Cortical excitability and visual discomfort in epilepsy: SEEG study
| Název česky | Kortikální excitabilita a vizuální diskomfort u epilepsie: SEEG studie |
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| Autoři | |
| Rok publikování | 2019 |
| Druh | Konferenční abstrakty |
| Fakulta / Pracoviště MU | |
| Citace | |
| Popis | Cortical excitability (CE) is defined as the strength of the response of cortical neurons to a given stimulation. Increased level of CE is a key neurophysiological mechanism in several neurological disorders, including epilepsy.Studies proved the existence of a relationship between increased CE and subjective visual discomfort during presentation of striped patterns of spatial frequency of approx. 3 cycles / degree, i.e. a pattern glare phenomenon. Individuals with increased CE, e.g. migraine patients, experience significantly higher frequency of visual distortions in comparison with healthy subjects. The study aims to examine intracranial electrophysiological correlates of the pattern glare during visual presentation of striped stimuli with spatial frequency of 0.5, 3 and 11 cpd. Eleven patients with pharmacoresistant epilepsy with depth electrodes implanted to localize seizure origin agreed to participate in the study. Subjective evaluation of stimuli was correlated with intracranial EEG record. High frequency oscillations (HFOs), power spectral analysis and connectivity patterns in 55-80 Hz, 80-250 Hz, 250-600 Hz and 600-1000 Hz frequency bands were analysed. Higher occurrence of HFOs, increased connectivity and mean EEG power mainly in the 80-250 Hz frequency band in anterior and posterior hippocampi, anterior insula and precuneus were observed during the presentation of the subjectively most irritable stimuli. Our results point to possible electrophysiological correlates of increased cortical excitability related to perception of irritable stimuli during pattern glare task in epileptic patients. |
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