Association of Standard Electroencephalography Findings With Mortality and Command Following in Mechanically Ventilated Patients Remaining Unresponsive After Sedation Interruption.

CONTEXT: Delayed awakening after sedation interruption is frequent in critically ill patients receiving mechanical ventilation. OBJECTIVES: We aimed to investigate the association of standard electroencephalography with mortality and command following in this setting. DESIGN, SETTING, AND PATIENTS: In a single-center study, we retrospectively analyzed standard electroencephalography performed in consecutive mechanically ventilated patients remaining unresponsive (comatose/stuporous or unable to follow commands) after sedation interruption. Standard electroencephalography parameters (background activity, continuity, and reactivity) were reassessed by neurophysiologists, blinded to patients' outcome. Patients were categorized during follow-up into three groups based on their best examination as: 1) command following, 2) unresponsive, or 3) deceased. Cause-specific models were used to identify independent standard electroencephalography parameters associated with main outcomes, that is, mortality and command following. Follow-up was right-censored 30 days after standard electroencephalography. MEASUREMENTS AND MAIN RESULTS: Main standard electroencephalography parameters recorded in 121 unresponsive patients (median time between sedation interruption and standard electroencephalography: 2 d [interquartile range, 1-4 d]) consisted of a background frequency greater than 4 Hz in 71 (59%), a discontinuous background in 19 (16%), and a preserved reactivity in 98/120 (82%) patients. At 30 days, 66 patients (55%) were command following, nine (7%) were unresponsive, and 46 (38%) had died. In a multivariate analysis adjusted for nonneurologic organ failure, a reactive standard electroencephalography with a background frequency greater than 4 Hz was independently associated with a reduced risk of death (cause-specific hazard ratio, 0.38; CI 95%, 0.16-0.9). By contrast, none of the standard electroencephalography parameters were independently associated with command following. Sensitivity analyses conducted after exclusion of 29 patients with hypoxic brain injury revealed similar findings. CONCLUSIONS: In patients remaining unresponsive after sedation interruption, a pattern consisting of a reactive standard electroencephalography with a background frequency greater than 4 Hz was associated with decreased odds of death. None of the standard electroencephalography parameters were independently associated with command following.

Early EEG for Prognostication Under Venoarterial Extracorporeal Membrane Oxygenation.

BACKGROUND/OBJECTIVES: Tools for prognostication of neurologic outcome of adult patients under venoarterial ECMO (VA-ECMO) have not been thoroughly investigated. We aimed to determine whether early standard electroencephalography (stdEEG) can be used for prognostication in adults under VA-ECMO. METHODS: Prospective single-center observational study conducted in two intensive care units of a university hospital, Paris, France. Early stdEEG was performed on consecutive adult patients treated with VA-ECMO for refractory cardiogenic shock or refractory cardiac arrest. The association between stdEEG findings and unfavorable outcome was investigated. The primary endpoint was 28-day mortality. The secondary endpoint was severe disability or death at 90 days, defined by a score of 4-6 on the modified Rankin scale. RESULTS: A total of 122 patients were included, of whom 35 (29%) received cardiopulmonary resuscitation before VA-ECMO cannulation. Main stdEEG findings included low background frequency ≤ 4 Hz (n = 27, 22%) and background abnormalities, i.e., a discontinuous (n = 20, 17%) and/or an unreactive background (n = 12, 10%). Background abnormalities displayed better performances for prediction of unfavorable outcomes, as compared to clinical parameters at time of recording. An unreactive stdEEG background in combination with a background frequency ≤ 4 Hz had a false positive rate of 0% for prediction of unfavorable outcome at 28 days and 90 days, with sensitivities of 8% and 6%, respectively. After adjustment for confounders, a lower background frequency was independently associated with unfavorable outcome at 28 days (adjusted odds ratio per 1-Hz increment, 95% CI 0.71, 0.52-0.97), whereas no such independent association was observed at 90 days. CONCLUSION: Standard EEG abnormalities recorded at time of VA-ECMO initiation are predictive of unfavorable outcomes. However, the low sensitivity of these parameters highlights the need for a multimodal evaluation for improving management of care and prognostication.

A Simplified Electroencephalography Montage and Interpretation for Evaluation of Comatose Patients in the ICU.

