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Background: Epilepsy is highly heritable, with numerous known genetic risk loci. However, the genetic predisposition's role in poststroke epilepsy (PSE) remains understudied. This study assesses whether a higher genetic predisposition to epilepsy raises poststroke survivor's risk of PSE., Methods: We conducted a case-control genetic association study nested within the UK Biobank, a large UK-based prospective cohort. Our exposures of interest were 2 distinct polygenic risk scores-generalized and focal epilepsy-modeled as deciles and constructed using genetic variants identified in the latest International League Against Epilepsy genome-wide association study meta-analysis. We aimed to evaluate the association between these polygenic risk scores and their corresponding subtype of PSE-generalized and focal. In sensitivity analyses, we evaluated participants of European ancestry separately and considered focal and generalized epilepsy outcomes in participants without a history of stroke. In secondary analyses, we evaluated the polygenic risk of PSE by stroke subtype (ischemic, hemorrhagic, or any stroke). Multivariable logistic regression models were fitted, adjusting for age, sex, genetic ancestry, and the first 5 principal genetic components., Results: Among 17 549 UK Biobank stroke survivors with available genetic information (mean age, 61; 43% female), 185 (1%) developed generalized PSE, while 124 (0.7%) developed focal PSE. Multivariable logistic regression results showed that, when compared against the lowest decile, participants within the highest PRS decile for generalized PSE had 5-fold higher odds of developing generalized PSE (OR, 5.05 [95% CI, 2.37-12.5]; P trend<0.001). Similarly, when compared against the lowest decile, participants within the highest polygenic risk score decile for focal PSE had 3-fold higher odds of developing focal PSE (OR, 3.20; [5% CI, 1.25-9.82]; P trend=0.024). Sensitivity analyses among participants of European ancestry yielded similar results., Conclusions: Our findings suggest that, like other forms of epilepsy, genetic predisposition plays an essential role in PSE. These results underscore the need for future studies to elucidate the mechanisms underlying PSE development and to identify novel therapeutic avenues.

Background: Cranial nerve (CN) palsies are rare presenting symptoms of intracranial aneurysms. Our objectives were to report our institutional outcomes and study-level meta-analysis summarizing rates of improvement and identifying factors associated with recovery from CN symptoms after flow diversion., Methods: We conducted a retrospective review of our institutional database for patients with intracranial aneurysms presenting with CN palsies who underwent treatment with flow diversion between 2015 and 2023. Systematic review of the literature was performed using Medline, EMBASE, Cochrane, as well as manual citation searches. Random effects meta-analysis was used., Results: Thirteen of 136 studies were included in the meta-analysis and were combined with our institutional data. The pooled rate of improvement in any CN palsies following flow diversion was 71 % (95 %CI, 60 %-82 %, n=322). Patients presenting with CN II deficits were less likely to improve following treatment compared to other CN deficits (pooled OR [pOR] 0.32, 95 %CI, 0.16-0.63, n=224). The pooled rate of clinical improvement was 53 % in CNII deficits (95 %CI, 42 %-65 %, n=80) and 80 % in other CN deficits (95 %CI, 71 %-88 %, n=106). An increased rate of improvement was associated with acute intervention (pOR 9.12, 95 % CI, 2.26-36.73, n = 71) and radiographic aneurysm occlusion (pOR 5.29, 95 %CI, 1.66-16.90, n=118)., Conclusions: Flow diversion improves CN palsy outcomes in patients with symptomatic intracranial aneurysms. The lower rate of improvement in visual acuity compared to other CN deficits may point to a different mechanism of injury or potential recoverability in these patients., Competing Interests: Declaration of Competing Interest The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article., (Copyright © 2024. Published by Elsevier B.V.)

Study Objective: Temperature control trials in cardiac arrest patients have not reliably conferred neuroprotective benefit but have been limited by inconsistent treatment parameters. To evaluate the presence of a time dependent treatment effect, we assessed the association between preinduction time and clinical outcomes., Methods: In this retrospective, single academic center study between 2014 and 2022, consecutive out-of-hospital cardiac arrest (OHCA) patients treated with temperature control were identified. Preinduction was defined as the time from hospital arrival to initiation of a closed-loop temperature feedback device [door to temperature control initiation time], and early door to temperature control device time was defined a priori as <3 hours. We assessed the association between good neurologic outcome (cerebral performance category 1 to 2) and door to temperature control device time using logistic regression. The proportion of patients who survived to hospital discharge was evaluated as a secondary outcome. A sensitivity analysis using inverse probability treatment weighting, created using a propensity score, was performed to minimize measurable confounding., Results: Three hundred and forty-seven OHCA patients were included; the early door to temperature control device cohort included 75 (21.6%) patients with a median (interquartile range) door to temperature control device time of 2.50 (2.03 to 2.75) hours, whereas the late door to temperature control device cohort included 272 (78.4%) patients with a median (interquartile range) door to temperature control device time of 5.18 (4.19 to 6.41) hours. In the multivariable logistic regression model, early door to temperature control device time was associated with improved good neurologic outcome and survival before [adjusted odds ratio (OR) (95% confidence interval) 2.36 (1.16 to 4.81) and 3.02 (1.54 to 6.02)] and after [adjusted OR (95% confidence interval) 1.95 (1.19 to 3.79) and 2.14 (1.33 to 3.36)] inverse probability of treatment weighting, respectively., Conclusion: In our study of OHCA patients, a shorter preinduction time for temperature control was associated with improved good neurologic outcome and survival. This finding may indicate that early initiation in the emergency department will confer benefit. Our findings are hypothesis generating and need to be validated in future prospective trials., (Copyright © 2024 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.)

Introduction: Increasing use of continuous EEG monitoring (cEEG) provides the opportunity to observe temporal trends in EEG patterns during the acute phase of brain injury. These trends have not been extensively documented. Methods We conducted a retrospective chart review of patients undergoing cEEG between January 1st and June 30th, 2019, at two academic medical centers. Only patients with acute brain injury having electrographic or electroclinical seizures or epileptic EEG findings on day one of monitoring and ≥ two calendar days of cEEG were included. The temporal evolution of EEG patterns was depicted as a heatmap. Results Of 1356 screened patients, 101 met the study criteria. Clinical acute symptomatic seizures occurred in 30 patients (29.7%) prior to EEG. The median number of days of cEEG was four (IQR 3-6). Amongst patients with electrographic seizures, status epilepticus, generalized periodic discharges, or sporadic epileptiform discharges, 24.6% had improvement and 54.1% had resolution of epileptic EEG findings by the final day of monitoring. In contrast, 65% with lateralized periodic discharges or lateralized rhythmic delta activity persisted or worsened. Overall, 61.4% (62/101) showed either improvement (19.8%) or resolution (41.6%) of their EEG findings prior to hospital discharge. Of the 36 patients with follow-up EEGs at a median of 4.5 (IQR 3-8) months after admission for acute brain injury, 83% (30/36) showed either improvement (1/36; 2.7%) or resolution (29/36; 80.6%). Conclusions We observed a trend towards normalization of most epileptiform patterns except LPDs and LRDA, over time in patients with acute brain injury. The clinical significance of this trend as it relates to antiseizure medication treatment and neurologic outcomes warrants further investigation in an independent cohort.

