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

2017 ◽  
Vol 15 (3) ◽  
pp. 310-317 ◽  
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.

209 Surgical Outcomes with Insular and Insular-Plus Pediatric Epilepsy: A Single-Institution Experience

Neurosurgery ◽  
2017 ◽  
Vol 64 (CN_suppl_1) ◽  
pp. 256-256
Author(s):  
Andrew T Hale ◽  
Luke Tomycz ◽  
Ali S Haider ◽  
Dave Clarke ◽  
Mark R Lee
Keyword(s):  
Surgical Resection ◽  
Surgical Outcomes ◽  
Insular Cortex ◽  
Clinical Information ◽  
Primary Brain Tumor ◽  
Cortical Dysplasia ◽  
Electrode Placement ◽  
Pediatric Epilepsy ◽  
Depth Electrode ◽  
Operative Care

Abstract INTRODUCTION It has been increasingly recognized that the insular cortex plays an important role in frontotemporal-parietal epilepsy (FTPE) 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 non-invasive modalities. At last year's meeting, we reported on the safety and utility of insular-depth electrode placement for interrogation of the insula. Here, we report post-surgical outcomes on 31 patients with insular-depth electrode confirmed refractory epilepsy. METHODS We used Current Procedural Terminology (CPT) billing records to identify cases of depth electrode insertion performed at our institution. Clinical information, operative reports, and pathology data from patients undergoing operative intervention was then retrospectively collected. RESULTS >Thirty-one patients underwent direct invasive sampling implicating the insula in seizure onset and prompted either thermoablation or surgical resection of some portion of the insula. Fourteen patients had biopsy-proven cortical dysplasia, Fourteen patients had suspected cortical dysplasia, two patients had tuberous sclerosis and one patient had a primary brain tumor. Fourteen patients had prior intracranial operations. Fourteen patients underwent thermoablation of the insula and seventeen underwent resection of some portion of the insula. 31% of patients who underwent thermoablation of the insular had an Engel Class outcome of I compared to 63% of patients who underwent open insular resection. Thus, in our cohort, insular resection was superior to thermoablation in achieving superior functional outcomes as measured by Engel Class. CONCLUSION Surgical resection and thermoablation of the insula are both acceptable treatments for insular and insular-plus epilepsy. In our cohort, outcomes with surgical resection were improved, although the reasons for this are unclear. Further study is required to delineate optimal operative care in patients with insular and insular-plus epilepsy.

Freehand placement of depth electrodes using electromagnetic frameless stereotactic guidance

2011 ◽  
Vol 8 (5) ◽  
pp. 464-467 ◽  
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.

scholarly journals Utility and safety of depth electrodes within the supratemporal plane for intracranial EEG

2019 ◽  
Vol 131 (3) ◽  
pp. 772-780 ◽  
Author(s):  
Yasunori Nagahama ◽  
Alan J. Schmitt ◽  
Brian J. Dlouhy ◽  
Adam S. Vesole ◽  
Phillip E. Gander ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Clinical Information ◽  
Epileptic Activity ◽  
Temporal Lobectomy ◽  
Electrode Placement ◽  
Seizure Freedom ◽  
Seizure Onset ◽  
Prognostic Information ◽  
Depth Electrodes ◽  
Electrode Coverage

OBJECTIVEThe epileptogenic zones in some patients with temporal lobe epilepsy (TLE) involve regions outside the typical extent of anterior temporal lobectomy (i.e., “temporal plus epilepsy”), including portions of the supratemporal plane (STP). Failure to identify this subset of patients and adjust the surgical plan accordingly results in suboptimum surgical outcomes. There are unique technical challenges associated with obtaining recordings from the STP. The authors sought to examine the clinical utility and safety of placing depth electrodes within the STP in patients with TLE.METHODSThis study is a retrospective review and analysis of all cases in which patients underwent intracranial electroencephalography (iEEG) with use of at least one STP depth electrode over the 10 years from January 2006 through December 2015 at University of Iowa Hospitals and Clinics. Basic clinical information was collected, including the presence of ictal auditory symptoms, electrode coverage, monitoring results, resection extent, outcomes, and complications. Additionally, cases in which the temporal lobe was primarily or secondarily involved in seizure onset and propagation were categorized based upon how rapidly epileptic activity was observed within the STP following seizure onsets: within 1 second, between 1 and 15 seconds, after 15 seconds, and not involved.RESULTSFifty-two patients underwent iEEG with STP coverage, with 1 STP electrode used in 45 (86.5%) cases and 2 STP electrodes in the other cases. There were no complications related to STP electrode placement. Of 42 cases in which the temporal lobe was primarily or secondarily involved, seizure activity was recorded from the STP in 36 cases (85.7%): in 5 cases (11.9%) within 1 second, in 5 (11.9%) between 1 and 15 seconds, and in 26 (61.9%) more than 15 seconds following seizure onset. Seizure outcomes inversely correlated with rapid ictal involvement of the STP (Engel class I achieved in 25%, 67%, and 82% of patients in the above categories, respectively). All patients without ictal STP involvement achieved seizure freedom. Only 4 (11.1%) patients with STP ictal involvement reported auditory symptoms.CONCLUSIONSIctal involvement of the STP is common even in the absence of auditory symptoms and can be effectively detected by the STP electrodes. These electrodes are safe to implant and provide useful prognostic information.

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

2008 ◽  
Vol 25 (3) ◽  
pp. E19 ◽  
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.

