[Indicators of the background spectral power of the EEG in patients with alcohol dependence complicated by exogenous organic brain disease].

Abstract

Objective: To conduct a comparative analysis of EEG spectral power indicators in patients with alcoholism with- or without exogenous organic brain disease.

Material and methods: An analysis of 119 EEG of patients with alcohol dependence was carried out. The presence of exogenous organic brain disease in patients was assessed retrospectively (through anamnesis). The EEG signals received from 16 electrodes were first divided into 3 frequency spectra (i.e. theta, alpha and beta), then the values of absolute spectral power were calculated, and then they were reordered, combined and topographically transferred to a spectral map. Data analysis was carried out in 5 different ways: electrode analysis, analysis based on cortical regions, lateralization, antero-posterior locus and throughout the whole cortex.

Results: In the group of alcohol-dependent patients with comorbid exogenous organic brain damage, significantly (p<0.05) lower values of the spectral power of alpha activity on the Fp2, F3, F4, C3 and C4 electrodes as well as higher values of the spectral power of beta activity on the F8, T5 and T6 electrodes compared with the group of patients with «pure» alcohol dependence were observed. The intergroup data analysis, taking into account the topographic distribution, revealed significant differences in the spectral power of alpha activity in the prefrontal (F=4.201; p=0.043), frontal (F=3.951; p=0.049), central (F=4.033; p=0.047) and parietal (F=3.926; p=0.049) regions, as well as beta activity in the temporal region (F=5.656; p=0.019) of the cerebral cortex. Compared with patients suffering only from alcohol dependence, the group of patients with alcohol dependence and exogenous organic brain damage had significantly lower spectral power of alpha activity on the left (F=5.329; p=0.019) and on the right (F=5.191; p=0.027), as well as in the anterior locus (F=3.975; p=0.049).

Conclusion: The results clearly indicate that the presence of exogenous organic brain damage in patients with alcohol dependence is accompanied by a change in the spectral power of the EEG mainly in the alpha frequency range.