Efficacy of Cyclooxygenase-2 Inhibitors for Headache in Acute Brain Injury: A Systematic Review

Background

Headache management after acute brain injury (ABI) is challenging. While opioids are commonly used, selective cyclooxygenase-2 inhibitors (COXIBs) may be promising alternatives. However, concerns about cardiovascular effects and bleeding risk have limited their use. We aimed at summarizing available data on efficacy of COXIBs for headache management following ABI.

Methods

A systematic review was conducted through MEDLINE and Embase for articles published through 09/2023 (PROSPERO CRD42022320453). No language filters were applied to the initial searches. Interventional or observational studies and systematic reviews assessing efficacy of COXIBs for headache in adults with ABI were eligible. Article selection was performed by two independent reviewers using Distiller SR®. Descriptive statistics were used for data analysis, while meta-analysis was unfeasible due to study heterogeneity.

Results

Of 3190 articles identified, six studies met inclusion criteria: four randomized controlled trials and two retrospective cohort studies, all conducted in neurosurgical patients (total n=738) between 2006-2022. Five studies used COXIBs in the intervention group only. Of the six studies, four found a reduction in overall pain scores in the intervention group, while one showed improvement only at 6 hours postoperative, and one did not find significant differences. Pain scores decreased between 4-15%, the largest shift being from moderate to mild severity. Three studies found an overall opioid use reduction throughout hospitalization in the intervention group, while one reported a reduction at 12 hours postoperative only. Opioid consumption decreased between 9-90%. Two studies found a decrease in hospital-length-of-stay by ~1 day in the intervention group. The one study reporting postoperative hemorrhage found a statistically non-significant 3% reduction in the intervention group.

Conclusions

In adults with ABI, COXIBs may serve as opioid-sparing adjunctive analgesics for headache control, with limited but pointed data to indicate efficacy in the post-neurosurgical setting. However, further safety data remains to be elucidated.

After the storm: Extracorporeal membrane oxygenation after hemicraniectomy in a child

Ventricular arrhythmias following neurological injury have been attributed to sympathetic surge in subarachnoid hemorrhage and traumatic brain injury. Despite associated risks of bleeding and thrombosis, veno-arterial extracorporeal membrane oxygenation (ECMO) in critically ill, clinically unstable postoperative neurosurgical patients can be lifesaving. In the context of neurological injury and the neurosurgical population, the literature available regarding ECMO utilization is limited, especially in children. We report a case of successful ECMO utilization in a child with malignant ventricular tachycardia after decompressive craniectomy for refractory intracranial hypertension following evacuation of extensive subdural empyema.

Wolf Creek XVII part 9: Wolf Creek Innovator in Cardiac Arrest and Resuscitation Science Award

The Wolf Creek Conferences on Cardiac Arrest Resuscitation began in 1975, and have served as an important forum for thought leaders and scientists from industry and academia to come together with the common goal of advancing the field of cardiac arrest resuscitation. The Wolf Creek XVII Conference was hosted by the Max Harry Weil Institute of Critical Care Research and Innovation in Ann Arbor, Michigan on June 14-17, 2023. A new component of the conference was the Wolf Creek Innovator in Cardiac Arrest and Resuscitation Science Award competition. The competition was designed to recognize early career investigators from around the world who's science is challenging the current paradigms in the field. Finalists were selected by a panel of international experts and invited to present in-person at the conference. The winner was chosen by electronic vote of conference participants and awarded a $10,0000 cash prize. Finalists included Carolina Barbosa Maciel from the University of Florida, Adam Gottula from the University of Michigan, Rajat Kalra from the University of Minnesota, Ryan Morgan from the Children's Hospital of Philadelphia, Mitsuaki Nishikimi form Hiroshima University, and Jacob Sunshine from the University of Washington. Ryan Morgan from the Children's Hospital of Philadelphia was selected as the 2023 Wolf Creek Innovator Awardee. This manuscript provides a summary of the work presented by each of the finalists and provides a preview of the future of resuscitation science.

2023 American Heart Association Focused Update on Adult Advanced Cardiovascular Life Support: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

Cardiac arrest is common and deadly, affecting up to 700 000 people in the United States annually. Advanced cardiac life support measures are commonly used to improve outcomes. This "2023 American Heart Association Focused Update on Adult Advanced Cardiovascular Life Support" summarizes the most recent published evidence for and recommendations on the use of medications, temperature management, percutaneous coronary angiography, extracorporeal cardiopulmonary resuscitation, and seizure management in this population. We discuss the lack of data in recent cardiac arrest literature that limits our ability to evaluate diversity, equity, and inclusion in this population. Last, we consider how the cardiac arrest population may make up an important pool of organ donors for those awaiting organ transplantation.

Practice Standards for the Use of Multimodality Neuromonitoring: A Delphi Consensus Process

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.

Pre-operative prediction of post-operative urinary retention in lumbar surgery: a prospective validation of machine learning model

PURPOSE

Predicting urinary retention is difficult. The aim of this study is to prospectively validate a previously developed model using machine learning techniques.

METHODS

Patients were recruited from pre-operative clinic. Prediction of urinary retention was completed pre-operatively by 4 individuals and compared to ground truth POUR outcomes. Inter-rater reliability was calculated with intercorrelation coefficient (2,1).

RESULTS

171 patients were included with age 63 ± 14 years, 58.5% (100/171) male, BMI 30.4 ± 5.9 kg/m2, American Society of Anesthesiologists class 2.6 ± 0.5, 1.7 ± 1.0 levels, 56% (96/171) fusions. The observed rate of POUR was 25.7%. The model's performance was found to be 0.663 (0.567-0.759). With a regression model probability cutoff of 0.24 and a neural network cutoff of 0.23, the following predictive power was achieved: specificity 90.6%, sensitivity 22.7%, negative predictive value 77.2%, positive predictive value 45.5%, and accuracy 73.1%. Intercorrelation coefficient for the regression aspect of the model was found to be 0.889 and intercorrelation coefficient for the neural network aspect of the model was found to be 0.874.

CONCLUSIONS

This prospective study confirms performance of the prediction model for POUR developed with retrospective data, showing great correlation. This supports the use of machine learning techniques in the prediction of postoperative complications such as urinary retention.

