Postanoxic Coma Research Articles

Postanoxic alpha, theta or alpha-theta coma: Clinical setting and neurological outcome

AimThe aim of this study was to determine the prognosis of 26 consecutive adults with alpha coma (AC), theta coma (TC) or alpha-theta coma (ATC) following CRA and to describe the clinical setting and EEG features of these patients. MethodsWe retrospective analyzed a prospectively collected cohort of adult patients diagnosed as having AC, TC or ATC after CRA between January 2008 and June 2016. None of patients included in this analysis underwent therapeutic hypothermia (TH). Neurological outcome was expressed as the best score 6 months after CRA using the five-point Glasgow-Pisttsburgh Cerebral Performance Categories (CPC) ResultsTwenty-six patients were identified with a diagnosis of postanoxic AC, TC or ATC coma. There were 20 (77%) men and 6 (23%) women. The mean age was 63 ± 16 years. The most frequent EEG pattern was TC (21 patients, 80%), followed by AC (3 patients, 12%) and ATC (2 patients, 8%). The cardiac rhythm as primary origin of the CRA was ventricular fibrillation (VF) in 16 patients (61.5%), asystole in 8 patients (34.6%) and ventricular tachycardia (VT) in one patient (3.8%). The presence of EEG reactivity was present in 8 patients (30%). The mortality rate was 85%. Of the 4 surviving patients, two (3.8%) had moderate disability (CPC 2), one (3.8%) had severe disability (CPC 3) and one (3.8%) reached a good recovery. The age was significantly lower in survivors 46.2 ± 10.8 versus nonsurvivors 63.3 ± 15.5 (p = 0.04). There was increased association of EEG reactivity with survival (p = 0.07). ConclusionHypoxic-ischemic AC, TC and ATC are associated with a poor prognosis and a high rate of mortality. In younger patients with AC, TC and ATC and incomplete forms showing reactivity on the EEG, there is a greater probability of clinical recovery.

10. Neurophysiological prognosis in comatose patients after cardiac arrest: The Italian Multicentric Study (ProNeCA)

SEPs are reliable predictor of poor outcome in comatose patients after cardiac arrest (CA). Recently also the role of EEG has been reassessed. To evaluate the prognostic value of EEG and SEPs association in post-anoxic coma at different recording time. We included comatose patients after CA. EEG and SEPs were recorded within 12 hs and at 72 hs after CA. EEG was classified into grade 1(“continuous”/“nearly-continuous”) and grade 2(discontinuous/burst-suppression/suppression/isoelectric). SEPs were dichotomized into “bilaterally absent” (BA) and “present”. Outcome was evaluated at 6 months by GOS. “Recovery of consciousness” was considered good outcome. Ten centers took part to the study and 282 patients were included. EEG and SEPs were recorded in 141 within 12 hs in 162 at 72 hs. Grade 1 EEG at 12 hs always predicted good outcome, grade 2 pattern at 72 hs predicted poor outcome with higher predictive power. BA SEPs always predicted poor outcome. Grade 1 EEG was always associated with present SEPs. EEG is a reliable time-dependent predictor of good outcome (within 12 h) and poor outcome (after 72 h). SEP is time-independent predictor of poor outcome. Early grade 1 EEG is never associated with BA SEP. Early association recordings of EEG and SEPs increase of the reliability of prognosis prediction in post-anoxic coma.

