Accuracy and Workflow Improvements for Responsive Neurostimulation Hippocampal Depth Electrode Placement Using Robotic Stereotaxy

Background: Robotic stereotaxy is increasingly common in epilepsy surgery for the implantation of stereo-electroencephalography (sEEG) electrodes for intracranial seizure monitoring. The use of robots is also gaining popularity for permanent stereotactic lead implantation applications such as in deep brain stimulation and responsive neurostimulation (RNS) procedures.Objective: We describe the evolution of our robotic stereotactic implantation technique for placement of occipital-approach hippocampal RNS depth leads.Methods: We performed a retrospective review of 10 consecutive patients who underwent robotic RNS hippocampal depth electrode implantation. Accuracy of depth lead implantation was measured by registering intraoperative post-implantation fluoroscopic CT images and post-operative CT scans with the stereotactic plan to measure implantation accuracy. Seizure data were also collected from the RNS devices and analyzed to obtain initial seizure control outcome estimates.Results: Ten patients underwent occipital-approach hippocampal RNS depth electrode placement for medically refractory epilepsy. A total of 18 depth electrodes were included in the analysis. Six patients (10 electrodes) were implanted in the supine position, with mean target radial error of 1.9 ± 0.9 mm (mean ± SD). Four patients (8 electrodes) were implanted in the prone position, with mean radial error of 0.8 ± 0.3 mm. The radial error was significantly smaller when electrodes were implanted in the prone position compared to the supine position (p = 0.002). Early results (median follow-up time 7.4 months) demonstrate mean seizure frequency reduction of 26% (n = 8), with 37.5% achieving ≥50% reduction in seizure frequency as measured by RNS long episode counts.Conclusion: Prone positioning for robotic implantation of occipital-approach hippocampal RNS depth electrodes led to lower radial target error compared to supine positioning. The robotic platform offers a number of workflow advantages over traditional frame-based approaches, including parallel rather than serial operation in a bilateral case, decreased concern regarding human error in setting frame coordinates, and surgeon comfort.

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Medically resistant pediatric insular-opercular/perisylvian epilepsy. Part 1: invasive monitoring using the parasagittal transinsular apex depth electrode

Journal of Neurosurgery Pediatrics ◽

10.3171/2016.4.peds15636 ◽

2016 ◽

Vol 18 (5) ◽

pp. 511-522 ◽

Cited By ~ 13

Author(s):

Alexander G. Weil ◽

Aria Fallah ◽

Evan C. Lewis ◽

Sanjiv Bhatia

Keyword(s):

Epilepsy Surgery ◽

Electrode Placement ◽

Epileptogenic Zone ◽

Drug Resistant ◽

Depth Electrodes ◽

Depth Electrode ◽

Age At Surgery ◽

Feasible Alternative ◽

The Mean ◽

Drug Resistant Epilepsy

OBJECTIVE Insular lobe epilepsy (ILE) is an under-recognized cause of extratemporal epilepsy and explains some epilepsy surgery failures in children with drug-resistant epilepsy. The diagnosis of ILE usually requires invasive investigation with insular sampling; however, the location of the insula below the opercula and the dense middle cerebral artery vasculature renders its sampling challenging. Several techniques have been described, ranging from open direct placement of orthogonal subpial depth and strip electrodes through a craniotomy to frame-based stereotactic placement of orthogonal or oblique electrodes using stereo-electroencephalography principles. The authors describe an alternative method for sampling the insula, which involves placing insular depth electrodes along the long axis of the insula through the insular apex following dissection of the sylvian fissure in conjunction with subdural electrodes over the lateral hemispheric/opercular region. The authors report the feasibility, advantages, disadvantages, and role of this approach in investigating pediatric insular-opercular refractory epilepsy. METHODS The authors performed a retrospective analysis of all children (< 18 years old) who underwent invasive intracranial studies involving the insula between 2002 and 2015. RESULTS Eleven patients were included in the study (5 boys). The mean age at surgery was 7.6 years (range 0.5–16 years). All patients had drug-resistant epilepsy as defined by the International League Against Epilepsy and underwent comprehensive noninvasive epilepsy surgery workup. Intracranial monitoring was performed in all patients using 1 parasagittal insular electrode (1 patient had 2 electrodes) in addition to subdural grids and strips tailored to the suspected epileptogenic zone. In 10 patients, extraoperative monitoring was used; in 1 patient, intraoperative electrocorticography was used alone without extraoperative monitoring. The mean number of insular contacts was 6.8 (range 4–8), and the mean number of fronto-parieto-temporal hemispheric contacts was 61.7 (range 40–92). There were no complications related to placement of these depth electrodes. All 11 patients underwent subsequent resective surgery involving the insula. CONCLUSIONS Parasagittal transinsular apex depth electrode placement is a feasible alternative to orthogonally placed open or oblique-placed stereotactic methodologies. This method is safe and best suited for suspected unilateral cases with a possible extensive insular-opercular epileptogenic zone.

