EEG Mapping and Source Imaging

This chapter describes methods to analyze the scalp electric field recorded with multichannel electroencephalography (EEG). With advances in high-density EEG, systems now allow fast and easy recording from 64 to 256 channels simultaneously. Pattern-recognition algorithms can characterize the topography of scalp electric fields and detect changes in topography over time and between experimental or clinical conditions. Methods for estimating the sources underlying the recorded scalp potential maps have increased the spatial resolution of EEG. The use of anatomical information in EEG source reconstruction has increased the precision of EEG source localization. Algorithms of functional connectivity applied to the source space allow determination of communication between large-scale brain networks in certain frequencies and identification of the directionality of this information flow and detection of crucial drivers in these networks. These methods have boosted the use of EEG as a functional neuroimaging method in experimental and clinical applications.

Clinical Features Neuropsychological Disorders in Multiple Sclerosis Patients in Aspect Comorbidity

The objective: to investigate the relationship between clinical manifestations of neuropsychological disorders and neuroimaging data (MRI) and electrophysiological (EEG mapping, somatosensory evoked potentials) methods of diagnosis in patients with multiple sclerosis (MS) in the aspect of comorbidity. Patients and methods. Achieved the clinical, neuropsychological, instrumental study 216 MS patients with the presence of (107) or absence (109) comorbid pathology. Spend a numerical score of neurological deficit symptoms (the FS scale) with the total score counting, defined EDSS level evaluated symptoms of fatigue (the FSS), pain (VAS), depression (BDI-II), the degree of cognitive impairment (MMSE). Implemented neyrovizualizuatsionnoe (MRI) study of the brain and spinal cord and EEG mapping study of electrical activity (EA) of the brain., somatosensory evoked potentials (SSEP). Results. It is found that the presence of foci of demyelination in the brain stem in both groups correlated with the severity of the manifestations of depression BDI-II data. It also shows that about 65% of both groups of MS patients had signs of decrease ascending activating effects on the cortex from the reticular formation of the brainstem. It was found that 70% of MS patients in both groups there are irritative and hypersynchronous types EA brain, reducing the symptoms of seizure threshold, with the presence of a strong direct correlation between them and multimodal pain. Conclusions. In the presence of comorbid disease in MS patients observed clinically deeper and more frequent manifestations of NPM, which is confirmed by the results of neuropsychological testing conducted. The presence of foci of demyelination in the cervical spinal cord was significantly more frequent in the MS group with comorbidity (p<0.05), and both groups of patients clinically directly correlates with the severity of pain according to VAS.