1
|
Matsuda D, Higashi T, Sato M, Hosoyama H, Otsubo T, Hanaya R. Posterior cerebral artery stenosis related to implanted intracranial electrodes for temporal lobe epilepsy: A case report. Int J Surg Case Rep 2023; 105:107988. [PMID: 36963228 PMCID: PMC10060667 DOI: 10.1016/j.ijscr.2023.107988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/27/2023] [Accepted: 03/11/2023] [Indexed: 03/19/2023] Open
Abstract
INTRODUCTION Intracranial electroencephalography is a crucial diagnostic technique for epilepsy surgery, though it is associated with a range of complications, including infection, intracranial hemorrhage, increased intracranial pressure, and cerebral infarction. This case study presents an uncommon occurrence of stenosis of the left posterior cerebral artery (PCA) following intracranial electrode implantation. CASE PRESENTATION A woman in her thirties with drug-resistant focal impaired awareness seizures underwent implantation of subdural and depth electrodes on the bilateral temporal lobes to lateralize seizure onset. A left anterior-temporal lobectomy was performed based on the evaluation results. Following the resection of the hippocampus, stenosis of the left PCA, with a pinched appearance, was observed. Postoperatively, extensive cerebral edema in the bilateral temporal lobes and a defect in the left PCA were detected on magnetic resonance (MR) imaging. MR imaging performed the day after surgery showed cerebral infarction in the left medial temporal lobe and left lateral thalamus. A video review indicated that surgical manipulation was not the cause of vascular stenosis. MR angiography one week later confirmed the recanalization of the PCA. DISCUSSION We surmised that the subdural electrodes inserted along the middle skull base might have induced the PCA stenosis or spasms. The patient did not experience any significant sequelae, with no episodes of seizures for more than five years after surgery. CONCLUSION It is essential to note that subdural grid electrodes placed in the medial temporal lobe can cause vascular stenosis, albeit with an extremely rare occurrence.
Collapse
Affiliation(s)
- Daiki Matsuda
- Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Kagoshima, Japan
| | - Takuichiro Higashi
- Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Kagoshima, Japan
| | - Masanori Sato
- Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Kagoshima, Japan
| | - Hiroshi Hosoyama
- Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Kagoshima, Japan
| | | | - Ryosuke Hanaya
- Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Kagoshima, Japan.
| |
Collapse
|
2
|
Remick M, Ibrahim GM, Mansouri A, Abel TJ. Patient phenotypes and clinical outcomes in invasive monitoring for epilepsy: An individual patient data meta-analysis. Epilepsy Behav 2020; 102:106652. [PMID: 31770717 DOI: 10.1016/j.yebeh.2019.106652] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 10/16/2019] [Accepted: 10/17/2019] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Invasive monitoring provides valuable clinical information in patients with drug-resistant epilepsy (DRE). However, there is no clear evidence indicating either stereoelectroencephalography (SEEG) or subdural electrodes (SDE) as the optimal method. Our goal was to examine differences in postresection seizure freedom rates between SEEG- and SDE-informed resective epilepsy surgeries. Additionally, we aimed to determine potential clinical indicators for SEEG or SDE monitoring in patients with drug-resistant epilepsy. METHODS A systematic literature review was performed in which we searched for primary articles using keywords such as "electroencephalography", "intracranial grid", and "epilepsy." Only studies containing individual patient data (IPD) were included for analysis. A one-stage IPD meta-analysis was performed to determine differences in rates of seizure freedom (International League Against Epilepsy (ILAE) guidelines and Engel classification) and resection status between SEEG and SDE patients. A Cox proportional-hazards regression was performed to determine the effect of time on seizure freedom status. Additionally, a principal component analysis was performed to investigate primary drivers of variance between these two groups. RESULTS This IPD meta-analysis compared differences between SEEG and SDE invasive monitoring techniques in 595 patients from 33 studies. Our results demonstrate that while there was no difference in seizure freedom rates regardless of resection (p = 0.0565), SEEG was associated with a lower rate of resection compared with SDE (82.00% SEEG, 92.74% SDE, p = 0.0002). Additionally, while SDE was associated with a higher rate of postresection seizure freedom (54.04% SEEG, 64.32% SDE, p = 0.0247), the difference between seizure freedom rates following SEEG- or SDE-informed resection decreased with long-term follow-up. A principal component analysis showed that cases resulting in SEEG were associated with lower risk of morbidity than SDE cases, which were strongly collinear with multiple subpial transections, anterior temporal lobectomy, amygdalectomy, and hippocampectomy. SIGNIFICANCE In this IPD meta-analysis of SEEG and SDE invasive monitoring techniques, SEEG and SDE were associated with similar rates of seizure freedom at latest follow-up. The former was associated with lower rates of resection. Furthermore, the clinical phenotypes of patients undergoing SEEG monitoring was associated with lower rates of complications. Future long-term prospective registries of IPD are promising options for clarifying the differences in these intracranial monitoring techniques as well as the unique patient phenotypes that may be associated with their indication.
