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• The relationship between EEG and neuron specific enolase (NSE) has been previously described, but without considering the influence of EEG background. • NSE is higher in patients with repetitive epileptiform discharges on continuous, discontinuous, and burst-suppression. • NSE is however lower with epileptiform features on suppression, likely reflecting the need of viable neurons to generate them. Electroencephalogram (EEG) and serum neuron specific enolase (NSE) are frequently used prognosticators after cardiac arrest (CA). This study explored the association between NSE and EEG, considering the role of EEG timing, its background continuity, reactivity, occurrence of epileptiform discharges, and pre-defined malignancy degree. Retrospective analysis including 445 consecutive adults from a prospective registry, surviving the first 24 hours after CA and undergoing multimodal evaluation. EEG were interpreted blinded to NSE results. Higher NSE was associated with poor EEG prognosticators, such as increasing malignancy, repetitive epileptiform discharges and lack of background reactivity, independently of EEG timing (including sedation and temperature). When stratified for background continuity, NSE was higher with repetitive epileptiform discharges, except in the case of suppressed EEGs. This relationship showed some variation according to the recording time. Neuronal injury after CA, reflected by NSE, correlates with several EEG features: increasing EEG malignancy, lack of background reactivity, and presence of repetitive epileptiform discharges. The correlation between epileptiform discharges and NSE is influenced by underlying EEG background and timing. This study, describing the complex interplay between serum NSE and epileptiform features, suggests that epileptiform discharges reflect neuronal injury particularly in non-suppressed EEG. [ABSTRACT FROM AUTHOR]

Background: Electroencephalography (EEG) is essential to assess prognosis in patients after cardiac arrest (CA). Use of continuous EEG (cEEG) is increasing in critically-ill patients, but it is more resource-consuming than routine EEG (rEEG). Observational studies did not show a major impact of cEEG versus rEEG on outcome, but randomized studies are lacking.Methods: We analyzed data of the CERTA trial (NCT03129438), including comatose adults after CA undergoing cEEG (30-48 hours) or two rEEG (20-30 minutes each). We explored correlations between recording EEG type and mortality (primary outcome), or Cerebral Performance Categories (CPC, secondary outcome), assessed blindly at 6 months, using uni- and multivariable analyses (adjusting for other prognostic variables showing some imbalance across groups).Results: We analyzed 112 adults (52 underwent rEEG, 60 cEEG,); 31 (27.7%) were women; 68 (60.7%) patients died. In univariate analysis, mortality (rEEG 59%, cEEG 65%, p = 0.318) and good outcome (CPC 1-2; rEEG 33%, cEEG 27%, p = 0.247) were comparable across EEG groups. This did not change after multiple logistic regressions, adjusting for shockable rhythm, time to return of spontaneous circulation, serum neuron-specific enolase, EEG background reactivity, regarding mortality (cEEG vs rEEG: OR 1.60, 95% CI 0.43-5.83, p = 0.477), and good outcome (OR 0.51, 95% CI 0.14-1.90, p = 0.318).Conclusion: This analysis suggests that cEEG or repeated rEEG are related to comparable outcomes of comatose patients after CA. Pending a prospective, large randomized trial, this finding does not support the routine use of cEEG for prognostication in this setting.Trial Registration: Continuous EEG Randomized Trial in Adults (CERTA); NCT03129438; July 25, 2019. [ABSTRACT FROM AUTHOR]