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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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A new instrument for improved accuracy of stereotactic depth electrode placement

Journal of Neurosurgery ◽

10.3171/jns.1996.85.2.0357 ◽

1996 ◽

Vol 85 (2) ◽

pp. 357-358 ◽

Cited By ~ 1

Author(s):

Richard D. Ashpole ◽

Gavin C. A. Fabinyi ◽

Milos Vosmansky

Keyword(s):

Simple Device ◽

Electrode Placement ◽

Content Type ◽

Depth Electrodes ◽

Depth Electrode ◽

New Instrument ◽

Improved Accuracy ◽

Fine Print

✓ A disadvantage of stereotactic placement of flexible depth electrodes is the risk of inaccurate positioning as a result of electrode movement when the introducer is withdrawn. A simple device that virtually eliminates this error is described.

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A novel miniature robotic device for frameless implantation of depth electrodes in refractory epilepsy

Journal of Neurosurgery ◽

10.3171/2016.5.jns16388 ◽

2017 ◽

Vol 126 (5) ◽

pp. 1622-1628 ◽

Cited By ~ 25

Author(s):

Christian Dorfer ◽

Georgi Minchev ◽

Thomas Czech ◽

Harald Stefanits ◽

Martha Feucht ◽

...

Keyword(s):

Surgical Navigation ◽

Phantom Study ◽

Entry Point ◽

Electrode Placement ◽

Robotic Device ◽

Robot Assisted ◽

Skull Model ◽

Depth Electrodes ◽

Depth Electrode ◽

Superficial Wound

OBJECTIVEThe authors' group recently published a novel technique for a navigation-guided frameless stereotactic approach for the placement of depth electrodes in epilepsy patients. To improve the accuracy of the trajectory and enhance the procedural workflow, the authors implemented the iSys1 miniature robotic device in the present study into this routine.METHODSAs a first step, a preclinical phantom study was performed using a human skull model, and the accuracy and timing between 5 electrodes implanted with the manual technique and 5 with the aid of the robot were compared. After this phantom study showed an increased accuracy with robot-assisted electrode placement and confirmed the robot's ability to maintain stability despite the rotational forces and the leverage effect from drilling and screwing, patients were enrolled and analyzed for robot-assisted depth electrode placement at the authors' institution from January 2014 to December 2015. All procedures were performed with the S7 Surgical Navigation System with Synergy Cranial software and the iSys1 miniature robotic device.RESULTSNinety-three electrodes were implanted in 16 patients (median age 33 years, range 3–55 years; 9 females, 7 males). The authors saw a significant increase in accuracy compared with their manual technique, with a median deviation from the planned entry and target points of 1.3 mm (range 0.1–3.4 mm) and 1.5 mm (range 0.3–6.7 mm), respectively. For the last 5 patients (31 electrodes) of this series the authors modified their technique in placing a guide for implantation of depth electrodes (GIDE) on the bone and saw a significant further increase in the accuracy at the entry point to 1.18 ± 0.5 mm (mean ± SD) compared with 1.54 ± 0.8 mm for the first 11 patients (p = 0.021). The median length of the trajectories was 45.4 mm (range 19–102.6 mm). The mean duration of depth electrode placement from the start of trajectory alignment to fixation of the electrode was 15.7 minutes (range 8.5–26.6 minutes), which was significantly faster than with the manual technique. In 12 patients, depth electrode placement was combined with subdural electrode placement. The procedure was well tolerated in all patients. The authors did not encounter any case of hemorrhage or neurological deficit related to the electrode placement. In 1 patient with a psoriasis vulgaris, a superficial wound infection was encountered. Adequate physiological recordings were obtained from all electrodes. No additional electrodes had to be implanted because of misplacement.CONCLUSIONSThe iSys1 robotic device is a versatile and easy to use tool for frameless implantation of depth electrodes for the treatment of epilepsy. It increased the accuracy of the authors' manual technique by 60% at the entry point and over 30% at the target. It further enhanced and expedited the authors' procedural workflow.