Collapse
Affiliation(s)
- Madison Remick
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - George M Ibrahim
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Canada; Division of Neurosurgery, Hospital for Sick Children, Program in Neuroscience and Mental Health, Hospital for Sick Children Research Institute, Toronto, Canada
| | - Alireza Mansouri
- Department of Neurosurgery, Penn State University, Hershey, PA, USA
| | - Taylor J Abel
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
3
|
Quantitative Signal Characteristics of Electrocorticography and Stereoelectroencephalography: The Effect of Contact Depth. J Clin Neurophysiol 2019; 36:195-203. [PMID: 30925509 PMCID: PMC6493682 DOI: 10.1097/wnp.0000000000000577] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Supplemental Digital Content is Available in the Text. Purpose: Patients undergoing epilepsy surgery often require invasive EEG, but few studies have examined the signal characteristics of contacts on the surface of the brain (electrocorticography, ECOG) versus depth contacts, used in stereoelectroencephalography (SEEG). As SEEG and ECOG have significant differences in complication rates, it is important to determine whether both modalities produce similar signals for analysis, to ultimately guide management of medically intractable epilepsy. Methods: Twenty-seven patients who underwent SEEG (19), ECOG (6), or both (2) were analyzed for quantitative measures of activity including spectral power and phase–amplitude coupling during approximately 1 hour of wakefulness. The position of the contacts was calculated by coregistering the postoperative computed tomography with a reconstructed preoperative MRI. Using two types of referencing schemes—local versus common average reference—the brain regions where any quantitative measure differed systematically with contact depth were established. Results: Using even the most permissive statistical criterion, few quantitative measures were significantly correlated with contact depth in either ECOG or SEEG contacts. The factors that predicted changes in spectral power and phase–amplitude coupling with contact depth were failing to baseline correct spectral power measures, use of a local rather than common average reference, using baseline correction for phase–amplitude coupling measures, and proximity of other grey matter structures near the region where the contact was located. Conclusions: The signals recorded by ECOG and SEEG have very similar spectral power and phase–amplitude coupling, suggesting that both modalities are comparable from an electrodiagnostic standpoint in delineation of the epileptogenic network.
Collapse
|
4
|
Yan H, Katz JS, Anderson M, Mansouri A, Remick M, Ibrahim GM, Abel TJ. Method of invasive monitoring in epilepsy surgery and seizure freedom and morbidity: A systematic review. Epilepsia 2019; 60:1960-1972. [PMID: 31423575 DOI: 10.1111/epi.16315] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 07/23/2019] [Accepted: 07/23/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Invasive monitoring is sometimes necessary to guide resective surgery in epilepsy patients, but the ideal method is unknown. In this systematic review, we assess the association of postresection seizure freedom and adverse events in stereoelectroencephalography (SEEG) and subdural electrodes (SDE). METHODS We searched three electronic databases (MEDLINE, Embase, and CENTRAL [Cochrane Central Register of Controlled Trials]) from their inception to January 2018 with the keywords "electroencephalography," "intracranial grid," and "epilepsy." Studies that presented primary quantitative patient data for postresection seizure freedom with at least 1 year of follow-up or complication rates of SEEG- or SDE-monitored patients were included. Two trained investigators independently collected data from eligible studies. Weighted mean differences (WMDs) with 95% confidence interval (CIs) were used as a measure of the association of SEEG or SDE with seizure freedom and with adverse event outcomes. RESULTS Of 11 462 screened records, 48 studies met inclusion criteria. These studies reported on 1973 SEEG patients and 2036 SDE patients. Our systematic review revealed SEEG was associated with 61.0% and SDE was associated with 56.4% seizure freedom after resection (WMD = +5.8%, 95% CI = 4.7-6.9%, P = .001). Furthermore, SEEG was associated with 4.8% and SDE was associated with 15.5% morbidity (WMD = -10.6%, 95% CI = -11.6 to -9.6%, P = .001). SEEG was associated with 0.2% mortality and SDE was associated with 0.4% mortality (WMD = -0.2%, 95% CI = -0.3 to -0.1%, P = .001). SIGNIFICANCE In this systematic review of SEEG and SDE invasive monitoring techniques, SEEG was associated with fewer surgical resections yet better seizure freedom outcomes in those undergoing resections. SEEG was also associated with lower mortality and morbidity than SDE. Clinical studies directly comparing these modalities are necessary to understand the relative rates of seizure freedom, morbidity, and mortality associated with these techniques.