Aim: Generalized periodic discharge (GPD) is an EEG pattern of poor neurological outcome, frequently observed in comatose patients after cardiac arrest. The aim of our study was to identify the neuronal network generating ≤2.5 Hz GPD using EEG source localization and connectivity analysis.Methods: We analyzed 40 comatose adult patients with anoxic-ischemic encephalopathy, who had 19 channel-EEG recording. We computed electric source analysis based on distributed inverse solution (LAURA) and we estimated cortical activity in 82 atlas-based cortical brain regions. We applied directed connectivity analysis (Partial Directed Coherence) on these sources to estimate the main drivers.Results: Source analysis suggested that the GPD are generated in the cortex of the limbic system in the majority of patients (87.5%). Connectivity analysis revealed main drivers located in thalamus and hippocampus for the large majority of patients (80%), together with important activation also in amygdala (70%).Conclusions: We hypothesize that the anoxic-ischemic dysfunction, leading to hyperactivity of the thalamo-cortical (limbic presumably) circuit, can result in an oscillatory thalamic activity capable of inducing periodic cortical (limbic, mostly medial-temporal and orbitofrontal) discharges, similarly to the case of generalized rhythmic spike-wave discharge in convulsive or non-convulsive status epilepticus. [ABSTRACT FROM AUTHOR]

Purpose: To quantitatively assess the severity of anoxic-ischemic brain injury early after cardiac arrest (CA) using a novel automated method applied to head computed tomography (HCT).Methods: Adult patients who were comatose and underwent HCT < 24 h after arrest were included in a retrospective analysis. Principal endpoint was unfavorable outcome (UO) defined as Cerebral Performance Category (CPC) of 3-5 at hospital discharge. We developed an automated processing algorithm for HCT images to be registered, atlas-segmented in 181 regions, and region-specific radiologic densities determined in Hounsfield Units. This approach was compared with an established manual method evaluating grey-white matter ratios (GWR). We tested univariable and multivariable prognostic models which integrated clinical and HCT features including densities in lobes and in nodes of cerebral networks linked to CA recovery.Results: Ninety-one patients were enrolled among whom 66 (73%) had an UO. HCTs were interpreted as normal or without acute abnormality by a neuroradiologist in 77 cases (85%). Compared to the favorable outcome group, UO patients had significantly lower densities in all lobes and in nodes of cerebral networks. A model combining clinical variables with the automated method applied to cerebral network nodes had the highest prognostic performance although not significantly different than the combined clinical-GWR method (AUC [95% CI] 0.94 [0.86-1.00] and 0.92 [0.83-1.00] respectively).Conclusion: In comatose survivors of CA, automated quantitative analysis of HCT revealed very early multifocal changes in brain tissue density which are mostly overlooked on conventional neuroradiologic interpretation and are associated with neurological outcome. [ABSTRACT FROM AUTHOR]

Background: Non-invasive, easy-to-use bedside tools to estimate prognosis in unresponsive patients with postanoxic brain injury are needed. We assessed the usefulness of otoacoustic emissions as outcome markers after cardiac arrest.Methods: Distortion product otoacoustic emissions (DPOAE) and transient evoked otoacoustic emissions (TEOAE) were measured in cardiac arrest patients whose prognosis was deemed to be poor following standard neurological assessment (n = 10). Ten patients with myocardial infarction without prior loss of consciousness served as controls.Results: Compared to controls with myocardial infarction, cardiac arrest patients with poor neurological prognosis had significantly less often preserved DPOAE (9.2 vs. 40.8% positive measurements; OR 0.15 (CI 0.07–0.30); p < 0.0001). Partially preserved DPOAE were noted in 4 cardiac arrest patients. TEOAE were not statistically different between the two groups.Conclusions: Despite their convenience, otoacoustic emissions cannot be used as reliable prognostic markers in cardiac arrest survivors. This is because we identified 4 cases with partially preserved otoacoustic emissions in a sample of 10 unresponsive post-cardiac arrest patients whose neurological condition was so poor that active treatment was withdrawn. However, we suggest that future research should address if decaying outer hair cell function over time may serve as a proxy for evolving ischemic brain damage.

