Slow wave comparative analysis during non-REM sleep stages for normal subjects and epileptic patients.

During an ordinary night, the human body goes through various sleep stages, most commonly classified as REM and non-REM sleep cycles. These cycles have been studied and characterized by means of polysomnography studies, and have revealed different brain activities visible in the EEG recording. From this, the slow waves, a hallmark for the non-REM sleep stage, have been associated with important functional processes, such as long term memory storage, synaptic regulation and plasticity. Abnormalities in the electrical expression of such slows waves could be an indicator of long term deficiencies in these functional process as a consequence of some neurological disorders like epilepsy. In this work, we have studied different characteristics measured from the electrical expression of slow waves between normal and epileptic subjects. These parameters allowed us to determine significant differences in the preferential depolarization and hyperpolarization times, suggesting a possible alterations in the underlying neuronal processes.