Subdural electrode implantation and recording in MRI-negative epilepsy surgery

Abstract OBJECTIVE Detailed investigations of cortical physiology require the ability to record brain electrical activity at a submillimeter scale. Standard intracranial electrodes result in significant averaging of potentials generated by large numbers of neurons. In contrast, microelectrode arrays allow for recording of local field potentials and single-unit activity. We describe our initial surgical experience with the NeuroPort microelectrode array (Cyberkinetics Neurotechnology Systems, Inc., Salt Lake City, UT) in a series of patients undergoing subdural electrode implantation for epilepsy monitoring. METHODS Seven patients were implanted with and underwent semichronic recording from the NeuroPort array during standard subdural electrode monitoring for epilepsy. The electrode was placed according to company specifications in putative noneloquent epileptogenic cortex. After the monitoring period, microelectrode arrays were removed during explantation of subdural electrodes and resection of epileptogenic tissue. RESULTS Successful implantation of the microelectrode array was achieved in all patients, with minor operative difficulties. Robust and durable local field potentials and single-unit recordings were obtained from all implanted individuals. Implantation times ranged from 3 to 28 days; histological analysis of implanted tissue demonstrated no significant tissue injury or inflammatory response. There were no neurological complications or infections associated with electrode implantation or prolonged monitoring. Two patients developed postresection issues with wound healing at the site of scalp egress, with 1 requiring operative wound revision. CONCLUSION Our experience demonstrates that semichronic microelectroencephalographic recording can be safely and effectively achieved using the NeuroPort microarray. Although significant tissue injury, infection, or cerebrospinal fluid leak was not encountered, the large profile of the connection pedestal resulted in suboptimal wound closure and healing in several patients. We predict that this problem will be easily addressed in second-generation devices.

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1 Subdural and Stereotactic Depth Electrode Implantation in the Evaluation of Ablative Epilepsy Surgery Candidates

Functional Neurosurgery ◽

10.1055/b-0034-89940 ◽

2009 ◽

Keyword(s):

Epilepsy Surgery ◽

Electrode Implantation ◽

Depth Electrode

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Robotic Navigated Laser Craniotomy for Depth Electrode Implantation in Epilepsy Surgery: A Cadaver Lab Study

Journal of Neurological Surgery Part A Central European Neurosurgery ◽

10.1055/s-0040-1720998 ◽

2020 ◽

Author(s):

Karl Roessler ◽

Fabian Winter ◽

Tobias Wilken ◽

Ekaterina Pataraia ◽

Magdalena Mueller-Gerbl ◽

...

Keyword(s):

Laser Beam ◽

Epilepsy Surgery ◽

Entry Point ◽

Occipital Bone ◽

Electrode Placement ◽

Target Point ◽

Twist Drill ◽

Electrode Implantation ◽

Depth Electrodes ◽

Depth Electrode

Abstract Objective Depth electrode implantation for invasive monitoring in epilepsy surgery has become a standard procedure. We describe a new frameless stereotactic intervention using robot-guided laser beam for making precise bone channels for depth electrode placement. Methods A laboratory investigation on a head cadaver specimen was performed using a CT scan planning of depth electrodes in various positions. Precise bone channels were made by a navigated robot-driven laser beam (erbium:yttrium aluminum garnet [Er:YAG], 2.94-μm wavelength,) instead of twist drill holes. Entry point and target point precision was calculated using postimplantation CT scans and comparison to the preoperative trajectory plan. Results Frontal, parietal, and occipital bone channels for bolt implantation were made. The occipital bone channel had an angulation of more than 60 degrees to the surface. Bolts and depth electrodes were implanted solely guided by the trajectory given by the precise bone channels. The mean depth electrode length was 45.5 mm. Entry point deviation was 0.73 mm (±0.66 mm SD) and target point deviation was 2.0 mm (±0.64 mm SD). Bone channel laser time was ∼30 seconds per channel. Altogether, the implantation time was ∼10 to 15 minutes per electrode. Conclusion Navigated robot-assisted laser for making precise bone channels for depth electrode implantation in epilepsy surgery is a promising new, exact and straightforward implantation technique and may have many advantages over twist drill hole implantation.

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Intraoperative computed tomography for intracranial electrode implantation surgery in medically refractory epilepsy

Journal of Neurosurgery ◽

10.3171/2014.9.jns13919 ◽

2015 ◽

Vol 122 (3) ◽

pp. 526-531 ◽

Cited By ~ 16

Author(s):

Darrin J. Lee ◽

Marike Zwienenberg-Lee ◽

Masud Seyal ◽

Kiarash Shahlaie

Keyword(s):

