More than 80 years after its introduction by Hans Berger, the electroencephalogram (EEG) remains as an important supplementary examination in the investigation of neurological disorders and gives valuable and accurate information about cerebral function. Abnormal EEG findings may include ictal patterns, interictal epileptiform activity and non-epileptiform abnormalities. The aim of this study i...

Extracellular signal-regulated protein kinase, ERK1/2 is activated by phosphorylation (p-ERK1/2) during environmental stress such as epileptiform discharge. We investigated the role of ERK1/2 in abnormal axon growth and synapse reorganization in cultured neurons displaying epileptiform activity. The cultured neurons displaying epileptiform activity were treated with magnesium-free extracellular...

Heterozygous loss-of-function mutations in the alpha subunit of the type I voltage-gated sodium channel Na(V)1.1 cause severe myoclonic epilepsy in infancy (SMEI), an infantile-onset epileptic encephalopathy characterized by normal development followed by treatment-refractory febrile and afebrile seizures and psychomotor decline. Mice with SMEI (mSMEI), created by heterozygous deletion of Na(V)...

Under conditions of increased excitability, such as application of the K(+) channel blocker 4-aminopyridine (4-AP, 100 microM), interneurons in the hippocampal slice show an additional form of synchronized activity that is distinct from the ictal and interictal epileptiform activity induced by these manipulations. In principal neurons, i.e., pyramidal and granule cells, this synchronized intern...

Calcium-activated potassium conductances regulate neuronal excitability, but their role in epileptogenesis remains elusive. We investigated in rat CA3 pyramidal neurons the contribution of the Ca(2+)-activated K(+)-mediated afterhyperpolarizations (AHPs) in the genesis and regulation of epileptiform activity induced in vitro by 4-aminopyridine (4-AP) in Mg(2+)-free Ringer. Recurring spike burst...

PURPOSE Ictal behaviors during psychogenic nonepileptic seizures (NES) vary considerably among individuals, and can closely resemble common semiologies of epileptic seizures (ES). We tested the hypothesis that behaviors during NES in patients who have temporal spikes would more closely resemble behaviors during ES in patients with temporal lobe epilepsy than would behaviors during NES in patien...

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...

Identification of interictal epileptiform activity (IEA), seizures and the specific EEG patterns that accompany epilepsy syndromes remains an electroencephalographer’s most critical task. Fortunately, IEA and seizures are also often easily distinguished and stand out in sharp contrast from background EEG frequencies. This chapter will focus on providing practical guidance in recognizing these p...