Collapse
Affiliation(s)
- Han Yan
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Joel S Katz
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Melanie Anderson
- Library and Information Services, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Alireza Mansouri
- Division of Neurosurgery, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Madison Remick
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - George M Ibrahim
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada.,Division of Neurosurgery, Hospital for Sick Children, Program in Neuroscience and Mental Health, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Taylor J Abel
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| |
Collapse
|
5
|
Antony AR, Abramovici S, Krafty RT, Pan J, Richardson RM, Bagic A, Haneef Z. Simultaneous scalp EEG improves seizure lateralization during unilateral intracranial EEG evaluation in temporal lobe epilepsy. Seizure 2018; 64:8-15. [PMID: 30502684 DOI: 10.1016/j.seizure.2018.11.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/23/2018] [Accepted: 11/24/2018] [Indexed: 11/16/2022] Open
Abstract
PURPOSE To determine if simultaneous bilateral scalp EEG (scEEG) can accurately detect a contralateral seizure onset in patients with unilateral intracranial EEG (IEEG) implantation. METHODS We evaluated 39 seizures from 9 patients with bitemporal epilepsy who underwent simultaneous scEEG and IEEG (SSIEEG). To simulate conditions of unilateral IEEG implantation with a missed contralateral seizure onset, we analyzed the IEEG recording contralateral to the seizure onset (CL- IEEG), in conjunction with simultaneous scEEG. The following criteria were evaluated between scEEG and CL- IEEG (1) latency: the time to onset of EEG seizure (2) location: concordance of ictal onset zones and (3) pattern: congruence of EEG morphology and frequency. RESULTS SSIEEG correctly lateralized 36/39 (92.3%) seizures compared to 13/39 (33.3%) seizures using CL- IEEG alone (OR = 24.0, p < 0.01), 33 (84.6%) seizures using scEEG alone (OR = 2.2, p = 0.29) and 26 (66.9%) seizures using time of clinical onset alone (OR = 6.0, p = 0.01). For the three criteria evaluated, (1) 22/39 (56.4%) seizures had an earlier onset on the scEEG, compared to CL- IEEG; (2) lack of congruence of location of seizure onset was noted in 33/39 (84.6%) of the seizures; and (3) 22/39 (56.4%) seizures did not have a congruent ictal pattern. CONCLUSIONS The chronological, topographic and morphologic features of SSIEEG can accurately detect the hemisphere of seizure onset in most cases with unilateral IEEG implantation. SSIEEG is significantly better than, IEEG, scEEG or clinical onset alone in this scenario. We propose that SSIEEG should be considered in all cases of intractable focal epilepsy undergoing unilateral IEEG evaluation.
Collapse
Affiliation(s)
- Arun Raj Antony
- Division of Neurology, UPMC Passavant, 9100 Babcock Boulevard, Professional Building T, Pittsburgh, PA 15237, United States.
| | - Sergiu Abramovici
- UPMC Hamot, Neurology 201 State Street, Erie, PA, 16550, United States
| | - Robert Todd Krafty
- Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA 15213, United States
| | - Jullie Pan
- University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), Department of Neurology, University of Pittsburgh Medical Center, 8111 Kaufmann Medical Building, 3471 Fifth Avenue, Pittsburgh, PA 15213, United States
| | - Robert Mark Richardson
- Department of Neurological Surgery, University of Pittsburgh Medical Center, UPMC Presbyterian, Suite B400, 200 Lothrop Street, Pittsburgh, PA 15213, United States
| | - Anto Bagic
- University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), Department of Neurology, University of Pittsburgh Medical Center, 8111 Kaufmann Medical Building, 3471 Fifth Avenue, Pittsburgh, PA 15213, United States
| | - Zulfi Haneef
- Department of Neurology, Baylor College of Medicine, Houston, TX 77030, United States; Neurology care line, VA Houston Medical Center, Houston, TX 77030, United States
| |
Collapse
|
6
|
Nagahama Y, Schmitt AJ, Nakagawa D, Vesole AS, Kamm J, Kovach CK, Hasan D, Granner M, Dlouhy BJ, Howard MA, Kawasaki H. Intracranial EEG for seizure focus localization: evolving techniques, outcomes, complications, and utility of combining surface and depth electrodes. J Neurosurg 2018:1-13. [DOI: 10.3171/2018.1.jns171808] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 01/15/2018] [Indexed: 11/06/2022]
Abstract
