Neurostimulation EEG artifacts: VNS, RNS, and DBS

Accurately recognizing artifacts on electroencephalogram (EEG) is necessary to prevent EEG misinterpretation and epilepsy misdiagnosis. EEG artifacts generated by neurostimulation devices ([Figures 1] and [2]) can be identified based on their unique spatial and frequency properties[1].

Figure 1 Vagus nerve stimulation (VNS) EEG artifact. Scalp EEG: sensitivity 7 μV/mm, LF 1 Hz, HF 70 Hz, notch on; invasive EEG: sensitivity 100 μV, LF 0.53 Hz, HF 600 Hz, notch off. Scalp EEG (top), extended longitudinal bipolar montage (with additional frontotemporal electrodes) showing a burst of low-voltage sharply contoured artifact mostly at the EKG channel but also at the across FT9-FT10 and A1-A2 bipolar channels. Invasive EEG (bottom), bipolar montage showing a burst of low-voltage 20 Hz sharply contoured artifact at the EKG channel. The artifacts’ 20 Hz frequency corresponded to the stimulating frequency in both cases.

Figure 2 Responsive neurostimulation (RNS) and deep brain stimulation (DBS) scalp EEG artifacts - extended longitudinal bipolar montages (with additional frontotemporal electrodes). EEG: sensitivity 7 μV/mm, LF 1 Hz, HF 70 Hz, notch on.RNS (top, 15-second; middle, 5-second view): repetitive 200 Hz stimulation artifact (red rectangles) followed by C3-P3 device detection artifact (blue stars). RNS strip electrodes were in the left posterior temporal topography with generator in the left frontal region. DBS (bottom): continuous, diffuse, electrical interference without evolution.

VNS and RNS artifacts display an electrical interference-like “spiky” morphology with a distribution that is incompatible with a cerebral source and frequencies that mirror stimulation settings. DBS artifact features diffuse electrical interference with a relatively monomorphic appearance, and its frequency can vary depending on intermittent versus continuous neurostimulation - indicated for epilepsy and movement disorders, respectively.

Authors’ contribution:

JC, SF, VK, AM: collected, analyzed, and interpreted the data, revised the manuscript; JRG: conceptualized and designed study, collected, analyzed and interpreted the data, revised the manuscript; FAN: conceptualized and designed study, collected, analyzed and interpreted the data, drafted the manuscript.

Statement of ethics:

This study was conducted ethically and in compliance with the guidelines for human studies. Informed consent was not obtained because all patient data in this manuscript was de-identified.

Publication History

Received: 23 August 2020

Accepted: 28 October 2020

Article published online:
01 June 2023

• REFERENCES

• 1 McKay JH, Tatum WO. Artifact mimicking ictal epileptiform activity in EEG. J Clin Neurophysiol. 2019 Jul;36(4):275-88. https://doi.org/10.1097/wnp.20200392202003920597