St-Petersburg State Research Institute for Emergency named after I.I. Dzhanelidze,
Saint-Petersburg, Russia; North-West State Medical University named after I.I. Mechnikov,
Saint-Petersburg, Russia; firstname.lastname@example.org
The objective of the research is to form the comparative characteristics of the amplitude-frequency parameters of the options of the Electroencephalography (EEG) with rhythmic alpha- activity in the various
outcomes of severe poisoning by the neurotoxic substances. The research is undertaken with the purpose of formation of the comparative characteristics of the amplitude-frequency parameters of the options of the EEG with rhythmic alpha-activity in the various outcomes of severe poisoning by the substances of neurotoxic actions. The work is performed on the basis of the St. Petersburg state research institute for emergency named after I.I. Dzhanelidze. The research comprises 24 patients (15 men, 9 women) at the age of 26 to 43 y.o. The causes of acute poisoning were: opiates (11 cases), psychopharmacological drugs (10 cases) and the products of combustion (3 cases). Spectral power was estimated in standard ranges; the SEF-50 and SEF-90 parameters were calculated. Linear connections of the electrical processes in the different regions of the cortex were evaluated by a coherent analysis.
The research included only those patients whose EEG pattern registered on the background of the 2-3 degree coma was presented by diffuse rhythmic alpha-activity. Depending on the outcome of the comatose period the registered options of the EEG conditionally were divided into two: 1) a rhythmic alpha-activity pattern at an awakening (16 patients) and 2) an alpha-coma pattern at a lethal outcome (8 patients). These EEG-syndromes have clear differential diagnostic differences in the frequency of dominating activity and its regional distribution, in the reactivity state. The pattern registered at awakening, is formed by the diffuse activity with a frequency of 8-11 Hz keeping ability to desynchronization when stimulated. According to the results of a coherent analysis the alpha-activity has strong interhemispheric connections, and that reflects the consolidated work of the various parts of the brain. The alpha-coma pattern is formed by the slow alpha-activity at a frequency of 6–8 Hz; SEF90 is of 7.5–9 Hz. The distribution of the slow alpha-activity is characterized by the maximum amplitude in the frontal-central leads and the minimum one ‑ in the occipital lead. Light, sound and painful stimulation does not block the alpha- activity. The activity in the alpha-coma is formed from a number of sources, the main of which are the hippocampus and the mediobasal structures to a lesser extent.