High-frequency oscillations (HFOs) in electroencephalography: Review and case study

This article presents a review focusing technological aspects of EEG recordings considering the frequency band 40–500 Hz. This includes the “Gamma” (40–80 Hz) and “Supergamma” (80–100 Hz) rhythms, which has been extensively analysed for animal models since the 80's. On the other hand, the band 100–500 Hz, abbreviated by “High-Frequency Oscillations”-HFO, has been studied since 1995, focusing epilepsy in both human and rat models. Current challenges are highlighted from the literature, leading to guidelines for those starting in the field, so that at the end we present two examples of HF0 recorded (1–100 Hz) in normal individual and in a patient from our local university hospital.