Large-scale network dynamics underlying the first few hundred milliseconds after stimulus presentation: An investigation of visual recognition memory using iEEG.

Recognition memory is the ability to recognize previously encountered objects. Even this relatively simple, yet extremely fast, ability requires the coordinated activity of large-scale brain networks. However, little is known about the sub-second dynamics of these networks.

How valid are proxy assessment of mental health and sleep comorbidities of patients with epilepsy using standardized questionnaires?

Background: The study aimed to determine the level of agreement between patients with epilepsy and their proxies when assessing psychiatric comorbidities, sleep disorders, and medication adherence using standardized questionnaires.

Methods: This agreement study is an ancillary analysis of the PRERIES study, a matched case-control study exploring SUDEP risk factors. Controls aged 15 years and older, with active epilepsy or in remission for less than 5 years were recruited between 01/01/2011 and 03/31/2019.

Specific profiles of new-onset vs. non-inaugural status epilepticus: From diagnosis to 1-year outcome.

While new-onset status epilepticus (NOSE) is a harbinger of chronic epilepsy, prospective medical data are sparse in terms of specifying whether the evolution of status epilepticus (SE) and seizure expression in NOSE resembles what occurs in patients who have already been diagnosed with epilepsy [non-inaugural SE (NISE)] in all aspects apart from its inaugural nature. The aim of this study was to compare the clinical, MRI, and EEG features that could distinguish NOSE from NISE. We conducted a prospective monocentric study in which all patients ≥18 years admitted for SE over a 6-month period were included.

Local neuronal excitation and global inhibition during epileptic fast ripples in humans.

Understanding the neuronal basis of epileptic activity is a major challenge in neurology. Cellular integration into larger scale networks is all the more challenging. In the local field potential, interictal epileptic discharges can be associated with fast ripples (200-600 Hz), which are a promising marker of the epileptogenic zone.

Intracerebral mechanisms explaining the impact of incidental feedback on mood state and risky choice.

Identifying factors whose fluctuations are associated with choice inconsistency is a major issue for rational decision theory. Here, we investigated the neuro-computational mechanisms through which mood fluctuations may bias human choice behavior. Intracerebral EEG data were collected in a large group of subjects (n=30) while they were performing interleaved quiz and choice tasks that were designed to examine how a series of unrelated feedbacks affect decisions between safe and risky options.

Interactions between antiseizure medications and contraception: A study about the knowledge of patients and their specialist physicians.

Planning pregnancy is very important for women with epilepsy (WWE), because of the potential teratogenic effects and neurodevelopmental disorders of different antiseizure medications (ASMs). Nevertheless, contraception in WWE can be challenging due to the existence of drug interactions between ASMs and hormonal contraception. The aim of this study was to assess women's knowledge of potential interactions between their ASMs and contraceptive options.

Hidden Objective Memory Deficits Behind Subjective Memory Complaints in Patients With Temporal Lobe Epilepsy.

Background And Objectives: The aim of this work was to test the hypothesis that patients with temporal lobe epilepsy (TLE) with subjective initial memory complaints (not confirmed by an objective standard assessment) and various phenotypes also show objective very long-term memory deficit with accelerated long-term forgetting. We tested patients with TLE with 2 surprise memory tests after 3 weeks: the standard Free and Cued Selective Reminding Test (FCSRT) and Epireal, a new test specifically designed to capture more ecologic aspects of autobiographical memory.

Methods: Forty-seven patients with TLE (12 with hippocampal sclerosis, 12 with amygdala enlargement, 11 with extensive lesions, 12 with normal MRI) who complained about their memory, but for whom the standard neuropsychological assessment did not reveal any memory impairment after a standard delay of 20 minutes, underwent 2 surprise memory tests after 3 weeks.

Recording local field potential and neuronal activity with tetrodes in epileptic patients.

Background: Recordings with tetrodes have proven to be more effective in isolating single neuron spiking activity than with single microwires. However, tetrodes have never been used in humans. We report on the characteristics, safety, compatibility with clinical intracranial recordings in epileptic patients, and performance, of a new type of hybrid electrode equipped with tetrodes.

A Fast Visual Recognition Memory System in Humans Identified Using Intracerebral ERP.

One key item of information retrieved when surveying our visual world is whether or not objects are familiar. However, there is no consensus on the respective roles of medial temporal lobe structures, particularly the perirhinal cortex (PRC) and hippocampus. We considered whether the PRC could support a fast recognition memory system independently from the hippocampus.

