[Changes in EEG-complexity after subcortical ischemic brain damage].

Introduction: Complexity analysis of the EEG is a relatively new field in theoretical and clinical electrophysiology. The authors present results of EEG-analysis in a patient with stroke, utilizing the sensitivity of the new procedures with respect to linear and nonlinear synchronization.

Participants And Methods: The EEG (19 channels) was recorded in a patient with subcortical unilateral ischaemic completed stroke involving the frontoparietal white matter while leaving the cortex intact and in 12 healthy controls in eyes open and in eyes closed conditions.

[Spectral EEG-characteristics of subcortical ischemic brain lesion--a case study].

Introduction: Although the EEG-changes caused by ischemic stroke are well known, data of the literature are rather ambiguous. The EEG-findings recorded in a patient with a unilateral subcortical ischemic lesion are evaluated with special emphasis related to the effect of the dynamics caused by eye opening.

Participants And Methods: Data recorded from a patient (54 years old male with a completed stroke involving the frontal and parietal subcortical region in the left side) were compared to those of a control group (12 healthy age matched subjects).

Spectral and complexity features of the EEG changed by visual input in a case of subcortical stroke compared to healthy controls.

Objective: To compare spectral and complexity characteristics of the EEG in a unique case of subcortical infarct to those seen in healthy controls.

Methods: Absolute and relative frequency spectra, theta/beta ratio, the brain symmetry index (BSI), Omega-complexity and synchronization likelihood were calculated of the EEG recorded in eyes closed and eyes open conditions.

Results: Increased absolute delta, theta, and Omega-complexity in these frequency bands, higher theta/beta ratios, and decreased relative beta activity were found in the side of the infarct.

[Psychophysiologic and clinical aspects of EEG synchronization related to cognitive processes].

The authors review the various forms of EEG-synchronization with special emphasis on the characteristics of the induced and enhanced rhythms. The suggested role of the various EEG frequency bands in the cognitive processes is demonstrated by examples from the literature. The relationship between linear and nonlinear electrophysiological complexity and EEG synchronization is analyzed, with a touch on the use of Omega-complexity and synchronization likelihood methods.