Comparison of four clinical risk scores in comatose patients after out-of-hospital cardiac arrest.

BACKGROUND AND AIMS: Several different scoring systems for early risk stratification after out-of-hospital cardiac arrest have been developed, but few have been validated in large datasets. The aim of the present study was to compare the well-validated Out-of-hospital Cardiac Arrest (OHCA) and Cardiac Arrest Hospital Prognosis (CAHP)-scores to the less complex MIRACLE2- and Target Temperature Management (TTM)-scores. METHODS: This was a post-hoc analysis of the Targeted Hypothermia versus Targeted Normothermia after Out-of-Hospital Cardiac Arrest (TTM2) trial. Missing data were handled by multiple imputation. The primary outcome was discriminatory performance assessed as the area under the receiver operating characteristics-curve (AUROC), with the outcome of interest being poor functional outcome or death (modified Rankin Scale 4-6) at 6 months after OHCA. RESULTS: Data on functional outcome at 6 months were available for 1829 cases, which constituted the study population. The pooled AUROC for the MIRACLE2-score was 0.810 (95% CI 0.790-0.828), 0.835 (95% CI 0.816-0.852) for the TTM-score, 0.820 (95% CI 0.800-0.839) for the CAHP-score and 0.770 (95% CI 0.748-0.791) for the OHCA-score. At the cut-offs needed to achieve specificities >95%, sensitivities were <40% for all four scoring systems. CONCLUSIONS: The TTM-, MIRACLE2- and CAHP-scores are all capable of providing objective risk estimates accurate enough to be used as part of a holistic patient assessment after OHCA of a suspected cardiac origin. Due to its simplicity, the MIRACLE2-score could be a practical solution for both clinical application and risk stratification within trials.

Auditory stimulation and deep learning predict awakening from coma after cardiac arrest.

Assessing the integrity of neural functions in coma after cardiac arrest remains an open challenge. Prognostication of coma outcome relies mainly on visual expert scoring of physiological signals, which is prone to subjectivity and leaves a considerable number of patients in a 'grey zone', with uncertain prognosis. Quantitative analysis of EEG responses to auditory stimuli can provide a window into neural functions in coma and information about patients' chances of awakening. However, responses to standardized auditory stimulation are far from being used in a clinical routine due to heterogeneous and cumbersome protocols. Here, we hypothesize that convolutional neural networks can assist in extracting interpretable patterns of EEG responses to auditory stimuli during the first day of coma that are predictive of patients' chances of awakening and survival at 3 months. We used convolutional neural networks (CNNs) to model single-trial EEG responses to auditory stimuli in the first day of coma, under standardized sedation and targeted temperature management, in a multicentre and multiprotocol patient cohort and predict outcome at 3 months. The use of CNNs resulted in a positive predictive power for predicting awakening of 0.83 ± 0.04 and 0.81 ± 0.06 and an area under the curve in predicting outcome of 0.69 ± 0.05 and 0.70 ± 0.05, for patients undergoing therapeutic hypothermia and normothermia, respectively. These results also persisted in a subset of patients that were in a clinical 'grey zone'. The network's confidence in predicting outcome was based on interpretable features: it strongly correlated to the neural synchrony and complexity of EEG responses and was modulated by independent clinical evaluations, such as the EEG reactivity, background burst-suppression or motor responses. Our results highlight the strong potential of interpretable deep learning algorithms in combination with auditory stimulation to improve prognostication of coma outcome.

Hypercalcemia: A Review.