Electroencephalography (EEG) is one of the main tools for diagnosis and prognostication of encephalopathy. Our two objectives were to assess: 1) the reliability of intensivists' interpretations (one trained intensivist and nonexpert intensivists) on specific EEG patterns and 2) the feasibility of performing simplified EEG by a trained intensivist in ICU. DESIGN: Prospective, single-center study. SETTING: One French tertiary-care center. PATIENTS: Thirty-six consecutive ICU patients with encephalopathy. INTERVENTION: A trained intensivist (1-year specific electrophysiologic course) recorded and interpreted EEGs using a 10 monopod montage at bedside. Then, 22 nonexpert intensivists underwent a 1-hour educational session on interpretation of EEG background (activity, continuity, and reactivity) and common patterns seen in ICU. Trained and nonexpert intensivists' interpretation of EEG recordings was evaluated and compared with an expert neurophysiologist's interpretation (gold standard). The agreement between the two interpretations was evaluated. Second, the duration of the entire EEG procedure (specifically EEG installation) at bedside was recorded. MEASUREMENTS AND MAIN RESULTS: Agreements and reliability between the trained intensivist and the neurophysiologist were acceptable for minimal (agreement, 94%; Pearson coefficient, 0.60) and maximal (89%, 0.89) background frequency, burst suppression (agreement, 100%; Kappa coefficient, 1), background continuity (83%, 0.59), and reactivity to auditory stimulus (78%, 0.44). Agreements between the 22 nonexpert intensivists and the neurophysiologist were heterogeneous. As a result, 87% of the 22 nonexpert intensivists obtained an acceptable reliability for the minimum background frequency, 95% for the maximum background frequency, and 73% and 95% for burst suppression and isoelectric background identification, respectively. The median duration of the entire EEG procedure was 47 minutes (43-53 min), including 22 minutes (20-28 min) of EEG installation. CONCLUSIONS: Intensivists can rapidly learn background activity and identify burst-suppression and isoelectric background. However, more educational sessions are required for interpretation of other EEG patterns frequently observed in the ICU setting.

Narcolepsy Type 1: A Remitting Disease? An Unusual Case Report.

We describe the case of a male patient who was diagnosed with narcolepsy type 1 on the basis of sleep and wake symptoms, and the results of investigations including video-polysomnography, multiple sleep latency test, human leukocyte antigen status and orexin level in cerebrospinal fluid. During the first years after disease onset, the patient did not show any significant improvement despite treatment with a variety of stimulant and anti-cataplectic drugs. However, spontaneous remission of disease occurred after 15 years.

Simplified frontal EEG in adults under veno-arterial extracorporeal membrane oxygenation.

BACKGROUND: EEG-based prognostication studies in intensive care units often rely on a standard 21-electrode montage (stdEEG) requiring substantial human, technical, and financial resources. We here evaluate whether a simplified 4-frontal electrode montage (4-frontEEG) can detect EEG patterns associated with poor outcomes in adult patients under veno-arterial extracorporeal membrane oxygenation (VA-ECMO). METHODS: We conducted a reanalysis of EEG data from a prospective cohort on 118 adult patients under VA-ECMO, in whom EEG was performed on admission to intensive care. EEG patterns of interest included background rhythm, discontinuity, reactivity, and the Synek's score. They were all reassessed by an intensivist on a 4-frontEEG montage, whose analysis was then compared to an expert's interpretation made on stdEEG recordings. The main outcome measure was the degree of correlation between 4-frontEEG and stdEEG montages to identify EEG patterns of interest. The performance of the Synek scores calculated on 4-frontEEG and stdEEG montage to predict outcomes (i.e., 28-day mortality and 90-day Rankin score [Formula: see text]) was investigated in a secondary exploratory analysis. RESULTS: The detection of EEG patterns using 4-frontEEG was statistically similar to that of stdEEG for background rhythm (Spearman rank test, ρ = 0.66, p < 0.001), discontinuity (Cohen's kappa, [Formula: see text] = 0.955), reactivity ([Formula: see text] = 0.739) and the Synek's score (ρ = 0.794, p < 0.001). Using the Synek classification, we found similar performances between 4-frontEEG and stdEEG montages in predicting 28-day mortality (AUC 4-frontEEG 0.71, AUC stdEEG 0.68) and for 90-day poor neurologic outcome (AUC 4-frontEEG 0.71, AUC stdEEG 0.66). An exploratory analysis confirmed that the Synek scores determined by 4 or 21 electrodes were independently associated with 28-day mortality and poor 90-day functional outcome. CONCLUSION: In adult patients under VA-ECMO, a simplified 4-frontal electrode EEG montage interpreted by an intensivist, detected common EEG patterns associated with poor outcomes, with a performance similar to that of a standard EEG montage interpreted by expert neurophysiologists. This simplified montage could be implemented as part of a multimodal evaluation for bedside prognostication.