Introduction: Rocky Mountain Spotted Fever (RMSF) is a tick-borne disease caused by Rickettsia rickettsii (R. rickettsii). RMSF presents after a tick bite with fever, rash, and headache but can also cause more serious neurological manifestations. We report a case of RMSF encephalitis presenting with altered sensorium and rapid progression to coma, fever, and petechial rash, and an magnetic resonance imaging (MRI) brain notable for a "starry sky" pattern., Case Report: A 61-year-old woman presented with confusion and fever and was diagnosed with a urinary tract infection. Two days later, she became comatose. MRI brain revealed lacunar infarcts in the right centrum semiovale and splenium of the corpus callosum. Lumbar puncture was notable for neutrophilic pleocytosis and elevated protein with negative bacterial and viral cultures. Empiric meningitis therapy was initiated, and she was transferred to our institution. On transfer, she was febrile, comatose, and had a diffuse petechial rash. Repeat MRI brain demonstrated diffuse, innumerable punctate foci of diffusion restriction with susceptibility-weighted signal attenuation throughout cerebral hemispheres in a "starry sky" pattern. Skin biopsy revealed perivascular lymphocytic infiltrates. Serologic RSMF antibody titers were obtained, and doxycycline was initiated for presumed RMSF encephalitis. The family opted to pursue palliative measures, given no clinical improvement. RSMF titers and postmortem PCR from brain tissue were positive for R. rickettsii., Conclusions: This case report highlights the clinical presentation of RMSF encephalitis. RMSF encephalitis should be suspected in a patient presenting with encephalopathy, fever, petechial rash, and MRI brain findings of diffuse punctate foci of diffusion restriction and susceptibility-weighted signal attenuation in a "starry-sky" pattern., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Aim: Temperature control is a complex bundled intervention; the synergistic impact of each individual component is ill defined and underreported. Resultantly, the influence of parameter optimization on temperature control's overall neuroprotective effect remains poorly understood. To characterize variability in temperature control parameters and barriers to short pre-induction and induction times, we surveyed sites enrolling in an ongoing multicenter clinical trial., Methods: This was a cross-sectional, survey study evaluating temperature control practices within the Influence of Cooling duration on Efficacy in Cardiac Arrest Patients (ICECAP) trial (NCT04217551). A 23-question web-based survey (Qualtrics) was distributed to the site principal investigators by email. Respondents were asked about site practices pertaining to the use of temperature control, including the request to upload individual institutional protocols. Open-ended responses were analyzed qualitatively by categorizing responses into identified themes. To complement survey level data, records pertaining to the quality of temperature control were extracted from the ICECAP trial database., Results: The survey response rate was 75% (n = 51) including 23.5% (n = 12) survey respondents who uploaded institutional protocols. Most sites reported having institutional protocols for temperature control (n = 41; 80%), including 62.5% (n = 32) who had separate protocols for initiation of temperature control in the emergency department (ED). Fewer sites had protocols specific to sedation or neuromuscular blockade (NMB) management (n = 35, 68.6%). Use of NMB during temperature control induction was variable; 61.7% (n = 29) of sites induced paralysis less than 20% of the time. While most institutional protocols (n = 11, 83.3%) commented on the importance of early initiation of temperature control, this was incongruent with the largest reported barrier, which was clinical nihilism regarding the importance of early temperature control initiation (n = 30, 62.5%). Within the ICECAP trial database, 1 in 2 patients were treated with NMB however, use of NMB and time to initiation of temperature control device varied widely between sites., Conclusion: Amongst ICECAP trial sites, there was significant variability in resources, methods, and barriers for early temperature control initiation. Defining and standardizing high-quality temperature control must be prioritized, as it may impact the interpretation of past and current clinical trial findings., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: ‘The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The following conflicts of interest should be reported: SY, RC, RR: support from NIH for ICECAP DCC work scope, PK, RG, RS, WM: support from NIH for ICECAP CCC work scope. Multiple authors are supported by the following grants: UG3HL145269, UH3HL145269, U24HL145272, U24NS100659, U24NS100655 from the National Heart, Lung and Blood Institute (NHLBI) and the National Institute of Neurological Disorders and Stroke (NINDS). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.’., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Aim: Magnetic Resonance Imaging (MRI) is an important prognostic tool in cardiac arrest (CA) survivors given its sensitivity for detecting hypoxic-ischemic brain injury (HIBI), however, it is limited by poorly defined objective thresholds. To address this limitation, we evaluated a qualitative MRI score for predicting neurological outcome in CA survivors., Methods: Adult comatose CA survivors who underwent MRI were retrospectively identified at a single academic medical center. Two blinded neurointensivists qualitatively scored HIBI amongst 12 MRI brain regions. Scores were summated to form four distinct score groups: cortex, deep grey nuclei (DGN), cortex-DGN combined, and total (cortex, DGN, brainstem, and cerebellum). Poor neurological outcome was defined as Cerebral Performance Category (CPC) score 3-5 at hospital discharge. Inter-rater reliability was tested using intra-class correlation (ICC) and discrimination of poor neurological outcome assessed using area under the receiver operating curve (AUC)., Results: Our cohort included 219 patients with median time to MRI of 96 (IQR 81-110) hours. ICC (95% CI) was good to excellent across all MRI scores: cortex 0.92 (0.89-0.94), DGN 0.88 (0.80-0.92), cortex-DGN 0.94 (0.92-0.95), and total 0.93 (0.91-0.95). AUC (95% CI) for poor outcome was good across all MRI scores: cortex 0.84 (0.78-0.90), DGN 0.83 (0.77-0.89), cortex-DGN 0.83 (0.77-0.89), and total 0.83 (0.77-0.88)., Conclusion: A simplified, qualitative MRI score had excellent reliability and good discrimination for poor neurologic outcome. Further work is necessary to externally validate our findings in an independent, ideally prospective, cohort., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: “Dr. Tripodis receives research support from the NIH and the AMA. Dr. Greer receives research funding in the form of a grant to Boston Medical Center to conduct the INTREPID study as co-PI, including reimbursed travel to present results at major conferences. In unrelated support, Dr. Greer receives research support from NIH/NINDS, as well as personal compensation as Editor-in-Chief for Seminars in Neurology, royalties for several books, as well as medical-legal expert work.”., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: The Brain Oxygen Optimization in Severe Traumatic Brain Injury Phase II randomized controlled trial used a tier-based management protocol based on brain tissue oxygen (PbtO 2 ) and intracranial pressure (ICP) monitoring to reduce brain tissue hypoxia after severe traumatic brain injury. We performed a secondary analysis to explore the relationship between brain tissue hypoxia, blood pressure (BP), and interventions to improve cerebral perfusion pressure (CPP). We hypothesized that BP management below the lower limit of autoregulation would lead to cerebral hypoperfusion and brain tissue hypoxia that could be improved with hemodynamic augmentation., Methods: Of the 119 patients enrolled in the Brain Oxygen Optimization in Severe Traumatic Brain Injury Phase II trial, 55 patients had simultaneous recordings of arterial BP, ICP, and PbtO 2 . Autoregulatory function was measured by interrogating changes in ICP and PbtO 2 in response to fluctuations in CPP using time-correlation analysis. The resulting autoregulatory indices (pressure reactivity index and oxygen reactivity index) were used to identify the "optimal" CPP and limits of autoregulation for each patient. Autoregulatory function and percent time with CPP outside personalized limits of autoregulation were calculated before, during, and after all interventions directed to optimize CPP., Results: Individualized limits of autoregulation were computed in 55 patients (mean age 38 years, mean monitoring time 92 h). We identified 35 episodes of brain tissue hypoxia (PbtO 2  < 20 mm Hg) treated with CPP augmentation. Following each intervention, mean CPP increased from 73 ± 14 mm Hg to 79 ± 17 mm Hg (p = 0.15), and mean PbtO 2 improved from 18.4 ± 5.6 mm Hg to 21.9 ± 5.6 mm Hg (p = 0.01), whereas autoregulatory function trended toward improvement (oxygen reactivity index 0.42 vs. 0.37, p = 0.14; pressure reactivity index 0.25 vs. 0.21, p = 0.2). Although optimal CPP and limits remained relatively unchanged, there was a significant decrease in the percent time with CPP below the lower limit of autoregulation in the 60 min after compared with before an intervention (11% vs. 23%, p = 0.05)., Conclusions: Our analysis suggests that brain tissue hypoxia is associated with cerebral hypoperfusion characterized by increased time with CPP below the lower limit of autoregulation. Interventions to increase CPP appear to improve autoregulation. Further studies are needed to validate the importance of autoregulation as a modifiable variable with the potential to improve outcomes., (© 2023. Springer Science+Business Media, LLC, part of Springer Nature and Neurocritical Care Society.)

Background: Cerebral edema is a common, potentially life-threatening complication in critically ill patients with acute brain injury. However, uncertainty remains regarding best monitoring and treatment strategies, which may result in wide practice variations., Methods: A 20-question digital survey on monitoring and management practices was disseminated between July 2022 and May 2023 to clinicians who manage cerebral edema. The survey was promoted through email, social media, medical conferences, and the Neurocritical Care Society Web site. We used the χ 2 test, Fisher's exact test, analysis of variance, and logistic regression to report factors associated with practice variation, diagnostic monitoring methods, and therapeutic triggers based on practitioner and institutional characteristics., Results: Of 321 participants from 160 institutions in 30 countries, 65% were from university-affiliated centers, 74% were attending physicians, 38% were woman, 38% had neurology training, and 55% were US-based. Eighty-four percent observed practice variations at their institutions, with "provider preference" being cited most (87%). Factors linked to variation included gender, experience, university affiliation, and practicing outside the United States. University affiliates tended to use more tests (median 3.87 vs. 3.43, p = 0.01) to monitor cerebral edema. Regarding management practices, 20% of respondents' preferred timing for decompressive hemicraniectomy was after 48 h, and 37% stated that radiographic findings only would be sufficient to trigger surgery. Fifty percent of respondents reported initiating osmotic therapy based on radiographic indications or prophylactically. There were no significant associations between management strategies and respondent or center characteristics. Twenty-seven percent of respondents indicated that they acquired neuroimaging at intervals of 24 h or less. Within this group, attending physicians were more likely to follow this practice (65.5% vs. 34.5%, p = 0.04)., Conclusions: Cerebral edema monitoring and management strategies vary. Features associated with practice variations include both practitioner and institutional characteristics. We provide a foundation for understanding practice patterns that is crucial for informing educational initiatives, standardizing guidelines, and conducting future trials., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature and Neurocritical Care Society.)

Hypoxic-ischemic brain injury (HIBI) is the leading cause of death and disability after cardiac arrest. To date, temperature control is the only intervention shown to improve neurologic outcomes in patients with HIBI. Despite robust preclinical evidence supporting hypothermia as neuroprotective therapy after cardiac arrest, there remains clinical equipoise regarding optimal core temperature, therapeutic window, and duration of therapy. Current guidelines recommend continuous temperature monitoring and active fever prevention for at least 72 h and additionally note insufficient evidence regarding temperature control targeting 32 °C-36 °C. However, population-based thresholds may be inadequate to support the metabolic demands of ischemic, reperfused, and dysregulated tissue. Promoting a more personalized approach with individualized targets has the potential to further improve outcomes. This review will analyze current knowledge and evidence, address research priorities, explore the components of high-quality temperature control, and define critical future steps that are needed to advance patient-centered care for cardiac arrest survivors., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: There is practice heterogeneity in the use, type, and duration of prophylactic antiseizure medications (ASMs) in patients with moderate-severe traumatic brain injury (TBI)., Methods: We conducted a systematic review and meta-analysis of articles assessing ASM prophylaxis in adults with moderate-severe TBI (acute radiographic findings and requiring hospitalization). The population, intervention, comparator, and outcome (PICO) questions were as follows: (1) Should ASM versus no ASM be used in patients with moderate-severe TBI and no history of clinical or electrographic seizures? (2) If an ASM is used, should levetiracetam (LEV) or phenytoin/fosphenytoin (PHT/fPHT) be preferentially used? (3) If an ASM is used, should a long versus short (> 7 vs. ≤ 7 days) duration of prophylaxis be used? The main outcomes were early seizure, late seizure, adverse events, mortality, and functional outcomes. We used Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology to generate recommendations., Results: The initial literature search yielded 1998 articles, of which 33 formed the basis of the recommendations: PICO 1: We did not detect any significant positive or negative effect of ASM compared to no ASM on the outcomes of early seizure, late seizure, adverse events, or mortality. PICO 2: We did not detect any significant positive or negative effect of PHT/fPHT compared to LEV for early seizures or mortality, though point estimates suggest fewer late seizures and fewer adverse events with LEV. PICO 3: There were no significant differences in early or late seizures with longer versus shorter ASM use, though cognitive outcomes and adverse events appear worse with protracted use., Conclusions: Based on GRADE criteria, we suggest that ASM or no ASM may be used in patients hospitalized with moderate-severe TBI (weak recommendation, low quality of evidence). If used, we suggest LEV over PHT/fPHT (weak recommendation, very low quality of evidence) for a short duration (≤ 7 days, weak recommendation, low quality of evidence)., (© 2024. Neurocritical Care Society.)