OBJECTIVEIntracranial electroencephalography (iEEG) provides valuable information that guides clinical decision-making in patients undergoing epilepsy surgery, but it carries technical challenges and risks. The technical approaches used and reported rates of complications vary across institutions and evolve over time with increasing experience. In this report, the authors describe the strategy at the University of Iowa using both surface and depth electrodes and analyze outcomes and complications.METHODSThe authors performed a retrospective review and analysis of all patients who underwent craniotomy and electrode implantation from January 2006 through December 2015 at the University of Iowa Hospitals and Clinics. The basic demographic and clinical information was collected, including electrode coverage, monitoring results, outcomes, and complications. The correlations between clinically significant complications with various clinical variables were analyzed using multivariate analysis. The Fisher exact test was used to evaluate a change in the rate of complications over the study period.RESULTSNinety-one patients (mean age 29 ± 14 years, range 3–62 years), including 22 pediatric patients, underwent iEEG. Subdural surface (grid and/or strip) electrodes were utilized in all patients, and depth electrodes were also placed in 89 (97.8%) patients. The total number of electrode contacts placed per patient averaged 151 ± 58. The duration of invasive monitoring averaged 12.0 ± 5.1 days. In 84 (92.3%) patients, a seizure focus was localized by ictal onset (82 cases) or inferred based on interictal discharges (2 patients). Localization was achieved based on data obtained from surface electrodes alone (29 patients), depth electrodes alone (13 patients), or a combination of both surface and depth electrodes (42 patients). Seventy-two (79.1%) patients ultimately underwent resective surgery. Forty-seven (65.3%) and 18 (25.0%) patients achieved modified Engel class I and II outcomes, respectively. The mean follow-up duration was 3.9 ± 2.9 (range 0.1–10.5) years. Clinically significant complications occurred in 8 patients, including hematoma in 3 (3.3%) patients, infection/osteomyelitis in 3 (3.3%) patients, and edema/compression in 2 (2.2%) patients. One patient developed a permanent neurological deficit (1.1%), and there were no deaths. The hemorrhagic and edema/compression complications correlated significantly with the total number of electrode contacts (p = 0.01), but not with age, a history of prior cranial surgery, laterality, monitoring duration, and the number of each electrode type. The small number of infectious complications precluded multivariate analysis. The number of complications decreased from 5 of 36 cases (13.9%) to 3 of 55 cases (5.5%) during the first and last 5 years, respectively, but this change was not statistically significant (p = 0.26).CONCLUSIONSAn iEEG implantation strategy that makes use of both surface and depth electrodes is safe and effective at identifying seizure foci in patients with medically refractory epilepsy. With experience and iterative refinement of technical surgical details, the risk of complications has decreased over time.
Collapse
Affiliation(s)
| | - Alan J. Schmitt
- 2Neurology, University of Iowa Hospitals and Clinics, Iowa City
| | | | - Adam S. Vesole
- 3Carver College of Medicine, University of Iowa Hospitals and Clinics, Iowa City; and
| | - Janina Kamm
- 2Neurology, University of Iowa Hospitals and Clinics, Iowa City
| | | | | | - Mark Granner
- 2Neurology, University of Iowa Hospitals and Clinics, Iowa City
| | - Brian J. Dlouhy
- Departments of 1Neurosurgery and
- 4Pappajohn Biomedical Institute, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Matthew A. Howard
- Departments of 1Neurosurgery and
- 4Pappajohn Biomedical Institute, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | | |
Collapse
|
7
|
Depth versus subdural temporal electrodes revisited: Impact on surgical outcome after resective surgery for epilepsy. Clin Neurophysiol 2016; 128:418-423. [PMID: 28160747 DOI: 10.1016/j.clinph.2016.12.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 11/23/2016] [Accepted: 12/18/2016] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To study retrospectively the impact of electrode modality (subdural or depth electrodes) during presurgical assessment on surgical outcome after temporal lobectomy. METHODS The study included 17 patients assessed with depth electrodes and 57 with bitemporal subdural strips. RESULTS MRI showed a larger proportion of bilateral pathology in patients undergoing depth recordings (29.41% versus 3.5%, p=0.00069). Among the operated patients, those undergoing depth electrode recordings showed better outcome at one year after surgery (11/12 versus 22/33; p=0.046). This difference disappears at longest follow up (10/12 versus 22/33; p=0.138). Moreover, the probability of undergoing surgery and having good outcome after assessment with intracranial recordings is higher for the depth electrode group at one-year follow up (11/17 versus 22/57; p=0.029) but statistical differences decrease to a trend for the longest follow up (10/17 versus 22/57; p=0.069). No other statistical differences were noted between subdural and depth electrodes. Depth electrodes showed lower complication rates than subdural electrodes. CONCLUSION Both depth and subdural electrodes are effective for presurgical assessment of temporal lobe epilepsy. SIGNIFICANCE Assessment with depth electrodes is associated with slightly increased likelihood of surgery and marginally better surgical outcome at one year follow up which disappears for longer follow up periods. Initial assessment with depth electrodes would have avoided a second implantation in 15% of patients.