Wound Closure ◽

Refractory Epilepsy ◽

Ct Scans ◽

Surgical Team ◽

Electrode Implantation ◽

Mri Studies ◽

Subdural Electrode ◽

Intracranial Electrode ◽

Epilepsy Monitoring ◽

Medically Refractory Epilepsy

OBJECT Accurate placement of intracranial depth and subdural electrodes is important in evaluating patients with medically refractory epilepsy for possible resection. Confirming electrode locations on postoperative CT scans does not allow for immediate replacement of malpositioned electrodes, and thus revision surgery is required in select cases. Intraoperative CT (iCT) using the Medtronic O-arm device has been performed to detect electrode locations in deep brain stimulation surgery, but its application in epilepsy surgery has not been explored. In the present study, the authors describe their institutional experience in using the O-arm to facilitate accurate placement of intracranial electrodes for epilepsy monitoring. METHODS In this retrospective study, the authors evaluated consecutive patients who had undergone subdural and/or depth electrode implantation for epilepsy monitoring between November 2010 and September 2012. The O-arm device is used to obtain iCT images, which are then merged with the preoperative planning MRI studies and reviewed by the surgical team to confirm final positioning. Minor modifications in patient positioning and operative field preparation are necessary to safely incorporate the O-arm device into routine intracranial electrode implantation surgery. The device does not obstruct surgeon access for bur hole or craniotomy surgery. Depth and subdural electrode locations are easily identified on iCT, which merge with MRI studies without difficulty, allowing the epilepsy surgical team to intraoperatively confirm lead locations. RESULTS Depth and subdural electrodes were implanted in 10 consecutive patients by using routine surgical techniques together with preoperative stereotactic planning and intraoperative neuronavigation. No wound infections or other surgical complications occurred. In one patient, the hippocampal depth electrode was believed to be in a suboptimal position and was repositioned before final wound closure. Additionally, 4 strip electrodes were replaced due to suboptimal positioning. Postoperative CT scans did not differ from iCT studies in the first 3 patients in the series and thus were not obtained in the final 7 patients. Overall, operative time was extended by approximately 10–15 minutes for O-arm positioning, less than 1 minute for image acquisition, and approximately 10 minutes for image transfer, fusion, and intraoperative analysis (total time 21–26 minutes). CONCLUSIONS The O-arm device can be easily incorporated into routine intracranial electrode implantation surgery in standard-sized operating rooms. The technique provides accurate 3D visualization of depth and subdural electrode contacts, and the intraoperative images can be easily merged with preoperative MRI studies to confirm lead positions before final wound closure. Intraoperative CT obviates the need for routine postoperative CT and has the potential to improve the accuracy of intracranial electroencephalography recordings and may reduce the necessity for revision surgery.

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Minimal Tissue Reaction after Chronic Subdural Electrode Implantation for Fully Implantable Brain–Machine Interfaces

Sensors ◽

10.3390/s21010178 ◽

2020 ◽

Vol 21 (1) ◽

pp. 178

Author(s):

Tianfang Yan ◽

Seiji Kameda ◽

Katsuyoshi Suzuki ◽

Taro Kaiju ◽

Masato Inoue ◽

...

Keyword(s):

Tissue Reaction ◽

Tissue Response ◽

Brain Machine Interfaces ◽

Electrode Implantation ◽

Subdural Electrodes ◽

Tissue Proliferation ◽

Significant Difference ◽

Subdural Electrode ◽

Cell Densities

There is a growing interest in the use of electrocorticographic (ECoG) signals in brain–machine interfaces (BMIs). However, there is still a lack of studies involving the long-term evaluation of the tissue response related to electrode implantation. Here, we investigated biocompatibility, including chronic tissue response to subdural electrodes and a fully implantable wireless BMI device. We implanted a half-sized fully implantable device with subdural electrodes in six beagles for 6 months. Histological analysis of the surrounding tissues, including the dural membrane and cortices, was performed to evaluate the effects of chronic implantation. Our results showed no adverse events, including infectious signs, throughout the 6-month implantation period. Thick connective tissue proliferation was found in the surrounding tissues in the epidural space and subcutaneous space. Quantitative measures of subdural reactive tissues showed minimal encapsulation between the electrodes and the underlying cortex. Immunohistochemical evaluation showed no significant difference in the cell densities of neurons, astrocytes, and microglia between the implanted sites and contralateral sites. In conclusion, we established a beagle model to evaluate cortical implantable devices. We confirmed that a fully implantable wireless device and subdural electrodes could be stably maintained with sufficient biocompatibility in vivo.

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Subdural Electrodes for Seizure Focus Localization

Neurosurgery ◽

10.1227/00006123-198607000-00011 ◽

1986 ◽

Vol 19 (1) ◽

pp. 73-81 ◽

Cited By ~ 56

Author(s):

Thomas J. Rosenbaum ◽

Kenneth D. Laxer ◽

Michael Vessely ◽

W. Brewster Smith

Keyword(s):

Electrode Placement ◽

Surgical Decision ◽

Electrode Implantation ◽

Seizure Focus ◽

Seizure Disorders ◽

Depth Electrodes ◽

Subdural Electrode ◽

Focus Localization ◽

Significant Addition ◽

Made In

Abstract Fifty patients with medically refractory partial seizure disorders have undergone subdural electrode placement for seizure focus localization. Standard scalp telemetry recordings of ictal events had failed to demonstrate accurately the site of seizure onset, and these patients were considered candidates for telemetry with intracerebral depth electrodes. Excellent recordings of interictal and ictal events were obtained, and localization of the epileptogenic focus was derived from recordings made during spontaneously occurring seizures. Electrocorticograms were monitored for up to 21 days. The recordings enabled a surgical decision to be made in 43 of 50 cases (86%). Thirty patients have subsequently undergone cortical excision of their foci with good results. Subdural electrode recordings are a significant addition to the armamentarium of the neurosurgeon attempting to localize surgical seizure foci, offering a low morbidity procedure as an alternative to depth electrode implantation.

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