The critical care management of patients after cardiac arrest is burdened by a lack of high-quality clinical studies and the resultant lack of high-certainty evidence. This results in limited practice guideline recommendations, which may lead to uncertainty and variability in management. Critical care management is crucial in patients after cardiac arrest and affects outcome. Although guidelines address some relevant topics (including temperature control and neurological prognostication of comatose survivors, 2 topics for which there are more robust clinical studies), many important subject areas have limited or nonexistent clinical studies, leading to the absence of guidelines or low-certainty evidence. The American Heart Association Emergency Cardiovascular Care Committee and the Neurocritical Care Society collaborated to address this gap by organizing an expert consensus panel and conference. Twenty-four experienced practitioners (including physicians, nurses, pharmacists, and a respiratory therapist) from multiple medical specialties, levels, institutions, and countries made up the panel. Topics were identified and prioritized by the panel and arranged by organ system to facilitate discussion, debate, and consensus building. Statements related to postarrest management were generated, and 80% agreement was required to approve a statement. Voting was anonymous and web based. Topics addressed include neurological, cardiac, pulmonary, hematological, infectious, gastrointestinal, endocrine, and general critical care management. Areas of uncertainty, areas for which no consensus was reached, and future research directions are also included. Until high-quality studies that inform practice guidelines in these areas are available, the expert panel consensus statements that are provided can advise clinicians on the critical care management of patients after cardiac arrest., (© 2023. The Author(s).)

The critical care management of patients after cardiac arrest is burdened by a lack of high-quality clinical studies and the resultant lack of high-certainty evidence. This results in limited practice guideline recommendations, which may lead to uncertainty and variability in management. Critical care management is crucial in patients after cardiac arrest and affects outcome. Although guidelines address some relevant topics (including temperature control and neurological prognostication of comatose survivors, 2 topics for which there are more robust clinical studies), many important subject areas have limited or nonexistent clinical studies, leading to the absence of guidelines or low-certainty evidence. The American Heart Association Emergency Cardiovascular Care Committee and the Neurocritical Care Society collaborated to address this gap by organizing an expert consensus panel and conference. Twenty-four experienced practitioners (including physicians, nurses, pharmacists, and a respiratory therapist) from multiple medical specialties, levels, institutions, and countries made up the panel. Topics were identified and prioritized by the panel and arranged by organ system to facilitate discussion, debate, and consensus building. Statements related to postarrest management were generated, and 80% agreement was required to approve a statement. Voting was anonymous and web based. Topics addressed include neurological, cardiac, pulmonary, hematological, infectious, gastrointestinal, endocrine, and general critical care management. Areas of uncertainty, areas for which no consensus was reached, and future research directions are also included. Until high-quality studies that inform practice guidelines in these areas are available, the expert panel consensus statements that are provided can advise clinicians on the critical care management of patients after cardiac arrest.

Endotracheal intubation, frequently required during management of refractory status epilepticus (RSE), can be facilitated by anesthetic medications; however, their effectiveness for RSE control is unknown. We performed a single-center retrospective review of patients admitted to a neurocritical care unit (NCCU) who underwent in-hospital intubation during RSE management. Patients intubated with propofol, ketamine, or benzodiazepines, termed anti-seizure induction (ASI), were compared to patients who received etomidate induction (EI). The primary endpoint was clinical or electrographic seizures within 12 h post-intubation. We estimated the association of ASI on post-intubation seizure using logistic regression. A sub-group of patients undergoing electroencephalography during intubation was identified to evaluate the immediate effect of ASI on RSE. We screened 697 patients admitted to the NCCU for RSE and identified 148 intubated in-hospital (n = 90 ASI, n = 58 EI). There was no difference in post-intubation seizure (26 % (n = 23) ASI, 29 % (n = 17) EI) in the cohort, however, there was increased RSE resolution with ASI in 24 patients with electrographic RSE during intubation (ASI: 61 % (n = 11/18) vs EI: 0 % (n = 0/6), p =.016). While anti-seizure induction did not appear to affect post-intubation seizure occurrence overall, a sub-group of patients undergoing electroencephalography during intubation had a higher incidence of seizure cessation, suggesting potential benefit in an enriched population., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Objectives: To address areas in which there is no consensus for the technologies, effort, and training necessary to integrate and interpret information from multimodality neuromonitoring (MNM)., Design: A three-round Delphi consensus process., Setting: Electronic surveys and virtual meeting., Subjects: Participants with broad MNM expertise from adult and pediatric intensive care backgrounds., Interventions: None., Measurements and Main Results: Two rounds of surveys were completed followed by a virtual meeting to resolve areas without consensus and a final survey to conclude the Delphi process. With 35 participants consensus was achieved on 49% statements concerning MNM. Neurologic impairment and the potential for MNM to guide management were important clinical considerations. Experts reached consensus for the use of MNM-both invasive and noninvasive-for patients in coma with traumatic brain injury, aneurysmal subarachnoid hemorrhage, and intracranial hemorrhage. There was consensus that effort to integrate and interpret MNM requires time independent of daily clinical duties, along with specific skills and expertise. Consensus was reached that training and educational platforms are necessary to develop this expertise and to provide clinical correlation., Conclusions: We provide expert consensus in the clinical considerations, minimum necessary technologies, implementation, and training/education to provide practice standards for the use of MNM to individualize clinical care., Competing Interests: Dr. Foreman’s institution received funding from the U.S. Department of Defense (DoD) (W81XWH-18-DMRDP-PTCRA); he received funding from Marinus Pharmaceuticals; he disclosed that he is on the Scientific Advisory Committee for the Neurocritical Care Society Curing Coma Campaign. Drs. Foreman and Appavu perform dedicated neuromonitoring services locally. Drs. Foreman and Rosenthal received Institutional support through U.S. Army W81XWH-18-DMRDP-PTCRA through parent award to Moberg Analytics. Drs. Foreman and Gilmore received funding from UCB Pharma. Drs. Foreman and Wainwright received funding from SAGE Therapeutics. Dr. Ngwenya’s institution received funding from Abbott and Biogen; she received funding from General Dynamics Information Technology/DoD. Dr. O’Phelan received funding from Bard Medical CEC. Dr. LaRovere disclosed that she has U.S. National Phase Applications (No.: 17/601,603, No.: US-2022-0181008-A1, Ref. No.: 21233 CMCC, Ref. No.: 3440 WGS, Ref. No.: M0437.70143US01 Patent—Issued). Dr. Appavu’s institution received funding from the U.S. DoD Congressionally Directed Medical Research Programs and the American Heart Association (AHA). Drs. Alkhachroum and Rosenthal received support for article research from the National Institutes of Health (NIH). Dr. Amorim received funding from the AHA (20CDA35310297, 83457), the CURE Epilepsy Foundation (Taking Flight Award), the NIH (1K23NS090900), the Hellman Fellows Fund, the Regents of the University of California (Resource Allocation Program), Cures Within Reach, and the Zoll Foundation. Dr. Gilmore received funding from the American Academy of Neurology and Caring Analytics Platform (CARPL.ai); she serves as Director of Neuromonitoring locally; co-founded Intracranial Bio Analytics; and holds NIH grant funding for development of a multimodal intracranial monitoring device and data visualization platform (UG3 NS123307). Dr. Rosenthal’s institution received funding from the NIH, the U.S. Army, Moberg Analytics, and Marinus Pharmaceuticals. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2023 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.)

