Topographic EEG brain mapping before, during and after Obstructive Sleep Apnea Episodes

Obstructive Sleep Apnea Syndrome (OSAS) is a very common sleep disorder that is associated with several neurocognitive impairments. The present study aims to assess the electroencephalographic (EEG) power before, during and after obstructive apnea episodes, in four frequency bands: delta (δ), theta (θ), alpha α and beta (β). For that propose, continuous wavelet transform was applied to the EEG signals obtained with polysomnography, and topographic EEG brain mapping to visualize the power differences across the whole brain. The results demonstrate that there is a significant decrease in the EEG δ power during OSAS that does not totally recover immediately after the episode. Since δ waves are linked to learning and plasticity processes, it is hypothesized that decreased δ power during the episode may contribute to the cognitive deterioration in patients with OSAS.