Functional connectivity of hypothalamus in chronic migraine with medication overuse.

Objective: To investigate the functional connectivity of the hypothalamus in chronic migraine compared to interictal episodic migraine in order to improve our understanding of migraine chronification.

Methods: Using task-free fMRI and ROI-to-ROI analysis, we compared anterior hypothalamus intrinsic connectivity with the spinal trigeminal nucleus in patients with chronic migraine (n = 25) to age- and sex-matched patients with episodic migraine in the interictal phase (n = 22). We also conducted a seed-to-voxel analysis with anterior hypothalamus as a seed.

Neuronal spiking activity highlights a gradient of epileptogenicity in human tuberous sclerosis lesions.

Objective: The mechanisms underlying epileptogenicity in tuberous sclerosis complex (TSC) are poorly understood.

Methods: We analysed neuronal spiking activity (84 neurons), fast ripples (FRs), local field potentials and intracranial electroencephalogram during interictal epileptiform discharges (IEDs) in the tuber and perituber of a patient using novel hybrid electrodes equipped with tetrodes.

Results: IEDs were recorded in the tuber and perituber.

Déjà-rêvé: Prior dreams induced by direct electrical brain stimulation.

Background: Epileptic patients sometimes report experiential phenomena related to a previous dream they had during seizures or electrical brain stimulation (EBS). This has been alluded to in the literature as "déjà-rêvé" ("already dreamed"). However, there is no neuroscientific evidence to support its existence and this concept is commonly mixed up with déjà-vu.

Interpretation of SEEG recordings.

The interpretation of SEEG recordings is a crucial step. It must be carried out by an epileptologist/neurophysiologist with sufficient training and qualification in this field. The objectives of the interpretation are to define the brain topography of interictal activities (irritative zone) and the epileptogenic zone, defined as the site of primary organization of ictal discharges.

Memory scrutinized through electrical brain stimulation: A review of 80 years of experiential phenomena.

Electrical brain stimulations (EBS) sometimes induce reminiscences, but it is largely unknown what type of memories they can trigger. We reviewed 80 years of literature on reminiscences induced by EBS and added our own database. We classified them according to modern conceptions of memory.

Noonan syndrome, PTPN11 mutations, and brain tumors. A clinical report and review of the literature.

Noonan syndrome (NS), an autosomal dominant disorder, is characterized by short stature, congenital heart defects, developmental delay, and facial dysmorphism. PTPN11 mutations are the most common cause of NS. PTPN11 encodes a non-receptor protein tyrosine phosphatase, SHP2.

Risk factors of postictal generalized EEG suppression in generalized convulsive seizures.

Objective: To identify the clinical determinants of occurrence of postictal generalized EEG suppression (PGES) after generalized convulsive seizures (GCS).

Methods: We reviewed the video-EEG recordings of 417 patients included in the REPO2MSE study, a multicenter prospective cohort study of patients with drug-resistant focal epilepsy. According to ictal semiology, we classified GCS into 3 types: tonic-clonic GCS with bilateral and symmetric tonic arm extension (type 1), clonic GCS without tonic arm extension or flexion (type 2), and GCS with unilateral or asymmetric tonic arm extension or flexion (type 3).

Object and proper name retrieval in temporal lobe epilepsy: a study of difficulties and latencies.

Purpose: Retrieving a specific name is sometimes difficult and can be even harder when pathology affects the temporal lobes. Word finding difficulties have been well documented in temporal lobe epilepsy (TLE) but analyses have mostly concentrated on the study of accuracy. Our aim here was to go beyond simple accuracy and to provide both a quantitative and a qualitative assessment of naming difficulties and latencies in patients with TLE.

Photophobia in migraine: an interictal PET study of cortical hyperexcitability and its modulation by pain.

Objective: Photophobia is an abnormal sensitivity to light experienced by migraineurs and is perhaps caused by cortical hyperexcitability. In clinical studies, an inter-relation between light perception and trigeminal nociception has been demonstrated in migraineurs but not in controls. The purpose of the study was to verify this interaction by functional imaging.

Hypothalamic activation in spontaneous migraine attacks.

Background: Migraine sufferers experience premonitory symptoms which suggest that primary hypothalamic dysfunction is a likely trigger of the attacks. Neuroendocrine and laboratory data also support this hypothesis. To date, positron emission tomography (PET) scans of migraine sufferers have demonstrated activation of brainstem nuclei, but not of the hypothalamus.