Background: Neuroimaging is essential for detecting spontaneous, nontraumatic intracerebral hemorrhage (ICH). Recent data suggest ICH can be characterized using low-field magnetic resonance imaging (MRI). Our primary objective was to investigate the sensitivity and specificity of ICH on a 0.064T portable MRI (pMRI) scanner using a methodology that provided clinical information to inform rater interpretations. As a secondary aim, we investigated whether the incorporation of a deep learning (DL) reconstruction algorithm affected ICH detection., Methods: The pMRI device was deployed at Yale New Haven Hospital to examine patients presenting with stroke symptoms from October 26, 2020 to February 21, 2022. Three raters independently evaluated pMRI examinations. Raters were provided the images alongside the patient's clinical information to simulate real-world context of use. Ground truth was the closest conventional computed tomography or 1.5/3T MRI. Sensitivity and specificity results were grouped by DL and non-DL software to investigate the effects of software advances., Results: A total of 189 exams (38 ICH, 89 acute ischemic stroke, 8 subarachnoid hemorrhage, 3 primary intraventricular hemorrhage, 51 no intracranial abnormality) were evaluated. Exams were correctly classified as positive or negative for ICH in 185 of 189 cases (97.9% overall accuracy). ICH was correctly detected in 35 of 38 cases (92.1% sensitivity). Ischemic stroke and no intracranial abnormality cases were correctly identified as blood-negative in 139 of 140 cases (99.3% specificity). Non-DL scans had a sensitivity and specificity for ICH of 77.8% and 97.1%, respectively. DL scans had a sensitivity and specificity for ICH of 96.6% and 99.3%, respectively., Conclusions: These results demonstrate improvements in ICH detection accuracy on pMRI that may be attributed to the integration of clinical information in rater review and the incorporation of a DL-based algorithm. The use of pMRI holds promise in providing diagnostic neuroimaging for patients with ICH., Competing Interests: Disclosures Dr Sheth is the principal investigator. Dr Sheth reports compensation from CSL Behring for consultant services; grants from BARD; compensation from Astrocyte for consultant services; compensation from Rhaeos for consultant services; compensation from Certus for consultant services; grants from Novartis; a patent pending for Stroke wearables licensed to Alva Health; compensation from Cerevasc for consultant services; compensation from ZOLL Medical Corporation for data and safety monitoring services; grants from Hyperfine; employment by Yale School of Medicine; compensation from Sense for data and safety monitoring services; grants from Hyperfine to other; and grants from Biogen. Dr Kimberly reports grants from NControl Therapeutics; compensation from Astrocyte Pharmaceuticals for consultant services; compensation from Acasti Pharmaceuticals for consultant services; grants from Hyperfine Research Inc; a patent pending for No. 16/486 687, Methods and Compositions for Treating a Brain Injury. licensed to NControl Therapeutics; grants from Biogen; stock holdings in Woolsey Pharmaceuticals; and compensation from NControl Therapeutics for consultant services. Dr de Havenon reports compensation from Novo Nordisk for consultant services; compensation from Integra for consultant services; grants from National Institutes of Health (NIH); stock options in Certus; and stock options in TitinKM. Dr Rosen reports grants from American Heart Association (AHA), Advanced Research Projects Agency–Energy (ARPA-E), Department of Energy (DOE), and the NIH. Dr Rosen is on the scientific advisory board of ABQMR, Synex Medical, Inc, Nanalysis, Inc, O2M Technologies, Inc, Quantum Catalyzer, Inc, and Lincoln Agritech LTD. Dr Rosen is a Founder and equity holder of Hyperfine, Vizma Life Sciences, Intact Data Services, and Q4ML. He acknowledges the support of the Kiyomi and Ed Baird Research Scholar award. Dr Matouk reports compensation from Silk Road Medical, Inc, for consultant services; compensation from MicroVention, Inc, for consultant services; and compensation from Penumbra, Inc, for consultant services. Dr Falcone reports grants from AHA and grants from National Institutes of Health. Dr Sorby-Adams reports grants from Australian-American Fulbright Commission and grants from AHA. The other authors report no conflicts.

Background and Objectives: Brain death (BD) occurs in 9-24% of successfully resuscitated out-of-hospital cardiac arrests (OHCA). To predict BD after OHCA, we developed a novel brain death risk (BDR) score., Methods: We identified independent predictors of BD after OHCA in a retrospective, single academic center cohort between 2011 and 2021. The BDR score ranges from 0 to 7 points and includes: non-shockable rhythm (1 point), drug overdose as etiology of arrest (1 point), evidence of grey-white differentiation loss or sulcal effacement on head computed tomography (CT) radiology report within 24 hours of arrest (2 points), Full-Outline-Of-UnResponsiveness (FOUR) score of 0 (2 points), FOUR score 1-5 (1 point), and age <45 years (1 point). We internally validated the BDR score using k-fold cross validation (k = 8) and externally validated the score at an independent academic center. The main outcome was BD., Results: The development cohort included 362OHCA patients, of whom 18% (N = 58) experienced BD. Internal validation provided an area under the receiving operator characteristic curve (AUC) (95% CI) of 0.931 (0.905-0.957). In the validation cohort, 19.8% (N = 17) experienced BD. The AUC (95% CI) was 0.849 (0.765-0.933). In both cohorts, a BDR score >4 was the optimal cut off (sensitivity 0.903 and 0.882, specificity 0.830 and 0.652, in the development and validation cohorts respectively)., Discussion: The BDR score identifies those at highest risk for BD after OHCA. Our data suggest that a BDR score >4 is the optimal cut off., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background and Purpose: Perihematomal edema (PHE) represents the secondary brain injury after intracerebral hemorrhage (ICH). However, neurobiological characteristics of post-ICH parenchymal injury other than PHE volume have not been fully characterized. Using intravoxel incoherent motion imaging (IVIM), we explored the clinical correlates of PHE diffusion and (micro)perfusion metrics in subacute ICH., Materials and Methods: In 41 consecutive patients scanned 1-to-7 days after supratentorial ICH, we determined the mean diffusion (D), pseudo-diffusion (D*), and perfusion fraction (F) within manually segmented PHE. Using univariable and multivariable statistics, we evaluated the relationship of these IVIM metrics with 3-month outcome based on the modified Rankin Scale (mRS)., Results: In our cohort, the average (± standard deviation) age of patients was 68.6±15.6 years, median (interquartile) baseline National Institute of Health Stroke Scale (NIHSS) was 7 (3-13), 11 (27 %) patients had poor outcomes (mRS>3), and 4 (10 %) deceased during the follow-up period. In univariable analyses, admission NIHSS (p < 0.001), ICH volume (p = 0.019), ICH+PHE volume (p = 0.016), and average F of the PHE (p = 0.005) had significant correlation with 3-month mRS. In multivariable model, the admission NIHSS (p = 0.006) and average F perfusion fraction of the PHE (p = 0.003) were predictors of 3-month mRS., Conclusion: The IVIM perfusion fraction (F) maps represent the blood flow within microvasculature. Our pilot study shows that higher PHE microperfusion in subacute ICH is associated with worse outcomes. Once validated in larger cohorts, IVIM metrics may provide insight into neurobiology of post-ICH secondary brain injury and identify at-risk patients who may benefit from neuroprotective therapy., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Seyedmehdi Payabvash reports a relationship with National Institutes of Health that includes: funding grants. Seyedmehdi Payabvash reports a relationship with Doris Duke Charitable Foundation that includes: funding grants. Seyedmehdi Payabvash reports a relationship with Foundation of the American Society of Neuroradiology that includes: funding grants. Emily J Gilmore reports a relationship with National Institutes of Health that includes: funding grants. Emily J Gilmore reports a relationship with UCB that includes: consulting or advisory. Emily J Gilmore reports a relationship with Intracranial Bioanalytics that includes: non-financial support. Guido J. Falcone reports a relationship with National Institutes of Health that includes: funding grants. Guido J. Falcone reports a relationship with Neurocritical Care Society that includes: funding grants. Guido J. Falcone reports a relationship with Yale Pepper Scholar Award that includes: funding grants. Guido J. Falcone reports a relationship with American Heart Association that includes: funding grants. Kevin N. Sheth reports a relationship with National Institutes of Health that includes: funding grants. Kevin N. Sheth reports a relationship with American Heart Association that includes: funding grants. Kevin N. Sheth reports a relationship with Hyperfine Research Inc that includes: funding grants. Adam de Havenon reports a relationship with National Institutes of Health that includes: funding grants. Adam de Havenon reports a relationship with American Academy of Neurology that includes: funding grants. Adam de Havenon reports a relationship with Novo Nordisk that includes: consulting or advisory. Adam de Havenon reports a relationship with Integra that includes: consulting or advisory. Adam de Havenon reports a relationship with Titin KM that includes: equity or stocks. Adam de Havenon reports a relationship with UpToDate that includes: paid expert testimony., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose: To assess variability in interpretation of electroencephalogram (EEG) background activity and qualitative grading of cerebral dysfunction based on EEG findings, including which EEG features are deemed most important in this determination., Methods: A web-based survey (Qualtrics) was disseminated to electroencephalographers practicing in institutions participating in the Critical Care EEG Monitoring Research Consortium between May 2017 and August 2018. Respondents answered 12 questions pertaining to their training and EEG interpretation practices and graded 40 EEG segments (15-second epochs depicting patients' most stimulated state) using a 6-grade scale. Fleiss' Kappa statistic evaluated interrater agreement., Results: Of 110 respondents, 78.2% were attending electroencephalographers with a mean of 8.3 years of experience beyond training. Despite 83% supporting the need for a standardized approach to interpreting the degree of dysfunction on EEG, only 13.6% used a previously published or an institutional grading scale. The overall interrater agreement was fair ( k = 0.35). Having Critical Care EEG Monitoring Research Consortium nomenclature certification (40.9%) or EEG board certification (70%) did not improve interrater agreement ( k = 0.26). Predominant awake frequencies and posterior dominant rhythm were ranked as the most important variables in grading background dysfunction, followed by continuity and reactivity., Conclusions: Despite the preference for a standardized grading scale for background EEG interpretation, the lack of interrater agreement on levels of dysfunction even among experienced academic electroencephalographers unveils a barrier to the widespread use of EEG as a clinical and research neuromonitoring tool. There was reasonable agreement on the features that are most important in this determination. A standardized approach to grading cerebral dysfunction, currently used by the authors, and based on this work, is proposed., Competing Interests: C. B. Maciel has received funding from Claude D. Pepper Older Americans Independence Center and American Heart Association. M. B. Dhakar has received funding from the National Institutes of Health (R21- NS116726-01), American Epilepsy Society, and research money for clinical trials from Marinus Pharmaceuticals and Parexel Biopharmaceuticals. She has received honoraria for consulting for Adamas Pharmaceuticals. N. Rampal serves as consultant at Alexion Pharmaceuticals. L. J. Hirsch has received consultation fees for advising from Accure, Aquestive, Ceribell, Marinus, Medtronic, Neurelis, Neuropace, and UCB; royalties from Wolters-Kluwer for authoring chapters for UpToDate-Neurology and from Wiley for coauthoring the book “Atlas of EEG in Critical Care,” by Hirsch and Brenner; and honoraria for speaking from Neuropace and Natus. E. J. Gilmore receives consulting fees from UCB and is a cofounder of IBA (uncompensated). In addition, she receives funding from the National Institutes of Health (R01 NS117904-01). The other authors have no conflicts of interest to disclose., (Copyright © 2022 by the American Clinical Neurophysiology Society.)

