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.

Stereoencephalography Electrode Placement Accuracy and Utility Using a Frameless Insertion Platform Without a Rigid Cannula

2019 ◽  
Author(s):  
Erin D’Agostino ◽  
John Kanter ◽  
Yinchen Song ◽  
Joshua P Aronson
Keyword(s):  
Electrode Placement ◽  
Target Point ◽  
Localization Error ◽  
Drug Resistant ◽  
Guide Cannula ◽  
Lateral Entry ◽  
Accurate Localization ◽  
Depth Electrodes ◽  
Rigid Frame ◽  
Drug Resistant Epilepsy

Abstract BACKGROUND Implantation of depth electrodes to localize epileptogenic foci in patients with drug-resistant epilepsy can be accomplished using traditional rigid frame-based, custom frameless, and robotic stereotactic systems. OBJECTIVE To evaluate the accuracy of electrode implantation using the FHC microTargeting platform, a custom frameless platform, without a rigid insertion cannula. METHODS A total of 182 depth electrodes were implanted in 13 consecutive patients who underwent stereoelectroencephalography (SEEG) for drug-resistant epilepsy using the microTargeting platform and depth electrodes without a rigid guide cannula. MATLAB was utilized to evaluate targeting accuracy. Three manual coordinate measurements with high inter-rater reliability were averaged. RESULTS Patients were predominantly male (77%) with average age 35.62 (SD 11.0, range 21-57) and average age of epilepsy onset at 13.4 (SD 7.2, range 3-26). A mean of 14 electrodes were implanted (range 10-18). Mean operative time was 144 min (range 104-176). Implantation of 3 out of 182 electrodes resulted in nonoperative hemorrhage (2 small subdural hematomas and one small subarachnoid hemorrhage). Putative location of onset was identified in all patients. We demonstrated a median lateral target point localization error (LTPLE) of 3.95 mm (IQR 2.18-6.23), a lateral entry point localization error (LEPLE) of 1.98 mm (IQR 1.2-2.85), a target depth error of 1.71 mm (IQR 1.03-2.33), and total target point localization error (TPLE) of 4.95 mm (IQR 2.98-6.85). CONCLUSION Utilization of the FHC microTargeting platform without the use of insertion cannulae is safe, effective, and accurate. Localization of seizure foci was accomplished in all patients and accuracy of depth electrode placement was satisfactory.

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.

Frameless stereotactic placement of depth electrodes in epilepsy surgery

2005 ◽  
Vol 102 (6) ◽  
pp. 1040-1045 ◽  
Author(s):  
Ashesh D. Mehta ◽  
Douglas Labar ◽  
Andrew Dean ◽  
Cynthia Harden ◽  
Syed Hosain ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Accurate Method ◽  
Electrode Placement ◽  
Entry Site ◽  
Content Type ◽  
Depth Electrodes ◽  
Custom Made ◽  
Stereotactic Navigation ◽  
The Mean ◽  
Fine Print

Object. Depth electrodes are useful in the identification of deep epileptogenic foci. Computerized tomography—magnetic resonance (CT/MR)— and angiography-guided frame-based techniques are safe and accurate but require four-point skull fixation that limits cranial access for the placement of additional grids and strips. The authors investigated the viability and accuracy of placing depth electrodes by using a commercially available frameless system. Methods. A slotted, custom-designed adapter was built to interface with the StealthStation Guide Frame-DT and 960-525 StealthFighter. The Cranial Navigation software was used to plan the trajectory and entry site based on preoperative spoiled gradient MR imaging studies. Forty-one depth electrodes were placed in 51 targets in 20 patients. Thirty-one of these electrodes were inserted through the temporal neocortex following craniotomy and placement of subdural grids, whereas 10 were placed through burr holes. All electrodes had contact either within (71%) or touching (29%) the target, 50 of which (98%) provided adequate recordings. Although the mean distance of the distal electrode contact from the intended target was 3.1 ± 0.5 mm, the mean distance to the edge of the anatomical structure was 0.4 ± 0.9 mm. Placement via the laterotemporal approach was significantly (p < 0.001) more accurate than that via the occipitotemporal approach. No complication occurred. Conclusions. Depth electrodes can be placed safely and accurately by using a commercially available frameless stereotactic navigation system and a custom-made adapter. Depth electrode placement to record ictal onsets during epilepsy surgery only requires the contacts to touch rather than to reside within the intended structure. The laterotemporal approach is a more accurate method of placing electrodes than is the occipitotemporal one, likely due to the increased distance from the entry point to the target.

