Analysis of Clinical Characteristics, Background, and Paroxysmal Activity in EEG of Patients with Juvenile Myoclonic Epilepsy

Juvenile myoclonic epilepsy (JME) appears in adolescence with myoclonic, absence, and generalized tonic clonic (GTC) seizures with paroxysmal activity of polyspike and slow wave (PSW), or spike and wave (SW) complexes in EEG. Our aim was to analyze the clinical characteristics, background EEG activity, and paroxysmal events in 41 patients with JME. Background EEG activity was analyzed with visual, quantitative (QEEG), and neurometric parameters. Our JME patients started with absence seizures at 11.4 ± 1.5 years old, myoclonic seizures at 13.6 ± 2.5 years, and GTC seizures at 15.1 ± 0.8 years. The seizures presented in awakening at 7:39 h with sleep deprivation, alcoholic beverage intake, and stress as the most frequent precipitant factors. Paroxysmal activity was of PSW and fast SW complexes with 40.5 ± 62.6 events/hour and a duration of 1.7 s. Right asymmetric paroxysmal activity was present in 68.3% of patients. Background EEG activity was abnormal in 31.7% of patients with visual analysis. With QEEG beta AP (absolute power) increase and AP delta decrease were the most frequent abnormalities found. Spectral analysis showed that 48.7% of patients had normal results, and 26.83% and 24.4% had higher and lower frequencies than 10.156 Hz, respectively. We concluded that, with visual analysis, background EEG activity was abnormal in a few patients and the abnormalities increased when QEEG was used.

High-frequency electrical activity of the brain in patients with hemispheric ischemic stroke in combination with cognitive functions

The mathematical analysis of electroencephalography (EEG) provides information about the functional state of the brain, expands the understanding of the mechanisms of interaction between different areas of the brain, increases the possibilities of diagnostics and allows to put forward new tasks in the field of studying brain activity. Aim. To assess changes in the gamma-rhythm in patients with hemispheric ischemic stroke in the most acute and acute periods in comparison with cognitive and anxiety-depressive disorders. Material and methods. The study included 32 patients with hemispheric ischemic stroke. All patients underwent complex clinical, neurological, instrumental and laboratory studies. The study and recording of the EEG was carried out on the 1st and 21st days of the disease, lasting 20 minutes. The method of mathematical analysis was used to estimate the power spectra and the peak frequency of the gamma — rhythm of the background EEG. Results. As a result of the study, it was found that cognitive and anxiety-depressive disorders are detected already in the most acute and acute periods of ischemic stroke. In the mathematical analysis of the EEG statistically significant correlations between the gamma — rhythm index and cognitive, anxiety-depressive disorders in the frontal, central temporal areas are noted. Conclusion. The complex of examination of patients should include, in addition to clinical and neuropsychological research, mathematical analysis of EEG data.

Manganese encephalopathy and interhemispheric asymmetry of the brain

Patients suffering from manganese encephalopathy, which develops while taking surrogate drugs, suffer from pronounced subcortical pseudobulbar syndrome, pyramidal insufficiency and a complex of autonomic disorders. The most pronounced of them are disorders of motor functions. The work is devoted to the study of the bioelectrical activity of the brain of patients with manganese encephalopathy in order to develop an EEG-criterion for diagnosing this disease. The subjects underwent EEG recording using a 16-channel electroencephalograph "NeuroCom standart" (KhAI-Medika, Ukraine) in accordance with the international recording system "10-20". The following were analyzed: the power of the signals of the main rhythms of the background EEG, the relative characteristics of the power of the signals of the main EEG rhythms – the activation coefficient of the cortex, the activation coefficient of the sub cortex, the indices of interhemispheric asymmetries in terms of the power of bioelectric signals in bilaterally synchronous points of the head. It was found that in patients with manganese encephalopathy both the cortical activation coefficients and the sub cortex activation coefficients had values that can be observed in patients with аnother diseases. In turn, such indicators as interhemispheric asymmetry in the power of signals of individual rhythms and interhemispheric asymmetry in the total power of signals at bilaterally synchronous points of the head in patients with manganese encephalopathy had values that significantly differed from those in patients with other types of pathology. So, with indicators of 16-18 interhemispheric asymmetries in healthy people and 9-25 in patients in coma, in patients with manganese encephalopathy, it was observed: in one patient – 12 interhemispheric asymmetries, in the other of the patients – 9, 7, 3 and 2 interhemispheric asymmetries in signal power of individual rhythms at bilaterally synchronous points of the head. The reason for such a pronounced smoothing of interhemispheric asymmetries in patients with manganese encephalopathy, obviously, may be those destructive changes in the subcortical parts of the GM that are present in this group of patients.

