Electric Fence Artifact on Ambulatory EEG and Review of Common EEG Electrical Artifacts

Ambulatory electroencephalogram (AEEG) can be a cost-effective and valuable alternative to in-patient long-term EEG monitoring. A potential benefit of AEEG is that it allows monitoring in the patient's unique home environment. While this can be more affordable and convenient for the patient, it can also present unique challenges for the reviewer. Unlike long-term monitoring in an epilepsy unit, the AEEG recording occurs in a less controlled environment and most often without immediate EEG technical assistance during the recording. As a result, unique EEG artifacts can occur with AEEG. Their recognition and correct interpretation are crucial for proper EEG analysis. This report presents a case of a patient who underwent a 72-hour AEEG to evaluate symptoms initially concerning for subclinical seizures. During the AEEG recording, the patient had a tactile encounter with an electric fence. This tactile event resulted in a unique, not previously reported, pattern clouding an otherwise normal study. By conducting a brief review of the most common non-physiologic environmental artifacts encountered in modern EEG monitoring, we aim to emphasize the importance of patient education to prevent artifactual pollution. This knowledge can facilitate planning and help avoid environmental influences that may create artifacts when recording in an uncontrolled setting.