Publications (2)7.92 Total impact
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Article: NIRS-measured oxy- and deoxyhemoglobin changes associated with EEG spike-and-wave discharges in a genetic model of absence epilepsy: the GAERS.
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ABSTRACT: Absence epilepsy may be severe and is frequently accompanied by cognitive delay, yet its metabolic/hemodynamic aspects have not been established. The Genetic Absence Epilepsy Rats from Strasbourg (GAERS) are an isomorphic, predictive, and homologous model of human absence epilepsy. We studied hemodynamic changes related to generalized spike-and-wave discharges (GSWDs) in GAERS by using a technique with high temporal resolution: near-infrared spectroscopy (NIRS). We hypothesized that conflicting results from other techniques might be due to the averaging of a biphasic response such as the one we described in children. NIRS is particularly suitable for monitoring changes in the concentrations of oxy-, deoxy-, and total hemoglobin (HbO₂, HHb, and HbT), using the specific absorption properties of living tissues in the near infrared range. We obtained concomitant high quality electroencephalography (EEG)-NIRS recordings in six GAERS (total of 444 seizures), and tested whether the discharges were related to changes in cardiac or respiration rates. The onset of GSWDs was preceded by a deactivation, followed by an activation that was possibly due to seizure-suppression mechanisms. The end was marked by a deactivation. The onset of GSWDs was associated with a decrease and the end with a brief increase in respiratory rate. Our results differ partially from those of previous studies on hemodynamic aspects of GSWDs (many of which describe a simple deactivation), probably due to differences in temporal resolution and data processing; however, they are consistent with metabolic studies, functional magnetic resonance imaging (fMRI) studies on WAG/Rij rats, and some results in children with absence epilepsy.Epilepsia 04/2010; 51(8):1374-84. · 3.96 Impact Factor -
Article: NIRS-measured oxy- and deoxyhemoglobin changes associated with EEG spike-and-wave discharges in children.
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ABSTRACT: Absence epilepsy is characterized by 3-Hz generalized spike-and-wave discharges (GSWD) on the electroencephalogram, associated with behavioral arrest. It may be severe, and even in childhood benign absence epilepsy cognitive delay is frequent, yet the metabolic/hemodynamic aspects of this kind of epilepsy have not been established. We aimed to determine if the GSWD were related to hemodynamic changes by using a new technique with high temporal resolution: near infrared spectroscopy (NIRS). NIRS is gaining acceptance as a technique particularly suitable for routine follow-up in children, using the specific absorption properties of living tissues in the near infrared range to measure changes in the concentrations of oxy-, deoxy- and total hemoglobin (HbO(2), HHb, and HbT, respectively). We performed simultaneous electroencephalography (EEG) and left frontal NIRS recordings in six children with GSWD. We also tested if the discharges were related to changes in cardiac or respiratory rates. GSWD were associated in the frontal area with an oxygenation (beginning 10 s before the GSWD) followed by strong deoxygenation, then oxygenation again with [HbT] increase, and a return to baseline. We did not identify any relationship between the onset of the GSWD and heart or respiratory rates. Our results partially differ from previous studies on GSWD hemodynamic aspects (many of which described a simple deactivation), probably due to differences in temporal resolution and data processing. Simultaneous acquisition of EEG and NIRS can optimize the use of both techniques and help shed light on the mechanisms underlying spike-and-wave discharges.Epilepsia 11/2008; 49(11):1871-80. · 3.96 Impact Factor
