Under-sampling in epilepsy: Limitations of conventional EEG

Maxime O Baud; Kaspar Schindler; Vikram R Rao

doi:10.1016/j.cnp.2020.12.002

Under-sampling in epilepsy: Limitations of conventional EEG

Clin Neurophysiol Pract. 2020 Dec 30:6:41-49. doi: 10.1016/j.cnp.2020.12.002. eCollection 2021.

Authors

Maxime O Baud^{1

2}, Kaspar Schindler¹, Vikram R Rao³

Affiliations

¹ Sleep Wake Epilepsy Center, NeuroTec and Center for Experimental Neurology, Department of Neurology, Inselspital Bern, University Hospital, University of Bern, Switzerland.
² Wyss Center for Bio- and Neuro-engineering, Geneva, Switzerland.
³ Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, United States.

Abstract

The cyclical structure of epilepsy was recently (re)-discovered through years-long intracranial electroencephalography (EEG) obtained with implanted devices. In this review, we discuss how new revelations from chronic EEG relate to the practice and interpretation of conventional EEG. We argue for an electrographic definition of seizures and highlight the caveats of counting epileptiform discharges in EEG recordings of short duration. Limitations of conventional EEG have practical implications with regard to titrating anti-seizure medications and allowing patients to drive, and we propose that chronic monitoring of brain activity could greatly improve epilepsy care. An impending paradigm shift in epilepsy will involve using next-generation devices for chronic EEG to leverage known biomarkers of disease state.

Keywords: Chronic EEG; Chronobiology; Circadian; Interictal epileptiform activity; Multidien.

Publication types

Review