Headache Management in the Neuroscience Intensive Care Unit

PURPOSE OF REVIEW

Headache is a common symptom in the Neuroscience Intensive Care Unit (NeuroICU). Our goal is to provide an overview of approaches to headache management for common neurocritical care conditions.

RECENT FINDINGS

Headache disorders afflict nearly half of patients admitted to the NICU. Commonly encountered disorders featuring headache include cerebrovascular disease, trauma, and intracranial infection. Approaches to pain are highly variable, and multimodal pain regimens are commonly employed. The overall body of evidence supporting therapeutic strategies to manage headache in the critical care setting is slim, and pain control remains suboptimal in many cases with persistent reliance on opioids. Headache is a complex, frequently occurring phenomenon in the NeuroICU care setting. At present, literature on evidence-based practice for management of headache in the critical care setting remains scarce, and despite multimodal approaches, reliance on opioids is commonplace.

Electroencephalography as a Biomarker of Prognosis in Acute Brain Injury

Electroencephalography (EEG) is a noninvasive tool that allows the monitoring of cerebral brain function in critically ill patients, aiding with diagnosis, management, and prognostication. Specific EEG features have shown utility in the prediction of outcomes in critically ill patients with status epilepticus, acute brain injury (ischemic stroke, intracranial hemorrhage, subarachnoid hemorrhage, and traumatic brain injury), anoxic brain injury, and toxic-metabolic encephalopathy. Studies have also found an association between particular EEG patterns and long-term functional and cognitive outcomes as well as prediction of recovery of consciousness following acute brain injury. This review summarizes these findings and demonstrates the value of utilizing EEG findings in the determination of prognosis.

Temperature Management for Comatose Adult Survivors of Cardiac Arrest: A Science Advisory From the American Heart Association

Targeted temperature management has been a cornerstone of post-cardiac arrest care for patients remaining unresponsive after return of spontaneous circulation since the initial trials in 2002 found that mild therapeutic hypothermia improves neurological outcome. The suggested temperature range expanded in 2015 in response to a large trial finding that outcomes were not better with treatment at 33° C compared with 36° C. In 2021, another large trial was published in which outcomes with temperature control at 33° C were not better than those of patients treated with a strategy of strict normothermia. On the basis of these new data, the International Liaison Committee on Resuscitation and other organizations have altered their treatment recommendations for temperature management after cardiac arrest. The new American Heart Association guidelines on this topic will be introduced in a 2023 focused update. To provide guidance to clinicians while this focused update is forthcoming, the American Heart Association's Emergency Cardiovascular Care Committee convened a writing group to review the TTM2 trial (Hypothermia Versus Normothermia After Out-of-Hospital Cardiac Arrest) in the context of other recent evidence and to present an opinion on how this trial may influence clinical practice. This science advisory was informed by review of the TTM2 trial, consideration of other recent influential studies, and discussion between cardiac arrest experts in the fields of cardiology, critical care, emergency medicine, and neurology. Conclusions presented in this advisory statement do not replace current guidelines but are intended to provide an expert opinion on novel literature that will be incorporated into future guidelines and suggest the opportunity for reassessment of current clinical practice.

Developing a Standardized Approach to Grading the Level of Brain Dysfunction on EEG

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.

Evaluating analgesic medications utilized in the treatment of aneurysmal subarachnoid hemorrhage and association with delayed cerebral ischemia

BACKGROUND

Spontaneous aneurysmal subarachnoid hemorrhage (aSAH) recovery may be hampered by delayed cerebral ischemia (DCI). Herein, we sought to identify whether frequently administered medications in the intensive care unit (ICU) are associated with DCI.

METHODS

In this retrospective study, patients admitted to a tertiary care center neuro-ICU between 2012 and 2019 with aSAH who could verbalize pain intensity scores were included. Medication dosages and clinical characteristics were abstracted from the medical record. Both paired and unpaired analyses were utilized to measure individual DCI risk for a given patient in relation to drug dosages.

RESULTS

119 patients were included; average age was 61.7 ± 15.2 (SD) years, 89 (74.7%) were female, and 32 (26.9%) experienced DCI during admission. Patients with DCI had longer length of stay (19.3 ± 7.4 vs 12.7 ± 5.3 days, p < 0.0001). The combination medication of acetaminophen 325 mg/butalbital 50 mg/caffeine 40 mg (A/B/C) was associated with decreased DCI on paired (2.3 ± 2.0 vs 3.1 ± 1.9 tabs, p = 0.034) and unpaired analysis (1.84 ± 2.4 vs 2.6 ± 2.4 tabs, p < 0.001). No associations were found between DCI and opioids, dexamethasone, levetiracetam, or acetaminophen. Max and mean daily headache pain was not associated with DCI occurrence.

CONCLUSION

We identified an association between a commonly administered analgesic and DCI. A/B/C is associated with decreased DCI in this study, while other medications are not associated with DCI risk.

Sedation and shivering management after cardiac arrest

Management of sedation and shivering during targeted temperature management (TTM) after cardiac arrest is limited by a dearth of high-quality evidence to guide clinicians. Data from general intensive care unit (ICU) populations can likely be extrapolated to post-cardiac arrest patients, but clinicians should be mindful of key differences that exist between these populations. Most importantly, the goals of sedation after cardiac arrest are distinct from other ICU patients and may also involve suppression of shivering during TTM. Drug metabolism and clearance are altered considerably during TTM when a low goal temperature is used, which can delay accurate neuroprognostication. When neuromuscular blockade is used to prevent shivering, sedation should be deep enough to prevent awareness and providers should be aware that this can mask clinical manifestations of seizures. However, excessively deep or prolonged sedation is associated with complications including delirium, infections, increased duration of ventilatory support, prolonged ICU length of stay, and delays in neuroprognostication. In this manuscript, we review sedation and shivering management best practices in the post-cardiac arrest patient population.

Do Neuroprognostic Studies Account for Self-Fulfilling Prophecy Bias in Their Methodology? The SPIN Protocol for a Systematic Review

Self-fulfilling prophecy bias occurs when a perceived prognosis leads to treatment decisions that inherently modify outcomes of a patient, and thus, overinflate the prediction performance of prognostic methods. The goal of this series of systematic reviews is to characterize the extent to which neuroprognostic studies account for the potential impact of self-fulfilling prophecy bias in their methodology by assessing their adequacy of disclosing factors relevant to this bias.