Relationship of background electroencephalogram with cognitive impairment in patients with alcohol dependence

A significant number of studies have focused on the neurophysiological basis of cognitive dysfunction among individuals with neurological and psychiatric disorders, including alcoholism. However, the neural correlates of cognitive deficits in alcohol dependence are still not clear enough. The purposeof the study: to identify the relationship of background electroencephalogram indicators with cognitive disorders in patients with alcohol dependence. Material and methods.107patients with alcohol dependence aged 30 to 60years after detoxification were examined. The background electroencephalogram was recorded with closed eyes for 2min. The values of the absolute spectral power of theta, alpha and beta rhythms were analyzed. The study of the level of Executive functioning was conducted using the Go/Nogo test. The level of spatially working memory was evaluated using the Corsi Block-Tapping test. Results.Data analysis revealed statistically significant correlations between the spectral power of the alpha rhythm in the occipital cortex and the number of errors per inhibitory signal (Nogo) in the Go/Nogo problem (r=0.287; p=0.025). There were also statistically significant correlations between the values of alpha-rhythm spectral power and working memory in the Corsi test in the parietal cortex (r=0.273; p=0.037), occipital cortex (r=0.316; p=0.015) and temporal cortex (r=0.359; p=0.005). There were no statistically significant correlations of beta and theta rhythms with the results of cognitive tests (p0.05). Conclusion.Thus, all of the above results indicate that the background EEG indicators, in particular the spectral power of alpha activity, can with a certain probability indicate violations of cognitive functioning (inhibitory control and working memory) in patients with alcohol dependence.

Early EEG and behavioral alterations in Dravet mice

Dravet Syndrome (Dravet) is a severe childhood epileptic encephalopathy. The disease begins around the age of six months, with a febrile stage, characterized by febrile seizures with otherwise normal development. By the end of the first year of life, the disease progresses to the worsening stage, featuring recurrent intractable seizures and the appearance of additional comorbidities, including global developmental delay, cognitive deficits, hyperactivity and motor problems. Later, in early school years, Dravet reaches the stabilization stage, in which seizure burden decreases, while Dravet-associated comorbidities persist. Dravet syndrome mouse models (DS) faithfully recapitulate the three stages of the human syndrome. Here, we performed power spectral analyses of background EEG activity in DS and their wild-type (WT) littermates, demonstrating disease stage-related alterations. Specifically, while the febrile stage activity resembled that of WT mice, we observed a marked reduction in total power during the worsening stage and a smaller reduction during the stabilization stage. Moreover, low EEG power at the worsening stage correlated with increased risk for premature death, suggesting that such measurements can potentially be used as a marker for Dravet severity. With normal development at the febrile stage and the presentation of developmental delay at the worsening stage, the contribution of recurrent seizures to the emergence of Dravet-associated comorbidities is still debated. Thus, we further characterized the behavior of WT and DS mice during the different stages of Dravet. At the febrile stage, despite their normal background EEG patterns, DS mice already demonstrated motor impairment and hyperactivity in the open field, that persisted to the worsening and stabilization stages. Conversely, clear evidence for deficits in working memory emerged later in life, during the worsening stage. These results indicate that despite the mild epilepsy at the febrile stage, DS development is already altered, suggesting that the pathophysiological mechanisms governing the appearance of some Dravet behavioral comorbidities may be independent of the epileptic phenotype.HighlightsReduction in background EEG power in DravetLow EEG power correlates with the risk of premature deathMotor deficits and hyperactivity are evident as early as the febrile stageCognitive deficits and detection of increased anxiety begin at the worsening stage