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

2016 ◽  
Vol 18 (5) ◽  
pp. 511-522 ◽  
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.

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

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.

scholarly journals Depth Electrodes in Pediatric Epilepsy Surgery

2013 ◽  
Vol 40 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Janani Kassiri ◽  
Jeff Pugh ◽  
Sharon Carline ◽  
Laura Jurasek ◽  
Thomas Snyder ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Pediatric Epilepsy ◽  
Surgical Removal ◽  
Seizure Freedom ◽  
Sufficient Information ◽  
Epileptogenic Zone ◽  
Depth Electrodes ◽  
Depth Electrode ◽  
Intractable Seizures ◽  
Clinical Scenarios

Abstract:Background:The surgical removal of the epileptogenic zone in medically intractable seizures depends on accurate localization to minimize the neurological sequelae and prevent future seizures. To date, few studies have demonstrated the use of depth electrodes in a pediatric epilepsy population. Here, we report our study of pediatric epilepsy patients at our epilepsy center who were successfully operated for medically intractable seizures following the use of intracranial depth electrodes. In addition, we detail three individuals with distinct clinical scenarios in which depth electrodes were helpful and describe our technical approach to implantation and surgery.Methods:We retrospectively reviewed 18 pediatric epilepsy patients requiring depth electrode studies who presented at the University of Alberta Comprehensive Epilepsy Program between 1999 and 2010 with medically intractable epilepsy. Patients underwent cortical resection following depth electrode placement according to the Comprehensive Epilepsy Program surgical protocols after failure of surface electroencephalogram and magnetic resonance imaging to localize ictal onset zone.Result:The ictal onset zone was successfully identified in all 18 patients. Treatment of all surgical patients resulted in successful seizure freedom (Engel class I) without neurological complications.Conclusion:Intracranial depth electrode use is safe and able to provide sufficient information for the identification of the epileptogenic zone in pediatric epilepsy patients previously not considered for epilepsy surgery.

Insular epilepsy masquerading as multifocal cortical epilepsy as proven by depth electrode

2010 ◽  
Vol 5 (4) ◽  
pp. 365-367 ◽  
Author(s):  
Michael R. Levitt ◽  
Jeffrey G. Ojemann ◽  
John Kuratani
Keyword(s):  
Seizure Control ◽  
Seizure Activity ◽  
Insular Cortex ◽  
Diagnosis And Treatment ◽  
Precise Localization ◽  
Partial Seizures ◽  
Complex Partial Seizures ◽  
Cortical Areas ◽  
Depth Electrodes ◽  
Depth Electrode

The insular cortex is an uncommon epileptogenic location from which complex partial seizures may arise. Seizure activity in insular epilepsy may mimic temporal, parietal, or other cortical areas. Semiology, electroencephalography, and even surface electrocorticography recordings may falsely localize other cortical foci, leading to inaccurate diagnosis and treatment. The use of insular depth electrodes allows more precise localization of seizure foci. The authors describe the case of a young girl with seizures falsely localized to the cortex, with foci arising from the insula, as proven by depth electrode recordings. Resection of the insula yielded seizure control.

A new instrument for improved accuracy of stereotactic depth electrode placement

1996 ◽  
Vol 85 (2) ◽  
pp. 357-358 ◽  
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.

The 3-Dimensional Grid

2015 ◽  
Vol 11 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Charles Munyon ◽  
Jennifer Sweet ◽  
Hans Luders ◽  
Samden Lhatoo ◽  
Jonathan Miller
Keyword(s):  
Intractable Epilepsy ◽  
Infectious Complications ◽  
Electrode Placement ◽  
Frameless Stereotaxy ◽  
Seizure Onset ◽  
3 Dimensional ◽  
Eloquent Areas ◽  
Depth Electrodes ◽  
Rectangular Pattern ◽  
Permanent Neurological Deficit

Abstract BACKGROUND Successful surgical treatment of epilepsy requires accurate definition of areas of ictal onset and eloquent brain. Although invasive monitoring can help, subdural grids cannot sample sulci or subcortical tissue; traditional stereoelectroencephalography depth electrodes are usually placed too far apart to provide sufficient resolution for mapping. OBJECTIVE To report a strategy of depth electrode placement in a dense array to allow precise anatomic localization of epileptic and eloquent cortex. METHODS Twenty patients with medically intractable epilepsy either poorly localized or found to arise adjacent to eloquent areas underwent placement of arrays of depth electrodes into and around the putative area of seizure onset with the use of framed stereotaxy. Each array consisted of a “grid” of parallel electrodes in a rectangular pattern with 1 cm between entry sites. In a subset of patients, a few electrodes were placed initially, with additional electrodes placed in a second stage. Trajectories were modified to avoid cortical vessels defined on magnetic resonance imaging. Patients were monitored for 4 to 21 days to establish the precise location of seizure onset. Stimulation was performed to map cortical and subcortical eloquent regions. Electrode locations were coregistered for frameless stereotaxy during subsequent resection of seizure focus. RESULTS Two hundred fifty-four electrodes were implanted. Discrete regions of seizure onset and functional cortex were identified, which were used during resection to remove epileptogenic tissue while preserving eloquent areas. There were no hemorrhagic or infectious complications; no patient suffered permanent neurological deficit. CONCLUSION The 3-dimensional intraparenchymal grid is useful for identifying the location and extent of epileptic and eloquent brain.

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