Purpose: Lateralized rhythmic delta activity (LRDA) is highly associated with seizures but generalized rhythmic delta activity (GRDA; symmetric by definition) has no known seizure association. A subset of LRDA includes patterns that are "bilateral asymmetric LRDA" (LRDA-ba), falling between purely unilateral LRDA and GRDA. The significance of this finding has not been previously addressed., Methods: Clinical, EEG, and imaging findings were reviewed in all patients with >6 hours of continuous EEG and LRDA-ba between 2014 and 2019. They were compared with a control group of patients with GRDA, matched 1:1 for prevalence, duration, and frequency of the predominant rhythmic pattern., Results: Two hundred fifty-eight patients with LRDA-ba and 258 matched controls with GRDA were identified. Statistically significant findings included that patients with LRDA-ba were more likely to have presented with an ischemic stroke (LRDA-ba 12.4% vs. GRDA 3.9%) or subdural hemorrhage (8.9% vs. 4.3%); those with GRDA were more likely to have a metabolic encephalopathy (GRDA 10.5% vs. LRDA-ba 3.5%) or "altered mental state" without clear etiology (12.5% vs. 4.3%). Patients with LRDA-ba were significantly more likely to have a background EEG asymmetry (LRDA-ba 62.0% vs. GRDA 25.6%) or focal (arrhythmic) slowing (40.3% vs. 15.5%), and acute (65.5% vs. 46.1%) or focal (49.6% vs. 28.3%) abnormalities on computed tomography scan. Patients with LRDA-ba were more likely to have focal sporadic epileptiform discharges (95.4% vs. 37.9%), lateralized periodic discharges (32.2% vs. 5.0%), and focal electrographic seizures (33.3% vs. 11.2%); however, patients with LRDA-ba alone (i.e., without sporadic epileptiform discharges or PDs) showed only a trend toward increased seizures (17.3%) compared with a matched group of patients with GRDA alone (9.9%, P = 0.08)., Conclusions: Patients with LRDA-ba had a higher proportion of acute focal abnormalities compared with a matched group of patients with GRDA. The LRDA-ba was associated with additional evidence of focal cortical excitability on EEG (sporadic epileptiform discharges and lateralized periodic discharges) and seizures but with only a trend toward increased seizures when other signs of focal excitability were absent., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2021 by the American Clinical Neurophysiology Society.)

Purpose: The Critical Care EEG Monitoring Research Consortium (CCEMRC) is an international research group focusing on critical care EEG and epilepsy. As CCEMRC grew to include 50+ institutions over the past decade, members met to establish research priorities., Methods: The authors used an analytical hierarchy process-based research prioritization method, adapted from an approach previously applied to a Department of Defense health-related research program. Forty-six CCEMRC members identified and scored a set of eight clinical problems (CPs) and 15 research topic areas (RTAs) at an annual CCEMRC meeting. Members scored CPs on three criteria using a five-point ordinal scale: Incidence, Impact, and Gap Size; and RTAs on four additional criteria: Niche, Feasibility, Scientific Importance, and Medical Importance, each of which was assigned a weight. The first three RTA criteria were scored using a five-point scale, and CPs were mapped to RTAs using a four-point scale. The Medical Importance score was a weighted average of its mapping scores and the CP score. Finally, a Priority score was calculated for each RTA as a product of the four RTA criteria scores., Results: The CPs with the highest scores were "Altered mental status" and "Long-term neurologic disability after hospital discharge." The RTAs with the highest priority scores were "Development of risk prediction tools," "Multicenter observational studies," and "Outcome prediction.", Conclusions: Research prioritization helped CCEMRC evaluate its current research trajectory, identify high-priority near-term research pursuits, and create a roadmap for future research plans aligned with its mission. This approach may be helpful to other academic consortia and research programs., (Copyright © 2022 by the American Clinical Neurophysiology Society.)

Aim: Early, accurate outcome prediction after out-of-hospital cardiac arrest (OHCA) is critical for clinical decision-making and resource allocation. We sought to validate the revised post-Cardiac Arrest Syndrome for Therapeutic hypothermia (rCAST) score in a United States cohort and compare its prognostic performance to the Pittsburgh Cardiac Arrest Category (PCAC) and Full Outline of UnResponsiveness (FOUR) scores., Methods: This is a single-center, retrospective study of OHCA patients admitted between January 2014-August 2022. Area under the receiver operating curve (AUC) was computed for each score for predicting poor neurologic outcome at discharge and in-hospital mortality. We compared the scores' predictive abilities via Delong's test., Results: Of 505 OHCA patients with all scores available, the medians [IQR] for rCAST, PCAC, and FOUR scores were 9.5 [6.0, 11.5], 4 [3, 4], and 2 [0, 5], respectively. The AUC [95% confidence interval] of the rCAST, PCAC, and FOUR scores for predicting poor neurologic outcome were 0.815 [0.763-0.867], 0.753 [0.697-0.809], and 0.841 [0.796-0.886], respectively. The AUC [95% confidence interval] of the rCAST, PCAC, and FOUR scores for predicting mortality were 0.799 [0.751-0.847], 0.723 [0.673-0.773], and 0.813 [0.770-0.855], respectively. The rCAST score was superior to the PCAC score for predicting mortality (p = 0.017). The FOUR score was superior to the PCAC score for predicting poor neurological outcome (p < 0.001) and mortality (p < 0.001)., Conclusion: The rCAST score can reliably predict poor outcome in a United States cohort of OHCA patients regardless of TTM status and outperforms the PCAC score., Competing Interests: Declaration of Competing Interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

In the 20th century, the advent of neuroimaging dramatically altered the field of neurologic care. However, despite iterative advances since the invention of CT and MRI, little progress has been made to bring MR neuroimaging to the point of care. Recently, the emergence of a low-field (<1 T) portable MRI (pMRI) is setting the stage to revolutionize the landscape of accessible neuroimaging. Users can transport the pMRI into a variety of locations, using a standard 110-220 V wall outlet. In this article, we discuss current applications for pMRI, including in the acute and critical care settings, the barriers to broad implementation, and future opportunities., (© 2023 American Academy of Neurology.)

Background and Objectives: The validity of brain monitoring using electroencephalography (EEG), particularly to guide care in patients with acute or critical illness, requires that experts can reliably identify seizures and other potentially harmful rhythmic and periodic brain activity, collectively referred to as "ictal-interictal-injury continuum" (IIIC). Previous interrater reliability (IRR) studies are limited by small samples and selection bias. This study was conducted to assess the reliability of experts in identifying IIIC., Methods: This prospective analysis included 30 experts with subspecialty clinical neurophysiology training from 18 institutions. Experts independently scored varying numbers of ten-second EEG segments as "seizure (SZ)," "lateralized periodic discharges (LPDs)," "generalized periodic discharges (GPDs)," "lateralized rhythmic delta activity (LRDA)," "generalized rhythmic delta activity (GRDA)," or "other." EEGs were performed for clinical indications at Massachusetts General Hospital between 2006 and 2020. Primary outcome measures were pairwise IRR (average percent agreement [PA] between pairs of experts) and majority IRR (average PA with group consensus) for each class and beyond chance agreement (κ). Secondary outcomes were calibration of expert scoring to group consensus, and latent trait analysis to investigate contributions of bias and noise to scoring variability., Results: Among 2,711 EEGs, 49% were from women, and the median (IQR) age was 55 (41) years. In total, experts scored 50,697 EEG segments; the median [range] number scored by each expert was 6,287.5 [1,002, 45,267]. Overall pairwise IRR was moderate (PA 52%, κ 42%), and majority IRR was substantial (PA 65%, κ 61%). Noise-bias analysis demonstrated that a single underlying receiver operating curve can account for most variation in experts' false-positive vs true-positive characteristics (median [range] of variance explained ([Formula: see text]): 95 [93, 98]%) and for most variation in experts' precision vs sensitivity characteristics ([Formula: see text]: 75 [59, 89]%). Thus, variation between experts is mostly attributable not to differences in expertise but rather to variation in decision thresholds., Discussion: Our results provide precise estimates of expert reliability from a large and diverse sample and a parsimonious theory to explain the origin of disagreements between experts. The results also establish a standard for how well an automated IIIC classifier must perform to match experts., Classification of Evidence: This study provides Class II evidence that an independent expert review reliably identifies ictal-interictal injury continuum patterns on EEG compared with expert consensus., (© 2022 American Academy of Neurology.)

