Magnetoencephalography (MEG) detects rectification of abnormal brain hypercorrelations following abstinence from alcohol in chronic alcoholism

Here we used magnetoencephalography (MEG) to investigate changes in brain functional organization, and their time course, following alcohol abstinence in chronic alcoholic patients. Eighteen male veterans (10 control and 8 currently alcohol-dependent) participated in this study. MEG in alcoholic participants were obtained on various days, starting at day 3 of alcohol abstinence. A MEG scan consisted of a 60-s data acquisition period from 248 whole-head axial gradiometers at a frequency of 1.017 kHz. All 30628 pairwise zero-lag cross correlations (CC0) between prewhitened sensor time courses per scan were computed and analyzed. We found the following. At day 3 post abstinence, the mean |CC0| was 2.1x higher than that of controls, indicating a strongly hypercorrelated state. This hypercorrelation decreased gradually in a logarithmic fit, both for negative and positive CC0, which became less negative and less positive with time, respectively. These results demonstrate the power of MEG as a sensitive tool to detect, quantify, and track functional brain status during alcohol detoxification.