O76 EEG continuity features predict outcome in postanoxic encephalopathy

Objectives In postanoxic encephalopathy, a rapid restoration of EEG background continuity predicts a good neurological outcome. Patterns with sharp amplitude transitions, such as burst-suppression with identical bursts, have a clear association with a poor outcome. We aim to capture these visual observations by two quantitative measures, in order to improve predictive accuracy. Methods We defined EEG background continuity as the fraction of signal without suppressions (segments with amplitudes μ V for >0.5 s). The burst-suppression contrast ratio was defined as the mean amplitude ratio between “bursts” (segments not classified as suppressions) and suppressions. Features were extracted from continuous EEG recordings in patients with postanoxic coma, using 5-min epochs for each hour between 0 and 72 h after cardiac arrest. Epochs with muscle artifacts were rejected automatically. The algorithm was optimized for a random set of 50 patients, and tested on an independent set of 410 patients. Outcome was assessed at 6 months after cardiac arrest and defined as “good” (Cerebral Performance Category 1–2) or “poor” (CPC 3–5). Results In the test set, EEG background continuity predicted good outcome best at 13 h after cardiac arrest, with sensitivity of 0.50 (95%-CI: 0.44–0.56) and specificity of 0.91 (95%-CI: 0.86–0.94). The burst-suppression contrast ratio predicted poor outcome best at 15 h after cardiac arrest, with sensitivity of 0.46 (95%-CI: 0.40–0.52) and specificity of 1.00 (95%-CI: 0.98–1.00). Discussion The quantitative measures outperform visual EEG assessment in terms of predictive accuracy. Still, they remain closely related to key features of visual EEG assessment, in contrast to other commonly used quantitative EEG features. A visual check of the EEG in the burst-suppression contrast ratio calculation remains essential, to rule out unwanted effects of high-amplitude artifacts. Conclusions Quantitative measures of EEG continuity reliably predict outcome in postanoxic encephalopathy. Significance The presented continuity features provide an objective, rapid, and reliable tool to assist in EEG interpretation in the ICU.

P329 Repeatability of SSEPs during and after targeted temperature management

Objectives In patients treated with mild therapeutic hypothermia after cardiac arrest, a bilateral absent cortical SSEP response (N20) at day 3 is a reliable predictor of poor neurological outcome. Little is known about the effect of hypothermia on the SSEP and the reliability of this prognostic marker in an earlier stage. We evaluated the N20 response during the first 5 days of ICU admission. Methods In a prospective cohort of 58 patients with postanoxic coma, treated with mild therapeutic hypothermia, the SSEP was measured once a day during the first 5 days of ICU admission. The SSEP at day one was performed within 12 h after cardiac arrest. Presence of the N20 response was retrospectively evaluated. Clinical outcome at six months was classified by the Cerebral Performance Category scale (CPC), dichotomized as good (CPC 1–2) or poor (CPC 3–5). Results In none of the eight patients with an absent SSEP at day one (during hypothermia), the SSEP returned during later days. All eight patients had poor neurological outcome. In patients with a present cortical response at day one, the N20 remained present during later days. The sensitivity for prediction of poor outcome was 23% with a specificity of 100%. During hypothermia, the latency of the N20 was prolonged by 2–4 ms. Discussion In this pilot study, SSEPs are stationary during the first 5 days after cardiac arrest: no differences are observed between presence or absence of responses at day one during treatment with mild therapeutic hypothermia and hereafter. Although an absent N20 is a reliable predictor for poor neurological outcome its sensitivity is low. Conclusions The presence or absence of the cortical N20 response is stable during the first 5 days in patients after cardiac arrest treated with hypothermia. Significance A bilateral absent SSEP at day one might be a reliable predictor of poor neurological outcome.

Synaptic damage underlies EEG abnormalities in postanoxic encephalopathy: A computational study.

In postanoxic coma, EEG patterns indicate the severity of encephalopathy and typically evolve in time. We aim to improve the understanding of pathophysiological mechanisms underlying these EEG abnormalities. We used a mean field model comprising excitatory and inhibitory neurons, local synaptic connections, and input from thalamic afferents. Anoxic damage is modeled as aggravated short-term synaptic depression, with gradual recovery over many hours. Additionally, excitatory neurotransmission is potentiated, scaling with the severity of anoxic encephalopathy. Simulations were compared with continuous EEG recordings of 155 comatose patients after cardiac arrest. The simulations agree well with six common categories of EEG rhythms in postanoxic encephalopathy, including typical transitions in time. Plausible results were only obtained if excitatory synapses were more severely affected by short-term synaptic depression than inhibitory synapses. In postanoxic encephalopathy, the evolution of EEG patterns presumably results from gradual improvement of complete synaptic failure, where excitatory synapses are more severely affected than inhibitory synapses. The range of EEG patterns depends on the excitation-inhibition imbalance, probably resulting from long-term potentiation of excitatory neurotransmission. Our study is the first to relate microscopic synaptic dynamics in anoxic brain injury to both typical EEG observations and their evolution in time.

