[Electroencephalographic normal variants or with uncertain significance].

Area of Science:

• Neuroscience
• Clinical Electrophysiology
• Neurology

Context:

• Electroencephalography (EEG) is crucial for diagnosing central nervous system disorders, particularly epilepsy.
• Normal EEG activity can sometimes resemble epileptiform discharges, posing a diagnostic challenge.
• Understanding EEG variants is essential for accurate neurological assessment.

Purpose:

• To review and describe common variants of normal electroencephalography (EEG) activity.
• To differentiate non-pathological EEG patterns from true epileptiform discharges.
• To prevent misinterpretation of normal brain activity as abnormal.

Summary:

• Classifies normal EEG variants including rhythmic patterns, epileptiform patterns, lambda waves, and age-dependent changes (Blum and Cervone classification).
• Highlights that these variants often occur during drowsiness, sleep, or activation procedures, especially in children and adolescents.
• Emphasizes the non-pathological nature of these EEG findings, distinguishing them from abnormal brain activity.

Impact:

• Enhances diagnostic precision in electroencephalography (EEG) interpretation.
• Reduces the risk of misdiagnosing epilepsy or other neurological conditions.
• Provides clinicians with a guide to identify and interpret normal EEG variations accurately.