What are epileptiform normal variants on electroencephalographic (EEG)?

Updated: May 11, 2018
  • Author: Selim R Benbadis, MD; Chief Editor: Helmi L Lutsep, MD  more...
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Answer

Epileptiform normal variants are electroencephalographic (EEG) patterns that resemble epileptogenic abnormalities. Most of these patterns initially were thought to be associated with epilepsy or other neurologic conditions but subsequently were demonstrated to have no such significance. [1] They now are considered normal variants of no clinical significance; however, their recognition is important to avoid overinterpretation or misinterpretation of their significance. [2, 3]

This article reviews the following such patterns: small sharp spikes (SSSs), wicket spikes, 14- and 6-Hz positive spikes, phantom spike and waves, psychomotor variant, subclinical rhythmic EEG discharges of adults (SREDA), and midline theta rhythm.

Most of these patterns initially were described in the 1950s. Gibbs and Gibbs described small sharp spikes in 1952, [4] and 14- and 6-Hz positive spikes were described at approximately the same time. [5, 6, 7, 8] The 6-Hz phantom spike-wave was described by Walter in 1950, [9] and the psychomotor variant was described by Gibbs and Gibbs in 1952. [4] Wickets were described in 1977 by Reiher and Lebel. [10] Midline theta rhythm was described by Ciganek in 1961. [11]

Go to Epilepsy and Seizures for an overview of these topics.


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