Overcoming traps and pitfalls leading to misinterpretation of normal EEG variants and variation of the background activity.

Normal EEG variants, especially the epileptiform variants, can be challenging to interpret because they often have sharp contours and may be confused with "epileptic" interictal activities. However, they can be recognized by the fact that "most spikes or sharp wave discharges of clinical import are followed by a slow wave or a series of slow deflections" (Maulsby, 1971). If there is no wave after the spike, electroencephalographers should be suspicious of artifacts and normal EEG variants.

Stimulus-induced arousal with transient electroencephalographic improvement distinguishes nonictal from ictal generalized periodic discharges.

In the case of suspicion of nonconvulsive status epilepticus (NCSE), reactivity on electroencephalograms (EEGs) can provide valuable diagnostic information. Reactivity refers to responses to auditory or somatosensory stimulation, with changes in amplitude and frequency of background activity. Because of self-perpetuating processes and the failure of self-terminating mechanisms, status epilepticus is unlikely to cease when patients spontaneously move, and it cannot typically be stopped by external stimulation (i.

Determining ICU EEG periodic patterns and why it matters.

Historically, periodic EEG patterns were described as any pattern with stereotyped paroxysmal complexes occurring at regular intervals, i.e., the period (T).

Core Features Differentiate Dravet Syndrome from Febrile Seizures.

An 11-month-old girl with febrile seizures and first unprovoked seizures was evaluated in the hospital. Relevant history included developmental delay and strong family history of febrile seizures and migraines. A routine electroencephalogram was performed and was abnormal due to the presence of a slowed posterior dominant rhythm, generalized spike-wave discharges, and multifocal sharp waves.

Normal EEG variants.

Understanding common variations of normal EEG and benign variants of uncertain significance is essential to discern the boundary between normal and abnormal EEG. Wide variation and fluctuation can occur with normal signals generated by the brain, and these can be a pitfall for less-experienced electroencephalographers in accurately interpreting the EEG. Normal EEG variants are benign and do not portend specific pathological conditions.