COVID-19-Associated Neurological Manifestations: An Emerging Electroencephalographic Literature.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide since the end of year 2019 and is currently responsive for coronavirus infectious disease 2019 (COVID-19). The first reports considered COVID-19 as a respiratory tract disease responsible for pneumonia, but numerous studies rapidly emerged to warn the medical community of COVID-19-associated neurological manifestations, including encephalopathy at the acute phase and other postinfectious manifestations. Using standard visual analysis or spectral analysis, recent studies reported electroencephalographic (EEG) findings of COVID-19 patients with various neurological symptoms. Most EEG recordings were normal or revealed non-specific abnormalities, such as focal or generalized slowing, interictal epileptic figures, seizures, or status epilepticus. Interestingly, novel EEG abnormalities over frontal areas were also described at the acute phase. Underlying mechanisms leading to brain injury in COVID-19 are still unknown and matters of debate. These frontal EEG abnormalities could emphasize the hypothesis whereby SARS-CoV-2 enters the central nervous system (CNS) through olfactory structures and then spreads in CNS via frontal lobes. This hypothesis is reinforced by the presence of anosmia in a significant proportion of COVID-19 patients and by neuroimaging studies confirming orbitofrontal abnormalities. COVID-19 represents a new viral disease characterized by not only respiratory symptoms but also a systemic invasion associated with extra-respiratory signs. Neurological symptoms must be the focus of our attention, and functional brain evaluation with EEG is crucial, in combination with anatomical and functional brain imaging, to better understand its pathophysiology. Evolution of symptoms together with EEG patterns at the distance of the acute episode should also be scrutinized.

OSA treatment with CPAP: Randomized crossover study comparing tolerance and efficacy with and without humidification by ThermoSmart.

OBJECTIVES: Adherence to continuous positive airway pressure (CPAP) remains an issue, as adverse effects (AE) such as rhinitis, dry/congested nose, dry mouth or throat are commonly experienced. The aim of the study was to compare CPAP efficacy and tolerance in severe obstructive sleep apnea (OSA) patients with or without (w/o) heated humidification using the ThermoSmart system. METHODS: Multicenter RCT study in which CPAP-naive patients with severe OSA and meeting one or more of the following criteria: >65 years, using >1 drying medication, previous nasal symptoms or nasal surgery, were included. Patients were randomized to CPAP w/o heated humidification for 1 month and then crossed-over to the other treatment arm for another month. Naso-pharyngeal symptoms, Quality of life (FOSQ-10), sleepiness (ESS) and CPAP compliance and efficacy data were collected. RESULTS: Forty patients were enrolled: age 62 ± 9 years, diagnostic AHI 46.7 ± 15.3/hour. About 70% were using >1 drying medication, mainly antihypertensives. Both treatment modalities were found to normalize AHI and decrease sleepiness with no differences between 2 modes, compliance (4.63 ± 0.39 vs 4.70 ± 0.36 h/night) or leaks (32.4 ± 2.0 versus 31.1 ± 1.7l/min). With heated humidification, there was a significant decrease in nasal symptoms such as dry/congested nose. At the study end, 26 patients preferred ThermoSmart ON, 3 did not have preference and 11 preferred ThermoSmart OFF. CONCLUSION: ThermoSmart helps to decrease nose and throat discomfort because of CPAP therapy, these effects did not translate to better compliance but patients had a preference for ThermoSmart.

Obstructive Sleep Apnoea Modulates Airway Inflammation and Remodelling in Severe Asthma.

BACKGROUND: Obstructive sleep apnoea (OSA) is frequently observed in severe asthma but the causal link between the 2 diseases remains hypothetical. The role of OSA-related systemic and airway neutrophilic inflammation in asthma bronchial inflammation or remodelling has been rarely investigated. The aim of this study was to compare hallmarks of inflammation in induced sputum and features of airway remodelling in bronchial biopsies from adult patients with severe asthma with and without OSA. MATERIALS AND METHODS: An overnight polygraphy was performed in 55 patients referred for difficult-to-treat asthma, who complained of nocturnal respiratory symptoms, poor sleep quality or fatigue. We compared sputum analysis, reticular basement membrane (RBM) thickness, smooth muscle area, vascular density and inflammatory cell infiltration in bronchial biopsies. RESULTS: In total, 27/55 patients (49%) had OSA diagnosed by overnight polygraphy. Despite a moderate increase in apnoea-hypopnoea index (AHI; 14.2 ± 1.6 event/h [5-35]), the proportion of sputum neutrophils was higher and that of macrophages lower in OSA than non-OSA patients, with higher levels of interleukin 8 and matrix metalloproteinase 9. The RBM was significantly thinner in OSA than non-OSA patients (5.8 ± 0.4 vs. 7.8 ± 0.4 µm, p<0.05). RBM thickness and OSA severity assessed by the AHI were negatively correlated (rho = -0.65, p<0.05). OSA and non-OSA patients did not differ in age, sex, BMI, lung function, asthma control findings or treatment. CONCLUSION: Mild OSA in patients with severe asthma is associated with increased proportion of neutrophils in sputum and changes in airway remodelling.

Epilepsy among the homeless: prevalence and characteristics.

Homelessness is associated with several risk factors for epileptic seizures. Epilepsy is a stigmatizing condition, which can lead to problematic social adjustment and competence. We found a markedly higher prevalence of seizures among the homeless than that estimated in the general population, with a large majority of non-alcoholic etiology. Unexpected proportion of subject taking treatment and compliance rate call for reflection on the optimal management of epilepsy in this population.