scholarly journals Localization of irritative zones in epilepsy with thermochromic silicone

2022 ◽  
Vol 13 ◽  
pp. 14
Author(s):  
Enrique de Font-Réaulx ◽  
Javier Terrazo-Lluch ◽  
Luis Guillermo Díaz-López ◽  
Miguel Ángel Collado-Corona ◽  
Paul Shkurovich-Bialik ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Cohort Study ◽  
Epilepsy Surgery ◽  
Gold Standard ◽  
Late Complications ◽  
Drug Resistant ◽  
Proof Of Concept ◽  
New Techniques ◽  
The Mean ◽  
Drug Resistant Epilepsy

Background: During epilepsy surgery, the gold standard to identify irritative zones (IZ) is electrocorticography (ECoG); however, new techniques are being developed to detect IZ in epilepsy surgery and in neurosurgery in general, such as infrared thermography mapping (ITM), and the use of thermosensitive/thermochromic materials. Methods: In a cohort study of consecutive patients with focal drug-resistant epilepsy of the temporal lobe treated with surgery, we evaluated possible adverse effects to the transient placement of a thermochromic/thermosensitive silicone (TTS) on the cerebral cortex and their postoperative evolution. Furthermore, we compared the precision of TTS for detecting cortical IZ against the gold standard ECoG and with ITM, as proof of concept. Results: We included 10 consecutive patients, 6 women (60%) and 4 men (40%). Age ranges from 15 to 56 years, mean 33.2 years. All were treated with unilateral temporal functional lobectomy. The mean hospital stay was 4 days. There were no immediate or late complications associated with the use of any of the modalities described. In the 10 patients, we obtained consistency in locating the IZ with ECoG, ITM, and the TTS. Conclusion: The TTS demonstrated biosecurity in this series. The accuracy of the TTS to locate IZ was similar to that of ECoG and ITM in this study. More extensive studies are required to determine its sensitivity and specificity.

scholarly journals Focal Cortical Resection and Hippocampectomy in a Cat With Drug-Resistant Structural Epilepsy

2021 ◽  
Vol 8 ◽  
Author(s):  
Daisuke Hasegawa ◽  
Rikako Asada ◽  
Yuji Hamamoto ◽  
Yoshihiko Yu ◽  
Takayuki Kuwabara ◽  
...  
Keyword(s):  
Veterinary Medicine ◽  
Epilepsy Surgery ◽  
Therapeutic Option ◽  
Occipital Cortex ◽  
Epileptogenic Zone ◽  
Drug Resistant ◽  
Naturally Occurring ◽  
Alternative Treatment Option ◽  
Drug Resistant Epilepsy ◽  
The Right