Background: Non-invasive, easy-to-use bedside tools to estimate prognosis in unresponsive patients with postanoxic brain injury are needed. We assessed the usefulness of otoacoustic emissions as outcome markers after cardiac arrest. Methods: Distortion product otoacoustic emissions (DPOAE) and transient evoked otoacoustic emissions (TEOAE) were measured in cardiac arrest patients whose prognosis was deemed to be poor following standard neurological assessment (n = 10). Ten patients with myocardial infarction without prior loss of consciousness served as controls. Results: Compared to controls with myocardial infarction, cardiac arrest patients with poor neurological prognosis had significantly less often preserved DPOAE (9.2 vs. 40.8% positive measurements; OR 0.15 (CI 0.07–0.30); p < 0.0001). Partially preserved DPOAE were noted in 4 cardiac arrest patients. TEOAE were not statistically different between the two groups. Conclusions: Despite their convenience, otoacoustic emissions cannot be used as reliable prognostic markers in cardiac arrest survivors. This is because we identified 4 cases with partially preserved otoacoustic emissions in a sample of 10 unresponsive post-cardiac arrest patients whose neurological condition was so poor that active treatment was withdrawn. However, we suggest that future research should address if decaying outer hair cell function over time may serve as a proxy for evolving ischemic brain damage. [ABSTRACT FROM AUTHOR]

Introduction: Standardized EEG patterns according to the American Clinical Neurophysiology Society (ACNS) ("highly malignant", "malignant" and "benign") demonstrated good correlation with outcome after cardiac arrest (CA). However, this approach relates to EEGs after target temperature management (TTM), and correlation to other recognized outcome predictors remains unknown.Objectives: To investigate the relationship between categorized EEG and other outcome predictors, during and after TTM, at different temperatures.Methods: In a prospective adult CA registry between 01.2014 and 06.2017, EEG at day one and two after CA were reclassified into pre-defined categories. Correlations between EEG and clinical, biochemical, neurophysiological outcome predictors, and prognosis (CPC at three months; good: 1-2), were assessed.Results: Of 203 CA episodes, 31.5% were managed targeting 33 °C, 60.6% targeting 36 °C, and 7.9% with spontaneous temperature. "Highly malignant" EEG was found in 36.7% of patients at day one (predicting poor prognosis with 91% specificity -95%CI: 83%-97%-, and 63% sensitivity -95% CI: 53%-72%), and 27.1% at day two. "Benign" EEG occurred in 19.2% at day one (sensitivity to good prognosis: 35% -95%CI: 26%-46%-, positive predictive value: 89% -95% CI: 75%-97%), and in 33.2% at day two. Categorized EEG showed robust correlations with all prognostic predictors. Results were similar between EEGs recorded at day one or two, and, especially for poor prognosis, across TTM targets.Discussion: Standardized EEG categorization after CA shows strong correlation with other outcome predictors, without marked variation across EEG recording time or TTM targets, underscoring its prognostic role in a multimodal approach. [ABSTRACT FROM AUTHOR]

Objective To determine whether neurologic consultation influences the use of therapeutic hypothermia. Methods We identified adult patients treated for cardiac arrest from October 2009 through September 2015 at 149 academic medical centers and their affiliate hospitals using discharge diagnosis codes in Vizient database. Neurology consultation was defined as a neurologist participating in patient care at any point during the hospitalization. Use of therapeutic hypothermia was identified using procedure codes. We used multivariable models to evaluate the association between neurologic consultation and therapeutic hypothermia before and after adjustment for patient baseline characteristics and hospital factors including inpatient volume and relative volume of cardiac arrest cases. Results We identified 136,830 hospitalizations for cardiac arrest. The 9,336 (6.8%) encounters involving a neurologist had higher severity of illness, longer hospital stay, and longer intensive care unit stay. There were 5,034 (3.7%) encounters where patients underwent therapeutic hypothermia. Hypothermia use was significantly more common when neurologists were involved during hospitalization (7.9% vs. 3.4%; OR 2.44, 95% CI 2.2-2.6; p < 0.01). After adjustment, neurologic consultation continued to be associated with the use of therapeutic hypothermia (adjusted OR 2.5, 95% CI 2.3–2.8), particularly among hospitals in the highest quartile of total inpatient volume (OR 4.6, 95% CI 4.0–5.3). Lower in-hospital mortality was also associated with neurological consultation after adjusting for therapeutic hypothermia (59.2% vs. 61.3%, p < 0.01). Conclusions The involvement of a neurologist in cardiac arrest patients is associated with increased use of therapeutic hypothermia, though therapeutic hypothermia for cardiac arrest likely remains underutilized. [ABSTRACT FROM AUTHOR]