Post-anoxic status epilepticus: which variable could modify prognosis? A single-center experience.

Status epilepticus (SE) is associated with high mortality in post-anoxic coma despite antiepileptic treatment. The aim of our study was to assess the percentage of awakening in a consecutive series of post-anoxic comatose patients with an EEG pattern consistent with SE and to verify any correlation with clinical, neurophysiological or pharmacological parameters. We retrospectively analyzed data collected from seventeen patients affected by post-anoxic SE matching them with outcome scores by means of univariate statistical analysis. Four patients were not pharmacologically treated while thirteen patients were treated with a combination of benzodiazepines, antiepileptic or anesthetic drugs: seven patients awakened even if they showed a moderate-severe disability A statistically significant correlation with preserved median nerve cortical somatosensory evoked potentials (SSEP), with the use of anesthetics and with the duration of SE was found. In post-anoxic coma, SE does not always correlate with poor outcome. In patients with favorable patterns on multimodal prognostication approach, pharmacologic treatment, even aggressive, could be attempted.

Early EEG for outcome prediction of postanoxic coma: prospective cohort study with cost-minimization analysis

BackgroundWe recently showed that electroencephalography (EEG) patterns within the first 24 hours robustly contribute to multimodal prediction of poor or good neurological outcome of comatose patients after cardiac arrest. Here, we confirm these results and present a cost-minimization analysis. Early prognosis contributes to communication between doctors and family, and may prevent inappropriate treatment.MethodsA prospective cohort study including 430 subsequent comatose patients after cardiac arrest was conducted at intensive care units of two teaching hospitals. Continuous EEG was started within 12 hours after cardiac arrest and continued up to 3 days. EEG patterns were visually classified as unfavorable (isoelectric, low-voltage, or burst suppression with identical bursts) or favorable (continuous patterns) at 12 and 24 hours after cardiac arrest. Outcome at 6 months was classified as good (cerebral performance category (CPC) 1 or 2) or poor (CPC 3, 4, or 5). Predictive values of EEG measures and cost-consequences from a hospital perspective were investigated, assuming EEG-based decision- making about withdrawal of life-sustaining treatment in the case of a poor predicted outcome.ResultsPoor outcome occurred in 197 patients (51% of those included in the analyses). Unfavorable EEG patterns at 24 hours predicted a poor outcome with specificity of 100% (95% CI 98–100%) and sensitivity of 29% (95% CI 22–36%). Favorable patterns at 12 hours predicted good outcome with specificity of 88% (95% CI 81–93%) and sensitivity of 51% (95% CI 42–60%). Treatment withdrawal based on an unfavorable EEG pattern at 24 hours resulted in a reduced mean ICU length of stay without increased mortality in the long term. This gave small cost reductions, depending on the timing of withdrawal.ConclusionsEarly EEG contributes to reliable prediction of good or poor outcome of postanoxic coma and may lead to reduced length of ICU stay. In turn, this may bring small cost reductions.

The potential role of pain-related SSEPs in the early prognostication of long-term functional outcome in post-anoxic coma

Cardiac arrest (CA) is a common cause of disability. Multimodal evaluation has improved prognosis but precocious biomarkers are not appropriate in determining long-term functional outcome. To identify early prognostication markers of long-term functional outcome in post-anoxic coma. Retrospective assessment of outcomes. Individuals older than 18 years with post-anoxic coma hospitalized in intensive care units after cardiac arrest (CA) regardless of cause (cardiac or non-cardiac) and location of event (in or out-of-hospital). Clinical, biological and neurophysiological data were collected within 48 hours from CA. Clinical data included time of no and low flow, CA rhythm, pupillary reflex, Glasgow motor score at admission and hyperthermia. Biological marker was the highest creatinine level. Neurophysiological parameters included EEG pattern and reactivity, Somatosensory Evoked Potential (SSEP), and Middle-Latency (ML) SSEP evoked at low (10 mA) and high (50 mA) intensity stimulation. Level of Cognitive Functioning Scale (LCFS), Disability Rating Scale and recovery from coma (Revised coma Recovery Scale [CRS-R]) were collected at 12 months. A LASSO multiple regression analysis was fitted to data to investigate the best predictors of LCF, DRS and CRS-R. In-sample prediction was obtained to verify the quality of fitting, and accuracy indices (i.e., total error rate) produced. Presence of short and medium latency SSEPs with low and high stimulation intensity were identified as prognostic predictors of outcome for all the scales. Error rate was 4.5% for CRS and LCF, and 9.1% for DRS. Middle latency somatosensory evoked potentials associated with short latency somatosensory evoked potentials during the first 48 hours after a cardiac arrest are strong predictors of functional outcome at 12 months from the event. Replication on larger cohorts is needed to support their routine use as prognostic markers. These markers could inform more appropriate allocation of resources, provide a basis for realistic goal-setting, and help the family to adjust its expectations.

