ABSTRACT
Electrical status epilepticus in sleep (ESES) indicates a special electroencephalographic pattern showing sleep-induced continuous paroxysmal discharges of spike-wave complexes.ESES can be seen in a series of epileptic syndromes in children characterized by seizures,ESES and cognitive impairment,including epilepsy with continuous spikes and waves during slow sleep,Landau Kleffner syndrome,typical and atypical benign childhood epilepsy with centro-temporal spikes.Though the mechanism generating ESES remains elusive,great advances in several aspects,such as genetic studies (GRIN2A,copy number variations,ect.),high-frequency oscillations and brain networks have been achieved.Treatment for ESES related disorders should focus on both epileptic seizures and ESES,and the introduction of appropriate antiepileptic drugs or other strategies like hormone therapy should be considered to furthest eliminate epileptic seizures and protect cognitive function.
ABSTRACT
High-frequency oscillations are used more and more widely on localizing epileptogenic zone and evaluating outcome as the surgery on epilepsy cases are increasing and the technique of electroencephalogram (EEG) are being improved.High-frequency oscillations are recorded by intracranial electrodes on most previous studies.However,recent reports describing high-frequency oscillations on scalp EEG recordings have created significant interest.Scalp high-frequency EEG provides a safe,non-invasive and simple method for us to study the special brain electrical activity.This paper summary the clinical applications and some questions on scalp high-frequency EEG.
ABSTRACT
Lots of studies implicate that pathological high-frequency oscillation (HFO) was associated with epilepsy. In recent years, new recording technologies have advanced such that, at high temporal and spatial resolutions, high-frequency oscillation can be recorded in partial epilepsy by intracranial electrodes. More and more researchers focus on the study of high frequency oscillation. The techniques, which were used to record, automatic mine, analysis and quantify high-frequency oscillation, are develop quickly. As a new biomarker of epilepsy, high-frequency oscillation can reflect the epileptic form activity. The HFO has a great value in localization of human epileptic brain and epilepsy surgery.
ABSTRACT
BACKGROUND AND PURPOSE: There is growing interest in high-frequency oscillations (HFO) as electrophysiological biomarkers of the epileptic brain. We evaluated the clinical utility of interictal HFO events, especially their occurrence rates, by comparing the spatial distribution with a clinically determined epileptogenic zone by using subdural macroelectrodes. METHODS: We obtained intracranial electroencephalogram data with a high temporal resolution (2000 Hz sampling rate, 0.05-500 Hz band-pass filter) from seven patients with medically refractory epilepsy. Three epochs of 5-minute, artifact-free data were selected randomly from the interictal period. HFO candidates were first detected by an automated algorithm and subsequently screened to discard false detections. Validated events were further categorized as fast ripple (FR) and ripple (R) according to their spectral profiles. The occurrence rate of HFOs was calculated for each electrode contact. An HFO events distribution map (EDM) was constructed for each patient to allow visualization of the spatial distribution of their HFO events. RESULTS: The subdural macroelectrodes were capable of detecting both R and FR events from the epileptic neocortex. The occurrence rate of HFO events, both FR and R, was significantly higher in the seizure onset zone (SOZ) than in other brain regions. Patient-specific HFO EDMs can facilitate the identification of the location of HFO-generating tissue, and comparison with findings from ictal recordings can provide additional useful information regarding the epileptogenic zone. CONCLUSIONS: The distribution of interictal HFOs was reasonably consistent with the SOZ. The detection of HFO events and construction of spatial distribution maps appears to be useful for the presurgical mapping of the epileptogenic zone.