Objective Outcome prognostication in comatose patients after cardiac arrest (CA) remains a major challenge. Here we investigated the prognostic value of combinations of linear and non-linear bivariate EEG synchronization measures. Methods 94 comatose patients with EEG within 24 h after CA were included. Clinical outcome was assessed at 3 months using the Cerebral Performance Categories (CPC). EEG synchronization between the left and right parasagittal, and between the frontal and parietal brain regions was assessed with 4 different quantitative measures (delta power asymmetry, cross-correlation, mutual information, and transfer entropy). 2/3 of patients were used to assess the predictive power of all possible combinations of these eight features (4 measures × 2 directions) using cross-validation. The predictive power of the best combination was tested on the remaining 1/3 of patients. Results The best combination for prognostication consisted of 4 of the 8 features, and contained linear and non-linear measures. Predictive power for poor outcome (CPC 3–5), measured with the area under the ROC curve, was 0.84 during cross-validation, and 0.81 on the test set. At specificity of 1.0 the sensitivity was 0.54, and the accuracy 0.81. Conclusion Combinations of EEG synchronization measures can contribute to early prognostication after CA. In particular, combining linear and non-linear measures is important for good predictive power. Significance Quantitative methods might increase the prognostic yield of currently used multi-modal approaches. [ABSTRACT FROM AUTHOR]

Aim: The current EEG role for prognostication after cardiac arrest (CA) essentially aims at reliably identifying patients with poor prognosis ("highly malignant" patterns, defined by Westhall et al. in 2014). Conversely, "benign EEGs", defined by the absence of elements of "highly malignant" and "malignant" categories, has limited sensitivity in detecting good prognosis. We postulate that a less stringent "benign EEG" definition would improve sensitivity to detect patients with favorable outcomes.Methods: Retrospectively assessing our registry of unconscious adults after CA (1.2018-8.2021), we scored EEGs within 72 h after CA using a modified "benign EEG" classification (allowing discontinuity, low-voltage, or reversed anterio-posterior amplitude development), versus Westhall's "benign EEG" classification (not allowing the former items). We compared predictive performances towards good outcome (Cerebral Performance Category 1-2 at 3 months), using 2x2 tables (and binomial 95% confidence intervals) and proportions comparisons.Results: Among 381 patients (mean age 61.9 ± 15.4 years, 104 (27.2%) females, 240 (62.9%) having cardiac origin), the modified "benign EEG" definition identified a higher number of patients with potential good outcome (252, 66%, vs 163, 43%). Sensitivity of the modified EEG definition was 0.97 (95% CI: 0.92-0.97) vs 0.71 (95% CI: 0.62-0.78) (p < 0.001). Positive predictive values (PPV) were 0.53 (95% CI: 0.46-0.59) versus 0.59 (95% CI: 0.51-0.67; p = 0.17). Similar statistics were observed at definite recording times, and for survivors.Discussion: The modified "benign EEG" classification demonstrated a markedly higher sensitivity towards favorable outcome, with minor impact on PPV. Adaptation of "benign EEG" criteria may improve efficient identification of patients who may reach a good outcome. [ABSTRACT FROM AUTHOR]

