Long-term Electrode Impedance Performance in Ambulatory Video-EEG: A Retrospective Comparison of Two Adhesives

To compare collodion and a water-soluble adhesive for maintaining electrode impedance during prolonged ambulatory video-EEG.

We retrospectively analyzed sequential ambulatory video-EEG studies performed from September 2022 to May 2024 across 22 Australian clinics. The primary outcome was the proportion of analyzed electrodes with impedance <10 kOhm over study days 0 to 6. Adjusted longitudinal associations were assessed using generalized estimating equations.

Among 4,844 patients, 4,602 received water-soluble adhesive and 242 received collodion. Mean proportions of electrodes with impedance <10 kOhm were closely comparable on study days 0 to 2, with progressive separation thereafter, reaching 75.4% with water-soluble adhesive and 45.2% with collodion by day 6. Day-specific adjusted comparisons were significant on days 1 and 3 to 6 after multiple comparison correction. In adjusted analyses of 16,737 patient-days, impedance performance declined with study day, but this decline was less steep with water-soluble adhesive, as reflected by a significant day-by-adhesive interaction. The adhesive main effect was not significant, indicating that the principal difference emerged over time rather than at baseline.

Water-soluble adhesive was associated with greater longitudinal electrode impedance stability than collodion during prolonged ambulatory video-EEG. Adhesive choice may influence technical performance during prolonged ambulatory video-EEG and may help preserve channel-level impedance targets during week-long recordings.