Epilepsy surgery is a common therapeutic option in humans with drug-resistant epilepsy. However, there are few reports of intracranial epilepsy surgery for naturally occurring epilepsy in veterinary medicine. A 12-year-old neutered female domestic shorthair cat with presumed congenital cortical abnormalities (atrophy) in the right temporo-occipital cortex and hippocampus had been affected with epilepsy from 3 months of age. In addition to recurrent epileptic seizures, the cat exhibited cognitive dysfunction, bilateral blindness, and right forebrain signs. Seizures had been partially controlled (approximately 0.3–0.7 seizures per month) by phenobarbital, zonisamide, diazepam, and gabapentin until 10 years of age; however, they gradually became uncontrollable (approximately 2–3 seizures per month). In order to plan epilepsy surgery, presurgical evaluations including advanced structural magnetic resonance imaging and long-term intracranial video-electroencephalography monitoring were conducted to identify the epileptogenic zone. The epileptogenic zone was suspected in the right atrophied temporo-occipital cortex and hippocampus. Two-step surgery was planned, and a focal cortical resection of that area was performed initially. After the first surgery, seizures were not observed for 2 months, but they then recurred. The second surgery was performed to remove the right atrophic hippocampus and extended area of the right cortex, which showed spikes on intraoperative electrocorticography. After the second operation, although epileptogenic spikes remained in the contralateral occipital lobe, which was suspected as the second epileptogenic focus, seizure frequency decreased to &lt;0.3 seizure per month under treatment with antiseizure drugs at 1.5 years after surgery. There were no apparent complications associated with either operation, although the original neurological signs were unchanged. This is the first exploratory study of intracranial epilepsy surgery for naturally occurring epilepsy, with modern electroclinical and imaging evidence, in veterinary medicine. Along with the spread of advanced diagnostic modalities and neurosurgical devices in veterinary medicine, epilepsy surgery may be an alternative treatment option for drug-resistant epilepsy in cats.

SEEG in Polymicrogyria: When and How?

2018 ◽  
pp. 246-262
Author(s):  
Louis Maillard ◽  
Georgia Ramantani
Keyword(s):  
Antiepileptic Drug ◽  
Epilepsy Surgery ◽  
The Other ◽  
Seizure Freedom ◽  
Epileptogenic Zone ◽  
Drug Resistant ◽  
Malformations Of Cortical Development ◽  
Cortical Areas ◽  
Related Drug ◽  
Drug Resistant Epilepsy

Polymicrogyria (PMG) is one of the most common malformations of cortical development (MCDs), with epilepsy affecting most patients. PMG-related drug-resistant epilepsy patients can be considered for surgery in well-selected cases. In this context, a comprehensive presurgical evaluation, often including stereo electroencephalography, is warranted to accurately delineate the epileptogenic zone. The heterogeneity of intrinsic epileptogenicity in the PMG, together with the additional or predominant involvement of remote cortical areas, calls for a different strategy in PMG compared with other MCDs, one that is not predominantly MRI- but rather SEEG-oriented. Favourable results in terms of seizure freedom and antiepileptic drug cessation are feasible in a large proportion of patients with unilateral PMG. PMG extent should not exclude the possibility of epilepsy surgery. On the other hand, patients with hemispheric PMG can be excellent hemispherotomy candidates, particularly in the presence of contralateral hemiparesis. Recent findings support early consideration of surgery in PMG-related drug-resistant epilepsy.

Safety of Staged Epilepsy Surgery in Children

Neurosurgery ◽  
2013 ◽  
Vol 74 (2) ◽  
pp. 154-162 ◽  
Author(s):  
Jonathan Roth ◽  
Chad Carlson ◽  
Orrin Devinsky ◽  
David H. Harter ◽  
William S. MacAllister ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Refractory Epilepsy ◽  
Electrode Placement ◽  
Wound Complications ◽  
Neurosurgical Procedures ◽  
Epileptogenic Zone ◽  
Invasive Monitoring ◽  
Depth Electrodes ◽  
Major Complications ◽  
Medically Refractory Epilepsy

Abstract BACKGROUND: Surgical resection of epileptic foci relies on accurate localization of the epileptogenic zone, often achieved by subdural and depth electrodes. Our epilepsy center has treated selected children with poorly localized medically refractory epilepsy with a staged surgical protocol, with at least 1 phase of invasive monitoring for localization and resection of epileptic foci. OBJECTIVE: To evaluate the safety of staged surgical treatments for refractory epilepsy among children. METHODS: Data were retrospectively collected, including surgical details and complications of all patients who underwent invasive monitoring. RESULTS: A total of 161 children underwent 200 admissions including staged procedures (&gt;1 surgery during 1 hospital admission), and 496 total surgeries. Average age at surgery was 7 years (range, 8 months to 16.5 years). A total of 250 surgeries included resections (and invasive monitoring), and 189 involved electrode placement only. The cumulative total number of surgeries per patient ranged from 2 to 10 (average, 3). The average duration of monitoring was 10 days (range, 1–30). There were no deaths. Follow-up ranged from 1 month to 10 years. Major complications included unexpected new permanent mild neurological deficits (2%/admission), central nervous system or bone flap infections (1.5%/admission), intracranial hemorrhage, cerebrospinal fluid leak, and a retained strip (each 0.5%/admission). Minor complications included bone absorption (5%/admission), positive surveillance sub-/epidural cultures in asymptomatic patients (5.5%/admission), noninfectious fever (5%/admission), and wound complications (3%/admission). Thirty complications necessitated additional surgical treatment. CONCLUSION: Staged epilepsy surgery with invasive electrode monitoring is safe in children with poorly localized medically refractory epilepsy. The rate of major complications is low and appears comparable to that associated with other elective neurosurgical procedures.

