Breathing orchestrates synchronization of sleep oscillations in the human hippocampus.

Nested sleep oscillations, emerging from asynchronous states in coordinated bursts, are critical for memory consolidation. Whether these bursts emerge intrinsically or from an underlying rhythm is unknown. Here, we show a previously undescribed respiratory-driven oscillation in the human hippocampus that couples with cardinal sleep oscillations.

The development of aperiodic neural activity in the human brain.

The neurophysiological mechanisms supporting brain maturation are fundamental to attention and memory capacity across the lifespan. Human brain regions develop at different rates, with many regions developing into the third and fourth decades of life. Here, in this preregistered study (https://osf.

Human hippocampal responses to network intracranial stimulation vary with theta phase.

Hippocampal-dependent memory is thought to be supported by distinct connectivity states, with strong input to the hippocampus benefitting encoding and weak input benefitting retrieval. Previous research in rodents suggests that the hippocampal theta oscillation orchestrates the transition between these states, with opposite phase angles predicting minimal versus maximal input. We investigated whether this phase dependence exists in humans using network-targeted intracranial stimulation.

High-Frequency Oscillations in Tumor-Related Epilepsy.

Introduction: To define the patient characteristics, tumor characteristics, and clinical course of patients with primary brain tumors with high-frequency oscillations (HFOs) recorded on electrocorticography. Furthermore, we evaluated whether the presence of HFOs portends a greater risk of postoperative tumor-related epilepsy and whether the resection of HFO-generating tissue reduces likelihood of postoperative tumor-related epilepsy.

Methods: This was a retrospective study of 35 patients undergoing awake craniotomy for tumor resection, all of whom underwent intraoperative electrocorticography.

Impact of the COVID-19 Pandemic on Epilepsy Center Practice in the United States.

Background And Objectives: Persons with epilepsy, especially those with drug resistant epilepsy (DRE), may benefit from inpatient services such as admission to the epilepsy monitoring unit (EMU) and epilepsy surgery. The COVID-19 pandemic caused reductions in these services within the US during 2020. This article highlights changes in resources, admissions, and procedures among epilepsy centers accredited by the National Association of Epilepsy Centers (NAEC).

Smell-induced gamma oscillations in human olfactory cortex are required for accurate perception of odor identity.

Studies of neuronal oscillations have contributed substantial insight into the mechanisms of visual, auditory, and somatosensory perception. However, progress in such research in the human olfactory system has lagged behind. As a result, the electrophysiological properties of the human olfactory system are poorly understood, and, in particular, whether stimulus-driven high-frequency oscillations play a role in odor processing is unknown.

Development and Validation of the 5-SENSE Score to Predict Focality of the Seizure-Onset Zone as Assessed by Stereoelectroencephalography.

Importance: Stereoelectroencephalography (SEEG) has become the criterion standard in case of inconclusive noninvasive presurgical epilepsy workup. However, up to 40% of patients are subsequently not offered surgery because the seizure-onset zone is less focal than expected or cannot be identified.

Objective: To predict focality of the seizure-onset zone in SEEG, the 5-point 5-SENSE score was developed and validated.

The what and when of olfactory working memory in humans.

Encoding and retaining novel sequences of sensory stimuli in working memory is crucial for adaptive behavior. A fundamental challenge for the central nervous system is to maintain each sequence item in an active and discriminable state, while also preserving their temporal context. Nested neural oscillations have been postulated to disambiguate the "what" and "when" of sequences, but the mechanisms by which these multiple streams of information are coordinated in the human brain remain unclear.

Early Seizures Are Predictive of Worse Health-Related Quality of Life at Follow-Up After Intracerebral Hemorrhage.

Objectives: Early seizures are a common complication of intracerebral hemorrhage, occurring in ~10% of patients. However, the independent effect of early seizures on patient outcomes, particularly health-related quality of life, is unclear. Without a potential benefit to patient outcomes, the widespread use (~40%) of prophylactic seizure medications has no reasonable chance of improving patient outcomes.

Human hippocampal connectivity is stronger in olfaction than other sensory systems.

