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Review
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Chronically Implanted Intracranial Electrodes: Tissue Reaction and Electrical Changes

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Review

Chronically Implanted Intracranial Electrodes: Tissue Reaction and Electrical Changes

Andrew Campbell et al. Micromachines (Basel).

Abstract

The brain-electrode interface is arguably one of the most important areas of study in neuroscience today. A stronger foundation in this topic will allow us to probe the architecture of the brain in unprecedented functional detail and augment our ability to intervene in disease states. Over many years, significant progress has been made in this field, but some obstacles have remained elusive-notably preventing glial encapsulation and electrode degradation. In this review, we discuss the tissue response to electrode implantation on acute and chronic timescales, the electrical changes that occur in electrode systems over time, and strategies that are being investigated in order to minimize the tissue response to implantation and maximize functional electrode longevity. We also highlight the current and future clinical applications and relevance of electrode technology.

Keywords: electrode degradation; foreign body reaction; glial encapsulation; intracranial electrodes.

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Computed tomography (CT) reconstruction images of patients after implantation of (A) sEEG electrodes and (B) RNS system.
Figure 2
Figure 2
Types of brain interfacing electrodes and their locations in reference to the brain. Reproduced with permission from Creative Commons open access policy from [2].
Figure 3
Figure 3
Illustration of the glial encapsulation response (A) prior to implantation, (B) 12 h post-implantation, (C) 1 week post-implantation, (D) 4 weeks post-implantation, and (E) 12 weeks post-implantation. Panels (F), (G), and (H) represent cross sectional views of (C), (D), and (E), respectively.
Figure 4
Figure 4
Two models of electrode degradation. (A) Pristine electrode with intact metal and insulation, (B) electrode with corroded metal and no insulation delamination, and (C) electrode with corroded metal and noticeable insulation delamination. (D) Pristine electrode with intact metal and insulation, (E) electrode with corroded metal and no insulation crack, and (F) electrode with corroded metal and noticeable insulation crack. Inset on the left, middle and right images shows a closer view of the gold layer around the tungsten. Illustration and caption reproduced with permission from Creative Commons open access policy from [58].

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References

    1. Adewole D.O., Serruya M.D., Harris J.P., Burrell J.C., Petrov D., Chen H.I., Wolf J.A., Cullen D.K. The Evolution of Neuroprosthetic Interfaces. Crit. Rev. Biomed. Eng. 2016;44:123–152. doi: 10.1615/CritRevBiomedEng.2016017198. - DOI - PMC - PubMed
    1. Szostak K.M., Grand L., Constandinou T.G. Neural Interfaces for Intracortical Recording: Requirements, Fabrication Methods, and Characteristics. Front. Neurosci. 2017;11:665. doi: 10.3389/fnins.2017.00665. - DOI - PMC - PubMed
    1. Polikov V.S., Tresco P.A., Reichert W.M. Response of brain tissue to chronically implanted neural electrodes. J. Neurosci. Methods. 2005;148:1–18. doi: 10.1016/j.jneumeth.2005.08.015. - DOI - PubMed
    1. Kozai T.D.Y., Jaquins-Gerstl A.S., Vazquez A.L., Michael A.C., Cui X.T. Brain Tissue Responses to Neural Implants Impact Signal Sensitivity and Intervention Strategies. ACS Chem. Neurosci. 2015;6:48–67. doi: 10.1021/cn500256e. - DOI - PMC - PubMed
    1. Winslow B.D., Tresco P.A. Quantitative analysis of the tissue response to chronically implanted microwire electrodes in rat cortex. Biomaterials. 2010;31:1558–1567. doi: 10.1016/j.biomaterials.2009.11.049. - DOI - PubMed
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