Abstracts

Rationale: Artifact in EEG refers to activity seen on the EEG that is due to extracerebral electrical potentials. Artifact can interfere with interpretation of EEG, and mimic features of electrographic seizures or interictal epileptiform discharges. This carries a risk for “over-calling” non-cerebral activity and overtreatment. With the rise of continuous video EEG monitoring (CV-EEG) in electrical device-laden ICUs, recognition and scrutiny of suspicious patterns that deviate from the expected characteristics of cerebral activity is paramount. In this report, we discuss a unique source of non-physiologic artifact mimicking a rhythmic, evolving discharge that had not previously been encountered in our institution or reported in the literature.

Methods: CV-EEG was performed on a 6 week old boy born at term to evaluate if abnormal movements were seizures. He was transported from the ER to a pediatric unit via rolling pediatric cradle-bed. A suspicious electrographic pattern was observed.

Results: As the rolling started of the cradle-bed, there was buildup of rhythmic, 3-6 Hz sharp waves with alternating polarity seen at Fp1, Cz, and C4. This activity increased in amplitude and frequency as the bed increased in rolling speed. The activity would wax/wane when the cart was slowed and turned as it was navigated through the halls. The changing speed at times mimicked evolution in amplitude and frequency of the pattern, but there was never actual spread. Morphology and spatial orientation of the pattern was not consistent with a cerebral pattern. After the move, there were no similar patterns. There were no seizures, and the EEG was normal for the child's age.

Conclusions: We present a unique rhythmic, evolving pattern on the EEG of an infant being monitored for seizures, not previously reported in the literature. By recognizing features of the pattern that were atypical of cerebral patterns, as well as corroboration with video, it was found that this artifact was due to the rolling wheels of a cradle-bed during transport. It is important for clinicians to recognize the possibility of this variation of artifact in CV-EEG patients as to avoid overinterpretation as an insidious pattern.

Funding: No funding