Predicting Outcome in Postanoxic Coma: Are Ten EEG Electrodes Enough?

Increasing evidence supports that early EEG recordings reliably contribute to outcome prediction in comatose patients with postanoxic encephalopathy. As postanoxic encephalopathy typically results in generalized EEG abnormalities, spatial resolution of a small number of electrodes is likely sufficient, which will reduce set-up time. Here, the authors compare a reduced and a 21-channel EEG for outcome prediction. EEG recordings from 142 prospectively collected patients with postanoxic encephalopathy were reassessed by two independent reviewers using a reduced (10 electrodes) bipolar montage. Classification and prognostic accuracy were compared with the full (21 electrodes) montage. The full montage consensus was considered Gold Standard. Sixty-seven patients (47%) had good outcome. The agreement between the individual reviewers using the reduced montage and the Gold Standard score was good (κ = 0.75-0.79). The interobserver agreement was not affected by reducing the number of electrodes (κ = 0.78 for the reduced montage vs. 0.71 for the full montage). An isoelectric, low-voltage, or burst-suppression with identical bursts pattern at 24 hours invariably predicted poor outcome in both montages, with similar prognostic accuracy. A diffusely slowed or normal EEG pattern at 12 hours was associated with good outcome in both montages. Reducing the number of electrodes from 21 to 10 does not affect EEG classification or prognostic accuracy in patients with postanoxic coma.

The impact of extracerebral organ failure on outcome of patients after cardiac arrest: an observational study from the ICON database.

BackgroundWe used data from a large international database to assess the incidence and impact of extracerebral organ dysfunction on prognosis of patients admitted after cardiac arrest (CA).MethodsThis was a sub-analysis of the Intensive Care Over Nations (ICON) database, which contains data from all adult patients admitted to one of 730 participating intensive care units (ICUs) in 84 countries from 8–18 May 2012, except admissions for routine postoperative surveillance. For this analysis, patients admitted after CA (defined as those with “post-anoxic coma” or “cardiac arrest” as the reason for ICU admission) were included. Data were collected daily in the ICU for a maximum of 28 days; patients were followed up for outcome data until death, hospital discharge, or a maximum of 60 days in-hospital. Favorable neurological outcome was defined as alive at hospital discharge with a last available neurological Sequential Organ Failure Assessment (SOFA) subscore of 0–2.ResultsAmong the 469 patients admitted after CA, 250 (53 %) had had out-of-hospital CA; 210 (45 %) patients died in the ICU and 357 (76 %) had an unfavorable neurological outcome. Non-survivors had a higher incidence of renal (43 vs. 16 %), cardiovascular (56 vs. 45 %), and respiratory (62 vs. 48 %) failure on admission and during the ICU stay than survivors (all p < 0.05). Similar results were found for patients with unfavorable vs. favorable neurological outcomes. In multivariable analysis, independent predictors of ICU mortality were renal failure on admission, high admission Simplified Acute Physiology Score (SAPS) II, high maximum serum lactate levels within the first 24 h after ICU admission, and development of sepsis. Independent predictors of unfavorable neurological outcome were mechanical ventilation on admission, high admission SAPS II score, and neurological dysfunction on admission.ConclusionsIn this multicenter cohort, extracerebral organ dysfunction was common in CA patients. Renal failure on admission was the only extracerebral organ dysfunction independently associated with higher ICU mortality.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-016-1528-6) contains supplementary material, which is available to authorized users.

