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SleepTech Clinical Diagnostics
Research / Methodology

EEG MONTAGE | SleepTech

The 10-20 International System

The standardized method to describe the location of scalp electrodes for EEG recording. It ensures consistent spacing based on specific anatomical landmarks: the nasion (front), inion (back), and preauricular points (sides).

AASM Recommended PSG Montage

For standard adult polysomnography, the AASM recommends a minimum of three EEG derivations to adequately capture regional differences in sleep microarchitecture:

  • F4-M1 (Frontal): Best for visualizing slow wave activity (delta waves) characteristic of N3 sleep (Deep Sleep).
  • C4-M1 (Central): Best for visualizing sleep spindles and K-complexes, the hallmarks of N2 sleep.
  • O2-M1 (Occipital): Best for visualizing alpha rhythm (posterior dominant rhythm) during relaxed wakefulness with eyes closed. Essential for defining the onset of N1 sleep (attenuation of alpha).

Note: F3, C3, O1, and M2 are placed as backups to allow for re-referencing if an electrode fails or artifact occurs.

Technical review of the capabilities and limitations of this methodology in clinical sleep medicine.