Methods

Studies evaluating the prediction performance of neuroprognostic tools in cardiac arrest, malignant ischemic stroke, traumatic brain injury, subarachnoid hemorrhage, and spontaneous intracerebral hemorrhage will be identified through PubMed, Cochrane, and Embase database searches. Two reviewers blinded to each other's assessment will perform screening and data extraction of included studies using Distiller SR and following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We will abstract data pertinent to the methodology of the studies relevant to self-fulfilling prophecy bias.

Results

We will conduct a descriptive analysis of the data. We will summarize the reporting of mortality according to timing and mode of death, rates of exposure to withdrawal of life-sustaining therapy, reasoning behind limitations of supportive care, systematic use of standardized neuroprognostication algorithms and whether the tool being investigated is part of such assessments, and blinding of treatment team to results of neuroprognostic test being evaluated.

CONCLUSIONS

We will identify if neuroprognostic studies have been transparent in their methodology to factors that affect the self-fulfilling prophecy bias. Our results will serve as the foundation for standardization of neuroprognostic study methodologies by refining the quality of the data derived from such studies.

Utilization of the ketogenic diet for adults with status epilepticus

BACKGROUND

The ketogenic diet (KD) is a high-fat, low-carbohydrate diet with therapeutic potential in refractory seizures, both in outpatient and inpatient settings. Successful implementation of KD involves a multifaceted, interdisciplinary approach to address anticipated challenges. We sought to characterize the utilization of KD among healthcare providers caring for adults with status epilepticus (SE).

METHODS

We distributed a web-based survey through professional societies, including the American Academy of Neurology (AAN), Neurocritical Care Society (NCS), American Epilepsy Society (AES), Neuro Anesthesia and Critical Care Society (NACCS), and the Academy of Nutrition and Dietetics (AND), and via research contacts. We asked respondents about practice experience and experience using KD as a treatment for SE. Descriptive statistics and Chi-square tests were used to analyze the results.

RESULTS

Of 156 respondents, 80% of physicians and 18% of non-physicians reported experience with KD for SE. Anticipated difficulty in achieving ketosis (36.3%), lack of expertise (24.2%), and lack of resources (20.9%) were identified as the most important barriers limiting the utilization of KD. The absence of dietitians (37.1%) or pharmacists (25.7%) support was the most important missing resource. Reasons for stopping KD included perceived ineffectiveness (29.1%), difficulty achieving ketosis (24.6%), and side effects (17.3%). Academic centers had more experience with the use of KD and greater EEG monitoring availability and fewer barriers to its implementation. The need for randomized clinical trials supporting efficacy (36.5%) and better practice guidelines for implementation and maintenance of KD (29.6%) were cited most frequently as factors to increase utilization of KD.

CONCLUSION

This study identifies important barriers to the utilization of KD as a treatment for SE despite evidence supporting its efficacy in the appropriate clinical context, namely lack of resources and interdisciplinary support, and lack of established practice guidelines. Our results highlight the need for future research to improve understanding of the efficacy and safety of KD along with better interdisciplinary collaborations to increase its utilization.

Temperature Control After Cardiac Arrest: A Narrative Review

Cardiac arrest (CA) is a critical public health issue affecting more than half a million Americans annually. The main determinant of outcome post-CA is hypoxic-ischemic brain injury (HIBI), and temperature control is currently the only evidence-based, guideline-recommended intervention targeting secondary brain injury. Temperature control is a key component of a post-CA care bundle; however, conflicting evidence challenges its wide implementation across the vastly heterogeneous population of CA survivors. Here, we critically appraise the available literature on temperature control in HIBI, detail how the evidence has been integrated into clinical practice, and highlight the complications associated with its use and the timing of neuroprognostication after CA. Future clinical trials evaluating different temperature targets, rates of rewarming, duration of cooling, and identifying which patient phenotype benefits from different temperature control methods are needed to address these prevailing knowledge gaps.

Computable Phenotypes to Characterize Changing Patient Brain Dysfunction in the Intensive Care Unit

In the United States, more than 5 million patients are admitted annually to ICUs, with ICU mortality of 10%-29% and costs over $82 billion. Acute brain dysfunction status, delirium, is often underdiagnosed or undervalued. This study's objective was to develop automated computable phenotypes for acute brain dysfunction states and describe transitions among brain dysfunction states to illustrate the clinical trajectories of ICU patients. We created two single-center, longitudinal EHR datasets for 48,817 adult patients admitted to an ICU at UFH Gainesville (GNV) and Jacksonville (JAX). We developed algorithms to quantify acute brain dysfunction status including coma, delirium, normal, or death at 12-hour intervals of each ICU admission and to identify acute brain dysfunction phenotypes using continuous acute brain dysfunction status and k-means clustering approach. There were 49,770 admissions for 37,835 patients in UFH GNV dataset and 18,472 admissions for 10,982 patients in UFH JAX dataset. In total, 18% of patients had coma as the worst brain dysfunction status; every 12 hours, around 4%-7% would transit to delirium, 22%-25% would recover, 3%-4% would expire, and 67%-68% would remain in a coma in the ICU. Additionally, 7% of patients had delirium as the worst brain dysfunction status; around 6%-7% would transit to coma, 40%-42% would be no delirium, 1% would expire, and 51%-52% would remain delirium in the ICU. There were three phenotypes: persistent coma/delirium, persistently normal, and transition from coma/delirium to normal almost exclusively in first 48 hours after ICU admission. We developed phenotyping scoring algorithms that determined acute brain dysfunction status every 12 hours while admitted to the ICU. This approach may be useful in developing prognostic and decision-support tools to aid patients and clinicians in decision-making on resource use and escalation of care.

Quantitative epileptiform burden and electroencephalography background features predict post-traumatic epilepsy

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 (PTE1).

METHODS

We performed a multicentre, retrospective case-control study of patients with TBI. 63 PTE1 patients were matched with 63 non-PTE1 patients by admission Glasgow Coma Scale score, age and sex. We evaluated the association of quantitative electroencephalography features with PTE1 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 PTE1 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 PTE1 prediction. Future trials should incorporate quantitative electroencephalography features to validate this enhancement of PTE risk stratification models.

