Differential effects of propofol and ketamine on critical brain dynamics.

Whether the brain operates at a critical "tipping" point is a long standing scientific question, with evidence from both cellular and systems-scale studies suggesting that the brain does sit in, or near, a critical regime. Neuroimaging studies of humans in altered states of consciousness have prompted the suggestion that maintenance of critical dynamics is necessary for the emergence of consciousness and complex cognition, and that reduced or disorganized consciousness may be associated with deviations from criticality. Unfortunately, many of the cellular-level studies reporting signs of criticality were performed in non-conscious systems (in vitro neuronal cultures) or unconscious animals (e.

Are sleep paralysis and false awakenings different from REM sleep and from lucid REM sleep? A spectral EEG analysis.

Study Objectives: To determine the polysomnography characteristics during sleep paralysis, false awakenings, and lucid dreaming (which are states intermediate to rapid eye movement [REM] sleep and wake but exceptionally observed in sleep laboratory).

Methods: In 5 participants, we captured 5 episodes of sleep paralysis (2 time marked with the ocular left-right-left-right code normally used to signal lucid dreaming, 1 time marked by an external noise, and 2 retrospectively reported) and 2 episodes of false awakening. The sleep coding (using 3-second mini-epochs) and spectral electroencephalography analysis were compared during these episodes and normal REM sleep as well as wakefulness in the same 4 of 5 participants and vs lucid REM sleep in 4 other patients with narcolepsy.

Epilepsy after congenital zika virus infection: EEG and neuroimaging features.

Purpose: To describe epilepsy after congenital Zika virus infection (ZIKV) and its relationship with structural neuroimaging findings.

Methods: This was a cross-sectional study in children (aged 13-42 months) who were born with microcephaly due to ZIKV infection between 2015-2017. Patients underwent a brain imaging scan (magnetic resonance) and a video-EEG study.

The First Unprovoked Seizure in Typically Developing Children: A Real-Life Setting in Southern Brazil.

Aim: To describe the first unprovoked seizure in typically developing children, its clinical characteristics, recurrence rate, and possible risk factors in a real-life setting in Southern Brazil.

Method: In this retrospective cohort study, medical records of typically developing children aged 28 days to 14 years who had a first unprovoked seizure in a single tertiary care center were reviewed, in a 10-year period (2006-2016).

Results: Seventy-four children were included, 41 males and 33 females.

Decreased Alertness Reconfigures Cognitive Control Networks.

Humans' remarkable capacity to flexibly adapt their behavior based on rapid situational changes is termed cognitive control. Intuitively, cognitive control is thought to be affected by the state of alertness; for example, when drowsy, we feel less capable of adequately implementing effortful cognitive tasks. Although scientific investigations have focused on the effects of sleep deprivation and circadian time, little is known about how natural daily fluctuations in alertness in the regular awake state affect cognitive control.

Eight years follow-up of a generalized epilepsy patient with eating-induced late-onset epileptic spasms and atypical absence with myoclonic jerks.

Purpose: Eating epilepsy was previously known as a kind of focal reflex epilepsy. However, the development of eating-induced multiple generalized seizures and the associated EEG changes were rarely reported. Herein, we present a 13-year-old generalized epilepsy patient with eating-induced generalized seizures since the age of 5.

Nonlinear Analysis of Visually Normal EEGs to Differentiate Benign Childhood Epilepsy with Centrotemporal Spikes (BECTS).

Childhood epilepsy with centrotemporal spikes, previously known as Benign Epilepsy with Centro-temporal Spikes (BECTS) or Rolandic Epilepsy, is one of the most common forms of focal childhood epilepsy. Despite its prevalence, BECTS is often misdiagnosed or missed entirely. This is in part due to the nocturnal and brief nature of the seizures, making it difficult to identify during a routine electroencephalogram (EEG).

Electroencephalographic changes associated with subjective under- and overestimation of sleep duration.

Feeling awake although sleep recordings indicate clear-cut sleep sometimes occurs in good sleepers and to an extreme degree in patients with so-called paradoxical insomnia. It is unknown what underlies sleep misperception, as standard polysomnographic (PSG) parameters are often normal in these cases. Here we asked whether regional changes in brain activity could account for the mismatch between objective and subjective total sleep times (TST).

Neonatal sleep stage identification using long short-term memory learning system.

Neonatal sleep analysis at the neonatal intensive care units (NICU) is critical for the diagnosis of any brain growth risks during the early stages of life. In this paper, an investigation is carried out on the use of a long short-term memory (LSTM) learning system in automatic sleep stage scoring in neonates. The developed algorithm automatically classifies sleep stages based on inputs from a single channel EEG recording.

Is Resting-State EEG Longitudinally Associated With Recovery of Clinical Neurological Impairments Early Poststroke? A Prospective Cohort Study.

. The time course of cortical activation and its relation with clinical measures may elucidate mechanisms underlying spontaneous neurobiological recovery after stroke. .

Interaction between steady-state visually evoked potentials at nearby flicker frequencies.

Steady-state visually evoked potential (SSVEP) studies routinely employ simultaneous presentation of two temporally modulated stimuli, with SSVEP amplitude modulations serving to index top-down cognitive processes. However, the nature of SSVEP amplitude modulations as a function of competing temporal frequency (TF) has not been systematically studied, especially in relation to the normalization framework which has been extensively used to explain visual responses to multiple stimuli. We recorded spikes and local field potential (LFP) from the primary visual cortex (V1) as well as EEG from two awake macaque monkeys while they passively fixated plaid stimuli with components counterphasing at different TFs.