Importance: Hypercalcemia affects approximately 1% of the worldwide population. Mild hypercalcemia, defined as total calcium of less than 12 mg/dL (<3 mmol/L) or ionized calcium of 5.6 to 8.0 mg/dL (1.4-2 mmol/L), is usually asymptomatic but may be associated with constitutional symptoms such as fatigue and constipation in approximately 20% of people. Hypercalcemia that is severe, defined as total calcium of 14 mg/dL or greater (>3.5 mmol/L) or ionized calcium of 10 mg/dL or greater (≥2.5 mmol/L) or that develops rapidly over days to weeks, can cause nausea, vomiting, dehydration, confusion, somnolence, and coma. Observations: Approximately 90% of people with hypercalcemia have primary hyperparathyroidism (PHPT) or malignancy. Additional causes of hypercalcemia include granulomatous disease such as sarcoidosis, endocrinopathies such as thyroid disease, immobilization, genetic disorders, and medications such as thiazide diuretics and supplements such as calcium, vitamin D, or vitamin A. Hypercalcemia has been associated with sodium-glucose cotransporter 2 protein inhibitors, immune checkpoint inhibitors, denosumab discontinuation, SARS-CoV-2, ketogenic diets, and extreme exercise, but these account for less than 1% of causes. Serum intact parathyroid hormone (PTH), the most important initial test to evaluate hypercalcemia, distinguishes PTH-dependent from PTH-independent causes. In a patient with hypercalcemia, an elevated or normal PTH concentration is consistent with PHPT, while a suppressed PTH level (<20 pg/mL depending on assay) indicates another cause. Mild hypercalcemia usually does not need acute intervention. If due to PHPT, parathyroidectomy may be considered depending on age, serum calcium level, and kidney or skeletal involvement. In patients older than 50 years with serum calcium levels less than 1 mg above the upper normal limit and no evidence of skeletal or kidney disease, observation may be appropriate. Initial therapy of symptomatic or severe hypercalcemia consists of hydration and intravenous bisphosphonates, such as zoledronic acid or pamidronate. In patients with kidney failure, denosumab and dialysis may be indicated. Glucocorticoids may be used as primary treatment when hypercalcemia is due to excessive intestinal calcium absorption (vitamin D intoxication, granulomatous disorders, some lymphomas). Treatment reduces serum calcium and improves symptoms, at least transiently. The underlying cause of hypercalcemia should be identified and treated. The prognosis for asymptomatic PHPT is excellent with either medical or surgical management. Hypercalcemia of malignancy is associated with poor survival. Conclusions and Relevance: Mild hypercalcemia is typically asymptomatic, while severe hypercalcemia is associated with nausea, vomiting, dehydration, confusion, somnolence, and coma. Asymptomatic hypercalcemia due to primary hyperparathyroidism is managed with parathyroidectomy or observation with monitoring, while severe hypercalcemia is typically treated with hydration and intravenous bisphosphonates.

Marchiafava-Bignami disease presenting as reversible coma.

Marchiafava-Bignami disease (MBD) is a rare demyelinating condition of the corpus callosum and subcortical white matter that is most commonly seen in alcoholic patients. The course of the disease varies with symptoms that range from dementia to complete coma; severe intermittent sympathetic storming with abnormal posturing is often reported in literature. It is presumably secondary to a deficiency of B complex vitamins, specifically thiamine and many patients have clinical improvement after repletion of B vitamins. We present a case of a 35-year-old man who developed MBD secondary to polysubstance misuse without history of alcohol use. His clinical course was complicated by persistent comatose state with autonomic dysfunction. After the administration of high-dose thiamine and vitamin C and E, the patient regained consciousness and was able to follow commands within 48 hours. Furthermore, this case showed recognising brain MRI findings for MBD is a crucial step in disease identification.

Complementary roles of neural synchrony and complexity for indexing consciousness and chances of surviving in acute coma.

An open challenge in consciousness research is understanding how neural functions are altered by pathological loss of consciousness. To maintain consciousness, the brain needs synchronized communication of information across brain regions, and sufficient complexity in neural activity. Coordination of brain activity, typically indexed through measures of neural synchrony, has been shown to decrease when consciousness is lost and to reflect the clinical state of patients with disorders of consciousness. Moreover, when consciousness is lost, neural activity loses complexity, while the levels of neural noise, indexed by the slope of the electroencephalography (EEG) spectral exponent decrease. Although these properties have been well investigated in resting state activity, it remains unknown whether the sensory processing network, which has been shown to be preserved in coma, suffers from a loss of synchronization or information content. Here, we focused on acute coma and hypothesized that neural synchrony in response to auditory stimuli would reflect coma severity, while complexity, or neural noise, would reflect the presence or loss of consciousness. Results showed that neural synchrony of EEG signals was stronger for survivors than non-survivors and predictive of patients' outcome, but indistinguishable between survivors and healthy controls. Measures of neural complexity and neural noise were not informative of patients' outcome and had high or low values for patients compared to controls. Our results suggest different roles for neural synchrony and complexity in acute coma. Synchrony represents a precondition for consciousness, while complexity needs an equilibrium between high or low values to support conscious cognition.