Acute Headache Management for Patients with Subarachnoid Hemorrhage: An International Survey of Health Care Providers

BACKGROUND

Severe headaches are common after subarachnoid hemorrhage. Guidelines recommend treatment with acetaminophen and opioids, but patient data show that headaches often persist despite multimodal treatment approaches. Considering an overall slim body of data for a common complaint affecting patients with SAH during their intensive care stay, we set out to assess practice patterns in headache management among clinicians who treat patients with SAH.

METHODS

We conducted an international cross-sectional study through a 37-question Web-based survey distributed to members of five professional societies relevant to intensive and neurocritical care from November 2021 to January 2022. Responses were characterized through descriptive analyses. Fisher's exact test was used to test associations.

RESULTS

Of 516 respondents, 329 of 497 (66%) were from North America and 121 of 497 (24%) from Europe. Of 435 respondents, 379 (87%) reported headache as a major management concern for patients with SAH. Intensive care teams were primarily responsible for analgesia during hospitalization (249 of 435, 57%), whereas responsibility shifted to neurosurgery at discharge (233 of 501, 47%). Most used medications were acetaminophen (90%), opioids (66%), corticosteroids (28%), and antiseizure medications (28%). Opioids or medication combinations including opioids were most frequently perceived as most effective by 169 of 433 respondents (39%, predominantly intensivists), followed by corticosteroids or combinations with corticosteroids (96 of 433, 22%, predominantly neurologists). Of medications prescribed at discharge, acetaminophen was most common (303 of 381, 80%), followed by opioids (175 of 381, 46%) and antiseizure medications (173 of 381, 45%). Opioids during hospitalization were significantly more prescribed by intensivists, by providers managing higher numbers of patients with SAH, and in Europe. At discharge, opioids were more frequently prescribed in North America. Of 435 respondents, 299 (69%) indicated no change in prescription practice of opioids with the opioid crisis. Additional differences in prescription patterns between continents and providers and while inpatient versus at discharge were found.

CONCLUSIONS

Post-SAH headache in the intensive care setting is a major clinical concern. Analgesia heavily relies on opioids both in use and in perception of efficacy, with no reported change in prescription patterns for opioids for most providers despite the significant drawbacks of opioids. Responsibility for analgesia shifts between hospitalization and discharge. International and provider-related differences are evident. Novel treatment strategies and alignment of prescription between providers are urgently needed.

Pregabalin for Recurrent Seizures in Critical Illness: A Promising Adjunctive Therapy, Especially for cyclic Seizures

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.

Cardiac arrest: An interdisciplinary scoping review of clinical literature from 2020

Objectives

The Interdisciplinary Cardiac Arrest Research Review (ICARE) group was formed in 2018 to conduct an annual search of peer-reviewed literature relevant to cardiac arrest. Now in its third year, the goals of the review are to highlight annual updates in the interdisciplinary world of clinical cardiac arrest research with a focus on clinically relevant and impactful clinical and population-level studies from 2020.

Methods

A search of PubMed using keywords related to clinical research in cardiac arrest was conducted. Titles and abstracts were screened for relevance and sorted into 7 categories: Epidemiology & Public Health Initiatives; Prehospital Resuscitation, Technology & Care; In-Hospital Resuscitation & Post-Arrest Care; Prognostication & Outcomes; Pediatrics; Interdisciplinary Guidelines & Reviews; and a new section dedicated to the coronavirus disease 2019 (COVID-19) pandemic. Screened manuscripts underwent standardized scoring of methodological quality and impact on the respective fields by reviewer teams lead by a subject matter expert editor. Articles scoring higher than 99 percentiles by category were selected for full critique. Systematic differences between editors' and reviewers' scores were assessed using Wilcoxon signed-rank test.

Results

A total of 3594 articles were identified on initial search; of these, 1026 were scored after screening for relevance and deduplication, and 51 underwent full critique. The leading category was Prehospital Resuscitation, Technology & Care representing 35% (18/51) of fully reviewed articles. Four COVID-19 related articles were included for formal review that was attributed to a relative lack of high-quality data concerning cardiac arrest and COVID-19 specifically by the end of the 2020 calendar year. No significant differences between editor and reviewer scoring were found among review articles (P = 0.697). Among original research articles, section editors scored a median 1 point (interquartile range, 0-3; P < 0.01) less than reviewers.

Conclusions

Several clinically relevant studies have added to the evidence base for the management of cardiac arrest patients including methods for prognostication of neurologic outcome following arrest, airway management strategy, timing of coronary intervention, and methods to improve expeditious performance of key components of resuscitation such as chest compressions in adults and children.

Ultrasound-Guided Suprazygomatic Nerve Blocks to the Pterygopalatine Fossa: A Safe Procedure

OBJECTIVES

Large-scale procedural safety data on pterygopalatine fossa nerve blocks (PPFBs) performed via a suprazygomatic, ultrasound-guided approach are lacking, leading to hesitancy surrounding this technique. The aim of this study was to characterize the safety of PPFB.

METHODS

This retrospective chart review examined the records of adults who received an ultrasound-guided PPFB between January 1, 2016, and August 30, 2020, at the University of Florida. Indications included surgical procedures and nonsurgical pain. Clinical data describing PPFB were extracted from medical records. Descriptive statistics were calculated for all variables, and quantitative variables were analyzed with the paired t test to detect differences between before and after the procedure.

RESULTS

A total of 833 distinct PPFBs were performed on 411 subjects (59% female, mean age 48.5 years). Minor oozing from the injection site was the only reported side effect, in a single subject. Although systolic blood pressure, heart rate, and oxygen saturation were significantly different before and after the procedure (132.3 vs 136.4 mm Hg, P < 0.0001; 78.2 vs 80.8, P = 0.0003; and 97.8% vs 96.3%, P < 0.0001; respectively), mean arterial pressure and diastolic blood pressure were not significantly different (96.2 vs 97.1 mm Hg, P = 0.1545, and 78.2 vs 77.4 mm Hg, P = 0.1314, respectively). Similar results were found within subgroups, including subgroups by sex, race, and indication for PPFB.

DISCUSSION

We have not identified clinically significant adverse effects from PPFB performed with an ultrasound-guided suprazygomatic approach in a large cohort in the hospital setting. PPFBs are a safe and well-tolerated pain management strategy; however, prospective multicenter studies are needed.

