Histological Alterations Induced by Electrode Implantation and Electrical Stimulation in the Human Brain: A Review

Kuyck, Kris van; Welkenhuysen, Marleen; Arckens, Lutgarde; Sciot, Raf; Nuttin, Bart

doi:10.1111/j.1525-1403.2007.00114.x

Cited by 38 publications

(27 citation statements)

References 59 publications

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“…Subsequently, the role of glia as a cellular target of DBS treatment 118–120 has emerged among several candidate mechanisms. Gliosis is commonly observed in post-mortem brain tissue from DBS patients 121,122 and can be more pronounced when surrounding active devices 123 (Fig. 1).…”

Section: Glial-activation Challenges and Design Considerationsmentioning

confidence: 99%

Glial responses to implanted electrodes in the brain

et al. 2017

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The use of implants that can electrically stimulate or record electrophysiological or neurochemical activity in nervous tissue is rapidly expanding. Despite remarkable results in clinical studies and increasing market approvals, the mechanisms underlying the therapeutic effects of neuroprosthetic and neuromodulation devices, as well as their side effects and reasons for their failure, remain poorly understood. A major assumption has been that the signal-generating neurons are the only important target cells of neural-interface technologies. However, recent evidence indicates that the supporting glial cells remodel the structure and function of neuronal networks and are an effector of stimulation-based therapy. Here, we reframe the traditional view of glia as a passive barrier, and discuss their role as an active determinant of the outcomes of device implantation. We also discuss the implications that this has on the development of bioelectronic medical devices.

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Section: Glial-activation Challenges and Design Considerationsmentioning

confidence: 99%

Glial responses to implanted electrodes in the brain

et al. 2017

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“…These interactions have been studied extensively in electrodes implanted into animals and humans 7,9,10,18 and involve an acute inflammatory response followed by chronic fibrosis that significantly diminishes by 6–8 weeks 10,33–35 . Notably, many of these past studies analyzed the impact of intracortical electrodes, which penetrate the cortical surface and have an increased burden on the brain.…”

Section: Discussionmentioning

confidence: 99%

Intracranial EEG fluctuates over months after implanting electrodes in human brain

et al. 2017

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Objective Implanting subdural and penetrating electrodes in the brain cause acute trauma and inflammation that affect intracranial electroencephalographic (iEEG) recordings. This behavior and its potential impact on clinical decision-making and algorithms for implanted devices have not been assessed in detail. In this study we aim to characterize the temporal and spatial variability in continuous, prolonged human iEEG recordings. Approach Intracranial electroencephalography from 15 patients with drug-refractory epilepsy, each implanted with 16 subdural electrodes and continuously monitored for an average of 18 months, was included in this study. Time and spectral domain features were computed each day for each channel for the duration of each patient’s recording. Metrics to capture post-implantation feature changes and inflexion points were computed on group and individual levels. A linear mixed model was used to characterize transient group-level changes in feature values post-implantation and independent linear models were used to describe individual variability. Main Results A significant decline in features important to seizure detection and prediction algorithms (mean line length, energy, and half-wave), as well as mean power in the Berger and high gamma bands, was observed in many patients over 100 days following implantation. In addition, spatial variability across electrodes declines post-implantation following a similar timeframe. All selected features decreased by 14–50% in the initial 75 days of recording on the group level, and at least one feature demonstrated this pattern in 13 of the 15 patients. Our findings demonstrate that iEEG signal features demonstrate increased variability following implantation, most notably in the weeks immediately post-implant. Significance These findings suggest that conclusions drawn from iEEG, both clinically and for research, should account for signal variability and that properly assessing the iEEG in patients, depending upon the application, may require extended monitoring.

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“…In both cases, electrical fields can affect spiking activity of cortical neurons without intracortical tissue reaction, a typical problem of electrodes placed in the brain parenchyma (Polikov et al, 2005; van Kuyck et al, 2007). Importantly, nearly all effects of TMS on brain activity can be reproduced by applying electric fields via percutaneous or subcutaneous electrodes on the scalp.…”

Section: Discussionmentioning

confidence: 99%

Transcranial Electric Stimulation Entrains Cortical Neuronal Populations in Rats

Ozen¹,

Sirota²,

Belluscio³

et al. 2010

J. Neurosci.

370

352

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Low intensity electric fields have been suggested to affect the ongoing neuronal activity in vitro and in human studies. However, the physiological mechanism of how weak electrical fields affect and interact with intact brain activity is not well understood. We performed in vivo extracellular and intracellular recordings from the neocortex and hippocampus of anesthetized rats and extracellular recordings in behaving rats. Electric fields were generated by sinusoid patterns at slow frequency (0.8, 1.25 or 1.7 Hz) via electrodes placed on the surface of the skull or the dura. Transcranial electric stimulation (TES) reliably entrained neurons in widespread cortical areas, including the hippocampus. The percentage of TES phase-locked neurons increased with stimulus intensity and depended on the behavioral state of the animal. TES-induced voltage gradient, as low as 1 mV/mm at the recording sites, was sufficient to phase-bias neuronal spiking. Intracellular recordings showed that both spiking and subthreshold activity were under the combined influence of TES forced fields and network activity. We suggest that TES in chronic preparations may be used for experimental and therapeutic control of brain activity.

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Histological Alterations Induced by Electrode Implantation and Electrical Stimulation in the Human Brain: A Review

Cited by 38 publications

References 59 publications

Glial responses to implanted electrodes in the brain

Glial responses to implanted electrodes in the brain

Intracranial EEG fluctuates over months after implanting electrodes in human brain

Transcranial Electric Stimulation Entrains Cortical Neuronal Populations in Rats

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