Artifact Mimicking Ictal Epileptiform Activity in EEG

Area of Science:

• Neuroscience
• Clinical Neurophysiology

Background:

• Electroencephalography (EEG) records brain activity but is susceptible to extracerebral artifacts.
• Differentiating rhythmic artifacts from true electrographic seizures is a significant challenge for electroencephalographers.
• Technological advancements continually introduce new artifact sources mimicking ictal activity.

Purpose of the Study:

• To provide practical guidelines for identifying physiologic and nonphysiologic artifacts in EEG.
• To elucidate common pitfalls in artifact interpretation.
• To highlight the impact of artifact-induced misdiagnosis on epilepsy management.

Main Methods:

• Review of EEG characteristics, including polarity and physiologic electrical fields.
• Comparison of cerebral activity with waveforms generated by extracerebral sources (eyes, heart, muscles).
• Analysis of common artifactual patterns that mimic electrographic seizures.

Main Results:

• Understanding the distinct electrical field characteristics of the brain versus extracerebral sources is key to artifact recognition.
• Specific guidelines are presented to aid electroencephalographers in distinguishing true ictal activity from artifact.
• Common interpretation pitfalls and their consequences are detailed.

Conclusions:

• Accurate identification of EEG artifacts is crucial for correct epilepsy diagnosis.
• Misinterpretation of artifacts can lead to significant diagnostic and therapeutic errors.
• This review aims to improve the accuracy of EEG interpretation in clinical practice.