A 40-Year-Old Woman With COVID-19 and Bilateral Vision Loss

Mucormycosis is a fast-spreading angioinvasive fungal infection with a very high mortality rate. It is associated with immunodeficiency, diabetes mellitus, iron overload, stem cell transplantation and the use of steroids. As cultures and histopathological biopsy may have low yield in invasive fungal infections, new generation sequencing of cfDNA (cell free deoxyribonucleic acid) has become a cornerstone for diagnosis. Over the past 18 months, increasing reports of COVID-19 associated Mucormycosis have emerged, most specifically in India and other nearby developing countries. Awareness and knowledge of this newly discovered association is of high importance and clinical relevance as the global COVID-19 pandemic continues. Herein, we present a case of a patient who was treated with steroids for COVID-19 in the outpatient setting and presented with unilateral periorbital pain and blurry vision. She progressively developed bilateral vision loss, fixed bilateral mydriasis, ophthalmoplegia and coma. Imaging findings included leptomeningeal, vascular, and subcortical enhancement accompanied with multifocal infarction. Subsequent biopsy of the paranasal sinuses revealed broad type fungal elements and cfDNA sequencing identified the pathogen as Rhizopus species. She was treated with intravenous amphotericin B, but succumbed to the infection.

Severe headache trajectory following aneurysmal subarachnoid hemorrhage: the association with lower sodium levels

BACKGROUND

A clinical hallmark of aneurysmal SAH (aSAH) is headache. Little is known about post-aSAH headache factors which may point to underlying mechanisms. In this study, we aimed to characterize the severity and trajectory of headaches in relation to clinical features of patients with aSAH.

METHODS

This is a retrospective longitudinal study of adult patients admitted to an academic tertiary care center between 2012 and 2019 with aSAH who could verbalize pain scores. Factors recorded included demographics, aneurysm characteristics, analgesia, daily morning serum sodium concentration, and occurrence of vasospasm. Group-based trajectory modeling was used to identify headache pain trajectories, and clinical factors were compared between trajectories.

RESULTS

Of 91 patients included in the analysis, mean age was 57 years and 20 (22%) were male. Headache score trajectories clustered into two groups: patients with mild-moderate and moderate-severe pain. Patients in the moderate-severe pain group were younger (P<0.05), received more opioid analgesia (P<0.001), and had lower sodium concentrations (P<0.001) than patients in the mild-moderate pain group.

CONCLUSION

We identified two distinct post-aSAH headache pain trajectory cohorts and identified an association with age, analgesia, and sodium levels. Future prospective studies considering sodium homeostasis and volume status under standardized analgesic regimens are warranted.

Early vigabatrin augmenting GABA-ergic pathways in post-anoxic status epilepticus (VIGAB-STAT) phase IIa clinical trial study protocol

Background

Nearly one in three unconscious cardiac arrest survivors experience post-anoxic status epilepticus (PASE). Historically, PASE has been deemed untreatable resulting in its exclusion from status epilepticus clinical trials. However, emerging reports of survivors achieving functional independence following early and aggressive treatment of PASE challenged this widespread therapeutic nihilism. In the absence of proven therapies specific to PASE, standard of care treatment leans on general management strategies for status epilepticus. Vigabatrin—an approved therapy for refractory focal-onset seizures in adults—inhibits the enzyme responsible for GABA catabolism, increases brain GABA levels and may act synergistically with anesthetic agents to abort seizures. Our central hypothesis is that early inhibition of GABA breakdown is possible in the post-cardiac arrest period and may be an effective adjunctive treatment in PASE.

Methods

This is a phase IIa, single-center, open-label, pilot clinical trial with blinded outcome assessment, of a single dose of vigabatrin in 12 consecutive PASE subjects. Subjects will receive a single loading dose of 4500 mg of vigabatrin (or dose adjusted in moderate and severe renal impairment) via enteric tube within 48 h of PASE onset. Vigabatrin levels will be monitored at 0- (baseline), 0.5-, 1-, 2-, 3-, 6-, 12-, 24-, 48-, 72- and 168-h (7 days) post-vigabatrin. Serum biomarkers of neuronal injury will be measured at 0-, 24-, 48-, 72- and 96-h post-vigabatrin. The primary feasibility endpoint is the proportion of enrolled subjects among identified eligible subjects receiving vigabatrin within 48 h of PASE onset. The primary pharmacokinetic endpoint is the measured vigabatrin level at 3 h post-administration. Descriptive statistics with rates and proportions will be obtained regarding feasibility outcomes, along with the noncompartmental method for pharmacokinetic analyses. The area under the vigabatrin concentration-time curve in plasma from zero to the time of the last quantifiable concentration (AUC0-tlqc) will be calculated to estimate dose-linear pharmacokinetics.

Perspective

Vigabatrin demonstrates high potential for synergism with current standard of care therapies. Demonstration of the feasibility of vigabatrin administration and preliminary safety in PASE will pave the way for future efficacy and safety trials of this pharmacotherapeutic.

Trial Registration NCT04772547.

Review of novel therapeutics in cardiac arrest (ReNTICA): systematic review protocol

INTRODUCTION

Cardiac arrest remains a common and devastating cause of death and disability worldwide. While targeted temperature management has become standard of care to improve functional neurologic outcome, few pharmacologic interventions have shown similar promise.

METHODS/ANALYSIS

This systematic review will focus on prospective human studies from 2015 to 2020 available in PubMed, Web of Science and EMBASE with a primary focus on impact on functional neurologic outcome. Prospective studies that include pharmacologic agents given during or after cardiac arrest will be included. Study selection will be in keeping with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. If sufficient data involving a given agent are available, a meta-analysis will be conducted and compared with current evidence for therapies recommended in international practice guidelines.

ETHICS AND DISSEMINATION

Formal ethical approval will not be required as primary data will not be collected. The results will be disseminated through peer-reviewed publication, conference presentation and lay press.

PROSPERO REGISTRATION NUMBER

International Prospective Register for Systematic Reviews (CRD42021230216).

5-Fluorouracil Neurotoxicity in the Absence of Dihydropyrimidine Dehydrogenase Deficiency Case Report

5 fluorouracil (5-FU)-related neurotoxicity is a rare and severe complication of 5-FU administration. Dihydropyrimidine dehydrogenase (DPD) deficiency is associated with an increased risk of serious adverse reactions due to its role in 5-FU metabolism. We report a case of acute reversible neurotoxicity with global areas of diffusion restriction in a patient with colorectal adenocarcinoma being treated with leucovorin calcium, 5-fluorouracil, and oxaliplatin (FOLFOX) without DPD deficiency following uridine triacetate administration.

