with poor clinical outcome at 6 months' follow-up (aOR 0.91, 95% CI 0.39-2.15). CONCLUSIONS: Thrombocyte transfusion in patients with aSAH and prehemorrhage antiplatelet use is independently associated with a reduction in rebleeds but shows no impact on clinical outcome at 6 months' follow-up. Larger and randomized studies are needed to investigate the impact of thrombocyte transfusion on rebleed and outcome.

Successful weaning versus permanent cerebrospinal fluid diversion after aneurysmal subarachnoid hemorrhage: post hoc analysis of a Swiss multicenter study.

OBJECTIVE: Acute hydrocephalus is a frequent complication after aneurysmal subarachnoid hemorrhage (aSAH). Among patients needing CSF diversion, some cannot be weaned. Little is known about the comparative neurological, neuropsychological, and health-related quality-of-life (HRQOL) outcomes in patients with successful and unsuccessful CSF weaning. The authors aimed to assess outcomes of patients by comparing those with successful and unsuccessful CSF weaning; the latter was defined as occurring in patients with permanent CSF diversion at 3 months post-aSAH. METHODS: The authors included prospectively recruited alert (i.e., Glasgow Coma Scale score 13-15) patients with aSAH in this retrospective study from six Swiss neurovascular centers. Patients underwent serial neurological (National Institutes of Health Stroke Scale), neuropsychological (Montreal Cognitive Assessment), disability (modified Rankin Scale), and HRQOL (EuroQol-5D) examinations at < 72 hours, 14-28 days, and 3 months post-aSAH. RESULTS: Of 126 included patients, 54 (42.9%) developed acute hydrocephalus needing CSF diversion, of whom 37 (68.5%) could be successfully weaned and 17 (31.5%) required permanent CSF diversion. Patients with unsuccessful weaning were older (64.5 vs 50.8 years, p = 0.003) and had a higher rate of intraventricular hemorrhage (52.9% vs 24.3%, p = 0.04). Patients who succeed in restoration of physiological CSF dynamics improve on average by 2 points on the Montreal Cognitive Assessment between 48-72 hours and 14-28 days, whereas those in whom weaning fails worsen by 4 points (adjusted coefficient 6.80, 95% CI 1.57-12.04, p = 0.01). They show better neuropsychological recovery between 48-72 hours and 3 months, compared to patients in whom weaning fails (adjusted coefficient 7.60, 95% CI 3.09-12.11, p = 0.02). Patients who receive permanent CSF diversion (ventriculoperitoneal shunt) show significant neuropsychological improvement thereafter, catching up the delay in neuropsychological improvement between 14-28 days and 3 months post-aSAH. Neurological, disability, and HRQOL outcomes at 3 months were similar. CONCLUSIONS: These results show a temporary but clinically meaningful cognitive benefit in the first weeks after aSAH in successfully weaned patients. The resolution of this difference over time may be due to the positive effects of permanent CSF diversion and underlines its importance. Patients who do not show progressive neuropsychological improvement after weaning should be considered for repeat CT imaging to rule out chronic (untreated) hydrocephalus.

Spontaneous empyema and brain abscess in an intensive care population: clinical presentation, microbiology, and factors associated with outcome.

BACKGROUND: Data on critically ill patients with spontaneous empyema or brain abscess are limited. The aim was to evaluate clinical presentations, factors, and microbiological findings associated with the outcome in patients treated in a Neurocritical Care Unit. METHODS: In this retrospective study, we analyzed 45 out of 101 screened patients with spontaneous epidural or subdural empyema and/or brain abscess treated at a tertiary care center between January 2012 and December 2019. Patients with postoperative infections or spinal abscess were excluded. Medical records were reviewed for baseline characteristics, origin of infection, laboratory and microbiology findings, and treatment characteristics. The outcome was determined using the Glasgow outcome scale extended (GOSE). RESULTS: Favorable outcome (GOSE 5-8) was achieved in 38 of 45 patients (84%). Four patients died (9%), three remained severely disabled (7%). Unfavorable outcome was associated with a decreased level of consciousness at admission (Glasgow coma scale < 9) (43% versus 3%; p = 0.009), need of vasopressors (71% versus 11%; p = 0.002), sepsis (43% versus 8%; p = 0.013), higher age (65.1 ± 15.7 versus 46.9 ± 17.5 years; p = 0.014), shorter time between symptoms onset and ICU admission (5 ± 2.4 days versus 11.6 ± 16.8 days; p = 0.013), and higher median C-reactive protein (CRP) serum levels (206 mg/l, range 15-259 mg/l versus 17.5 mg/l, range 3.3-72.7 mg/l; p = 0.036). With antibiotics adapted according to culture sensitivities in the first 2 weeks, neuroimaging revealed a progression of empyema or abscess in 45% of the cases. CONCLUSION: Favorable outcome can be achieved in a considerable proportion of an intensive care population with spontaneous empyema or brain abscess. Sepsis and more frequent need for vasopressors, associated with unfavorable outcome, indicate a fulminant course of a not only cerebral but systemic infection. Change of antibiotic therapy according to microbiological findings in the first 2 weeks should be exercised with great caution.