Collapse
|
8
|
Jayakar P, Gotman J, Harvey AS, Palmini A, Tassi L, Schomer D, Dubeau F, Bartolomei F, Yu A, Kršek P, Velis D, Kahane P. Diagnostic utility of invasive EEG for epilepsy surgery: Indications, modalities, and techniques. Epilepsia 2016; 57:1735-1747. [PMID: 27677490 DOI: 10.1111/epi.13515] [Citation(s) in RCA: 166] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/02/2016] [Indexed: 12/21/2022]
Abstract
Many patients with medically refractory epilepsy now undergo successful surgery based on noninvasive diagnostic information, but intracranial electroencephalography (IEEG) continues to be used as increasingly complex cases are considered surgical candidates. The indications for IEEG and the modalities employed vary across epilepsy surgical centers; each modality has its advantages and limitations. IEEG can be performed in the same intraoperative setting, that is, intraoperative electrocorticography, or through an independent implantation procedure with chronic extraoperative recordings; the latter are not only resource intensive but also carry risk. A lack of understanding of IEEG limitations predisposes to data misinterpretation that can lead to denying surgery when indicated or, worse yet, incorrect resection with adverse outcomes. Given the lack of class 1 or 2 evidence on IEEG, a consensus-based expert recommendation on the diagnostic utility of IEEG is presented, with emphasis on the application of various modalities in specific substrates or locations, taking into account their relative efficacy, safety, ease, and incremental cost-benefit. These recommendations aim to curtail outlying indications that risk the over- or underutilization of IEEG, while retaining substantial flexibility in keeping with most standard practices at epilepsy centers and addressing some of the needs of resource-poor regions around the world.
Collapse
Affiliation(s)
- Prasanna Jayakar
- Brain Institute, Nicklaus Children's Hospital, Miami, Florida, U.S.A
| | - Jean Gotman
- Montreal Neurological Hospital and Institute, McGill University, Montréal, Quebec, Canada
| | - A Simon Harvey
- The Royal Children's Hospital, University of Melbourne, Melbourne, Victoria, Australia
| | - André Palmini
- Services of Neurology and Neurosurgery, Hospital São Lucas, Porto Alegre, Brazil
| | - Laura Tassi
- Claudio Munari Epilepsy Surgery Center, Niguarda Hospital, Milan, Italy
| | | | - Francois Dubeau
- Montreal Neurological Hospital and Institute, McGill University, Montréal, Quebec, Canada
| | - Fabrice Bartolomei
- Service of Neurophysiology Clinic, Public Hospital of Marseille, Marseille, France
| | - Alice Yu
- Neurology Department, Taipei Veterans General Hospital and National Yang Ming University, Taipei, Taiwan
| | - Pavel Kršek
- Department of Pediatric Neurology, Motol University Hospital, Charles University, Prague, Czech Republic
| | - Demetrios Velis
- Epilepsy Surgery Program, Free University Medical Center (VUmc), Amsterdam, The Netherlands
| | - Philippe Kahane
- GIN INSERM U1216, Grenoble-Alpes Hospital and University, Grenoble, France
| |
Collapse
|
9
|
Placement of subdural grids in pediatric patients: technique and results. Childs Nerv Syst 2014; 30:1897-904. [PMID: 25296551 DOI: 10.1007/s00381-014-2534-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 08/13/2014] [Indexed: 10/24/2022]
Abstract
PURPOSE The purpose of this study is to describe common indications and technique for the application of chronic invasive electrodes in the pediatric patient suffering from medically intractable epilepsy. METHODS This chapter was prepared based on a retrospective review of the literature and personal experience based from a large tertiary epilepsy center. CONCLUSIONS Invasive subdural recordings are a safe and efficacious tool to identify the epileptogenic zone and its relationship to functional cortex in highly selected patients with medically refractory epilepsy. The ability to localize the EZ approaches 90 to 100 %, but seizure-free outcome is more complex depending greatly on the experience of the surgical team and the extent of resection.