Understanding the genetics of intracranial aneurysms: A primer

The genetics of intracranial aneurysms is complex. Much work has been done looking at the extracellular matrix surrounding cerebral vasculature as well as the role of matrix metalloproteinases. This comprehensive review summarizes what is known to date about the important genetic components that predispose to aneurysm formation and critically discusses the published findings. We discuss promising pre-clinical models of aneurysm formation and subarachnoid hemorrhage, and highlight avenues for future discovery, while considering limitations in the research to date. This review will further serve as a comprehensive reference guide to understand the genetic underpinnings for aneurysm pathophysiology and act as a primer for further investigation.

Preoperative prediction of postoperative urinary retention in lumbar surgery: a comparison of regression to multilayer neural network

OBJECTIVE

Postoperative urinary retention (POUR) is a common complication after spine surgery and is associated with prolongation of hospital stay, increased hospital cost, increased rate of urinary tract infection, bladder overdistention, and autonomic dysregulation. POUR incidence following spine surgery ranges between 5.6% and 38%; no reliable prediction tool to identify those at higher risk is available, and that constitutes an important gap in the literature. The objective of this study was to develop and validate a preoperative risk model to predict the occurrence of POUR following routine elective spine surgery.

METHODS

The authors conducted a retrospective chart review of consecutive adults who underwent lumbar spine surgery between June 1, 2017, and June 1, 2019. Patient characteristics, preexisting ICD-10 codes, preoperative pain and opioid use, preoperative alpha-1 blocker use, details of surgical planning, development of POUR, and management strategies were abstracted from electronic medical records. A binomial logistic model and a multilayer perceptron (MLP) were optimized using training and validation sets. The models' performance was then evaluated on model-naïve patients (not a part of either cohort). The models were then stacked to take advantage of each model's strengths and to avoid their weaknesses. Four additional models were developed from previously published models adjusted to include only relevant factors (i.e., factors known preoperatively and applied to the lumbar spine).

RESULTS

Overall, 891 patients were included in the cohort, with a mean of 59.6 ± 15.5 years of age, 52.7% male, BMI 30.4 ± 6.4, American Society of Anesthesiologists class 2.8 ± 0.6, and a mean of 5.6 ± 5.7 comorbidities. The rate of POUR was found to be 25.9%. The two models were comparable, with an area under the curve (AUC) of 0.737 for the regression model and 0.735 for the neural network. By combining the two models, an AUC of 0.753 was achieved. With a regression model probability cutoff of 0.24 and a neural network cutoff of 0.23, maximal sensitivity and specificity were achieved, with specificity 68.2%, sensitivity 72.9%, negative predictive value 88.2%, and positive predictive value 43.4%. Both models individually outperformed previously published models (AUC 0.516-0.645) when applied to the current data set.

CONCLUSIONS

This predictive model can be a powerful preoperative tool in predicting patients who will be likely to develop POUR. By using a combination of regression and neural network modeling, good sensitivity, specificity, and NPV are achieved.

Neurologic Outcome Prediction in the Intensive Care Unit

PURPOSE OF REVIEW

The burden of severe and disabling neurologic injury on survivors, families, and society can be profound. Neurologic outcome prediction, or neuroprognostication, is a complex undertaking with many important ramifications. It allows patients with good prognoses to be supported aggressively, survive, and recover; conversely, it avoids inappropriate prolonged and costly care in those with devastating injuries.

RECENT FINDINGS

Striving to maintain a high prediction performance during prognostic assessments encompasses acknowledging the shortcomings of this task and the challenges created by advances in medicine, which constantly shift the natural history of neurologic conditions. Embracing the unknowns of outcome prediction and the boundaries of knowledge surrounding neurologic recovery and plasticity is a necessary step toward refining neuroprognostication practices and improving the accuracy of prognostic impressions. The pillars of modern neuroprognostication include comprehensive characterization of neurologic injury burden (primary and secondary injuries), gauging cerebral resilience and estimated neurologic reserve, and tying it all together with individual values surrounding the acceptable extent of disability and the difficulties of an arduous convalescence journey.

SUMMARY

Comprehensive multimodal frameworks of neuroprognostication using different prognostic tools to portray the burden of neurologic injury coupled with the characterization of individual values and the degree of cerebral reserve and resilience are the cornerstone of modern outcome prediction.

Change in opioid and analgesic use for headaches after aneurysmal subarachnoid hemorrhage over time

BACKGROUND

Severe headache, a hallmark of aneurysmal subarachnoid hemorrhage (aSAH), affects up to 90% of patients during hospitalization. Opioids remain the guideline recommended mainstay of acute therapy despite their significant side effects and potential for tolerance and addiction. We evaluated time trends in opioid prescriptions, hypothesizing a decline with increasing recognition of the opioid crisis.

METHODS

We performed a retrospective review of patients with aSAH admitted to a single tertiary care center between 2012 and 2019 and included patients with Hunt-Hess-Grade≤3 who were able to verbalize pain scores. Collected variables included mean and maximum daily headache scores, aneurysm treatment modality, and daily analgesic medication doses.

RESULTS

Of 340 patients with aSAH, 114 (86 from 2012-2016 and 28 from 2017-2019) were included. Of the included patients, 86/114 (75.4%) were female. Patients in the 2012-2016 had a median age of 55 compared to 63 in the 2017-2019 group (P=0.02). Otherwise, there was no significant difference in demographic data including time in hospital, treatment option utilized, or aneurysm characteristics. Maximal daily headache score ranged from 6 to 8 for 2012-2016 and 5 to 8 for 2017-2019 cohorts. Average oral morphine equivalents (in mg) administered during hospitalization were similar between groups (2012-2016: 251±345 95% CI [178,323]; 2017-2019: 207±237 95% CI [119,295]; P=0.319). When prescribed, doses of opioids provided at discharge were less in the more recent group (2012-2016: 84.4±78.9 95% CI [57.5, 111]; 2017-2019: 38.1±20.2 95% CI [33.7, 42.5]; P=0.004) CONCLUSION: Despite recognition of important drawbacks of opioid use for headache control, and efforts to reduce opioid use during hospitalization, we found that utilization during hospitalization for SAH did not decrease over time. Maximal headache scores remained similar in the studied time periods, indicative of insufficient pain relief. This points out a pressing need to further investigate alternative opioid and narcotic sparing strategies for patients with SAH.