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Freehand placement of depth electrodes using electromagnetic frameless stereotactic guidance

Journal of Neurosurgery Pediatrics ◽

10.3171/2011.8.peds11143 ◽

2011 ◽

Vol 8 (5) ◽

pp. 464-467 ◽

Cited By ~ 8

Author(s):

Carter D. Wray ◽

Diana L. Kraemer ◽

Tong Yang ◽

Sandra L. Poliachik ◽

Andrew L. Ko ◽

...

Keyword(s):

Electrode Placement ◽

Frameless Stereotaxy ◽

Seizure Onset ◽

Presurgical Evaluation ◽

Electromagnetic System ◽

Depth Electrodes ◽

Depth Electrode ◽

Stereotactic Frame ◽

Stereotactic Guidance ◽

Patients With Epilepsy

The presurgical evaluation of patients with epilepsy often requires an intracranial study in which both subdural grid electrodes and depth electrodes are needed. Performing a craniotomy for grid placement with a stereotactic frame in place can be problematic, especially in young children, leading some surgeons to consider frameless stereotaxy for such surgery. The authors report on the use of a system that uses electromagnetic impulses to track the tip of the depth electrode. Ten pediatric patients with medically refractory focal lobar epilepsy required placement of both subdural grid and intraparenchymal depth electrodes to map seizure onset. Presurgical frameless stereotaxic targeting was performed using a commercially available electromagnetic image-guided system. Freehand depth electrode placement was then performed with intraoperative guidance using an electromagnetic system that provided imaging of the tip of the electrode, something that has not been possible using visually or sonically based systems. Accuracy of placement of depth electrodes within the deep structures of interest was confirmed postoperatively using CT and CT/MR imaging fusion. Depth electrodes were appropriately placed in all patients. Electromagnetic-tracking–based stereotactic targeting improves the accuracy of freehand placement of depth electrodes in patients with medically refractory epilepsy. The ability to track the electrode tip, rather than the electrode tail, is a major feature that enhances accuracy. Additional advantages of electromagnetic frameless guidance are discussed.

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Novel Use of Stimulating Fence-Post Technique for Functional Mapping of Subcortical White Matter During Tumor Resection: A Technical Case Series

Operative Neurosurgery ◽

10.1093/ons/opaa027 ◽

2020 ◽

Vol 19 (3) ◽

pp. 264-270 ◽

Cited By ~ 1

Author(s):

Seunggu Jude Han ◽

Zoe Teton ◽

Kunal Gupta ◽

Aaron Kawamoto ◽

Ahmed M Raslan

Keyword(s):

White Matter ◽

Tumor Resection ◽

Case Series ◽

Electrode Placement ◽

Language Mapping ◽

Depth Electrodes ◽

Depth Electrode ◽

Fence Post ◽

Motor And Language Mapping ◽

Functional Morbidity

Abstract Background Maximal safe resection remains a key principle in infiltrating glioma management. Stimulation mapping is a key adjunct for minimizing functional morbidity while “fence-post” procedures use catheters or dye to mark the tumor border at the start of the procedure prior to brain shift. Objective To report a novel technique using stereotactically placed electrodes to guide tumor resection near critical descending subcortical fibers. Methods Navigated electrodes were placed prior to tumor resection along the deep margin bordering presumed eloquent tracts. Stimulation was administered through these depth electrodes for subcortical motor and language mapping. Results Twelve patients were included in this preliminary technical report. Seven patients (7/12, 58%) were in asleep cases, while the other 5 cases (5/12, 42%) were performed awake. Mapping of motor fibers was performed in 8 cases, and language mapping was done in 1 case. In 3 cases, both motor and language mapping were performed using the same depth electrode spanning corticospinal tract and the arcuate fasciculus. Conclusion Stereotactic depth electrode placement coupled with stimulation mapping of white matter tracts can be used concomitantly to demarcate the border between deep tumor margins and eloquent brain, thus helping to maximize extent of resection while minimizing functional morbidity.

