25 Hyperpolarization-activated, cyclic-nucleotide gated, non-specific cation (HCN) 26 channels have a well-characterized role in regulation of cellular excitability and network 27 activity. The role of these channels in control of epileptiform discharges is less 28 thoroughly understood. This is especially pertinent given altered HCN channel 29 expression in epilepsy. We hypothesized that inhib...

1. Lowering of the extracellular Mg(2+)-concentration induces various patterns of epileptiform activity in combined rat entorhinal cortex-hippocampal brain slices. After a prolonged period of exposure to Mg(2+)-free medium seizure-like events in the entorhinal cortex change to a state of late recurrent discharges which cannot be blocked by clinically available antiepileptic drugs. This late epi...

PURPOSE To characterize seizure types and electroencephalographic features of glucose transporter type 1 deficiency syndrome (Glut-1 DS). METHODS Twenty children with clinical and laboratory features of Glut-1 DS were evaluated. Age at seizure diagnosis, seizure classification, and response to treatment were determined by chart review. Thirty-two continuous 24-h EEG monitoring sessions and re...

Voltage-sensitive-dye imaging was used to study the initiation and propagation of epileptiform activity in transverse hippocampal slices. A portion of the slices tested generated epileptiform discharges in response to electrical shocks under normal physiological conditions. The fraction of slices showing epileptiform responses increased from 44 to 86% when bathing [K+] increased from 3.2 to 4 m...

The routine use of stimulants in pediatrics has increased dramatically over the past 3 decades and the long-term consequences have yet to be fully studied. Since 1978 there have been 7 articles identifying electroencephalogram (EEG) abnormalities, particularly epileptiform discharges in children with attention deficit hyperactivity disorder (ADHD). Many have studied the prevalence of these disc...

We have investigated the propagation of epileptiform discharges induced by 4-aminopyridine (4-AP, 50 microM) in adult mouse hippocampus-entorhinal cortex slices, before and after Schaffer collateral cut. 4-AP application induced 1) ictal epileptiform activity that disappeared over time and 2) interictal epileptiform discharges, which continued throughout the experiment. Using simultaneous field...

EEG-triggered functional MRI (fMRI) offers the potential to localize the generators of scalp EEG events, such as interictal epileptiform discharges, using a biological measurement as opposed to relying solely on modelling techniques. Although recent studies have demonstrated these possibilities in a small number of patients, wider application has been limited by concerns about patient safety, s...

OBJECTIVE To characterize the risk for seizures over time in relation to EEG findings in hospitalized adults undergoing continuous EEG monitoring (cEEG). METHODS Retrospective analysis of cEEG data and medical records from 625 consecutive adult inpatients monitored at a tertiary medical center. Using survival analysis methods, we estimated the time-dependent probability that a seizure will oc...

We present a child with myoclonic seizures, epileptic spasms and generalized epileptiform discharges on scalp EEG. Magnetoencephalography and coherence-phase analysis for scalp EEG suggested focal onset in the left hemisphere. Intracranial video EEG confirmed seizure onset in the left frontal lobe with ictal high-frequency oscillations. Left frontal lobectomy suppressed his seizures. Subsets of...