Expanding the clinical and EEG spectrum of CNKSR2-related encephalopathy with status epilepticus during slow sleep (ESES).

Objective: To investigate the clinical and EEG features of Encephalopathy with Status Epilepticus during slow Sleep (ESES) related to CNKSR2 pathogenic variants.

Methods: Detailed clinical history, repeated wakefulness/overnight sleep EEGs, brain MRI were collected in five patients, including one female, with CNKSR2-related ESES.

Results: Neurodevelopment in infancy was normal in two patients, delayed in three.

The Inconsistent Nature of Heart Rate Variability During Sleep in Normal Children and Adolescents.

Cardiac function is modulated by multiple factors including exogenous (circadian rhythm) and endogenous (ultradian 90-110 min sleep cycle) factors. By evaluating heart rate variability (HRV) during sleep, we will better understand their influence on cardiac activity. The aim of this study was to evaluate HRV in the dark phase of the circadian rhythm during sleep in healthy children and adolescents.

Absence of inspiratory premotor potentials during quiet breathing in cervical spinal cord injury.

A premotor potential, or Bereitschaftspotential (BP), is a low-amplitude negativity in the electroencephalographic activity (EEG) of the sensorimotor cortex. It begins ~1 s prior to the onset of inspiration in the averaged EEG. Although normally absent during quiet breathing in healthy, younger people, inspiration-related BPs are present in people with respiratory disease and healthy, older people, indicating a cortical contribution to quiet breathing.

Awake functional MRI detects neural circuit dysfunction in a mouse model of autism.

MRI has potential as a translational approach from rodents to humans. However, given that mouse functional MRI (fMRI) uses anesthetics for suppression of motion, it has been difficult to directly compare the result of fMRI in "unconsciousness" disease model mice with that in "consciousness" patients. We develop awake fMRI to investigate brain function in mice, a copy number variation model of autism.

Weakly encoded memories due to acute sleep restriction can be rescued after one night of recovery sleep.

Sleep is thought to play a complementary role in human memory processing: sleep loss impairs the formation of new memories during the following awake period and, conversely, normal sleep promotes the strengthening of the already encoded memories. However, whether sleep can strengthen deteriorated memories caused by insufficient sleep remains unknown. Here, we showed that sleep restriction in a group of participants caused a reduction in the stability of EEG activity patterns across multiple encoding of the same event during awake, compared with a group of participants that got a full night's sleep.

First do no harm: Preventing harm and optimizing care in psychogenic nonepileptic seizures.

Psychogenic nonepileptic seizures (PNES) are challenging clinical occurrences consisting of any combination of altered movement, sensation, or awareness that resemble epileptic seizures (ES) but do not coincide with electrographic ictal discharges and are presumed to be neuropsychiatric-neurobehavioral in origin. Securing the PNES diagnosis is a crucial first step and is best confirmed by recording events on video-electroencephalogram (v-EEG) and finding an absence of ictal EEG changes and the presence of normal awake EEG rhythms before, during, and after the event. However, obstacles to timely diagnosis and referral to psychiatric treatment frequently occur, placing these patients at risk for harm from unnecessary medications and procedure as well as placing high burden on medical systems.

Language Monitoring in Brain Surgery Under General Anesthesia.

Background: Awake surgeries for cerebral lesion resection have several limitations including patient fear, discomfort, or pain. This study aimed to determine whether components of language function could be measured under general anesthesia. In this study, the occurrence of mismatch negativity (MMN) was searched in evoked potentials for phonological sounds.

Interictal epileptiform discharges on electroencephalography in children with methylenetetrahydrofolate reductase (MTHFR) polymorphisms.

Objective: Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism. MTHFR C677T and A1298C polymorphisms are best-defined variants of MTHFR that were reported to be associated with epilepsy development. The aim of the study was to determine the incidence of interictal epileptiform discharges on electroencephalography (EEG) in asymptomatic children with C677T and A1298C polymorphisms who had no history of seizure.

Multi-band SWIFT enables quiet and artefact-free EEG-fMRI and awake fMRI studies in rat.

Functional magnetic resonance imaging (fMRI) studies in animal models provide invaluable information regarding normal and abnormal brain function, especially when combined with complementary stimulation and recording techniques. The echo planar imaging (EPI) pulse sequence is the most common choice for fMRI investigations, but it has several shortcomings. EPI is one of the loudest sequences and very prone to movement and susceptibility-induced artefacts, making it suboptimal for awake imaging.

Fear-Related Signals in the Primary Visual Cortex.

Neuronal responses in the primary visual cortex (V1) are driven by simple stimuli, but these stimulus-evoked responses can be markedly modulated by non-sensory factors, such as attention and reward [1], and shaped by perceptual training [2]. In real-life situations, neutral visual stimuli can become emotionally tagged by experience, resulting in altered perceptual abilities to detect and discriminate these stimuli [3-5]. Human imaging [4] and electroencephalography (EEG) studies [6-9] have shown that visual fear learning (the acquisition of aversive emotion associated with a visual stimulus) affects the activities in visual cortical areas as early as in V1.

The Odds Ratio Product (An Objective Sleep Depth Measure): Normal Values, Repeatability, and Change With CPAP in Patients With OSA.

Study Objectives: The Odds Ratio Product (ORP) is an objective measure of sleep depth using the relationships of the powers of different electroencephalogram (EEG) frequencies in a single index. The range of the ORP is 0 (deeply asleep) to 2.5 (fully awake).

Normal Awake, Drowsy, and Sleep EEG Patterns That Might Be Overinterpreted as Abnormal.

Knowledge of normal patterns is essential for correct EEG interpretation. The overinterpretation of EEG (i.e.