Jean Gotman — Page 3 | Search PubMed

PubMed2002

Digital tools in polysomnography.

Recent advances in the computing power and storage devices have made computer-based recording of polysomnograms (PSGs) very attractive. Digital PSGs offer the possibility of automating many tedious and time-consuming tasks of identifying sleep related events. Automation not only alleviates these laborious tasks, but also introduces a measure of objectivity in the scoring of various discrete events. In this paper we briefly review some automatic methods that have been previously developed by the authors. Automatic sleep staging methods is emphasized with some illustrative results on inter-scorer variations. We also discuss the leg movement event, respiratory event, sleep spindle and rapid-eye-movement detection methods.

Computers↗

PubMedDate not supplied

Combining EEG and FMRI in epilepsy: methodological challenges and clinical results.

It is now possible to combine continuous recording of the EEG and continuous functional MRI scanning. This makes it possible to determine the regions of the brain showing changes in the fMRI signal in response to epileptic spikes occurring in the EEG. This article reviews the experience with this method in more than 100 studies performed over the last 4 years at the Montreal Neurological Institute. The technique is complex, and the authors review the various issues related to obtaining a good-quality EEG in the hostile environment of the magnetic resonance scanner, the statistical analysis of magnetic resonance images, in particular the issue of knowing what is the hemodynamic response function appropriate for the analysis of epileptic spikes, and the combination of EEG and fMRI results. The difficult theoretical issues raised by the interpretation of activation and deactivation, both frequently seen in response to spikes, are discussed. Finally, the authors give examples of fMRI responses seen with focal spikes and with generalized spike and wave discharges.

Brain↗