Background and Objectives: Seizures (SZs) and other SZ-like patterns of brain activity can harm the brain and contribute to in-hospital death, particularly when prolonged. However, experts qualified to interpret EEG data are scarce. Prior attempts to automate this task have been limited by small or inadequately labeled samples and have not convincingly demonstrated generalizable expert-level performance. There exists a critical unmet need for an automated method to classify SZs and other SZ-like events with expert-level reliability. This study was conducted to develop and validate a computer algorithm that matches the reliability and accuracy of experts in identifying SZs and SZ-like events, known as "ictal-interictal-injury continuum" (IIIC) patterns on EEG, including SZs, lateralized and generalized periodic discharges (LPD, GPD), and lateralized and generalized rhythmic delta activity (LRDA, GRDA), and in differentiating these patterns from non-IIIC patterns., Methods: We used 6,095 scalp EEGs from 2,711 patients with and without IIIC events to train a deep neural network, SPaRCNet , to perform IIIC event classification. Independent training and test data sets were generated from 50,697 EEG segments, independently annotated by 20 fellowship-trained neurophysiologists. We assessed whether SPaRCNet performs at or above the sensitivity, specificity, precision, and calibration of fellowship-trained neurophysiologists for identifying IIIC events. Statistical performance was assessed by the calibration index and by the percentage of experts whose operating points were below the model's receiver operating characteristic curves (ROCs) and precision recall curves (PRCs) for the 6 pattern classes., Results: SPaRCNet matches or exceeds most experts in classifying IIIC events based on both calibration and discrimination metrics. For SZ, LPD, GPD, LRDA, GRDA, and "other" classes, SPaRCNet exceeds the following percentages of 20 experts-ROC: 45%, 20%, 50%, 75%, 55%, and 40%; PRC: 50%, 35%, 50%, 90%, 70%, and 45%; and calibration: 95%, 100%, 95%, 100%, 100%, and 80%, respectively., Discussion: SPaRCNet is the first algorithm to match expert performance in detecting SZs and other SZ-like events in a representative sample of EEGs. With further development, SPaRCNet may thus be a valuable tool for an expedited review of EEGs., Classification of Evidence: This study provides Class II evidence that among patients with epilepsy or critical illness undergoing EEG monitoring, SPaRCNet can differentiate (IIIC) patterns from non-IIIC events and expert neurophysiologists., (© 2023 American Academy of Neurology.)

Background: Post-traumatic epilepsy (PTE) is a severe complication of traumatic brain injury (TBI). Electroencephalography aids early post-traumatic seizure diagnosis, but its optimal utility for PTE prediction remains unknown. We aim to evaluate the contribution of quantitative electroencephalograms to predict first-year PTE (PTE 1 )., Methods: We performed a multicentre, retrospective case-control study of patients with TBI. 63 PTE 1 patients were matched with 63 non-PTE 1 patients by admission Glasgow Coma Scale score, age and sex. We evaluated the association of quantitative electroencephalography features with PTE 1 using logistic regressions and examined their predictive value relative to TBI mechanism and CT abnormalities., Results: In the matched cohort (n=126), greater epileptiform burden, suppression burden and beta variability were associated with 4.6 times higher PTE 1 risk based on multivariable logistic regression analysis (area under the receiver operating characteristic curve, AUC (95% CI) 0.69 (0.60 to 0.78)). Among 116 (92%) patients with available CT reports, adding quantitative electroencephalography features to a combined mechanism and CT model improved performance (AUC (95% CI), 0.71 (0.61 to 0.80) vs 0.61 (0.51 to 0.72))., Conclusions: Epileptiform and spectral characteristics enhance covariates identified on TBI admission and CT abnormalities in PTE 1 prediction. Future trials should incorporate quantitative electroencephalography features to validate this enhancement of PTE risk stratification models., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Andexanet alfa (AA), a factor Xa-inhibitor (FXi) reversal agent, is given as a bolus followed by a 2-hour infusion. This long administration time can delay EVD placement in intracerebral hemorrhage (ICH) patients. We sought to evaluate the safety of EVD placement immediately post-AA bolus compared to post-AA infusion., Methods: We conducted a retrospective study that included adult patients admitted with FXi-associated ICH who received AA and underwent EVD placement The primary outcome was the occurrence of a new hemorrhage (tract, extra-axial, or intraventricular hemorrhage). Secondary outcomes included mortality, intensive care unit and hospital length of stay, and discharge modified Rankin Score. The primary safety outcome was documented thrombotic events., Results: Twelve patients with FXi related ICH were included (EVD placement post-AA bolus, N = 8; EVD placement post-AA infusion, N = 4). Each arm included one patient with bilateral EVD placed. There was no difference in the incidence of new hemorrhages, with one post-AA bolus patient had small, focal, nonoperative extra-axial hemorrhage. Morbidity and mortality were higher in post-AA infusion patients (mRS, post-AA bolus, 4 [4-6] vs. post-AA infusion 6 [5,6], p = 0.24 and post-AA bolus, 3 (37.5 %) vs. post-AA infusion, 3 (75 %), p = 0.54, respectively). One patient in the post-AA bolus group had thrombotic event. There was no difference in hospital LOS (post-AA bolus, 19 days [12-26] vs. post-AA infusion, 14 days [9-22], p = 0.55) and ICU LOS (post-AA bolus, 10 days [6-13] vs. post-AA infusion, 11 days [5-21], p = 0.86)., Conclusion: We report no differences in the incidence of tract hemorrhage, extra-axial hemorrhage, or intraventricular hemorrhage post-AA bolus versus post-AA infusion. Larger prospective studies to validate these results are warranted., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Purpose: The coronavirus disease 2019 (COVID-19) has significantly impacted healthcare delivery and utilization. The aim of this article was to assess the impact of the COVID-19 pandemic on in-hospital continuous electroencephalography (cEEG) utilization and identify areas for process improvement., Methods: A 38-question web-based survey was distributed to site principal investigators of the Critical Care EEG Monitoring Research Consortium, and institutional contacts for the Neurodiagnostic Credentialing and Accreditation Board. The survey addressed the following aspects of cEEG utilization: (1) general center characteristics, (2) cEEG utilization and review, (3) staffing and workflow, and (4) health impact on EEG technologists., Results: The survey was open from June 12, 2020 to June 30, 2020 and distributed to 174 centers with 79 responses (45.4%). Forty centers were located in COVID-19 hotspots. Fifty-seven centers (72.1%) reported cEEG volume reduction. Centers in the Northeast were most likely to report cEEG volume reduction (odds ratio [OR] 7.19 [1.53-33.83]; P = 0.012). Additionally, centers reporting decrease in outside hospital transfers reported cEEG volume reduction; OR 21.67 [4.57-102.81]; P ≤ 0.0001. Twenty-six centers (32.91%) reported reduction in EEG technologist coverage. Eighteen centers had personal protective equipment shortages for EEG technologists. Technologists at these centers were more likely to quarantine for suspected or confirmed COVID-19; OR 3.14 [1.01-9.63]; P = 0.058., Conclusions: There has been a widespread reduction in cEEG volume during the pandemic. Given the anticipated duration of the pandemic and the importance of cEEG in managing hospitalized patients, methods to optimize use need to be prioritized to provide optimal care. Because the survey provides a cross-sectional assessment, follow-up studies can determine the long-term impact of the pandemic on cEEG utilization., (Copyright © 2020 by the American Clinical Neurophysiology Society.)

Over the past decades, electroencephalography (EEG) has become a widely applied and highly sophisticated brain monitoring tool in a variety of intensive care unit (ICU) settings. The most common indication for EEG monitoring currently is the management of refractory status epilepticus. In addition, a number of studies have associated frequent seizures, including nonconvulsive status epilepticus (NCSE), with worsening secondary brain injury and with worse outcomes. With the widespread utilization of EEG (spot and continuous EEG), rhythmic and periodic patterns that do not fulfill strict seizure criteria have been identified, epidemiologically quantified, and linked to pathophysiological events across a wide spectrum of critical and acute illnesses, including acute brain injury. Increasingly, EEG is not just qualitatively described, but also quantitatively analyzed together with other modalities to generate innovative measurements with possible clinical relevance. In this review, we discuss the current knowledge and emerging applications of EEG in the ICU, including seizure detection, ischemia monitoring, detection of cortical spreading depolarizations, assessment of consciousness and prognostication. We also review some technical aspects and challenges of using EEG in the ICU including the logistics of setting up ICU EEG monitoring in resource-limited settings., (© 2022. Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: To investigate whether epileptiform discharge burden can identify those at risk for delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH)., Methods: Retrospective analysis of 113 moderate to severe grade SAH patients who had continuous EEG (cEEG) recordings during their hospitalization. We calculated the burden of epileptiform discharges (ED), measured as number of ED per hour., Results: We find that many SAH patients have an increase in ED burden during the first 3-10 days following rupture, the major risk period for DCI. However, those who develop DCI have a significantly higher hourly burden from days 3.5-6 after SAH vs. those who do not. ED burden is higher in DCI patients when assessed in relation to the onset of DCI (area under the receiver operator curve 0.72). Finally, specific trends of ED burden over time, assessed by group-based trajectory analysis, also help stratify DCI risk., Conclusions: These results suggest that ED burden is a useful parameter for identifying those at higher risk of developing DCI after SAH. The higher burden rate associated with DCI supports the theory of metabolic supply-demand mismatch which contributes to this complication., Significance: ED burden is a novel biomarker for predicting those at high risk of DCI., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

This proceedings article presents actionable research targets on the basis of the presentations and discussions at the 2nd Curing Coma National Institutes of Health (NIH) symposium held from May 3 to May 5, 2021. Here, we summarize the background, research priorities, panel discussions, and deliverables discussed during the symposium across six major domains related to disorders of consciousness. The six domains include (1) Biology of Coma, (2) Coma Database, (3) Neuroprognostication, (4) Care of Comatose Patients, (5) Early Clinical Trials, and (6) Long-term Recovery. Following the 1st Curing Coma NIH virtual symposium held on September 9 to September 10, 2020, six workgroups, each consisting of field experts in respective domains, were formed and tasked with identifying gaps and developing key priorities and deliverables to advance the mission of the Curing Coma Campaign. The highly interactive and inspiring presentations and panel discussions during the 3-day virtual NIH symposium identified several action items for the Curing Coma Campaign mission, which we summarize in this article., (© 2022. The Author(s).)

