SREDA: subclinical rhythmic electrographic discharges of adults

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  • abrupt onset and termination, unlike seizures which evolve
  • rhythmic, sharply contoured theta
  • may evolve slow to fast (from 1-2 Hz to 5-6 Hz) like a "seizure in reverse"
  • duration: 20 sec to minutes
  • usually bisynchronous and symmetric
  • temporal-parietal distribution
  • widespread or bilateral, maximal posteriorly
  • at rest or in drowsiness

    clinical significance

  • usually in normal adults (50 and older)
  • uncommon
  • may be mistaken for epileptiform activity