Postanoxic Coma with Myoclonus: Who Might Survive?

Patients with postanoxic multifocal myoclonus (PAMM) and burst suppression on electroencephalography (EEG) are believed to have a very low likelihood

Electroencephalography reactivity for prognostication of post-anoxic coma after cardiopulmonary resuscitation: A comparison of quantitative analysis and visual analysis

Electroencephalogram reactivity (EEG-R) is a positive predictive factor for assessing outcomes in comatose patients. Most studies assess the prognostic value of EEG-R utilizing visual analysis; however, this method is prone to subjectivity. We sought to categorize EEG-R with a quantitative approach. We retrospectively studied consecutive comatose patients who had an EEG-R recording performed 1–3 days after cardiopulmonary resuscitation (CPR) or during normothermia after therapeutic hypothermia. EEG-R was assessed via visual analysis and quantitative analysis separately. Clinical outcomes were followed-up at 3-month and dichotomized as recovery of awareness or no recovery of awareness. A total of 96 patients met the inclusion criteria, and 38 (40%) patients recovered awareness at 3-month followed-up. Of 27 patients with EEG-R measured with visual analysis, 22 patients recovered awareness; and of the 69 patients who did not demonstrated EEG-R, 16 patients recovered awareness. The sensitivity and specificity of visually measured EEG-R were 58% and 91%, respectively. The area under the receiver operating characteristic curve for the quantitative analysis was 0.92 (95% confidence interval, 0.87–0.97), with the best cut-off value of 0.10. EEG-R through quantitative analysis might be a good method in predicting the recovery of awareness in patients with post-anoxic coma after CPR.

Prediction of awakening from hypothermic postanoxic coma based on auditory discrimination.

Most of the available clinical tests for prognosis of postanoxic coma are informative of poor outcome. Previous work has shown that an improvement in auditory discrimination over the first days of coma is predictive of awakening. Here, we aimed at evaluating this test on a large cohort of patients undergoing therapeutic hypothermia and at investigating its added value on existing clinical measures. We recorded electroencephalographic responses to auditory stimuli in 94 comatose patients, under hypothermia and after rewarming to normal temperature. Auditory discrimination was semiautomatically quantified by decoding electroencephalographic responses to frequently repeated versus rare sounds. Outcome prediction was based on the change of decoding performance from hypothermia to normothermia. An increase in auditory discrimination from hypothermia to normothermia was observed for 33 of 94 patients. Among them, 27 awoke from coma, resulting in a positive predictive value of awakening of 82% (95% confidence interval = 0.65-0.93). Most nonsurvivors showing an improvement in auditory discrimination had incident status epilepticus. By excluding them, 27 of 29 patients with improvement in auditory discrimination survived, resulting in a considerable improvement of the predictive value for awakening (93%, with 95% confidence interval = 0.77-0.99). Importantly, this test predicted the awakening of 13 of 51 patients for whom the outcome was uncertain based on current tests. The progression of auditory discrimination from hypothermia to normothermia has a high predictive value for awakening. This quantitative measure provides an added value to existing clinical tests and encourages the maintenance of life support. Ann Neurol 2016;79:748-757.

ID 253 – Good functional outcome after prolonged postanoxic coma and myoclonic status epilepsy

Objective Present the possibility of a reasonable neurological recovery in early onset myoclonic status epilepsy (MSE) and prolonged postanoxic coma (PC). Methods A 43-year-old woman suffered a severe respiratory failure due to an anaphylactic reaction during anaesthetic induction before surgery. She required an urgent tracheostomy and remained in PC with reactive pupils and corneal reflexes, but with no withdrawal reaction to painful stimuli. Over the next hour she showed diffuse myoclonic jerks refractory to different antiepileptic drugs, midazolam and propofol. The EEG pattern revealed diffuse epileptiform discharges suggestive of MSE. Therapeutic hypothermia was induced, as was a barbituric coma using tiopental. Results PC and MSE persisted after suppression of the barbituric coma. The MRI was normal and repeated EEG confirmed MSE with stimulus-induced discharges. Cortical somatosensory evoked potentials (CSEP) were preserved and a second barbituric coma was induced. 48 days later the patient regained consciousness and was able to interact, being discharged on day 90. Conclusions Even in the event of an unfavourable initial prognosis, preserved brainstem reflexes, CSEP and EEG reactivity indicate the requirement for an intensive treatment of postanoxic status epilepsy. Key message Despite early onset of MSE and prolonged PC a global evaluation is necessary before establishing an accurate prognosis.

