What are the characteristics of subclinical rhythmic electroencephalographic (EEG) discharges of adults (SREDA)?

Updated: May 11, 2018
  • Author: Selim R Benbadis, MD; Chief Editor: Helmi L Lutsep, MD  more...
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Subclinical rhythmic electroencephalographic (EEG) discharges of adults (SREDA) is an uncommon pattern observed mainly in older persons (>50 y). It may occur at rest or during drowsiness.

Superficially, SREDA resembles an EEG seizure pattern. The frequency is typically 5-6 Hz. The location is widespread or bilateral with a posterior maximum. The morphology is seizurelike (ie, rhythmic sharply contoured theta). Abrupt onset and termination may help distinguish SREDA from an EEG seizure. The duration ranges from 20 seconds to minutes (average, 40-80 s).

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