Broad Range Eubacterial Polymerase Chain Reaction of Cerebrospinal Fluid Reduces the Time to Exclusion of and Costs Associated with Ventriculostomy-Related Infection in Hemorrhagic Stroke.

BACKGROUND: Patients with hemorrhagic stroke and an external ventricular drain in situ are at risk for ventriculostomy-related-infections (VRI). Because of the contamination of the cerebrospinal fluid (CSF) with blood and the high frequency of false negative CSF culture, the diagnosis of VRI remains challenging. This study investigated the introduction of CSF broad range eubacterial polymerase chain reaction (ePCR) and its effect on frequency and duration of antibiotic therapy for VRI, neurocritical care unit (NCCU) length of stay, related costs, and outcome. METHODS: Between 2020 and 2022, we prospectively included 193 patients admitted to the NCCU of the University Hospital of Zürich with hemorrhagic stroke and an external ventricular drain for more than 48 h. Patient characteristics, serum inflammatory markers, white blood cell count in CSF, use and duration of antibiotic treatment for VRI, microbiological findings (CSF cultures and ePCR tests), and NCCU length of stay were compared in patients with no infection, noncerebral infection, suspected VRI, and confirmed VRI. Data of patients with suspected VRI of this cohort were compared with a retrospective cohort of patients with suspected VRI treated at our NCCU before the introduction of CSF ePCR testing (2013-2019). RESULTS: Out of 193 patients, 12 (6%) were diagnosed with a confirmed VRI, 66 (34%) with suspected VRI, 90 (47%) with a noncerebral infection, and 25 (13%) had no infection at all. Compared with the retrospective cohort of patients, the use of CSF ePCR resulted in a reduction of patients treated for suspected VRI for the whole duration of 14 days (from 51 to 11%). Furthermore, compared with the retrospective group of patients with suspected VRI (n = 67), after the introduction of CSF ePCR, patients with suspected VRI had shorter antibiotic treatment duration of almost 10 days and, hence, lower related costs with comparable outcome at 3 months. CONCLUSIONS: The use of CSF ePCR to identify VRI resulted in shorter antibiotic treatment duration without changing the outcome, as compared with a retrospective cohort of patients with suspected VRI.

Clinical potential of automated convolutional neural network-based hematoma volumetry after aneurysmal subarachnoid hemorrhage.