Prognostic value of somatosensory-evoked potentials in neurology: A critical review in hypoxic encephalopathy.

Prediction of prognosis in comatose patients surviving a cardiac arrest is still one of the intractable problems in critical care neurology because of lack of fool-proof ways to assess the outcome. Of all these measures, somatosensory-evoked potential (SSEP) has been perhaps the most evaluated and heavily relied-upon tool over the past several decades for assessing coma. Recent studies have given rise to concerns regarding the "absoluteness" of SSEP signals for the prognostic evaluation of coma. In this critical review, we searched the literature to focus on studies conducted so far on the prognostic evaluation of postanoxic coma using SSEPs. All those studies published on the use of SSEP as a prognostication tool in postanoxic coma were reviewed. A narrative review was created that included the strengths as well as limitations of the use of SSEP in postanoxic coma. The use of SSEP in coma has been universal for the purpose of prognostication. However, it has its own advantages as well as limitations. The limitations include challenges in performing and getting SSEP signals during coma as well as the challenges involved in reading and interpreting the signals. The recent usage of therapeutic hypothermia has become another factor that often interferes with the SSEP recording. Finally, based on these study results, some recommendations are generated for the effective use of SSEPs in comatose patients for further prognostication. We advocate that SSEP should be an integral component for the assessment of postanoxic comatose patients due to its several advantages over other assessment tools. However, SSEP recordings should follow certain standards. One should be aware that its interpretation may be biased by several factors. The bias created by the concept of "self-fulfilling hypothesis" should always be borne in mind before discontinuation of life support systems in terminal patients.

EEG as an Indicator of Cerebral Functioning in Postanoxic Coma.

Postanoxic coma after cardiac arrest is one of the most serious acute cerebral conditions and a frequent cause of admission to critical care units. Given substantial improvement of outcome over the recent years, a reliable and timely assessment of clinical evolution and prognosis is essential in this context, but may be challenging. In addition to the classic neurologic examination, EEG is increasingly emerging as an important tool to assess cerebral functions noninvasively. Although targeted temperature management and related sedation may delay clinical assessment, EEG provides accurate prognostic information in the early phase of coma. Here, the most frequently encountered EEG patterns in postanoxic coma are summarized and their relations with outcome prediction are discussed. This article also addresses the influence of targeted temperature management on brain signals and the implication of the evolution of EEG patterns over time. Finally, the article ends with a view of the future prospects for EEG in postanoxic management and prognostication.

Pain-related Somato Sensory Evoked Potentials: a potential new tool to improve the prognostic prediction of coma after cardiac arrest.

IntroductionEarly prediction of a good outcome in comatose patients after cardiac arrest still remains an unsolved problem. The main aim of the present study was to examine the accuracy of middle-latency SSEP triggered by a painful electrical stimulation on median nerves to predict a favorable outcome.MethodsNo- and low-flow times, pupillary reflex, Glasgow motor score and biochemical data were evaluated at ICU admission. The following were considered within 72 h of cardiac arrest: highest creatinine value, hyperthermia occurrence, EEG, SSEP at low- (10 mA) and high-intensity (50 mA) stimulation, and blood pressure reactivity to 50 mA. Intensive care treatments were also considered. Data were compared to survival, consciousness recovery and 6-month CPC (Cerebral Performance Category).ResultsPupillary reflex and EEG were statistically significant in predicting survival; the absence of blood pressure reactivity seems to predict brain death within 7 days of cardiac arrest. Middle- and short-latency SSEP were statistically significant in predicting consciousness recovery, and middle-latency SSEP was statistically significant in predicting 6-month CPC outcome. The prognostic capability of 50 mA middle-latency-SSEP was demonstrated to occur earlier than that of EEG reactivity.ConclusionsNeurophysiological evaluation constitutes the key to early information about the neurological prognostication of postanoxic coma. In particular, the presence of 50 mA middle-latency SSEP seems to be an early and reliable predictor of good neurological outcome, and its absence constitutes a marker of poor prognosis. Moreover, the absence 50 mA blood pressure reactivity seems to identify patients evolving towards the brain death.

