Approach to visual analysis of EEG
EEG waves are generated by postsynaptic potentials in cortical pyramidal neuron and these signals reflect cortical electrical activity. In Epilepsy studies clinicians still perform intensive visual screening to identify abnormal oscillations or waveforms for many purposes. Here are some tips for visual analysis of EEGs.
Essential characteristics of EEG analysis
- Waveform
- Frequency (wavelength)
- Amplitude
- Locus (distribution)
- Persistence (manner of occurence)
- Rhythmicity (repitition)
- Interhemispheric coherence (symmetry, synchrony)
- Reactivity (eye opening, photic stimulation, hyperventilation, mental calculation, sensory stimulation,etc)
What is the most important?
- Do not overestimate EEG findings.
- You should know normal EEG.
- You should know drowsy response.
- You should know characteristics of artifacts.
- Understand the concepts of different montages.
- You should not use average reference.
Try to find Spikes or Sharp waves in the EEG recordings below & identify their maximums.