Ultra-early serum concentrations of neuronal and astroglial biomarkers predict poor neurological outcome after out-of-hospital cardiac arrest-a pilot neuroprognostic study

OBJECTIVES

To assess ultra-early neuroprognostic significance of GFAP, NF-L, UCH-L1, tau, and S100B concentrations, change trajectory, and combination profile after Out-of-Hospital Cardiac Arrest (OHCA).

METHODS

Prospective enrollment of 22 OHCA and 10 control patients at an academic tertiary care center between May 1, 2017 and January 28, 2020. Blood was collected within one hour of return of spontaneous circulation (ROSC) (H0), at hours 6 (H6), 12, 18, 24, and daily or until discharge or death. Biomarker concentrations, multifactor score, and trajectory change were assessed and compared to final neurologic status (good vs poor Cerebral Performance Category; CPC 1-2 vs CPC 3-5, respectively).

RESULTS

10 patients had good and 12 had poor neurologic outcomes. Poor outcome patients had higher biomarker concentrations and combined biomarker scores at early time points. The earliest significant difference between good and poor outcome patients' serum biomarkers were at H12 for GFAP (good median: 425 pg/mL [IQR:370-630] vs poor: 5954[1712-65,055] pg/mL; p < 0.001), H12 for NF-L (64[41-69] vs 898[348-1990] pg/mL; p < 0.001), H0 for Tau (31[8-51] vs 124[53-238] pg/mL; p = 0.025), H0 for UCH-L1 (898[375-1600] vs 2475[1898-4098] pg/mL; p = 0.008), and H6 for S100B (123[70-290] vs 895[360-1199] pg/mL; p = 0.002). Four biomarker composite scores differed by H12 (78.03[52.03-111.25] vs 749 [198.46-4870.63] pg/mL; p = 0.003). Machine-learning approach also identified that four-marker score trajectory group memberships are in concordance with patient outcome.

CONCLUSIONS

Ultra-early serial serum concentrations of neuronal and astroglial biomarkers may be of neuroprognostic significance following OHCA.

Evaluation and Management of Seizures and Status Epilepticus

Seizures are frequently triggered by an inciting event and result from uninhibited excitation and/or decreased inhibition of a pool of neurons. If physiologic seizure abortive mechanisms fail, the ensuing unrestrained synchronization of neurons-status epilepticus-can be life-threatening and is associated with the potential for marked morbidity in survivors and high medical care costs. Prognosis is intimately related to etiology and its response to therapeutic measures. Timely implementation of pharmacologic therapy while concurrently performing a stepwise workup for etiology are paramount. Neurodiagnostic testing should guide titration of pharmacologic therapies, and help determine if there is a role for immune modulation.

Early head CT in post-cardiac arrest patients: A helpful tool or contributor to self-fulfilling prophecy?

OBJECTIVE

Neuroprognostication guidelines suggest that early head computed tomography (HCT) might be useful in the evaluation of cardiac arrest (CA) patients following return of spontaneous circulation. We aimed to determine the impact of early HCT, performed within the first 6 h following CA, on decision-making following resuscitation.

METHODS

We identified a cohort of initially unconscious post-CA patients at a tertiary care academic medical center from 2012 to 2017. Variables pertaining to demographics, CA details, post-CA care, including neuroimaging and neurophysiologic testing, were abstracted retrospectively from the electronic medical records. Changes in management resulting from HCT findings were recorded. Blinded board-certified neurointensivists adjudicated HCT findings related to hypoxic-ischemic brain injury (HIBI) burden. The gray-white matter ratio (GWR) was also calculated.

RESULTS

Of 302 patients, 182 (60.2%) underwent HCT within six hours of CA (early HCT group). Approximately 1 in 4 early HCTs were abnormal (most commonly HIBI changes; 78.7%, n = 37), which resulted in a change in management in nearly half of cases (46.8%, n = 22). The most common changes in management were de-escalation in care [including transition to do not resuscitate status), withholding targeted temperature management, and withdrawal of life sustaining therapy (WLST)]. In cases with radiographic HIBI, mean [standard deviation] GWR was lower (1.20 [0.10] vs 1.30 [0.09], P < 0.001) and progression to brain death was higher (44.4% vs 2.9%; P < 0.001). The inter-rater reliability (IRR) of early HCT to determine presence of HIBI between radiology and three neurointensivists had a wide range (κ 0.13-0.66).

CONCLUSION

Early HCT identified abnormalities in 25% of cases and frequently influenced therapeutic decisions. Neuroimaging interpretation discrepancies between radiology and neurointensivists are common and agreement on severity of HIBI on early HCT is poor (k 0.11).

Spectrum Degradation of Hippocampal LFP During Euthanasia

The hippocampal local field potential (LFP) exhibits a strong correlation with behavior. During rest, the theta rhythm is not prominent, but during active behavior, there are strong rhythms in the theta, theta harmonics, and gamma ranges. With increasing running velocity, theta, theta harmonics and gamma increase in power and in cross-frequency coupling, suggesting that neural entrainment is a direct consequence of the total excitatory input. While it is common to study the parametric range between the LFP and its complementing power spectra between deep rest and epochs of high running velocity, it is also possible to explore how the spectra degrades as the energy is completely quenched from the system. Specifically, it is unknown whether the 1/f slope is preserved as synaptic activity becomes diminished, as low frequencies are generated by large pools of neurons while higher frequencies comprise the activity of more local neuronal populations. To test this hypothesis, we examined rat LFPs recorded from the hippocampus and entorhinal cortex during barbiturate overdose euthanasia. Within the hippocampus, the initial stage entailed a quasi-stationary LFP state with a power-law feature in the power spectral density. In the second stage, there was a successive erosion of power from high- to low-frequencies in the second stage that continued until the only dominant remaining power was <20 Hz. This stage was followed by a rapid collapse of power spectrum toward the absolute electrothermal noise background. As the collapse of activity occurred later in hippocampus compared with medial entorhinal cortex, it suggests that the ability of a neural network to maintain the 1/f slope with decreasing energy is a function of general connectivity. Broadly, these data support the energy cascade theory where there is a cascade of energy from large cortical populations into smaller loops, such as those that supports the higher frequency gamma rhythm. As energy is pulled from the system, neural entrainment at gamma frequency (and higher) decline first. The larger loops, comprising a larger population, are fault-tolerant to a point capable of maintaining their activity before a final collapse.