Prospective Cohort Study Evaluating the Prognostic Value of Simple EEG Parameters in Postanoxic Coma.

We prospectively studied early bedside standard EEG characteristics in 61 acute postanoxic coma patients. Five simple EEG features, namely, isoelectric, discontinuous, nonreactive to intense auditory and nociceptive stimuli, dominant delta frequency, and occurrence of paroxysms were classified yes or no. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC) of each of these variables for predicting an unfavorable outcome, defined as death, persistent vegetative state, minimally conscious state, or severe neurological disability, as assessed 1 year after coma onset were computed as well as Synek's score. The outcome was unfavorable in 56 (91.8%) patients. Sensitivity, specificity, PPV, NPV, and AUC of nonreactive EEG for predicting an unfavorable outcome were 84%, 80%, 98%, 31%, and 0.82, respectively; and were all very close to the ones of Synek score>3, which were 82%, 80%, 98%, 29%, and 0.81, respectively. Specificities for predicting an unfavorable outcome were 100% for isoelectric, discontinuous, or dominant delta activity EEG. These 3 last features were constantly associated to unfavorable outcome. Absent EEG reactivity strongly predicted an unfavorable outcome in postanoxic coma, and performed as accurate as a Synek score>3. Analyzing characteristics of some simple EEG features may easily help nonneurophysiologist physicians to investigate prognostic issue of postanoxic coma patient. In this study (a) discontinuous, isoelectric, or delta-dominant EEG were constantly associated with unfavorable outcome and (b) nonreactive EEG performed prognostic as accurate as a Synek score>3.

Spotlight on the July 14 Issue

#### Notable in Neurology This issue features articles discussing how early EEG contributes to multimodal outcome prediction of postanoxic coma and the development of and risk factors for excessive daytime sleepiness in early Parkinson disease. Two other featured reviews focus on the international consensus diagnostic criteria for neuromyelitis optica spectrum disorders and whether it is time to change the “blind men and elephant” approach to Parkinson disease. ### Residual fast ripples in the intraoperative corticogram predict epilepsy surgery outcome The clinical use of high-frequency oscillations or spikes for tailored epilepsy surgery is …

Early EEG contributes to multimodal outcome prediction of postanoxic coma.

Objectives:Early identification of potential recovery of postanoxic coma is a major challenge. We studied the additional predictive value of EEG.Methods:Two hundred seventy-seven consecutive comatose patients after cardiac arrest were included in a prospective cohort study on 2 intensive care units. Continuous EEG was measured during the first 3 days. EEGs were classified as unfavorable (isoelectric, low-voltage, burst-suppression with identical bursts), intermediate, or favorable (continuous patterns), at 12, 24, 48, and 72 hours. Outcome was dichotomized as good or poor. Resuscitation, demographic, clinical, somatosensory evoked potential, and EEG measures were related to outcome at 6 months using logistic regression analysis. Analyses of diagnostic accuracy included receiver operating characteristics and calculation of predictive values.Results:Poor outcome occurred in 149 patients (54%). Single measures unequivocally predicting poor outcome were an unfavorable EEG pattern at 24 hours, absent pupillary light responses at 48 hours, and absent somatosensory evoked potentials at 72 hours. Together, these had a specificity of 100% and a sensitivity of 50%. For the remaining 203 patients, who were still in the “gray zone” at 72 hours, a predictive model including unfavorable EEG patterns at 12 hours, absent or extensor motor response to pain at 72 hours, and higher age had an area under the curve of 0.90 (95% confidence interval 0.84–0.96). Favorable EEG patterns at 12 hours were strongly associated with good outcome. EEG beyond 24 hours had no additional predictive value.Conclusions:EEG within 24 hours is a robust contributor to prediction of poor or good outcome of comatose patients after cardiac arrest.