OBJECTIVES: Cerebrospinal fluid hemoglobin has been positioned as a potential biomarker and drug target for aneurysmal subarachnoid hemorrhage-related secondary brain injury (SAH-SBI). The maximum amount of hemoglobin, which may be released into the cerebrospinal fluid, is defined by the initial subarachnoid hematoma volume (ISHV). In patients without external ventricular or lumbar drain, there remains an unmet clinical need to predict the risk for SAH-SBI. The aim of this study was to explore automated segmentation of ISHV as a potential surrogate for cerebrospinal fluid hemoglobin to predict SAH-SBI. METHODS: This study is based on a retrospective analysis of imaging and clinical data from 220 consecutive patients with aneurysmal subarachnoid hemorrhage collected over a five-year period. 127 annotated initial non-contrast CT scans were used to train and test a convolutional neural network to automatically segment the ISHV in the remaining cohort. Performance was reported in terms of Dice score and intraclass correlation. We characterized the associations between ISHV and baseline cohort characteristics, SAH-SBI, ventriculoperitoneal shunt dependence, functional outcome, and survival. Established clinical (World Federation of Neurosurgical Societies, Hunt & Hess) and radiological (modified Fisher, Barrow Neurological Institute) scores served as references. RESULTS: A strong volume agreement (0.73 Dice, range 0.43 - 0.93) and intraclass correlation (0.89, 95% CI, 0.81-0.94) were shown. While ISHV was not associated with the use of antithrombotics or cardiovascular risk factors, there was strong evidence for an association with a lower Glasgow Coma Scale at hospital admission. Aneurysm size and location were not associated with ISHV, but the presence of intracerebral or intraventricular hemorrhage were independently associated with higher ISHV. Despite strong evidence for a positive association between ISHV and SAH-SBI, the discriminatory ability of ISHV for SAH-SBI was insufficient. The discriminatory ability of ISHV was, however, higher regarding ventriculoperitoneal shunt dependence and functional outcome at three-months follow-up. Multivariate survival analysis provided strong evidence for an independent negative association between survival probability and both ISHV and intraventricular hemorrhage. CONCLUSIONS: The proposed algorithm demonstrates strong performance in volumetric segmentation of the ISHV on the admission CT. While the discriminatory ability of ISHV for SAH-SBI was similar to established clinical and radiological scores, it showed a high discriminatory ability for ventriculoperitoneal shunt dependence and functional outcome at three-months follow-up.

Cerebrospinal fluid findings in COVID-19: a multicenter study of 150 lumbar punctures in 127 patients.

BACKGROUND: Comprehensive data on the cerebrospinal fluid (CSF) profile in patients with COVID-19 and neurological involvement from large-scale multicenter studies are missing so far. OBJECTIVE: To analyze systematically the CSF profile in COVID-19. METHODS: Retrospective analysis of 150 lumbar punctures in 127 patients with PCR-proven COVID-19 and neurological symptoms seen at 17 European university centers RESULTS: The most frequent pathological finding was blood-CSF barrier (BCB) dysfunction (median QAlb 11.4 [6.72-50.8]), which was present in 58/116 (50%) samples from patients without pre-/coexisting CNS diseases (group I). QAlb remained elevated > 14d (47.6%) and even > 30d (55.6%) after neurological onset. CSF total protein was elevated in 54/118 (45.8%) samples (median 65.35 mg/dl [45.3-240.4]) and strongly correlated with QAlb. The CSF white cell count (WCC) was increased in 14/128 (11%) samples (mostly lympho-monocytic; median 10 cells/µl, > 100 in only 4). An albuminocytological dissociation (ACD) was found in 43/115 (37.4%) samples. CSF L-lactate was increased in 26/109 (24%; median 3.04 mmol/l [2.2-4]). CSF-IgG was elevated in 50/100 (50%), but was of peripheral origin, since QIgG was normal in almost all cases, as were QIgA and QIgM. In 58/103 samples (56%) pattern 4 oligoclonal bands (OCB) compatible with systemic inflammation were present, while CSF-restricted OCB were found in only 2/103 (1.9%). SARS-CoV-2-CSF-PCR was negative in 76/76 samples. Routine CSF findings were normal in 35%. Cytokine levels were frequently elevated in the CSF (often associated with BCB dysfunction) and serum, partly remaining positive at high levels for weeks/months (939 tests). Of note, a positive SARS-CoV-2-IgG-antibody index (AI) was found in 2/19 (10.5%) patients which was associated with unusually high WCC in both of them and a strongly increased interleukin-6 (IL-6) index in one (not tested in the other). Anti-neuronal/anti-glial autoantibodies were mostly absent in the CSF and serum (1509 tests). In samples from patients with pre-/coexisting CNS disorders (group II [N = 19]; including multiple sclerosis, JC-virus-associated immune reconstitution inflammatory syndrome, HSV/VZV encephalitis/meningitis, CNS lymphoma, anti-Yo syndrome, subarachnoid hemorrhage), CSF findings were mostly representative of the respective disease. CONCLUSIONS: The CSF profile in COVID-19 with neurological symptoms is mainly characterized by BCB disruption in the absence of intrathecal inflammation, compatible with cerebrospinal endotheliopathy. Persistent BCB dysfunction and elevated cytokine levels may contribute to both acute symptoms and 'long COVID'. Direct infection of the CNS with SARS-CoV-2, if occurring at all, seems to be rare. Broad differential diagnostic considerations are recommended to avoid misinterpretation of treatable coexisting neurological disorders as complications of COVID-19.

