Composition of EEG oscillations and their temporal characteristics: methadone treatment.

In this study, we examine the composition of electroencephalographic (EEG) oscillations within a broad frequency band (0.5-30 Hz) for opioid abuse (22 patients), during withdrawal (13 patients), and after 6 months of methadone treatment (6 patients) and in 14 healthy subjects during a resting condition (closed eyes). The exact compositions of EEG oscillations and their temporal behaviour were assessed using the probability-classification analysis of short-term EEG spectral patterns. The study reveals the dynamics of particular EEG oscillations throughout the conditions of opioid dependency, withdrawal and methadone-based treatment. It was shown that methadone maintenance treatment normalized considerably the composition of EEG oscillations and their percentage ratio and restored the temporal structure of patients' EEG comparable with healthy subjects. The importance of the methadone's ability to restore a normal temporal structure of the brain's activity is discussed.