Background: Lack of electroencephalography (EEG) background reactivity during therapeutic hypothermia (TH) has been associated with poor outcome in post-anoxic comatose patients. However, decision on intensive care withdrawal is based on normothermic (NT) evaluations. This study aims at exploring whether patients showing recovery of EEG reactivity in NT after a non-reactive EEG in TH differ from those remaining non-reactive. Methods: Patients with non-reactive EEG during TH were identified from our prospective registry of consecutive comatose adults admitted after successful resuscitation from CA between April 2009 and June 2014. Variables including neurological examination, serum neuron-specific enolase (NSE), procalcitonin, and EEG features were compared regarding impact on functional outcome at 3 months. Results: Seventy-two of 197 patients (37 %) had a non-reactive EEG background during TH with thirteen (18 %) evolving towards reactivity in NT. Compared to those remaining non-reactive ( n = 59), they showed significantly better recovery of brainstem reflexes ( p < 0.001), better motor responses ( p < 0.001), transitory consciousness improvement ( p = 0.008), and a tendency toward lower NSE ( p = 0.067). One patient recovering EEG reactivity survived with good functional outcome at 3 months. Conclusions: Recovery of EEG reactivity from TH to NT seems to distinguish two patients' subgroups regarding early neurological assessment and transitory consciousness improvement, corroborating the role of EEG in providing information about cerebral functions. Understanding these dynamic changes encourages maintenance of intensive support in selected patients even after a non-reactive EEG background in TH, as a small subgroup may indeed recover with good functional outcome. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 55-year-old man who was taken to the intensive care unit of a tertiary care hospital due to cardiac arrest preceded by respiratory arrest. Several tests were conducted including the restoration of spontaneous perfusion, cardiopulmonary resuscitation, and neurologic examination. The patient regained spontaneous respirations, cough reflex, and corneal reflexes after being pronounced brain dead.

Introduction: Prognostic determination of patients in coma after resuscitation from cardiac arrest is both common and difficult. We explored clinical and electrophysiological testing to determine their associations with favorable and poor outcomes. Methods: We studied 75 comatose patients resuscitated from cardiac arrest, excluding those who were brain dead or continuously sedated; none received hypothermia therapy. Clinical examinations were performed on day 1. Results: The following proportions recovered awareness: 2 of 18 patients with absent pupillary reflexes; 18 of 57 with preserved pupillary reflexes ( p=0.08); 2 of 32 with absent corneal reflexes; 16 of 43 with preserved corneal reflexes ( p=0.001); 0 of 15 with absent oculovestibular reflexes; and 8 of 29 with preserved oculovestibular reflexes ( p<0.037). Purposeful movements were associated with a high probability of recovery, whereas other categories were unfavorable. Other categories of motor response were associated with an increased proportion of those who died without recovering awareness, but each category had some survivors. Somatosensory evoked potentials (SSEPs) were recorded from 47 patients. One of 21 patients with loss of the N20 component survived, compared with survival of 11 of 26 patients in whom it was present ( p=0.003). All 5 patients with preserved N70 responses recovered awareness in a subgroup of 33 patients. Sixteen of 22 subjects with mild electroencephalogram (EEG) abnormalities recovered consciousness, compared with the survival of 3 of 50 patients with malignant EEG patterns ( p= 0.0000001). Combining SSEP with EEG findings produced even greater predictive value. Conclusion: It seems unlikely that any single test will prove to have 100% predictive value for outcome; further studies combining clinical, EEG, and SSEP testing are warranted. [ABSTRACT FROM AUTHOR]

The author expresses his views on the incidence of reversible brain death in relation to a study conducted by researcher A.C. Webb and colleagues, published in a 2011 issue of the journal "Critical Care Medicine." The study focused on the occurrence of reversible brain death following cardiopulmonary arrest and induced hypothermia. The study procedure included the administration of a dose of fentanyl.

A neurocatastrophe or severe brain injury (SBI) is a central nervous system insult associated with a high likelihood of death or severe disability. While many etiologic processes may lead to SBI, the most common and best-studied clinical paradigms are traumatic brain injury and anoxic-ischemic encephalopathy following cardiac arrest. Clinical phenotypes following SBI include acute and chronic disorders of consciousness as well as a range of cognitive and behavioral impairments. A fundamental task for medical teams working in the acute phase is to estimate SBI recovery probabilities with the highest degree of accuracy possible. Predictions made on the basis of single features or variables lack discrimination and are generally supplanted by multivariable models that combine clinical, imaging, and laboratory data into tractable scoring systems. Yet existing scores fail to classify outcomes with the accuracy that would support individual patient-level decision making. Improved prognostication will likely depend on the use of molecular and imaging data that capture unique biologic features in individual patients with SBI. The integration of these additional layers of information will require iterative computational approaches., (© 2017 Elsevier B.V. All rights reserved.)