Background: Hypoglycemic coma (HC) is an uncommon but severe clinical condition associated with poor neurological outcome. There is a dearth of robust neurological prognostic factors after HC. On the other hand, there is an increasing body of literature on reliable prognostic markers in the postanoxic coma, a similar-albeit not identical-situation. The objective of this study was thus to investigate the use and predictive value of these markers in HC., Methods: We conducted a retrospective, multicenter, cohort study within five centers of the Critical Care EEG Monitoring Research Consortium. We queried our electroencephalography (EEG) databases to identify all patients undergoing continuous EEG monitoring after admission to an intensive care unit with HC (defined as Glasgow Coma Scale < 8 on admission and a first blood glucose level < 50 mg/dL or not documented but in an obvious clinical context) between 01/01/2010 and 12/31/2020. We studied the association of findings at neurological examination (Glasgow Coma Scale motor subscale, pupillary light and corneal reflexes) and at continuous EEG monitoring(highly malignant patterns, reactivity, periodic discharges, seizures) with best neurological outcome within 3 months after hospital discharge, defined by the Cerebral Performance Category as favorable (1-3: recovery of consciousness) versus unfavorable (4-5: lack of recovery of consciousness)., Results: We identified 60 patients (30 [50%] women; age 62 [51-72] years). Thirty-one and 29 patients had a favorable and unfavorable outcome, respectively. The presence of pupillary reflexes (24 [100%] vs. 17 [81%]; p value 0.04) and a motor subscore > 2 (22 [92%] vs. 12 [63%]; p value 0.03) at 48-72 h were associated with a favorable outcome. A highly malignant EEG pattern was observed in 7 of 29 (24%) patients with unfavorable outcome versus 0 of 31 (0%) with favorable outcome, whereas the presence of EEG reactivity was observed in 28 of 31 (90%) patients with favorable outcome versus 13 of 29 (45%) with unfavorable outcome (p < 0.001 for comparison of all background categories)., Conclusions: This preliminary study suggests that highly malignant EEG patterns might be reliable prognostic markers of unfavorable outcome after HC. Other EEG findings, including lack of EEG reactivity and seizures and clinical findings appear less accurate. These findings should be replicated in a larger multicenter prospective study., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature and Neurocritical Care Society.)

Oxygen supplementation has been a mainstay in the management of patients with acute cardiac disease. While hypoxia is known to be detrimental, the adverse effects of artificially high oxygen levels (hyperoxia) have only recently been recognized. Hyperoxia may induce harmful hemodynamic effects, including peripheral and coronary vasoconstriction, and direct cellular toxicity through the production of reactive oxygen species. In addition, emerging evidence has shown that hyperoxia is associated with adverse clinical outcomes. Thus, it is essential for the cardiac intensive care unit (CICU) clinician to understand the available evidence and titrate oxygen therapies to specific goals. This review summarizes the pathophysiology of oxygen within the cardiovascular system and the association between supplemental oxygen and hyperoxia in patients with common CICU diagnoses, including acute myocardial infarction, heart failure, shock, cardiac arrest, pulmonary hypertension, and respiratory failure. Finally, we highlight lessons learned from available trials, gaps in knowledge, and future directions.

Background: Pregabalin (PGB) is an effective adjunctive treatment for focal epilepsy and acts by binding to the alpha2-delta subunit of voltage-gated calcium channels to reduce excitatory neurotransmitter release. Limited data exist on its use in the neurocritical care setting, including cyclic seizures-a pattern of recurrent seizures occurring at nearly regular intervals. Although the mechanism underpinning cyclic seizures remains elusive, spreading excitation linked to spreading depolarizations may play a role in seizure recurrence and periodicity. PGB has been shown to increase spreading depolarization threshold; hence, we hypothesized that the magnitude of antiseizure effect from PGB is more pronounced in patients with cyclic versus noncyclic seizures in a critically ill cohort with recurrent seizures., Methods: We conducted a retrospective case series of adults admitted to two academic neurointensive care units between January 2017 and March 2019 who received PGB for treatment of seizures. Data collected included demographics, etiology of brain injury, antiseizure medications, and outcome. Continuous electroencephalogram recordings 48 hours before and after PGB administration were reviewed by electroencephalographers blinded to the administration of antiseizure medications to obtain granular data on electrographic seizure burden. Cyclic seizures were determined quantitatively (i.e., < 50% variation of interseizure intervals for at least 50% of consecutive seizures). Coprimary outcomes were decrease in hourly seizure burden in minutes and decrease in seizure frequency in the 48 hours after PGB initiation. We used nonparametric tests for comparison of seizure frequency and burden and segmented linear regression to assess PGB effect., Results: We included 16 patients; the median age was 69 years, 11 (68.7%) were women, three (18.8%) had undergone a neurosurgical procedure, and five (31%) had underlying epilepsy. All seizures had focal onset; ten patients (62.5%) had cyclic seizures. The median hourly seizure burden over the 48 hours prior to PGB initiation was 1.87 min/hour (interquartile range 1.49-8.53), and the median seizure frequency was 1.96 seizures/hour (interquartile range 1.06-3.41). In the 48 hours following PGB (median daily dose 300 mg, range 75-300 mg), the median number of seizures per hour was reduced by 0.80 seizures/hour (95% confidence interval 0.19-1.40), whereas the median hourly seizure burden decreased by 1.71 min/hour (95% confidence interval 0.38-3.04). When we compared patients with cyclic versus noncyclic seizures, there was a relative decrease in hourly seizure frequency (- 86.7% versus - 2%, p = 0.04) and hourly seizure burden (- 89% versus - 7.8%, p = 0.03) at 48 hours., Conclusions: PGB was associated with a relative reduction in seizure burden in neurocritically ill patients with recurrent seizures, especially those with cyclic seizures, and may be considered in the therapeutic arsenal for refractory seizures. Whether this effect is mediated via modulation of spreading depolarization requires further study., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature and Neurocritical Care Society.)

Background: Assessment of brain injury severity is critically important after survival from cardiac arrest (CA). Recent advances in low-field MRI technology have permitted the acquisition of clinically useful bedside brain imaging. Our objective was to deploy a novel approach for evaluating brain injury after CA in critically ill patients at high risk for adverse neurological outcome., Methods: This retrospective, single center study involved review of all consecutive portable MRIs performed as part of clinical care for CA patients between September 2020 and January 2022. Portable MR images were retrospectively reviewed by a blinded board-certified neuroradiologist (S.P.). Fluid-inversion recovery (FLAIR) signal intensities were measured in select regions of interest., Results: We performed 22 low-field MRI examinations in 19 patients resuscitated from CA (68.4% male, mean [standard deviation] age, 51.8 [13.1] years). Twelve patients (63.2%) had findings consistent with HIBI on conventional neuroimaging radiology report. Low-field MRI detected findings consistent with HIBI in all of these patients. Low-field MRI was acquired at a median (interquartile range) of 78 (40-136) hours post-arrest. Quantitatively, we measured FLAIR signal intensity in three regions of interest, which were higher amongst patients with confirmed HIBI. Low-field MRI was completed in all patients without disruption of intensive care unit equipment monitoring and no safety events occurred., Conclusion: In a critically ill CA population in whom MR imaging is often not feasible, low-field MRI can be deployed at the bedside to identify HIBI. Low-field MRI provides an opportunity to evaluate the time-dependent nature of MRI findings in CA survivors., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Dr. Rachel Beekman reports no disclosures. Anna Crawford reports no disclosures. Mercy H. Mazurek reports no disclosures. Anjali M. Prabhat reports no disclosures. Isha R. Chavva reports no disclosures. Nethra Parasuram reports no disclosures. Noah Kim reports no disclosures. Dr. Jennifer A. Kim reports no disclosures. Dr. Nils Petersen reports no disclosures. Dr. Adam de Havenon reports no disclosures. Dr. Akhil Khosla reports no disclosures. Dr. Shyoko Honiden reports no disclosures. Dr. P. Elliott Miller reports no disclosures. Dr. Charles Wira reports no disclosures. Dr. James Daley reports no disclosures. Dr. Seyedmehdi Payabvash reports no disclosures. Dr. David M. Greer reports no disclosures. Dr. Emily J. Gilmore reports no disclosures. Dr. W. Taylor Kimberly receives grants from the NIH and AHA to support his work with portable MRI. Dr. Kevin N. Sheth receives support from the Collaborative Science Award (American Heart Association), National Institutes of Health Supplement Grant (U01NS106513-S1), and Hyperfine Research, Inc. research grant for his work with portable MRI., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Objective: To determine whether baseline frailty is an independent predictor of extended hospital length of stay (LOS), nonroutine discharge, and in-hospital mortality after evacuation of an acute traumatic subdural hematoma (SDH)., Methods: A retrospective cohort study was performed. All adult patients who underwent surgery for an acute traumatic SDH were identified using the National Trauma Database from the year 2017. Patients were categorized into 3 cohorts based on the criteria of the 5-item modified frailty index (mFI-5): mFI = 0, mFI = 1, or mFI = 2+. A multivariate logistic regression analysis was used to identify independent predictors of extended LOS, nonroutine discharge, and in-hospital mortality., Results: Of the 2620 patients identified, 41.7% were classified as mFI = 0, 32.7% as mFI = 1, and 25.6% as mFI = 2+. Rates of extended LOS and in-hospital mortality did differ significantly between the cohorts, with the mFI = 0 cohort most often experiencing a prolonged LOS (mFI = 0: 29.41% vs. mFI = 1: 19.45% vs. mFI = 2+: 19.73%, P < 0.001) and in-hospital mortality (mFI = 0: 24.66% vs. mFI = 1: 18.11% vs. mFI = 2+: 21.58%, P = 0.002). On multivariate regression analysis, when compared with mFI = 0, mFI = 2+ (odds ratio 1.4, P = 0.03) predicted extended LOS and nonroutine discharge (odds ratio 1.61, P = 0.001)., Conclusions: Our study demonstrates that baseline frailty may be an independent predictor of extended LOS and nonroutine discharge, but not in-hospital mortality, in patients undergoing evacuation for an acute traumatic SDH. Further investigations are warranted as they may guide treatment plans and reduce health care expenditures for frail patients with SDH., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Brain imaging is essential to the clinical management of patients with ischemic stroke. Timely and accessible neuroimaging, however, can be limited in clinical stroke pathways. Here, portable magnetic resonance imaging (pMRI) acquired at very low magnetic field strength (0.064 T) is used to obtain actionable bedside neuroimaging for 50 confirmed patients with ischemic stroke. Low-field pMRI detected infarcts in 45 (90%) patients across cortical, subcortical, and cerebellar structures. Lesions as small as 4 mm were captured. Infarcts appeared as hyperintense regions on T2-weighted, fluid-attenuated inversion recovery and diffusion-weighted imaging sequences. Stroke volume measurements were consistent across pMRI sequences and between low-field pMRI and conventional high-field MRI studies. Low-field pMRI stroke volumes significantly correlated with stroke severity and functional outcome at discharge. These results validate the use of low-field pMRI to obtain clinically useful imaging of stroke, setting the stage for use in resource-limited environments.

