Normative brain mapping using scalp EEG and potential clinical application

Abstract

A normative electrographic activity map could be a powerful resource to understand normal brain function and identify abnormal activity. Here, we present a normative brain map using scalp EEG in terms of relative band power. In this exploratory study we investigate its temporal stability, its similarity to other imaging modalities, and explore a potential clinical application. We constructed scalp EEG normative maps of brain dynamics from 17 healthy controls using source-localised resting-state scalp recordings. We then correlated these maps with those acquired from MEG and intracranial EEG to investigate their similarity. Lastly, we use the normative maps to lateralise abnormal regions in epilepsy. Spatial patterns of band powers were broadly consistent with previous literature and stable across recordings. Scalp EEG normative maps were most similar to other modalities in the alpha band, and relatively similar across most bands. Towards a clinical application in epilepsy, we found abnormal temporal regions ipsilateral to the epileptogenic hemisphere. Scalp EEG relative band power normative maps are spatially stable across time, in keeping with MEG and intracranial EEG results. Normative mapping is feasible and may be potentially clinically useful in epilepsy. Future studies with larger sample sizes and high-density EEG are now required for validation.

Canine Electroencephalography Electrode Positioning Using a Neuronavigation System

“…Additionally, the 10-10 system, with more than 70 electrode positions and the ability to display up to 256 channels, is used in clinical EEG [ 5 ]. Besides diagnosing epilepsy in people, scalp electrodes can be used for brain mapping, which can identify and differentiate normal brain function and abnormal activity [ 6 ]. Scalp or invasive cortical surface electrode EEGs are also used to aid in identifying the area of the cortex from which clinical seizures are generated, i.e., the epileptogenic zone, the area of cortex which generates epileptic seizures ( Table 1 ) [ 7 ].…”