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Objective. To investigate and localize the sources of spontaneous, scalp-recorded theta activity in patients with partial epilepsy (PE).Methods. 9 patients with beginning, untreated PE (Group1), 31 patients with already treated PE (Group2), and 14 healthy persons were investigated by means of spectral analysis and LORETA, low resolution electromagnetic tomography (1 Hz very narrow band analysis, age-adjusted, Z-scored values). The frequency of main interest was 4 to 8 Hz Results. Group analysis. Group1 displayed bilateral theta maxima in the temporal theta area (TTA), parietal theta area (PTA), and frontal theta area (FTA). In Group2, theta activity increased all over the scalp as compared to the normative mean (Z=0) and also to Group1. Maximum activity was found in the TTA, PTA, and FTA. However, in the PTA and FTA the centers of the abnormality shifted towards the medial cortex. Individual analysis: all the patients showed preferential activation (maximum Zvalues) within one of the three theta areas. 2Conclusion. EEG activity in the theta band is increased in anatomically meaningful patterns in PE patients, which differs from the anatomical distribution of theta in healthy persons.Significance. The findings contribute to our understanding of the sources of theta rhythms and the pathophysiology of PE.

Areas of increased EEGfC topographically correspond to cortical areas that, based on relevant literature, are related to speech and attention deficit in BECTS children.

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Aim. To investigate the effect of chronic VPA treatment of EEG functional connectivity in successfully treated idiopathic generalized epilepsy (IGE) patients. Patients and Methods. 19-channel waking, resting-state EEG records of 26 IGE patients were analyzed before treatment (IGE) and after the 90th day of treatment (VPA), in seizurefree condition. Three minutes of artifact-free EEG background activity (without epileptiform potentials) was analyzed for each patient in both conditions. A group of 26 age-matched healthy normative control persons (NC) was analyzed in the same way. All the EEG samples were processed to LORETA (Low Resolution Electromagnetic Tomography) to localize multiple distributed sources of EEG activity. Current source density time series were generated for 33 regions of interest (ROI) in each hemisphere for four frequency bands. Pearson correlation coefficients (R) were computed between all ROIs in each hemisphere, for four bands across the investigated samples. R values corresponded to intrahemispheric, cortico-cortical functional EEG connectivity (EEGfC). Group and condition differences were analyzed by statistical parametric network method. Main results. (p<0.05, corrected for multiple comparisons). 1. The untreated IGE group showed increased EEGfC in the delta and theta bands, and decreased EEGfC in the alpha band (as compared to the NC group). 2. VPA treatment normalized EEGfC in the delta, theta and alpha bands. 3. Degree of normalization depended on frequency band and cortical region. Conclusions. VPA treatment normalizes EEGfC in IGE patients.

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AbstractObstructive sleep apnea syndrome (OSAS) is characterized by the recurrent cessation (apnea) or reduction (hypopnea) of airflow due to the partial or complete upper airway collapse during sleep. Respiratory disturbances causing sleep fragmentation and repetitive nocturnal hypoxia are responsible for a variety of nocturnal and daytime complaints of sleep apnea patients, such as snoring, daytime sleepiness, fatigue, or impaired cognitive functions. Different techniques, such as magnetic resonance imaging, magnetic resonance spectroscopy, and positron emission tomography, are used to evaluate the structural and functional changes in OSAS patients. With quantitative electroencephalographic (qEEG) analysis, the possible existence of alterations in the brain electrical activity of OSAS patients can be investigated. We review the articles on qEEG results of sleep apnea patients and summarize the possible explanations of these qEEG measures. Finally, we review the impact of continuous positive airway pressure (CPAP) treatment on these alterations to assess whether CPAP use can eliminate alterations in the brain activity of OSAS patients.