Sponge EEG is equivalent regarding signal quality, but faster than routine EEG

Objective

Emergency diagnostics, such as acquisition of an electroencephalogram (EEG), are of great diagnostic importance, but there is often a lack of experienced personnel. Wet active electrode sponge-based electroencephalogram (sp-EEG) systems can be applied rapidly and by inexperienced personnel. This makes them an attractive alternative to routine EEG (r-EEG) systems in these settings. Here, we examined the feasibility and signal quality of sp-EEG compared to r-EEG.

Methods

In this case-control, single-blind, non-randomized study, EEG recordings using a sp- and a r-EEG system were performed in 18 individuals with a variety of epileptiform discharges and 11 healthy control subjects. The time was stopped until all electrodes in both systems displayed adequate skin-electrode impedances. The resulting 58 EEGs were visually inspected by 7 experienced, blinded neurologists. Raters were asked to score physiological and pathological graphoelements, and to distinguish between the different systems by visual inspection of the EEGs.

Results

Time to signal acquisition for sp-EEG was significantly faster (4.8 min (SD 2.01) vs. r-EEG 13.3 min (SD 2.72), p < 0.001). All physiological and pathological graphoelements of all 58 EEGs could be identified. Raters were unable to distinguish between sp-EEG or r-EEG based on visual inspection of the EEGs alone.

Conclusions

Sp-EEG represents a feasible alternative to r-EEG in emergency diagnostics or resource-limited settings.

Significance

Given shortage of trained personnel or resources, the easy implementation and comparable quality of a novel sp-EEG system may increase general availability of EEG and thus improve patient care.