scholarly journals Presurgical Evaluation of Epilepsy Surgery

2020 ◽  
Author(s):  
Tak Lap Poon
Keyword(s):  
Epilepsy Surgery ◽  
Essential Elements ◽  
Epilepsy Syndrome ◽  
Drug Resistant ◽  
Eeg Monitoring ◽  
Presurgical Evaluation ◽  
Advanced Technique ◽  
Depth Electrodes ◽  
Drug Resistant Epilepsy ◽  
Modern Era

Drug-resistant epilepsy (DRE) is defined as failure of two adequate trials of appropriately chosen and administered antiepileptic drugs. Approximately about 30% of epilepsy patients are drug resistant. Accountable reasons to treatment failure including failure to recognize epilepsy syndrome, poor drug compliance, lifestyle factors, etc. In modern era of medicine, DRE patient should be encouraged to have early referral to tertiary epilepsy centre for presurgical evaluation. Comprehensive neurophysiology, structural neuroimaging, and neuropsychological and psychiatric assessment are regarded as essential elements. Invasive electroencephalography (EEG) monitoring in terms of subdural electrodes, depth electrodes, foramen ovale electrodes, and more advanced technique using stereoelectroencephalography (SEEG) are strong armamentarium for epilepsy surgeon. Epilepsy surgery in terms of resection, disconnection, or neuro-modulation should be recommended after a multi-disciplinary agreement.

Simultaneous Frame-assisted Stereotactic Placement of Subdural Grid Electrodes and Intracerebral Depth Electrodes

2019 ◽  
Vol 80 (05) ◽  
pp. 353-358 ◽  
Author(s):  
Peter C. Reinacher ◽  
Dirk-Matthias Altenmüller ◽  
Marie T. Krüger ◽  
Andreas Schulze-Bonhage ◽  
Horst Urbach ◽  
...  
Keyword(s):  
Focal Epilepsy ◽  
Epileptogenic Zone ◽  
Drug Resistant ◽  
Surgical Time ◽  
Depth Electrodes ◽  
Group A ◽  
The Mean ◽  
Group B ◽  
Intracranial Electrodes ◽  
Complex Cases

Background and Study Aims In complex cases of drug-resistant focal epilepsy, the precise localization of the epileptogenic zone requires simultaneous implantation of depth and subdural grid electrodes. This study describes a new simple frame-assisted method that facilitates the simultaneous placement of both types of intracranial electrodes. Material and Methods Ten consecutive patients were evaluated and divided into two groups. Group A included patients with simultaneous frame-assisted placement of depth and subdural grid electrodes. In group B, depth electrodes were implanted stereotactically; grid electrodes were implanted in a separate surgery. Results The placement of the subdural grid was accurate as individually designed by the epileptologists in all five patients from group A. In group B, one patient showed a slight and another one a significant deviation of the subdural grid position postoperatively. The mean surgical time in group A was shorter (280±62 minutes) compared with the mean duration of the surgical procedures in group B (336±51 minutes). Conclusion The frame-assisted placement of subdural grid electrodes facilitates the surgical procedure for invasive video-electroencephalography monitoring in complex cases of drug-resistant focal epilepsy in which a combination of depth electrodes and subdural grid electrodes is needed, by reducing the surgical time and guaranteeing highly accurate electrode localizations.

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