Purpose: The neuroimaging correlates of lateralized rhythmic delta activity (LRDA) are not well defined, and imaging findings between different epileptiform patterns have seldom been compared directly., Methods: Patients were retrospectively selected from a critical care EEG database between December 2014 and December 2017. Patients were included if they had greater than 6 hours of continuous EEG that contained LRDA, lateralized periodic discharges LPDs), or generalized rhythmic delta activity (GRDA) and had an MRI within 48 hours of the EEG. Clinical, EEG, and MRI characteristics were collected and compared., Results: All the following results showed statistical significance between the groups: Patients with GRDA were more likely to have a normal MRI (LRDA, 0%; LPDs, 0.8%; GRDA, 17.3%), although the majority were abnormal. In patients with LRDA and LPDs, the MRI abnormalities were much more likely lateralized to one side, whereas in those with GRDA, they were more likely to have bilateral or multifocal abnormalities. Across all groups most abnormalities were acute, although this proportion was higher in patients with LRDA and LPDs compared with that in those with GRDA (LRDA, 91.3%; LPDs, 86.0%; GRDA, 70.4%). An MRI abnormality that was concordant with the side of LRDA was present in 66.3%, with 17.3% having discordant findings. These were similar in patients with LPDs (concordant 67.4%; discordant 11.6%)., Conclusions: Patients with LRDA had a similarly high rate of acute focal abnormalities ipsilateral to the EEG pattern compared with those with LPDs. Patients with GRDA were more likely to have a normal MRI, but the majority of patients with GRDA still had acute focal findings., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2020 by the American Clinical Neurophysiology Society.)

Summary: In this review, we discuss the utility of quantitative EEG parameters for the detection of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage in the context of the complex pathophysiology of DCI and the limitations of current diagnostic methods. Because of the multifactorial pathophysiology of DCI, methodologies solely assessing blood vessel narrowing (vasospasm) are insufficient to detect all DCI. Quantitative EEG has facilitated the exploration of EEG as a diagnostic modality of DCI. Multiple quantitative EEG parameters such as alpha power, relative alpha variability, and alpha/delta ratio show reliable detection of DCI in multiple studies. Recent studies on epileptiform abnormalities suggest that their potential for the detection of DCI. Quantitative EEG is a promising, continuous, noninvasive, monitoring modality of DCI implementable in daily practice. Future work should validate these parameters in larger populations, facilitated by the development of automated detection algorithms and multimodal data integration., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2021 by the American Clinical Neurophysiology Society.)

Purpose: Continuous EEG can potentially be used as real-time brain telemetry for the early detection of neurologic decline. Scant literature on EEG changes related to elevated intracranial pressure (ICP) limits its use in this context., Methods: Retrospective, observational case series of patients in whom we noted EEG changes correlating with a clinical concern for elevated ICP, measured or unmeasured., Results: We noted EEG changes of varying severity and duration correlating with either measured or unmeasured clinical concern for elevated ICP. In two patients with recurrent transient unresponsiveness (presumed from plateau waves), generalized rhythmic delta activity and attenuation of fast activity occurred 30 minutes before a clinical change. Elevated ICP in two patients, one related to progressive mass effect from infarctions, and the other to dialysis, correlated with generalized slowing and attenuation of fast activity up to 24 hours before clinical deterioration, leading to diffuse suppression. Two patients with intraventricular hemorrhage had cyclic patterns at ∼1 per minute and ∼6 per minute (similar frequency to described frequency of Lundberg B and C waves, respectively)., Conclusions: Cyclic patterns and varying degrees of slowing and attenuation often preceded clinical deterioration associated with intracranial hypertension. Future systematic studies of EEG changes in this setting will facilitate early and noninvasive detection of elevated ICP., (Copyright © 2020 by the American Clinical Neurophysiology Society.)

Background and Objectives: Delayed cerebral ischemia (DCI) is the leading complication of subarachnoid hemorrhage (SAH). Because DCI was traditionally thought to be caused by large vessel vasospasm, transcranial Doppler ultrasounds (TCDs) have been the standard of care. Continuous EEG has emerged as a promising complementary monitoring modality and predicts increased DCI risk. Our objective was to determine whether combining EEG and TCD data improves prediction of DCI after SAH. We hypothesize that integrating these diagnostic modalities improves DCI prediction., Methods: We retrospectively assessed patients with moderate to severe SAH (2011-2015; Fisher 3-4 or Hunt-Hess 4-5) who had both prospective TCD and EEG acquisition during hospitalization. Middle cerebral artery (MCA) peak systolic velocities (PSVs) and the presence or absence of epileptiform abnormalities (EAs), defined as seizures, epileptiform discharges, and rhythmic/periodic activity, were recorded daily. Logistic regressions were used to identify significant covariates of EAs and TCD to predict DCI. Group-based trajectory modeling (GBTM) was used to account for changes over time by identifying distinct group trajectories of MCA PSV and EAs associated with DCI risk., Results: We assessed 107 patients; DCI developed in 56 (51.9%). Univariate predictors of DCI are presence of high-MCA velocity (PSV ≥200 cm/s, sensitivity 27%, specificity 89%) and EAs (sensitivity 66%, specificity 62%) on or before day 3. Two univariate GBTM trajectories of EAs predicted DCI (sensitivity 64%, specificity 62.75%). Logistic regression and GBTM models using both TCD and EEG monitoring performed better. The best logistic regression and GBTM models used both TCD and EEG data, Hunt-Hess score at admission, and aneurysm treatment as predictors of DCI (logistic regression: sensitivity 90%, specificity 70%; GBTM: sensitivity 89%, specificity 67%)., Discussion: EEG and TCD biomarkers combined provide the best prediction of DCI. The conjunction of clinical variables with the timing of EAs and high MCA velocities improved model performance. These results suggest that TCD and cEEG are promising complementary monitoring modalities for DCI prediction. Our model has potential to serve as a decision support tool in SAH management., Classification of Evidence: This study provides Class II evidence that combined TCD and EEG monitoring can identify delayed cerebral ischemia after SAH., (© 2021 American Academy of Neurology.)

Neuroimaging is crucial for assessing mass effect in brain-injured patients. Transport to an imaging suite, however, is challenging for critically ill patients. We evaluated the use of a low magnetic field, portable MRI (pMRI) for assessing midline shift (MLS). In this observational study, 0.064 T pMRI exams were performed on stroke patients admitted to the neuroscience intensive care unit at Yale New Haven Hospital. Dichotomous (present or absent) and continuous MLS measurements were obtained on pMRI exams and locally available and accessible standard-of-care imaging exams (CT or MRI). We evaluated the agreement between pMRI and standard-of-care measurements. Additionally, we assessed the relationship between pMRI-based MLS and functional outcome (modified Rankin Scale). A total of 102 patients were included in the final study (48 ischemic stroke; 54 intracranial hemorrhage). There was significant concordance between pMRI and standard-of-care measurements (dichotomous, κ = 0.87; continuous, ICC = 0.94). Low-field pMRI identified MLS with a sensitivity of 0.93 and specificity of 0.96. Moreover, pMRI MLS assessments predicted poor clinical outcome at discharge (dichotomous: adjusted OR 7.98, 95% CI 2.07-40.04, p = 0.005; continuous: adjusted OR 1.59, 95% CI 1.11-2.49, p = 0.021). Low-field pMRI may serve as a valuable bedside tool for detecting mass effect., (© 2022. The Author(s).)