The HeMoVal study protocol: a prospective international multicenter cohort study to validate cerebrospinal fluid hemoglobin as a monitoring biomarker for aneurysmal subarachnoid hemorrhage related secondary brain injury.

INTRODUCTION: Preclinical studies provided a strong rationale for a pathophysiological link between cell-free hemoglobin in the cerebrospinal fluid (CSF-Hb) and secondary brain injury after subarachnoid hemorrhage (SAH-SBI). In a single-center prospective observational clinical study, external ventricular drain (EVD) based CSF-Hb proved to be a promising biomarker to monitor for SAH-SBI. The primary objective of the HeMoVal study is to prospectively validate the association between EVD based CSF-Hb and SAH-SBI during the first 14 days post-SAH. Secondary objectives include the assessment of the discrimination ability of EVD based CSF-Hb for SAH-SBI and the definition of a clinically relevant range of EVD based CSF-Hb toxicity. In addition, lumbar drain (LD) based CSF-Hb will be assessed for its association with and discrimination ability for SAH-SBI. METHODS: HeMoVal is a prospective international multicenter observational cohort study. Adult patients admitted with aneurysmal subarachnoid hemorrhage (aSAH) are eligible. While all patients with aSAH are included, we target a sample size of 250 patients with EVD within the first 14 day after aSAH. Epidemiologic and disease-specific baseline measures are assessed at the time of study inclusion. In patients with EVD or LD, each day during the first 14 days post-SAH, 2 ml of CSF will be sampled in the morning, followed by assessment of the patients for SAH-SBI, co-interventions, and complications in the afternoon. After 3 months, a clinical follow-up will be performed. For statistical analysis, the cohort will be stratified into an EVD, LD and full cohort. The primary analysis will quantify the strength of association between EVD based CSF-Hb and SAH-SBI in the EVD cohort based on a generalized additive model. Secondary analyses include the strength of association between LD based CSF-Hb and SAH-SBI in the LD cohort based on a generalized additive model, as well as the discrimination ability of CSF-Hb for SAH-SBI based on receiver operating characteristic (ROC) analyses. DISCUSSION: We hypothesize that this study will validate the value of CSF-Hb as a biomarker to monitor for SAH-SBI. In addition, the results of this study will provide the potential base to define an intervention threshold for future studies targeting CSF-Hb toxicity after aSAH. STUDY REGISTRATION: ClinicalTrials.gov Identifier NCT04998370 . Date of registration: August 10, 2021.

Sex-Related Differences in Patients' Characteristics, Provided Care, and Outcomes Following Spontaneous Intracerebral Hemorrhage.

BACKGROUND: Sex-related differences in patients with spontaneous, non-traumatic intracerebral hemorrhage (ICH) are poorly investigated so far. This study elucidates whether sex-related differences in ICH care in a neurocritical care setting exist, particularly regarding provided care, while also taking patient characteristics, and outcomes into account. METHODS: This retrospective single center study includes all consecutive patients with spontaneous ICH admitted to the neurocritical care unit in a 10-year period. Patients' demographics, comorbidities, symptoms at presentation, radiological findings, surgical and medical provided care, intensive care unit mortality and 12 month-mortality, and functional outcome at discharge were compared among men and women. RESULTS: Overall, 398 patients were included (male = 198 and female = 200). No differences in demographics, Charlson Comorbidity Index (CCI), symptoms at presentation, radiological findings, intensive care unit mortality and 12-month mortality were observed among men and women. Men received an external ventricular drain (EVD) for hydrocephalus-therapy significantly more often than women, despite similar location of the ICH and radiographic parameters. In the multivariate analysis, EVD insertion was independently associated with male sex (odds ratio 2.82, 95% confidence interval 1.61-4.95, P < 0.001) irrespective of demographic or radiological features. Functional outcome after ICH as assessed by the modified Rankin scale, was more favorable for women (P = 0.044). CONCLUSIONS: Sex-related differences in patients with ICH regarding to provided neurosurgical care exist. We provide evidence that insertion of EVD is associated with male sex, disregarding clear reasoning. A sex-bias as well as social factors may play a significant role in decision-making for the insertion of an EVD.