Collapse
|
10
|
Yang PF, Zhang HJ, Pei JS, Tian J, Lin Q, Mei Z, Zhong ZH, Jia YZ, Chen ZQ, Zheng ZY. Intracranial electroencephalography with subdural and/or depth electrodes in children with epilepsy: techniques, complications, and outcomes. Epilepsy Res 2014; 108:1662-70. [PMID: 25241139 DOI: 10.1016/j.eplepsyres.2014.08.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 08/23/2014] [Indexed: 10/24/2022]
Abstract
Intracranial electroencephalographic monitoring with subdural and/or depth electrodes is widely used for the surgical localization of epileptic foci in patients with intractable partial epilepsy; however, data on safety and surgical outcome with this technique are still inadequate. The aims of this study were to assess the morbidity of intracranial recordings and the surgical outcomes in epileptic children. We retrospectively reviewed the clinical data for 137 children with epilepsy (mean age at implantation: 12.6 ± 3.8 years) who underwent intracranial monitoring with the implantation of strip or grid subdural electrodes and/or intracerebral depth electrodes from September 2004 to September 2011 at a tertiary epilepsy center in China. Complications were classified using five grades of severity (including mortality) and were further classified as either minor or severe. Outcome was classified according to Engel's classification. Regression analysis was performed to identify risk factors for complications. The mean duration of implantation was 5.3 ± 1.3 days. Among the 133 patients who underwent resection, 65 (48.9%) were seizure free (Engel Class I) at last known follow-up, which was >2 years after surgery for all patients. Also, 31 (23.3%) patients had a significant reduction in seizures (Engel Class II). Complications of any type were documented in 29 (21.7%) patients; 15 of these patients had intracranial hematoma. The results of multivariate analysis showed that the only independent risk factor for intracranial hematoma was number of electrode contacts. The most common pathologic diagnosis was focal cortical dysplasia (n=58). Our results showed that intracranial electroencephalographic monitoring in children provides good surgical outcomes and the level of risk is acceptable. When using this technique strategies such as using as few electrode contacts as possible should be adopted to minimize the risk of intracranial hematoma.
Collapse
Affiliation(s)
- Peng-Fan Yang
- Department of Neurosurgery, Epilepsy Center, Fuzhou General Hospital of Nanjing Command, PLA, Fuzhou 350025, China.
| | - Hui-Jian Zhang
- Department of Pediatric neurology, Epilepsy Center, Fuzhou General Hospital of Nanjing Command, PLA, Fuzhou 350025, China.
| | - Jia-Sheng Pei
- Department of Neurosurgery, Epilepsy Center, Fuzhou General Hospital of Nanjing Command, PLA, Fuzhou 350025, China.
| | - Jun Tian
- Department of Neurosurgery, Epilepsy Center, Fuzhou General Hospital of Nanjing Command, PLA, Fuzhou 350025, China.
| | - Qiao Lin
- Department of Epileptology, Epilepsy Center, Fuzhou General Hospital of Nanjing Command, PLA, Fuzhou 350025, China.
| | - Zhen Mei
- Department of Epileptology, Epilepsy Center, Fuzhou General Hospital of Nanjing Command, PLA, Fuzhou 350025, China.
| | - Zhong-Hui Zhong
- Department of Epileptology, Epilepsy Center, Fuzhou General Hospital of Nanjing Command, PLA, Fuzhou 350025, China.
| | - Yan-Zeng Jia
- Department of Epileptology, Epilepsy Center, Fuzhou General Hospital of Nanjing Command, PLA, Fuzhou 350025, China.
| | - Zi-Qian Chen
- Department of Neuroradiology, Epilepsy Center, Fuzhou General Hospital of Nanjing Command, PLA, Fuzhou 350025, China.
| | - Zhi-Yong Zheng
- Department of Pathology, Epilepsy Center, Fuzhou General Hospital of Nanjing Command, PLA, Fuzhou 350025, China.
| |
Collapse
|
11
|
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.