Pearls and Pitfalls of Introducing Ketogenic Diet in Adult Status Epilepticus: A Practical Guide for the Intensivist

Background: Status epilepticus (SE) carries an exceedingly high mortality and morbidity, often warranting an aggressive therapeutic approach. Recently, the implementation of a ketogenic diet (KD) in adults with refractory and super-refractory SE has been shown to be feasible and effective. Methods: We describe our experience, including the challenges of achieving and maintaining ketosis, in an adult with new onset refractory status epilepticus (NORSE). Case Vignette: A previously healthy 29-year-old woman was admitted with cryptogenic NORSE following a febrile illness; course was complicated by prolonged super-refractory SE. A comprehensive work-up was notable only for mild cerebral spinal fluid (CSF) pleocytosis, elevated nonspecific serum inflammatory markers, and edematous hippocampi with associated diffusion restriction on magnetic resonance imaging (MRI). Repeat CSF testing was normal and serial MRIs demonstrated resolution of edema and diffusion restriction with progressive hippocampal and diffuse atrophy. She required prolonged therapeutic coma with high anesthetic infusion rates, 16 antiseizure drug (ASD) trials, empiric immunosuppression and partial bilateral oophorectomy. Enteral ketogenic formula was started on hospital day 28. However, sustained beta-hydroxybutyrate levels >2 mmol/L were only achieved 37 days later following a comprehensive adjustment of the care plan. KD was challenging to maintain in the intensive care unit (ICU) and was discontinued due to poor nutritional state and pressure ulcers. KD was restarted again in a non-ICU unit facilitating ASD tapering without re-emergence of SE. Discussion: There are inconspicuous carbohydrates in commonly administered medications for SE including antibiotics, electrolyte repletion formulations, different preparations of the same drug (i.e., parenteral, tablet, or suspension) and even solutions used for oral care-all challenging the use of KD in the hospitalized patient. Tailoring comprehensive care and awareness of possible complications of KD are important for the successful implementation and maintenance of ketosis.

Which Spreading Depolarizations Are Deleterious To Brain Tissue?

Spreading depolarizations (SDs) are profound disruptions of cellular homeostasis that slowly propagate through gray matter and present an extraordinary metabolic challenge to brain tissue. Recent work has shown that SDs occur commonly in human patients in the neurointensive care setting and have established a compelling case for their importance in the pathophysiology of acute brain injury. The International Conference on Spreading Depolarizations (iCSD) held in Boca Raton, Florida, in September of 2018 included a discussion session focused on the question of "Which SDs are deleterious to brain tissue?" iCSD is attended by investigators studying various animal species including invertebrates, in vivo and in vitro preparations, diseases of acute brain injury and migraine, computational modeling, and clinical brain injury, among other topics. The discussion included general agreement on many key issues, but also revealed divergent views on some topics that are relevant to the design of clinical interventions targeting SDs. A draft summary of viewpoints offered was then written by a multidisciplinary writing group of iCSD members, based on a transcript of the session. Feedback of all discussants was then formally collated, reviewed and incorporated into the final document. It is hoped that this report will stimulate collection of data that are needed to develop a more nuanced understanding of SD in different pathophysiological states, as the field continues to move toward effective clinical interventions.

Pterygopalatine Fossa Blockade as Novel, Narcotic-Sparing Treatment for Headache in Patients with Spontaneous Subarachnoid Hemorrhage

BACKGROUND

Severe headache is a hallmark clinical feature of spontaneous subarachnoid hemorrhage (SAH), affecting nearly 90% of patients during index hospitalization, regardless of the SAH severity or presence of a culprit aneurysm. Up to 1 in 4 survivors of SAH experience chronic headaches, which may be severe and last for years. Data guiding the optimal management of post-SAH headache are lacking. Opioids, often in escalating doses, remain the guideline-recommended mainstay of acute therapy, but pain relief remains suboptimal.

METHODS

This study is a case series of adult patients who received bilateral pterygopalatine fossa (PPF) blockade for the management of refractory headaches after spontaneous SAH (aneurysmal and non-aneurysmal) at a single tertiary care center. We examined pain scores and analgesic requirements before and after block placement.

RESULTS

Seven patients (median age 54 years, 3 men, four aneurysmal and three non-aneurysmal) received a PPF-block between post-bleed day 6-11 during index hospitalization in the neurointensive care unit. The worst pain recorded in the 24-h period before the block was significantly higher than in the period 4 h after the block (9.1 vs. 3.1; p = 0.0156), and in the period 8 h after the block (9.1 vs. 2.8; p = 0.0313). The only complication was minor oozing from the needle insertion sites, which subsided completely with gauze pressure within 1 min.

CONCLUSIONS

PPF blockade might constitute a promising opioid-sparing therapeutic strategy for the management of post-SAH headache that merits further prospective controlled randomized studies.

Proceedings from the Neurotherapeutics Symposium on Neurological Emergencies: Shaping the Future of Neurocritical Care

Effective treatment options for patients with life-threatening neurological disorders are limited. To address this unmet need, high-impact translational research is essential for the advancement and development of novel therapeutic approaches in neurocritical care. "The Neurotherapeutics Symposium 2019-Neurological Emergencies" conference, held in Rochester, New York, in June 2019, was designed to accelerate translation of neurocritical care research via transdisciplinary team science and diversity enhancement. Diversity excellence in the neuroscience workforce brings innovative and creative perspectives, and team science broadens the scientific approach by incorporating views from multiple stakeholders. Both are essential components needed to address complex scientific questions. Under represented minorities and women were involved in the organization of the conference and accounted for 30-40% of speakers, moderators, and attendees. Participants represented a diverse group of stakeholders committed to translational research. Topics discussed at the conference included acute ischemic and hemorrhagic strokes, neurogenic respiratory dysregulation, seizures and status epilepticus, brain telemetry, neuroprognostication, disorders of consciousness, and multimodal monitoring. In these proceedings, we summarize the topics covered at the conference and suggest the groundwork for future high-yield research in neurologic emergencies.