A novel metabolic disorder in the degradation pathway of endogenous methanol due to a mutation in the gene of alcohol dehydrogenase.

BACKGROUND: A small amount of methanol is produced endogenously in the human body but it is efficiently metabolized by alcohol dehydrogenase (ADH) and other enzymes, and the products eliminated without harm. In this study, we present a new entity of inborn error of methanol metabolism due to a mutation in the ADH1C gene coding for the γ subunit that is part of several ADH isoenzymes. RESULTS: This disorder was discovered in an 11.58-year-old boy. During one 9-month hospital admission, he had periods of 1-4 days during which he was comatose, and between these periods he was sometimes verbose and euphoric, and had ataxia, dysarthria. Following hemodialysis treatments, he became conscious and appeared healthy. Organ evaluations and his laboratory tests were normal. Toxicological evaluation of his blood showed a high methanol level [12.2 mg/dL (3.8 mmol/L), normal range up to 3.5 mg/dL (1.09 mmol/L) while the formaldehyde level was undetectable. The finding of liver function tests that were within normal limits, coupled with a normal eye examination and size of the liver, elevated blood methanol levels and an undetectable formaldehyde level, suggested ADH insufficiency. Adding zinc to the drug regimen 15 mg/daily dramatically reduced the patient's methanol level and alleviated the abnormal symptoms. When zinc supplementation was discontinued, the patient relapsed into a coma and hemodialysis was once again required. A homozygous mutation in ADH1C gene located at exon 3 was found, and both parents were heterozygous for this mutation. CONCLUSION: Accumulation of methanol due to mutation in ADH1C gene may result in drunkenness and ataxia, and leads to coma. This condition can be successfully treated with zinc supplementation as the cofactor of ADH.

The time course of acute Percheron artery ischemic coma on imaging: A retrospective cohort study.

We were to investigate the time course of lesions for awakening in acute Percheron artery ischemic coma (PAIC), which was previously unknown. Patients who had newly identified acute PAIC events in 2012-2015 and had not received thrombolytic therapy were enrolled retrospectively. The time course of lesions in PAIC was investigated by diffusion-weighted imaging (DWI). Ninety-three patients met the inclusion criteria, of whom 63 and 30 had transient PAIC and persistent PAIC, respectively. The time course of awakening events in persistent PAIC decreased over time, with large lesions in the bilateral paramedian thalamus/ rostral midbrain on DWI almost in all patients who was either plus or minus a "top of basilar artery" strokes. Whereas awakening events in transient PAIC increased over time, with small or lacunar lesions in the unilateral or bilateral thalamus/rostral midbrain about in 30.2 % cases, and the rest in naturally recanalization of infarcts or TIA. Lesion volumes were larger for persistent PAIC than for transient PAIC (median, 2.4 cm3 vs. 0.03 cm3, P < 0.0001). In Cox hazards ratio (HR) analysis, a lower GCS score was associated with mortality (HR, 5.5; 95 % confidence interval [CI],1.427-21.45). Multivaliate analysis shown that the predictors of higher risk of persistent PAIC were only increased NIHSS scores (HR,1.3; 95 % CI,1.109-1.640) and large lesions in bilateral thalamus/rostral midbrain (HR,15.0; 95 % CI,1.440-58.13). The time course of acute PAIC included transient and persistent. Most persistent PAIC was associated with large lesions in bilateral paramedian thalamus/ rostral midbrain, and with high mortality.

Effect of acupuncture method of removing-stasisand resuscitating on the consciousness of patients with severe traumatic brain injury: A randomized clinical trial.

INTRODUCTION: With the development of social economy, transportation and various infrastructures have also developed, but it has objectively increased the number of patients with head injury. Although the current craniocerebral medicine technology continues to advance, long-term bed rest and other complications have led to an insignificant decrease in the mortality rate of coma patients. It is not uncommon for patients with disturbance of consciousness caused by head injury in major hospitals. METHODS/DESIGN: This will be a retrospective, single-blind clinical observational study. We will select 50 cases that meet the subject's selection criteria. According to whether they received acupuncture treatment or not, they will be randomly divided into 2 groups, namely treatment group and control group. The control group will be given conventional Western medicine treatment, and the treatment group will be given acupuncture method of removing-stasis and resuscitating treatment on the basis of the control group. DISCUSSION: Our purpose is to observe the role of acupuncture method of removing-stasis and resuscitating in promoting the recovery of patients with severe head injury. We aim to provide more evidence-based medical evidence for acupuncture treatment of this disease. TRIAL REGISTRATION: ClinicalTrials.gov, ChiCTR2000034732, Registered on 19 July 2020.

