GABA(B) receptor (GABA(B)R)-mediated presynaptic inhibition regulates neurotransmitter release from synaptic terminals. In the neonatal hippocampus, GABA(B)R activation reduces GABA release and terminates spontaneous network discharges called giant depolarizing potentials (GDPs). Blocking GABA(B)Rs transforms GDPs into longer epileptiform discharges. Thus, GABA(B)R-mediated presynaptic inhibiti...

OBJECTIVE To determine whether the absence of early epileptiform abnormalities predicts absence of later seizures on continuous EEG monitoring of hospitalized patients. METHODS We retrospectively reviewed 242 consecutive patients without a prior generalized convulsive seizure or active epilepsy who underwent continuous EEG monitoring lasting at least 18 hours for detection of nonconvulsive se...

PURPOSE Our aim was to establish the contribution of neuronal networks located in the entorhinal cortex (EC) and subiculum to the generation of interictal and ictal onset patterns recorded in vitro. METHODS We employed field potential recordings of epileptiform activity in rat brain slices induced with the application of the K(+) channel blocker 4-aminopyridine. Local connections between the ...

The hippocampus plays an important role in the genesis of mesial temporal lobe epilepsy, and the entorhinal cortex (EC) may affect the hippocampal network activity because of the heavy interconnection between them. However, the mechanism by which the EC affects the discharge patterns and the transmission mode of epileptiform discharges within the hippocampus needs further study. Here, multielec...

Epileptic encephalopathies are motor-mental retardations or cognitive disorders secondary to epileptic seizures or epileptiform activities. Encephalopaties due to brain damage, medications, or systemic diseases are generally not in the scope of this definition, but they may rarely accompany the condition. Appropriate differential diagnosis of epileptic seizures as well as subclinical electroenc...

We report a patient with epilepsy who experienced interictal and postictal psychoses. Her psychiatric symptoms consisted of grandiose and fantastic delusions during both psychotic states. During remission, electroencephalography showed bitemporal epileptiform discharges that were predominant in the right temporal region. Epileptiform discharges present during the psychotic states were predomina...

The existence of a relationship between epilepsy and sleep has been realized since ancient times. Despite extensive clinical observations and experimental investigations, the precise nature of this relationship however remains unclear and the mechanisms responsible for this are poorly understood. In this study, the authors review the neurophysiology of sleep, concentrating on the various oscill...

OBJECTIVES Protective effects of diuretics, particularly of hydrochlorothiazide (HCT), for the development of epilepsy have been described in vivo. However, its mechanism of action is unknown. MATERIALS AND METHODS Extracellular field potentials were recorded from the CA1- and CA3-subfields of the hippocampus of rats. Epileptiform discharges were induced by omission of Mg2+ from the artificia...

The modulatory role played by purinergic mechanisms on the epileptiform discharges induced by 4-aminopyridine (4AP, 50 microM) in juvenile (10 to 25-day-old) rat hippocampal slices was studied with field potential recordings in the CA3 stratum radiatum. 4AP-induced activity consisted of interictal and ictal discharges along with isolated gamma-aminobutyric acid-mediated potentials. The adenosin...