Imaging of focal seizures with Electrical Impedance Tomography and depth electrodes in real time

Witkowska-Wrobel, A; Aristovich, K; Crawford, A; Perkins, JD; Holder, D

Abstract

A B S T R A C T Intracranial EEG is the current gold standard technique for localizing seizures for surgery, but it can be insen-sitive to tangential dipole or distant sources. Electrical Impedance Tomography (EIT) offers a novel method to improve coverage and seizure onset localization. The feasibility of EIT has been previously assessed in a com-puter simulation, which revealed an improved accuracy of seizure detection with EIT compared to intracranial EEG. In this study, slow impedance changes, evoked by cell swelling occurring over seconds, were reconstructed in real time by frequency division multiplexing EIT using depth and subdural electrodes in a swine model of epilepsy. EIT allowed to generate repetitive images of ictal events at similar time course to fMRI but without its significant limitations. EIT was recorded with a system consisting of 32 parallel current sources and 64 voltage recorders. Seizures triggered with intracranial injection of benzylpenicillin (BPN) in five pigs caused a repetitive peak impedance increase of 3.4 +/- 1.5 mV and 9.5 +/- 3% (N = 205 seizures); the impedance signal change was seen already after a single, first seizure. EIT enabled reconstruction of the seizure onset 9 +/- 1.5 mm from the BPN cannula and 7.5 +/- 1.1 mm from the closest SEEG contact ( p < 0.05, n = 37 focal seizures in three pigs) and it could address problems with sampling error in intracranial EEG. The amplitude of the impedance change correlated with the spread of the seizure on the SEEG ( p

Citation

Witkowska-Wrobel, A., Aristovich, K., Crawford, A., Perkins, J., & Holder, D. (2021). Imaging of focal seizures with Electrical Impedance Tomography and depth electrodes in real time. NeuroImage, 234, https://doi.org/10.1016/j.neuroimage.2021.117972

• Journal Article Type: Article
• Acceptance Date: Mar 12, 2021
• Publication Date: 2021
• Deposit Date: Dec 2, 2021
• Publicly Available Date: Dec 2, 2021
• Journal: NeuroImage
• Print ISSN: 1053-8119
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 234
• DOI: https://doi.org/10.1016/j.neuroimage.2021.117972
• Keywords: EIT; Epilepsy; Seizure model; Seizure imaging; Intracranial electrodes; EXPERIMENTAL CORTICAL SEIZURES; EPILEPSY SURGERY; INTRACRANIAL EEG; BRAIN; MODEL; RECURRENCE; EIT
• Public URL: https://rvc-repository.worktribe.com/output/1552995