Seizure and coma secondary to Conn's syndrome: a case report.

BACKGROUND: Conn's syndrome is a curable condition if identified properly. It is characterized by autonomous secretion of aldosterone from the adrenal gland cortex. Its morbidity is related to the increased risk of cardiovascular diseases. CASE PRESENTATION: We report the case of a 48-year-old man of African descent presenting with generalized tonic-clonic seizure and coma secondary to hypertensive encephalopathy. A biochemical evaluation revealed a very high aldosterone level and an undetectable renin level, both are compatible with primary aldosteronism. The presentation of the following confirms the diagnosis of primary aldosteronism: spontaneous hypokalemia, an undetectable renin level, and a high aldosterone level. Abdominal computed tomography revealed a left adrenal adenoma. Adrenal venous sampling confirmed lateralization of aldosterone excretion from the left adrenal gland. Our patient underwent left laparoscopic adrenalectomy that confirmed a left functional adrenal adenoma. After 12 months of follow up, his hypertension was controlled on only one antihypertensive drug which was down from four drugs preoperatively. CONCLUSION: Conn's syndrome, in this case, was complicated by coma secondary to seizure. Adrenalectomy normalized the hypokalemia and improved resistant hypertension. Potassium supplementation and several antihypertensives were discontinued as our patient became normokalemic and normotensive on one antihypertensive agent.

Outcome prediction with resting-state functional connectivity after cardiac arrest.

Predicting outcome in comatose patients after successful cardiopulmonary resuscitation is challenging. Our primary aim was to assess the potential contribution of resting-state-functional magnetic resonance imaging (RS-fMRI) in predicting neurological outcome. RS-fMRI was used to evaluate functional and effective connectivity within the default mode network in a cohort of 90 comatose patients and their impact on functional neurological outcome after 3 months. The RS-fMRI processing protocol comprises the evaluation of functional and effective connectivity within the default mode network. Seed-to-voxel and ROI-to-ROI feature analysis was performed as starting point for a supervised machine-learning approach. Classification of the Cerebral Performance Category (CPC) 1-3 (good to acceptable outcome) versus CPC 4-5 (adverse outcome) achieved a positive predictive value of 91.7%, sensitivity of 90.2%, and accuracy of 87.8%. A direct link to the level of consciousness and outcome after 3 months was identified for measures of segregation in the precuneus, in medial and right frontal regions. Thalamic connectivity appeared significantly reduced in patients without conscious response. Decreased within-network connectivity in the default mode network and within cortico-thalamic circuits correlated with clinical outcome after 3 months. Our results indicate a potential role of these markers for decision-making in comatose patients early after cardiac arrest.

Brain Volume Changes in Patients with Acute Brain Dysfunction Due to Sepsis.

BACKGROUND: Sepsis-induced brain dysfunction (SIBD) is often encountered in sepsis patients and is related to increased morbidity. No specific tests are available for SIBD, and neuroimaging findings are often normal. In this study, our aim was to analyze the diagnostic value of volumetric analysis of the brain structures and to find out its significance as a prognostic measure. METHODS: In this prospective observational study, brain magnetic resonance imaging (MRI) sections of 25 consecutively enrolled SIBD patients (17 with encephalopathy and 8 with coma) and 22 healthy controls underwent volumetric evaluation by an automated segmentation method. RESULTS: Ten SIBD patients had normal MRI, and 15 patients showed brain lesions or atrophy. The most prominent volume reduction was found in cerebral and cerebellar white matter, cerebral cortex, hippocampus, and amygdala, whereas deep gray matter regions and cerebellar cortex were relatively less affected. SIBD patients with normal MRI showed significantly reduced volumes in hippocampus and cerebral white matter. Caudate nuclei, putamen, and thalamus showed lower volume values in non-survivor SIBD patients, and left putamen and right thalamus showed a more pronounced volume reduction in coma patients. CONCLUSIONS: Volumetric analysis of the brain appears to be a sensitive measure of volumetric changes in SIBD. Volume reduction in specific deep gray matter regions might be an indicator of unfavorable outcome.