During mammalian evolution, primate neocortex expanded, shifting hippocampal functional networks away from primary sensory cortices, towards association cortices. Reflecting this rerouting, human resting hippocampal functional networks preferentially include higher association cortices, while those in rodents retained primary sensory cortices. Research on human visual, auditory and somatosensory systems shows evidence of this rerouting.

Indications and yield of ambulatory EEG recordings.

To study the yield of prolonged ambulatory electroencephalogram (aEEG). A retrospective chart review of all patients who underwent aEEG studies between 2013 and 2017 was performed. Reasons for aEEG were classified into five categories: detection of interictal epileptiform discharges (IEDs), capturing clinical events, detection of unrecognized seizures, monitoring IEDs during treatment, and unclassifiable.

Efficacy of clobazam as add-on therapy in brain tumor-related epilepsy.

Purpose: Brain tumor-related epilepsy (TRE) is often resistant to currently available antiepileptic medications (AEDs). Clobazam was initially approved as adjunctive AED for patients with Lennox Gastaut syndrome but has been used in TRE, despite limited evidence in this context. This observational study aims to examine the effect of clobazam on seizure frequency on patients who have a primary CNS tumor and continued seizures despite their current AEDs.

Seizure outcome in patients with cavernous malformation after early surgery.

Objective: To describe seizure outcome and complications in patients with cavernous malformations (CM) undergoing early versus late surgery.

Methods: A database was created for all CM patients who presented with seizure referred to the neurosurgical clinic at an academic center. A telephone survey and chart review were conducted to evaluate for preoperative and postoperative seizure frequency.

True abdominal epilepsy is clonic jerking of the abdominal musculature.

Abdominal epilepsy (AE) has long been reported as a rare phenomenon in children with various episodic gastrointestinal sensory and painful symptoms suspected to be due to epileptic seizures. Originally, AE was diagnosed when abdominal sensory or painful symptoms were associated with pain, temporal lobe origin, an epileptiform or paroxysmal EEG pattern, and a clinical response to antiseizure medication. AE has also been associated with non-epileptic etiologies such as migraine.

Anticipation-induced delta phase reset improves human olfactory perception.

Anticipating an odor improves detection and perception, yet the underlying neural mechanisms of olfactory anticipation are not well understood. In this study, we used human intracranial electroencephalography (iEEG) to show that anticipation resets the phase of delta oscillations in piriform cortex prior to odor arrival. Anticipatory phase reset correlates with ensuing odor-evoked theta power and improvements in perceptual accuracy.

Evaluation of Seizure Etiology From Routine Testing to Genetic Evaluation.

Purpose Of Review: Recognizing the cause of a first seizure and identifying the etiology of epilepsy are essential for management. A systematic approach to patients who present with a first seizure helps distinguish between an acute symptomatic seizure, a provoked or unprovoked seizure, and potential mimickers. Routine testing with EEG and MRI may reveal a predisposition for further seizures and help to establish the underlying epilepsy syndrome.

Human olfactory-auditory integration requires phase synchrony between sensory cortices.

Multisensory integration is particularly important in the human olfactory system, which is highly dependent on non-olfactory cues, yet its underlying neural mechanisms are not well understood. In this study, we use intracranial electroencephalography techniques to record neural activity in auditory and olfactory cortices during an auditory-olfactory matching task. Spoken cues evoke phase locking between low frequency oscillations in auditory and olfactory cortices prior to odor arrival.

Clinical classification of post anoxic myoclonic status.

Introduction: Despite decades of research into the prognostic significance of post anoxic myoclonic status (MS), no consistent definition has been used to describe its clinical appearance. We set out to characterize the clinical features of MS and hypothesized that there are distinct clinical subtypes that may have prognostic implications.

Methods: Video EEG reports from 2008 to 2016 were searched to identify adult patients with post anoxic MS defined as persistent myoclonus for >30min beginning within 3days of cardiac arrest in a comatose patient.

New-Onset Seizure in Adults and Adolescents: A Review.

Importance: Approximately 8% to 10% of the population will experience a seizure during their lifetime. Only about 2% to 3% of patients go on to develop epilepsy. Understanding the underlying etiology leading to an accurate diagnosis is necessary to ensure appropriate treatment and that patients with low risk for recurrence are not treated unnecessarily.