Blood Pressure Variability Indices for Outcome Prediction After Thrombectomy in Stroke by Using High-Resolution Data.

BACKGROUND: Blood pressure variability (BPV) is associated with outcome after endovascular thrombectomy in acute large vessel occlusion stroke. We aimed to provide the optimal sampling frequency and BPV index for outcome prediction by using high-resolution blood pressure (BP) data. METHODS: Patient characteristics, 3-month outcome, and BP values measured intraarterially at 1 Hz for up to 24 h were extracted from 34 patients treated at a tertiary care center neurocritical care unit. Outcome was dichotomized (modified Rankin Scale 0-2, favorable, and 3-6, unfavorable) and associated with systolic BPV (as calculated by using standard deviation, coefficient of variation, averaged real variability, successive variation, number of trend changes, and a spectral approach using the power of specific BP frequencies). BP values were downsampled by either averaging or omitting all BP values within each prespecified time bin to compare the different sampling rates. RESULTS: Out of 34 patients (age 72 ± 12.7 years, 67.6% men), 10 (29.4%) achieved a favorable functional outcome and 24 (70.6%) had an unfavorable functional outcome at 3 months. No group differences were found in mean absolute systolic BP (SBP) (130 ± 18 mm Hg, p = 0.82) and diastolic BP (DBP) (59 ± 10 mm Hg, p = 1.00) during the monitoring time. BPV only reached predictive significance when using successive variation extracted from downsampled (averaged over 5 min) SBP data (median 4.8 mm Hg [range 3.8-7.1]) in patients with favorable versus 7.1 mmHg [range 5.5-9.7] in those with unfavorable outcome, area under the curve = 0.74 [confidence interval (CI) 0.57-0.85; p = 0.031], or the power of midrange frequencies between 1/20 and 1/5 min [area under the curve = 0.75 (CI 0.59-0.86), p = 0.020]. CONCLUSIONS: Using high-resolution BP data of 1 Hz, downsampling by averaging all BP values within 5-min intervals is essential to find relevant differences in systolic BPV, as noise can be avoided (confirmed by the significance of the power of midrange frequencies). These results demonstrate how high-resolution BP data can be processed for effective outcome prediction.

Impact of Seizures and Status Epilepticus on Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: We aimed to evaluate the association between seizures as divided by timing and type (seizures or status epilepticus) and outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). METHODS: All consecutive patients with aSAH admitted to the neurocritical care unit of the University Hospital Zurich between 2016 and 2020 were included. Seizure type and frequency were extracted from electronic patient files. RESULTS: Out of 245 patients, 76 experienced acute symptomatic seizures, with 39 experiencing seizures at onset, 18 experiencing acute seizures, and 19 experiencing acute nonconvulsive status epilepticus (NCSE). Multivariate analysis revealed that acute symptomatic NCSE was an independent predictor of unfavorable outcome (odds ratio 14.20, 95% confidence interval 1.74-116.17, p = 0.013) after correction for age, Hunt-Hess grade, Fisher grade, and delayed cerebral ischemia. Subgroup analysis showed a significant association of all seizures/NCSE with higher Fisher grade (p < 0.001 for acute symptomatic seizures/NCSE, p = 0.031 for remote symptomatic seizures). However, although acute seizures/NCSE (p = 0.750 and 0.060 for acute seizures/NCSE respectively) were not associated with unfavorable outcome in patients with a high Hunt-Hess grade, they were significantly associated with unfavorable outcome in patients with a low Hunt-Hess grade (p = 0.019 and p < 0.001 for acute seizures/NCSE, respectively). CONCLUSIONS: Acute symptomatic NCSE independently predicts unfavorable outcome after aSAH. Seizures and NCSE are associated with unfavorable outcome, particularly in patients with a low Hunt-Hess grade. We propose that NCSE and the ictal or postictal reduction of Glasgow Coma Scale may hamper close clinical evaluation for signs of delayed cerebral ischemia, and thus possibly leading to delayed diagnosis and therapy thereof in patients with a low Hunt-Hess grade.

Intracerebral endotheliitis and microbleeds are neuropathological features of COVID-19.

