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Subdural porous and notched mini-grid electrodes for wireless intracranial electroencephalographic recordings

Muhammad Tariqus Salam, Sebastien Gelinas, Sebastien Desgent, Sandra Duss, Felix Bernier Turmel, Lionel Carmant, Mohamad Sawan and Dang Khoa Nguyen

Article (2014)

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Terms of Use: Creative Commons Attribution.
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Cite this document: Salam, M. T., Gelinas, S., Desgent, S., Duss, S., Bernier Turmel, F., Carmant, L., ... Nguyen, D. K. (2014). Subdural porous and notched mini-grid electrodes for wireless intracranial electroencephalographic recordings. Journal of Multidisciplinary Healthcare, 7, p. 573-586. doi:10.2147/jmdh.s64269
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BACKGROUND: Intracranial electroencephalography (EEG) studies are widely used in the presurgical evaluation of drug-refractory patients with partial epilepsy. Because chronic implantation of intracranial electrodes carries a risk of infection, hemorrhage, and edema, it is best to limit the number of electrodes used without compromising the ability to localize the epileptogenic zone (EZ). There is always a risk that an intracranial study may fail to identify the EZ because of suboptimal coverage. We present a new subdural electrode design that will allow better sampling of suspected areas of epileptogenicity with lower risk to patients. METHOD: Impedance of the proposed electrodes was characterized in vitro using electrochemical impedance spectroscopy. The appearance of the novel electrodes on magnetic resonance imaging (MRI) was tested by placing the electrodes into a gel solution (0.9% NaCl with 14 g gelatin). In vivo neural recordings were performed in male Sprague Dawley rats. Performance comparisons were made using microelectrode recordings from rat cortex and subdural/depth recordings from epileptic patients. Histological examinations of rat brain after 3-week icEEG intracerebral electroencephalography (icEEG) recordings were performed. RESULTS: The in vitro results showed minimum impedances for optimum choice of pure gold materials for electrode contacts and wire. Different attributes of the new electrodes were identified on MRI. The results of in vivo recordings demonstrated signal stability, 50% noise reduction, and up to 6 dB signal-to-noise ratio (SNR) improvement as compared to commercial electrodes. The wireless icEEG recording system demonstrated on average a 2% normalized root-mean-square (RMS) deviation. Following the long-term icEEG recording, brain histological results showed no abnormal tissue reaction in the underlying cortex. CONCLUSION: The proposed subdural electrode system features attributes that could potentially translate into better icEEG recordings and allow sampling of large of areas of epileptogenicity at lower risk to patients. Further validation for use in humans is required.

Uncontrolled Keywords

electrodes; epilepsy; monitoring; seizure; surgery

Open Access document in PolyPublie
Subjects: 2500 Génie électrique et électronique > 2500 Génie électrique et électronique
9000 Sciences de la santé > 9000 Sciences de la santé
Department: Département de génie électrique
Research Center: Autre
Funders: CRSNG / NSERC - Discovery Grant, Canada Research Chair in Smart Medical Devices, Microsystems Strategic Alliance of Quebec (ReSMIQ), Savoy Foundation, Epilepsy Canada, CHU Sainte-Justine Foundation, Foundation of Stars
Date Deposited: 04 Feb 2019 10:34
Last Modified: 05 Feb 2019 01:20
PolyPublie URL: https://publications.polymtl.ca/3631/
Document issued by the official publisher
Journal Title: Journal of Multidisciplinary Healthcare (vol. 7)
Publisher: Dove Press Ltd
Official URL: https://doi.org/10.2147/jmdh.s64269


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