The article explores the prognostic usefulness of somatosensory-evoked potentials after cardiac arrest, which affects the brain, especially the cerebral cortex. The most reliable determination of a poor prognosis attributable to cortical damage, according to the American Academy of Neurology, can be provided by somatosensory-evoked potential testing. However, the testing is recommended to be performed in both hypothermic-treated and no-hypothermic-treated patients to have timing.

Objective: To explore the role of middle latency evoked potentials (EPs) as predictors for favorable outcome in patients with severe ischemic brain injuries by comparing the prognostic ability of short latency somatosensory and auditory evoked potentials (SLSEP and BAEP) with middle latency somatosensory and auditory evoked potentials (MLSEP and MLAEP)., Methods: MLSEP, MLAEP, SLSEP and BAEP were recorded in 112 patients with severe ischemic brain injuries (Glasgow Coma Scale ≤ 8). Among them, 83 patients suffered from cerebral ischemic stroke and 29 suffered from anoxic-ischemic encephalopathy after cardiopulmonary resuscitation between 1 and 7 days after the onset of stroke. Outcomes were reviewed 6 months later using the Glasgow Outcome Scale (GOS). A GOS score of 4-5 was considered as a good outcome while a score of 1-3 was considered as poor., Results: By using the prognostic authenticity analysis of predictors for good outcome, at least unilateral N20 of the SLSEP exit and at least unilateral N60 of the MLSEP exit showed the highest sensitivity which was 100% (95% CI: 86.7%-100%). The bilateral normal N60 showed a high specificity of 97.5% (95% CI: 90.4%-99.6%). It also showed the highest positive likelihood ratio of 6.25% (95% CI: 1.28%-30.59%), which was superior to N20 of SLSEP, V of BAEP, and Pa of MLAEP. The analysis demonstrated that the area under the curve for MLSEP grading was the highest (0.838) compared to that of SLSEP grading (0.784), MLAEP grading (0.659) and BAEP grading (0.621)., Conclusions: Compared with using N20 of SLSEP analysis alone, adding MLSEP improves the outcome prediction in patients with severe ischemic brain injuries. When an outcome is uncertain after initial evaluation using short-latency EPs, MLSEP is valuable to be used from the first week to further improve prognostication in these patients., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Objective: To describe the rationale and design of a new patient registry (Koma Outcome von Patienten der Frührehabilitation-Register [KOPF-R; Registry for Coma Outcome in Patients Undergoing Acute Rehabilitation]) that has the scope to examine determinants of long-term outcome and functioning of patients with severe disorders of consciousness (DOC)., Design: Prospective multicenter neurologic rehabilitation registry., Setting: Five specialized neurologic rehabilitation facilities., Participants: Patients (N=42) with DOC in vegetative state or minimally conscious state (MCS) as defined by the Coma Recovery Scale-Revised (CRS-R) after brain injury. Patients are being continuously enrolled. The data presented here cover the enrollment period from August 2011 to January 2012., Interventions: Not applicable., Main Outcome Measures: CRS-R, FIM, and emergence from MCS., Results: The registry was set up in 5 facilities across the state of Bavaria/Germany with a special expertise in the rehabilitation of acquired brain injury. Inclusion of patients started in August 2011. Measures include sociodemographic and clinical characteristics, course of acute therapy, electrophysiologic measures (evoked potentials, electroencephalogram), neuron-specific enolase, current medication, functioning, cognition, participation, quality of life, quantity and characteristics of rehabilitation therapy, caregiver burden, and attitudes toward end-of-life decisions. Main diagnoses were traumatic brain injury (24%), intracerebral or subarachnoid hemorrhage (31%), and anoxic-ischemic encephalopathy (45%). Mean CRS-R score ± SD at admission to rehabilitation was 5.9 ± 3.3, and mean FIM score ± SD at admission was 18 ± 0.4., Conclusions: The KOPF-R aspires to contribute prospective data on prognosis in severe DOC., (Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)