Coronavirus disease 19 (COVID-19) is a rapidly evolving pandemic caused by the coronavirus Sars-CoV-2. Clinically manifest central nervous system symptoms have been described in COVID-19 patients and could be the consequence of commonly associated vascular pathology, but the detailed neuropathological sequelae remain largely unknown. A total of six cases, all positive for Sars-CoV-2, showed evidence of cerebral petechial hemorrhages and microthrombi at autopsy. Two out of six patients showed an elevated risk for disseminated intravascular coagulopathy according to current criteria and were excluded from further analysis. In the remaining four patients, the hemorrhages were most prominent at the grey and white matter junction of the neocortex, but were also found in the brainstem, deep grey matter structures and cerebellum. Two patients showed vascular intramural inflammatory infiltrates, consistent with Sars-CoV-2-associated endotheliitis, which was associated by elevated levels of the Sars-CoV-2 receptor ACE2 in the brain vasculature. Distribution and morphology of patchy brain microbleeds was clearly distinct from hypertension-related hemorrhage, critical illness-associated microbleeds and cerebral amyloid angiopathy, which was ruled out by immunohistochemistry. Cerebral microhemorrhages in COVID-19 patients could be a consequence of Sars- CoV-2-induced endotheliitis and more general vasculopathic changes and may correlate with an increased risk of vascular encephalopathy.

The effect of nimodipine on pulmonary function in artificially ventilated patients with aneurysmal subarachnoid hemorrhage.

BACKGROUND: Nimodipine is routinely administered in patients with aneurysmal subarachnoid hemorrhage (aSAH). However, the effect of nimodipine on oxygen exchange in the lungs is insufficiently explored. METHODS: The study explored nimodipine medication in artificially ventilated patients with aSAH. The data collection period was divided into nimodipine-dependent (ND) and nimodipine-independent (NID) periods. Values for arterial partial pressure of oxygen (PaO2) and fraction of inspired oxygen (FiO2) were collected and compared between the periods. Patients were divided in those with lung injury (LI), defined as median Horowitz index (PaO2/FiO2) ≤40 kPa (≤300 mmHg), and without and in those with lower respiratory tract infection (LRTI) and without. RESULTS: A total of 53 out of 150 patients were artificially ventilated, and in 29 patients, the Horowitz index could be compared between ND and NID periods. A linear mixed model showed that during ND period the Horowitz index was 2.3 kPa (95% CI, 1.0-3.5 kPa, P<0.001) lower when compared to NID period. The model suggested that in the presence of LI, ND period is associated with a decrease of the index by 2.8 kPa (95% CI, 1.2-4.3 kPa, P<0.001). The decrease was more pronounced with LRTI than without: 3.4 kPa (95% CI, 0.8-6.1 kPa) vs. 2.1 kPa (95% CI, 0.7-3.4 kPa), P=0.011 and P=0.002, respectively. CONCLUSIONS: In patients with LI or LRTI in the context of aSAH, pulmonary function may worsen with nimodipine treatment. The drop of 2 to 3 kPa of the Horowitz index in patients with no lung pathology may not outweigh the benefits of nimodipine. However, in individuals with concomitant lung injury, the effect may be clinically relevant.

Large and Small Cerebral Vessel Involvement in Severe COVID-19: Detailed Clinical Workup of a Case Series.

BACKGROUND AND PURPOSE: Case series indicating cerebrovascular disorders in coronavirus disease 2019 (COVID-19) have been published. Comprehensive workups, including clinical characteristics, laboratory, electroencephalography, neuroimaging, and cerebrospinal fluid findings, are needed to understand the mechanisms. METHODS: We evaluated 32 consecutive critically ill patients with COVID-19 treated at a tertiary care center from March 9 to April 3, 2020, for concomitant severe central nervous system involvement. Patients identified underwent computed tomography, magnetic resonance imaging, electroencephalography, cerebrospinal fluid analysis, and autopsy in case of death. RESULTS: Of 32 critically ill patients with COVID-19, 8 (25%) had severe central nervous system involvement. Two presented with lacunar ischemic stroke in the early phase and 6 with prolonged impaired consciousness after termination of analgosedation. In all but one with delayed wake-up, neuroimaging or autopsy showed multiple cerebral microbleeds, in 3 with additional subarachnoid hemorrhage and in 2 with additional small ischemic lesions. In 3 patients, intracranial vessel wall sequence magnetic resonance imaging was performed for the first time to our knowledge. All showed contrast enhancement of vessel walls in large cerebral arteries, suggesting vascular wall pathologies with an inflammatory component. Reverse transcription-polymerase chain reactions for SARS-CoV-2 in cerebrospinal fluid were all negative. No intrathecal SARS-CoV-2-specific IgG synthesis was detectable. CONCLUSIONS: Different mechanisms of cerebrovascular disorders might be involved in COVID-19. Acute ischemic stroke might occur early. In a later phase, microinfarctions and vessel wall contrast enhancement occur, indicating small and large cerebral vessels involvement. Central nervous system disorders associated with COVID-19 may lead to long-term disabilities. Mechanisms should be urgently investigated to develop neuroprotective strategies.