Hyperbaric oxygen therapy in patients with hypoxic ischemic encephalopathy.

BACKGROUND AND AIM: To assess the efficacy of hyperbaric oxygen therapy (HBOT) in patients with hypoxic ischemic encephalopathy (HIE). DESIGN: Non-randomized case-control observational study. SETTING: Tertiary level neurorehabilitation unit. POPULATION: Twenty-five patients with HIE seen between 1 to 12 months after the injury and having a coma recovery scale-revised (CRS-R) score less than 7 at entry were recruited. METHODS: Out of the patients who received HBOT, 20 received 20 sessions of HBOT at two absolute atmosphere pressure (ATA), and two received 60 sessions at 2 ATA over three different treatment intervals. We compared the outcomes between cases (who received HBOT) and controls (who did not receive HBOT).Cases and controls were allocated to three groups based on the time interval after injury following which they were recruited to the study: 1-3 months (9 cases and 16 controls), 4-8 months (9 cases and 9 controls) and 9-12 months (8 cases and 3 controls). OUTCOME MEASURES: CRS-R, Karnofsky performance scale, and change in disorder of consciousness (DOC) at admission and discharge were assessed. RESULTS: We observed a significant difference in CRS-R favoring the HBOT group at time intervals of 1-3 and 4-8 months. More patients in the HBOT group improved in DOC than the control group. CONCLUSIONS: HBOT given in the first nine months post-HIE can result in a better recovery and functional outcome.

Thalamic strokes that severely impair arousal extend into the brainstem.

In this study, we evaluate the role of the thalamus in the neural circuitry of arousal. Level of consciousness within the first 12 hours of a thalamic stroke is assessed with lesion symptom mapping. Impaired arousal correlates with lesions in the paramedian posterior thalamus near the centromedian and parafascicular nuclei, posterior hypothalamus, and midbrain tegmentum. All patients with severely impaired arousal (coma, stupor) had lesion extension into the midbrain and/or pontine tegmentum, whereas purely thalamic lesions did not severely impair arousal. These results are consistent with growing evidence that pathways most critical for human arousal lie outside the thalamus. Ann Neurol 2018;84:926-930.

Serum levels of Selenium and C-reactive protein in comatose patients with severe traumatic brain injury during the first week of hospitalization: case-control study.

INTRODUCTION: Mortality and morbidity related to traumatic brain injuries still remain high in patients. Many authors reported the importance of Selenium in maintaining the integrity of brain functions. This fact is supported by clinical evidence that therapy with selenium supplementation could help patients suffering from brain disorders like neurodegenerative diseases. The aim of our study was to assess the relationship between Selenium concentration in serum and evolution of comatose patients with severe traumatic brain injury, in the first week of admission, and the correlation between selenium and C-reactive protein. METHODS: This case-control study was conducted with 64 comatose patients with TBI, in the Department of Anesthesiology and Reanimation, IbnSina University Hospital and Hospital of specialties in Rabat-Morocco, and healthy volunteers recruited in Blood transfusion center of Rabat. Blood sampling was collected from TBI patients, in the first week (3h after admission and each 48h during one week), and from healthy volunteers one time. Concentration of Se in serum was determined by electrochemical atomic absorption spectrometry. Statistical analysis was performed using Statistical software (SPSS) and the cases and controls were compared using the Mann-Whitney U test. A P-value < 0.05 was considered to be statistically significant. RESULTS: Comparison selenium concentration in the first day (D0), third day (D2) and fifth day according to the death and survival statue in patients did not show statistical significance (p > 0.05). Selenium concentration of D0 in patients and Selenium concentration in control group also did not show statistical significance (p > 0.05). Similarly, we did not report a correlation between selenium and C-reactive protein. CONCLUSION: According to our data selenium and CRP may not play a role in progression of coma state in patients with severe traumatic brain injury.

Auditory discrimination improvement predicts awakening of postanoxic comatose patients treated with targeted temperature management at 36°C.