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Implantation technique, safety and complications of robot-assisted stereoelectroencephalography exploration of the limbic thalamus in human focal epilepsy

10.1101/2020.01.27.922195 ◽

2020 ◽

Author(s):

Ganne Chaitanya ◽

Andrew K. Romeo ◽

Adeel Ilyas ◽

Auriana Irannejad ◽

Emilia Toth ◽

...

Keyword(s):

Focal Epilepsy ◽

Clinical Care ◽

Electrode Placement ◽

Implantation Technique ◽

Precentral Gyrus ◽

Thalamic Nuclei ◽

Robot Assisted ◽

Entry Site ◽

Depth Electrodes ◽

Medial Group

AbstractIntroductionDespite numerous imaging studies highlighting the importance of thalamus in surgical prognosis, human electrophysiological studies involving the limbic thalamic nuclei are limited. The objective of this study was to evaluate the safety and accuracy of robot-assisted stereotactic electrode placement in the limbic thalamic nuclei in patients with suspected temporal lobe epilepsy (TLE).MethodsAfter obtaining informed consent, 24 adults with drug-resistant suspected TLE undergoing Stereo-EEG evaluation were enrolled in this prospective study. The trajectory of one electrode planned for clinical sampling the operculo-insular cortex was modified to extend to the thalamus, thereby preventing the need for additional electrode placement for research. The anterior thalamus (ANT) (N=13) and the medial group of thalamic nuclei (MED) (N=11), including mediodorsal (MD) and centromedian (CeM) were targeted. The post-implantation CT was co-registered to the pre-operative MRI, and Morel’s thalamic atlas was used to confirm the accuracy of implantation.ResultsTen out of 13 (77%) in the ANT group and 10 out of 11 patients (90%) in the medial group had electrodes accurately placed in the thalamic nuclei. None of the patients had a thalamic hemorrhage. However, trace asymptomatic hemorrhages at the cortical level entry site were noted in 20.8% of patients and they did not require additional surgical intervention. SEEG data from all the patients were interpretable and analyzable. The trajectories for the ANT implant differed slightly from the medial group at the entry point i.e., precentral gyrus in the former and postcentral gyrus in the latter.ConclusionsUsing judiciously planned robot-assisted SEEG, we demonstrate the safety of electrophysiological sampling from various thalamic nuclei for research recordings, presenting a technique that avoids implanting additional depth electrodes, or comprising clinical care. With these results, we propose that if patients are fully informed of the risks involved, there are potential benefits of gaining mechanistic insights to seizure genesis, which may help to develop neuromodulation therapies.

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Robotic image-guided depth electrode implantation in the evaluation of medically intractable epilepsy

Neurosurgical FOCUS ◽

10.3171/foc/2008/25/9/e19 ◽

2008 ◽

Vol 25 (3) ◽

pp. E19 ◽

Cited By ~ 19

Author(s):

William J. Spire ◽

Barbara C. Jobst ◽

Vijay M. Thadani ◽

Peter D. Williamson ◽

Terrance M. Darcey ◽

...

