What are psychomotor EEG variants?

Updated: Oct 09, 2019
  • Author: Roy Sucholeiki, MD; Chief Editor: Selim R Benbadis, MD  more...
  • Print


The following waveforms are generally benign:

  • Psychomotor variant (rhythmic harmonic theta)

    • This is an unusual form that occurs as asymmetrical runs of theta or delta activity primarily in the temporal regions, lasting for a few seconds or as long as 30-45 seconds (see the following image).

    • Example of the psychomotor variant (rhythmic harmo Example of the psychomotor variant (rhythmic harmonic theta).
    • This waveform is clearly a harmonic of 2 or more rhythms. The waves often have a bifid appearance.

    • It starts suddenly on 1 side and lasts for several seconds before terminating suddenly. This behavior resembles a seizure discharge, hence the name "psychomotor variant."

    • Generally considered benign, this waveform does not correlate with seizure disorder. It is best seen on a prolonged EEG and tends to be more common in children and young people. [6]

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!