Collapse
|
12
|
Affiliation(s)
- Sebastian Bauer
- Department of Neurology, UKGM Marburg, Philipps University, Marburg, Germany.
| | | |
Collapse
|
13
|
Placantonakis DG, Shariff S, Lafaille F, Labar D, Harden C, Hosain S, Kandula P, Schaul N, Kolesnik D, Schwartz TH. Bilateral intracranial electrodes for lateralizing intractable epilepsy: efficacy, risk, and outcome. Neurosurgery 2010; 66:274-83. [PMID: 20087126 DOI: 10.1227/01.neu.0000363184.43723.94] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Medically refractory epilepsy is amenable to neurosurgical intervention if the epileptogenic focus is accurately localized. If the scalp video-electroencephalography (EEG) and magnetic resonance imaging are nonlateralizing, yet a single focus is suspected, video-EEG monitoring with bilateral intracranial electrode placement is helpful to lateralize the ictal onset zone. We describe the indications, risks, and utility of such bilateral surveys at our institution. METHODS We retrospectively reviewed 26 patients with medically refractory seizures who were treated over a 5-year period and underwent bilateral placement of intracranial electrodes. Subdural strips were used in all cases, and additional stereotactic implantation of depth electrodes into mesial temporal lobes occurred in 50%. The mean patient age was 37.7 years, and 65.4% of patients were male. RESULTS The most common indication for bilateral invasive monitoring was bilateral ictal onsets on surface video-EEG (76.9%), followed by frequent interictal spikes contralateral to a single ictal focus (7.7%). Intracranial monitoring lasted an average of 8.2 days, with ictal events recorded in all cases. Ten patients (38.5%) subsequently underwent more extensive unilateral monitoring via implantation of subdural and depth electrodes through a craniotomy. A therapeutic procedure was performed in 17 patients (65.4%), whereas 1 patient underwent a palliative corpus callosotomy (3.8%). Nine patients underwent a resection without unilateral invasive mapping. Reasons for no therapeutic surgery (n = 8) included multifocal onsets, failing the Wada test, refusal of further treatment, and negative intraoperative electrocorticogram. There was 1 surgical complication, involving a retained electrode fragment that was removed in a separate minor procedure. Of the 26 patients, 15 (57.7%) are now seizure-free or have seizure disorders that have substantially improved (modified Engel classes I and II). Of the 17 patients who underwent a potentially curative surgery, 13 (76.5%) were Engel classes I and II. CONCLUSION Bilateral placement of subdural strip and depth electrodes for epilepsy monitoring in patients with nonlateralizing scalp EEG and/or discordant imaging studies but clinical suspicion for focal seizure origin is both safe and effective. Given the safety and efficacy of this procedure, epileptologists should have a low threshold to consider bilateral implants for suitable patients.
Collapse
Affiliation(s)
- Dimitris G Placantonakis
- Department of Neurological Surgery, Weill Cornell Medical College, New York-Presbyterian Hospital, New York, New York 10065, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Al-Otaibi FAJ, Alabousi A, Burneo JG, Lee DH, Parrent AG, Steven DA. Clinically silent magnetic resonance imaging findings after subdural strip electrode implantation. J Neurosurg 2010; 112:461-6. [DOI: 10.3171/2009.6.jns09228] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Subdural strip electrodes (SSEs) are often used as part of the workup in patients being considered for epilepsy surgery. To assess for complications or to confirm electrode placement, postoperative imaging is often performed. Imaging performed with the electrodes in situ is limited by streak artifact on CT and susceptibility artifact on MR imaging. Therefore, the first opportunity for high-quality postoperative imaging is following explantation of electrodes. There is no data available to determine what would be the expected MR imaging appearance following insertion of SSE. The purpose of this study is to describe the MR imaging findings in asymptomatic patients who underwent insertion of SSEs.
Methods
Twenty consecutive patients who underwent SSE insertion were studied. Within 24 hours after removal of the electrodes, each patient underwent MR imaging that included axial T2-weighted, gradient echo, diffusion weighted, and coronal FLAIR sequences. No significant symptoms were reported by any of the patients. The studies were reviewed by an experienced, blinded neuroradiologist and categorized.
Results
Of the 20 patients studied, 11 were female (mean age 36 years). Clinically silent postexplantation MR imaging abnormalities were found in all patients: subdural hematomas in 7 (35%), cortical contusions in 5 (25%), local edema in 5 (25%), trans–bur hole cortical herniation in 5 (25%), subdural hygromas in 2 (10%), and pneumocranium in 4 (20%). The MR imaging abnormalities were subdivided into 2 types: Type A, abnormalities related to the site of electrode insertion; and Type B, abnormalities related to the location of the electrodes. The most common location for a Type A abnormality was occipitotemporal, with cortical contusions occurring in this location in 18% of cases, local edema in 24%, and trans–bur hole herniation in 24%. The next most common location was frontal, with cortical contusions found in this location in 10% of cases, local edema in 5% and trans–bur hole herniation in 5%. The most common Type B abnormality was a subdural hematoma, followed by pneumocranium and subdural hygroma.