Outcome, Return to Work and Health-Related Costs After Aneurysmal Subarachnoid Hemorrhage.

OBJECT: Data on health-related costs after aneurysmal subarachnoid hemorrhage (aSAH) are limited. The aim was to evaluate outcome, return to work and costs after aSAH with focus on differences between high- and low-grade aSAH (defined as World Federation of Neurological Surgeons [WFNS] grades 4-5 and WFNS 1-3, respectively). METHODS: A cross-sectional study was performed, including all consecutive survivors of aSAH over a 4-year period. A telephone interview was conducted to assess the Glasgow Outcome Scale Extended and employment status before and after aSAH. Direct costs were calculated by multiplying the length of hospitalization by the average daily costs. Indirect costs were calculated for productivity losses until retirement age according to the human capital approach. RESULTS: Follow-up was performed 2.7 years after aSAH (range 1.3-4.6). Favorable outcome was achieved in 114 of 150 patients (76%) and work recovery in 61 of 98 patients (62%) employed prior to aSAH. High-grade compared to low-grade aSAH resulted less frequently in favorable outcome (52% vs. 85%; p < 0.001) and work recovery (39% vs. 69%; p = 0.013). The total costs were € 344.277 (95% CI 268.383-420.171) per patient, mainly accounted to indirect costs (84%). The total costs increased with increasing degree of disability and were greater for high-grade compared to low-grade aSAH (€ 422.496 vs. € 329.193; p = 0.039). The effective costs per patient with favorable outcome were 2.1-fold greater for high-grade compared to low-grade aSAH (€ 308.625 vs. € 134.700). CONCLUSION: Favorable outcome can be achieved in a considerable proportion of high-grade aSAH patients, but costs are greater compared to low-grade aSAH. Further cost-effectiveness studies in the current era of aSAH management are needed.

Automated False Alarm Reduction in a Real-Life Intensive Care Setting Using Motion Detection.

BACKGROUND: Contemporary monitoring systems are sensitive to motion artifacts and cause an excess of false alarms. This results in alarm fatigue and hazardous alarm desensitization. To reduce the number of false alarms, we developed and validated a novel algorithm to classify alarms, based on automatic motion detection in videos. METHODS: We considered alarms generated by the following continuously measured parameters: arterial oxygen saturation, systolic blood pressure, mean blood pressure, heart rate, and mean intracranial pressure. The movements of the patient and in his/her surroundings were monitored by a camera situated at the ceiling. Using the algorithm, alarms were classified into RED (true), ORANGE (possibly false), and GREEN alarms (false, i.e., artifact). Alarms were reclassified by blinded clinicians. The performance was evaluated using confusion matrices. RESULTS: A total of 2349 alarms from 45 patients were reclassified. For RED alarms, sensitivity was high (87.0%) and specificity was low (29.6%) for all parameters. As the sensitivities and specificities for RED and GREEN alarms are interrelated, the opposite was observed for GREEN alarms, i.e., low sensitivity (30.2%) and high specificity (87.2%). As RED alarms should not be missed, even at the expense of false positives, the performance was acceptable. The low sensitivity for GREEN alarms is acceptable, as it is not harmful to tag a GREEN alarm as RED/ORANGE. It still contributes to alarm reduction. However, a 12.8% false-positive rate for GREEN alarms is critical. CONCLUSIONS: The proposed system is a step forward toward alarm reduction; however, implementation of additional layers, such as signal curve analysis, multiple parameter correlation analysis and/or more sophisticated video-based analytics are needed for improvement.