BACKGROUND: Outcome prognostication in postanoxic comatose patients is more accurate in predicting poor than good recovery. Using electroencephalography recordings in patients treated with targeted temperature management at 33°C (TTM 33), we have previously shown that improvement in auditory discrimination over the first days of coma predicted awakening. Given the increased application of a 36°C temperature target (TTM 36), here we aimed at validating the predictive value of auditory discrimination in the TTM 36 setting. METHODS: In this prospective multicenter study, we analyzed the EEG responses to auditory stimuli from 60 consecutive patients from the first and second coma day. A semiautomatic decoding analysis was applied to single patient data to quantify discrimination performance between frequently repeated and deviant sounds. The decoding change from the first to second day was used for predicting patient outcome. RESULTS: We observed an increase in auditory discrimination in 25 out of 60 patients. Among them, 17 awoke from coma (68% positive predictive value; 95% confidence interval: 0.46-0.85). By excluding patients with electroencephalographic epileptiform features, 15 of 18 exhibited improvement in auditory discrimination (83% positive predictive value; 95% confidence interval: 0.59-0.96). Specificity of good outcome prediction increased after adding auditory discrimination to EEG reactivity. CONCLUSION: These results suggest that tracking of auditory discrimination over time is informative of good recovery independent of the temperature target. This quantitative test provides complementary information to existing clinical tools by identifying patients with high chances of recovery and encouraging the maintenance of life support.

Disruption of Brain-Heart Coupling in Sepsis.

PURPOSE: To investigate heart rate and EEG variability and their coupling in patients with sepsis and determine their relationship to sepsis severity and severity of sepsis-associated brain dysfunction. METHODS: Fifty-two patients with sepsis were prospectively identified, categorized as comatose (N = 30) and noncomatose (N = 22), and compared with 11 control subjects. In a 30-minute EEG and electrocardiogram recording, heart rate variability and EEG variability (measured by the variability of relative power in a modified alpha band = RAP) and their coupled oscillations were quantified using linear (least-square periodogram and magnitude square coherence) and nonlinear (Shannon entropy and mutual information) measures. These measures were compared between the three groups and correlated with outcome, adjusting for severity of sepsis. RESULTS: Several measures of heart rate variability and EEG variability and of their coupled oscillations were significantly lower in patients with sepsis compared with controls and correlated with outcome. This correlation was not independent when adjusting for severity of sepsis. CONCLUSIONS: Sepsis is associated with lower variability of both heart rate and RAP on EEG and reduction of their coupled oscillations. This uncoupling is associated with the severity of encephalopathy. Combined EEG and electrocardiogram monitoring may be used to gain insight in underlying mechanisms of sepsis and quantify brainstem or thalamic dysfunction.

An interesting case of opium tea toxicity.

We present an unusual cause of respiratory arrest resulting from sole ingestion of home-brewed opium tea. A 64-year-old woman was found unresponsive and in respiratory arrest by a first responder. There were no obvious signs of regular recreational drug use. On presentation to the local district general hospital, the patient was in extremis, with severe physiological and biochemical derangements. A naloxone infusion was commenced and she later made a good recovery. It was subsequently discovered that she had brewed opium tea from opium buds she had picked from a nearby commercial poppy farm, a practice she had learnt while in Afghanistan.

Description of coma and coma arousal therapy in Caraka Samhita and its corollary in modern medicine.

The description of coma and coma arousal therapy in Caraka Samhita is described in smtra 24, verses 42-53. It describes the definition of coma, differential diagnosis of coma from other disorders of consciousness, signs of coma, etiology of coma, coma arousal therapy, and emergence from coma. The similarities and differences of these aspects of coma from the perspective of its interpretation in modern medicine are discussed in this article.

Stimulus induced bursts in severe postanoxic encephalopathy.

OBJECTIVE: To report on a distinct effect of auditory and sensory stimuli on the EEG in comatose patients with severe postanoxic encephalopathy. METHODS: In two comatose patients admitted to the Intensive Care Unit (ICU) with severe postanoxic encephalopathy and burst-suppression EEG, we studied the effect of external stimuli (sound and touch) on the occurrence of bursts. RESULTS: In patient A bursts could be induced by either auditory or sensory stimuli. In patient B bursts could only be induced by touching different facial regions (forehead, nose and chin). When stimuli were presented with relatively long intervals, bursts persistently followed the stimuli, while stimuli with short intervals (<1s) did not induce bursts. In both patients bursts were not accompanied by myoclonia. Both patients deceased. CONCLUSIONS: Bursts in patients with a severe postanoxic encephalopathy can be induced by external stimuli, resulting in stimulus-dependent burst-suppression. SIGNIFICANCE: Stimulus induced bursts should not be interpreted as prognostic favourable EEG reactivity.