Influence of Stainless Needle Electrodes and Silver Disk Electrodes over the Interhemispheric Cerebral Coherence Value in Vigil Dogs

Abstract

Electroencephalography (EEG) is an objective diagnostic tool in the evaluation of cerebral functionality, both in human and veterinary medicine. For EEG acquisition, different types of electrodes are used, as long as they have no impact on the recorded background activity. However, to date, the influence of electrode type on quantitative EEG and cerebral coherence has not been investigated. Twenty EEG traces (ten with needle electrodes and ten with disk electrodes) were recorded from ten mesocephalic vigil dogs in a monopolar montage. Values for interhemispheric coherence for each frequency band were compared between stainless needle and silver disk electrodes traces. Our results show that the values of interhemispheric coherence in vigil dogs are depending of the type of electrodes used in EEG recordings. In the frontal (FP) channel, for delta and theta frequency bands, the registered coherence is significantly higher when stainless needle electrodes are used. Our results might have important consequences in the field of canine neurology and applied neuroscience, as the frontal channel analysis is preferred in aging and behavior studies.

Seizure frequency discrepancy between subjective and objective ictal electroencephalography data in dogs

“… 18 Ambulatory EEG was recorded using current standard minimally invasive SC (needle or wire) electrodes. 19 , 20 The duration of AEEG recordings was not standardized for various reasons, including dogs removing electrodes during the recording, sufficient episodes of interest obtained, or time of hospital discharge.…”

“…Wireless AEEG with synchronized video was recorded using a Trackit MK3 AEEG/Polygraphy recorder (Lifelines Neurodiagnostic Systems, Troy, Illinois), with scalp EEG using 13 channels (both hemispheres symmetrically in the frontal [F3, F4, F7, F8], parietal [C3, C4], temporal [T3, T4] and occipital [O1, O2] regions and 3 midline anterior‐posterior locations [Fz, Cz, Pz]) in addition to a reference electrode (between the medial canthi) and a ground electrode (dorsal cervical midline, 2‐5 cm caudal to the nuchal crest) 18 . Ambulatory EEG was recorded using current standard minimally invasive SC (needle or wire) electrodes 19,20 . The duration of AEEG recordings was not standardized for various reasons, including dogs removing electrodes during the recording, sufficient episodes of interest obtained, or time of hospital discharge.…”

Sleep and cognition in aging dogs. A polysomnographic study

“…One of the main reasons could be that in our previous study we used needle electrodes that have a much smaller recording surface than the cup electrodes. In fact, Musteata et al found that values of interhemispheric coherence in dogs are dependent on the type of electrode used (94). A limitation of coherence analyses is that coherence values can be overestimated due to volume conduction in which the conductive properties of the brain, cerebrospinal fluid, skull, and scalp (and the conductive gel used during the recording), cause the neural source information to diffuse before reaching the electrodes (95, 96).…”

A Novel Approach for the Design of Fast-Settling Amplifiers for Biosignal Detection

“…As a consequence, removing the DC component of the input signal is a necessary stage when low-voltage signals are acquired. Especially in the case of neurophysiological monitoring, adhesive or needle electrodes are connected to the subject being monitored [14][15][16]; the half cell potential of the two electrodes between which the measurement is carried out are never exactly the same, causing an inherent differential voltage in the contact circuit. This results in a DC offset in the input signal that has to be removed [17,18].…”