Long-Term Measurement of Impedance in Chronically Implanted Depth and Subdural Electrodes During Responsive Neurostimulation in Humans
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- 作者：Karl A. Sillay ; Paul Rutecki ; Kathy Cicora ; Greg Worrell ; Joseph Drazkowski ; Jerry J. Shih ; Ashwini D. Sharan ; Martha J. Morrell ; Justin Williams ; Brett Wingeier
- 关键词：Epilepsy ; Responsive neurostimulation ; Impedance ; Current-controlled stimulation ; Electrode&ndash ; tissue interface
- 刊名：Brain Stimulation
- 出版年：2013
- 出版时间：September, 2013
- 年：2013
- 卷：6
- 期：5
- 页码：718-726
- 全文大小：959 K
文摘
Long-term stability of the electrode-tissue interface may be required to maintain optimal neural recording with subdural and deep brain implants and to permit appropriate delivery of neuromodulation therapy. Although short-term changes in impedance at the electrode-tissue interface are known to occur, long-term changes in impedance have not previously been examined in detail in humans. To provide further information about short- and long-term impedance changes in chronically implanted electrodes, a dataset from 191 persons with medically intractable epilepsy participating in a trial of an investigational responsive neurostimulation device (the RNS? System, NeuroPace, Inc.) was reviewed. Monopolar impedance measurements were available for 391 depth and subdural leads containing a total of 1564 electrodes; measurements were available for median 802 days post-implant (range 28-1634). Although there were statistically significant short-term impedance changes, long-term impedance was stable after one year. Impedances for depth electrodes transiently increased during the third week after lead implantation and impedances for subdural electrodes increased over 12 weeks post-implant, then were stable over the subsequent long-term follow-up. Both depth and subdural electrode impedances demonstrated long-term stability, suggesting that the quality of long-term electrographic recordings (the data used to control responsive brain stimulation) can be maintained over time.