Keyword(s):

Intractable Epilepsy ◽

Robotic System ◽

Electrode Placement ◽

Seizure Onset ◽

Electrode Implantation ◽

Grid Electrode ◽

Image Guided ◽

Depth Electrodes ◽

Depth Electrode ◽

Time Period

Object The authors describe their experience with a technique for robotic implantation of depth electrodes in patients concurrently undergoing craniotomy and placement of subdural monitoring electrodes for the evaluation of intractable epilepsy. Methods Patients included in this study underwent evaluation in the Dartmouth Surgical Epilepsy Program and were recommended for invasive seizure monitoring with depth electrodes between 2006 and the present. In all cases an image-guided robotic system was used during craniotomy for concurrent subdural grid electrode placement. A total of 7 electrodes were placed in 4 patients within the time period. Results Three of 4 patients had successful localization of seizure onset, and 2 underwent subsequent resection. Of the patients who underwent resection, 1 is now seizure free, and the second has only auras. There was 1 complication after subpial grid placement but no complications related to the depth electrodes. Conclusions Robotic image-guided placement of depth electrodes with concurrent craniotomy is feasible, and the technique is safe, accurate, and efficient.

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Invasive Insular Sampling in Pediatric Epilepsy: A Single-Institution Experience

Operative Neurosurgery ◽

10.1093/ons/opx253 ◽

2017 ◽

Vol 15 (3) ◽

pp. 310-317 ◽

Cited By ~ 2

Author(s):

Luke D Tomycz ◽

Andrew T Hale ◽

Ali S Haider ◽

Dave F Clarke ◽

Mark R Lee

Keyword(s):

Insular Cortex ◽

Clinical Information ◽

Electrode Placement ◽

Pediatric Epilepsy ◽

Seizure Onset ◽

Single Institution ◽

Invasive Treatment ◽

Depth Electrodes ◽

Depth Electrode ◽

Electrode Insertion

Abstract BACKGROUND It has been increasingly recognized that the insular cortex plays an important role in frontotemporal-parietal epilepsy in children. The insula, however, cannot be properly interrogated with conventional subdural grids, and its anatomy makes it difficult to implicate the insula with semiology or noninvasive modalities. Frame-based, stereotactic placement of insular depth electrodes for direct extraoperative monitoring is a relatively low-risk maneuver that allows for conclusive interrogation of this region, and, in select cases, can easily be replaced with a laser applicator for minimally invasive treatment via thermoablation. OBJECTIVE To describe the largest reported series of pediatric patients with refractory epilepsy undergoing insular depth electrode placement. METHODS We used current procedural terminology billing records to identify cases of depth electrode insertion performed at our institution. Clinical information from patients undergoing invasive insular sampling was then retrospectively collected. RESULTS Seventy-four insular depth electrodes were placed in 49 patients for extraoperative, inpatient monitoring. The decision to place insular depth electrodes was determined by a multidisciplinary epilepsy team. In 65.3% of cases, direct invasive sampling implicated the insula in seizure onset and prompted either thermoablation or surgical resection of some portion of the insula. There were no serious adverse effects or complications associated with the placement of insular depth electrodes. CONCLUSION Given the low morbidity of insular depth electrode insertion and the high proportion of patients who exhibited insular involvement, it is worth considering whether insular depth electrodes should be part of the standard presurgical evaluation in children with treatment-refractory frontotemporal-parietal epilepsy.

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Operative Nuances of Stereotactic Leksell Frame-Based Depth Electrode Implantation

Operative Neurosurgery ◽

10.1093/ons/opx245 ◽

2017 ◽

Vol 15 (3) ◽

pp. 292-295 ◽

Cited By ~ 6

Author(s):

Holger Joswig ◽

Carolyn M Benson ◽

Andrew G Parrent ◽

Keith W MacDougall ◽

David A Steven

Keyword(s):

Technical Note ◽

Implantation Technique ◽

Electrode Implantation ◽

Depth Electrodes ◽

Depth Electrode ◽

The World

Abstract Background For intracranial electroencephalographic monitoring, stereotactically implanted depth electrodes are increasingly used at epilepsy centers around the world. Objective To identify pearls and pitfalls from our experience with stereotactic Leksell (Elekta AB, Stockhom, Sweden) frame-based depth electrode implantation. Methods An intraoperative video of the implantation technique was recorded. Results A detailed description and a video on how to implant depth electrodes using the stereotactic Leksell frame is provided. Conclusion Neurosurgeons implanting depth electrodes for intracranial electroencephalographic monitoring might find the technical nuances and caveats described in this technical note useful for their practice.

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