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Electroencephalographic Recordings (electroencephalographic + recording)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

fMRI of Generalized Absence Status Epilepticus in Conscious Marmoset Monkeys Reveals Corticothalamic Activation

EPILEPSIA, Issue 10 2004
Jeffrey R. Tenney
Summary:,Purpose: A nonhuman primate model of generalized absence status epilepticus was developed for use in functional magnetic resonance imaging (fMRI) experiments to elucidate the brain mechanisms underlying this disorder. Methods: Adult male marmoset monkeys (Callithrix jacchus) were treated with ,-butyrolactone (GBL) to induce prolonged absence seizures, and the resulting spike,wave discharges (SWDs) were analyzed to determine the similarity to the 3-Hz SWDs that characterize the disorder. In addition, blood-oxygenation-level,dependent (BOLD) fMRI was measured at 4.7 Tesla after absence seizure induction with GBL. Results: Electroencephalographic recordings during imaging showed 3-Hz SWDs typical of human absence seizures. This synchronized EEG pattern started within 15 to 20 min of drug administration and persisted for >60 min. In addition, pretreatment with the antiepileptic drug, ethosuximide (ESM), blocked the behavioral and EEG changes caused by GBL. Changes in BOLD signal intensity in the thalamus and sensorimotor cortex correlated with the onset of 3-Hz SWDs. The change in BOLD signal intensity was bilateral but heterogeneous, affecting some brain areas more than others. No significant negative BOLD changes were seen. Conclusions: The BOLD fMRI data obtained in this marmoset monkey model of absence status epilepticus shows activation within the thalamus and cortex. [source]

Polygenic Control of Idiopathic Generalized Epilepsy Phenotypes in the Genetic Absence Rats from Strasbourg (GAERS)

EPILEPSIA, Issue 4 2004
Gabrielle Rudolf
Summary: Purpose: Generalized nonconvulsive absence seizures are characterized by the occurrence of synchronous and bilateral spike-and-wave discharges (SWDs) on electroencephalographic recordings, concomitant with behavioral arrest. The GAERS (genetic absence rats from Strasbourg) strain, a well-characterized inbred model for idiopathic generalized epilepsy, spontaneously develops EEG paroxysms that resemble those of typical absence seizures. The purpose of this study was to investigate the genetic control of SWD variables by using a combination of genetic analyses and electrophysiological measurements in an experimental cross derived from GAERS and Brown Norway (BN) rats. Methods: SWD subphenotypes were quantified on EEG recordings performed at both 3 and 6 months in a cohort of 118 GAERS × BN F2 animals. A genome-wide scan of the F2 progenies was carried out with 146 microsatellite markers that were used to test each marker locus for evidence of genetic linkage to the SWD quantitative traits. Results: We identified three quantitative trait loci (QTLs) in chromosomes 4, 7, and 8 controlling specific SWD variables in the cross, including frequency, amplitude, and severity of SWDs. Age was a major factor influencing the detection of genetic linkage to the various components of the SWDs. Conclusions: The identification of these QTLs demonstrates the polygenic control of SWDs in the GAERS strain. Genetic linkages to specific SWD features underline the complex mechanisms contributing to SWD development in idiopathic generalized epilepsy. [source]

Cortical lesions associated with transient neurological symptoms , not always a matter of cause and effect

EUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2003
S. Kipervasser
The occurrence of transient recurrent stereotypical neurological events mandates the exclusion of an underlying brain lesion. When imaging studies demonstrate the presence of a structural brain lesion, a cause and effect relationship between the two entities is assumed, and the decision for surgical intervention may then follow almost automatically. We describe five patients with transient neurological events suspected as being seizures that were referred for surgery because of an associated structural brain lesion. Video electroencephalographic recordings revealed that the events that brought these patients to neurosurgical attention were non-epileptic seizures. None of these patients underwent surgical intervention, and all were referred for behavioral therapy. Therefore, even in the presence of a confirmed brain lesion, the presenting paroxysmal events may be of a non-organic origin and should not necessarily be assumed to be caused by the concomitantly existing structural abnormality. [source]

Neural Correlates of Face and Object Recognition in Young Children with Autism Spectrum Disorder, Developmental Delay, and Typical Development

CHILD DEVELOPMENT, Issue 3 2002
Geraldine Dawson
This study utilized electroencephalographic recordings to examine whether young children with autism spectrum disorder (ASD) have impaired face recognition ability. High-density brain event-related potentials (ERPs) were recorded to photos of the child's mother's face versus an unfamiliar female face and photos of a favorite versus an unfamiliar toy from children with ASD, children with typical development, and children with developmental delay, all 3 to 4 years of age (N= 118). Typically developing children showed ERP amplitude differences in two components, P400 and Nc, to a familiar versus an unfamiliar face, and to a familiar versus an unfamiliar object. In contrast, children with ASD failed to show differences in ERPs to a familiar versus an unfamiliar face, but they did show P400 and Nc amplitude differences to a familiar versus an unfamiliar object. Developmentally delayed children showed significant ERP amplitude differences for the positive slow wave for both faces and objects. These data suggest that autism is associated with face recognition impairment that is manifest early in life. [source]