Conclusions
Clinically silent MR imaging abnormalities are common following SSE placement. Knowledge of these findings would be of assistance in interpreting MR imaging results in patients being assessed for complications.
Collapse
Affiliation(s)
| | | | - Jorge G. Burneo
- 1Epilepsy Programme, Department of Clinical Neurological Sciences
| | - Donald H. Lee
- 3Department of Diagnostic Radiology and Nuclear Medicine, University of Western Ontario, London, Ontario, Canada
| | | | - David A. Steven
- 1Epilepsy Programme, Department of Clinical Neurological Sciences
| |
Collapse
|
15
|
Liubinas SV, Cassidy D, Roten A, Kaye AH, O’Brien TJ. Tailored cortical resection following image guided subdural grid implantation for medically refractory epilepsy. J Clin Neurosci 2009; 16:1398-408. [DOI: 10.1016/j.jocn.2009.03.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Accepted: 03/31/2009] [Indexed: 10/20/2022]
|
16
|
|
17
|
Spire WJ, Jobst BC, Thadani VM, Williamson PD, Darcey TM, Roberts DW. Robotic image-guided depth electrode implantation in the evaluation of medically intractable epilepsy. Neurosurg Focus 2009; 25:E19. [PMID: 18759620 DOI: 10.3171/foc/2008/25/9/e19] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
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.
Collapse
Affiliation(s)
- William J Spire
- Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, One MedicalCenter Drive, Lebanon, New Hampshire 03756, USA.
| | | | | | | | | | | |
Collapse
|
18
|
Patel A, Alotaibi F, Blume WT, Mirsattari SM. Independent component analysis of subdurally recorded occipital seizures. Clin Neurophysiol 2008; 119:2437-46. [DOI: 10.1016/j.clinph.2008.07.276] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2008] [Revised: 06/16/2008] [Accepted: 07/17/2008] [Indexed: 11/30/2022]
|
19
|
Pondal-Sordo M, Diosy D, Téllez-Zenteno JF, Sahjpaul R, Wiebe S. Usefulness of intracranial EEG in the decision process for epilepsy surgery. Epilepsy Res 2007; 74:176-82. [PMID: 17448641 DOI: 10.1016/j.eplepsyres.2007.03.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Revised: 03/05/2007] [Accepted: 03/18/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND AND PURPOSE In patients with discordant results, non-localizing EEG, or bitemporal seizure onset, intracranial monitoring is done to confirm the seizure onset. Our aim was to assess the yield of intracranial recordings in patients with different clinical scenarios. METHODS The records of all patients who underwent prolonged intracranial EEG monitoring (IEM) at the London Health Sciences Centre, University of Western Ontario, Canada, between 1993 and 1999, identified using our EEG patient database in continuous use since December 1972, were reviewed. Patients were analyzed in the following groups according to perceived increasing degrees of uncertainty of epileptic zone localization-group 1: lesion on MRI congruent with focal ictal and interictal scalp EEG, but findings are subtle and of low level of certainty (n=13), group 2: focal MRI, focal ictal and multifocal interictal scalp EEG (n=11), group 3: focal MRI, non-localizing or incongruent scalp EEG (n=73), group 4: normal of multifocal MRI, focal ictal scalp EEG (n=11), group 5: multifocal MRI, non-localizing scalp EEG (n=18), and group 6: normal MRI, multifocal scalp EEG (n=36). RESULTS One hundred and seventy one patients underwent IEM at the London Health Sciences Centre between 1993 and 1999. All patients had localization-related epilepsy, plus or minus secondary generalization. IEM was helpful overall in 86% of patients, in 69% of group 1, 36% of group 2, 90% of group 3, 81% of group 4, 100 of group 5 and 92% of group 6. CONCLUSIONS Our study shows that the yield of the IEM was higher in the groups of patients with lack of congruence between the MRI and the scalp EEG. The yield was lower in patients with congruent but subtle or uncertain scalp EEG and MRI findings.
Collapse
Affiliation(s)
- Margarita Pondal-Sordo
- Department of Clinical Neurological Sciences, London Health Sciences Centre, London, Ontario, Canada
| | | | | | | | | |
Collapse
|
20
|
Cossu M, Cardinale F, Castana L, Citterio A, Francione S, Tassi L, Benabid AL, Lo Russo G. Stereoelectroencephalography in the presurgical evaluation of focal epilepsy: a retrospective analysis of 215 procedures. Neurosurgery 2006. [PMID: 16239883 DOI: 10.1227/01.neu.0000176656.33523.1e] [Citation(s) in RCA: 195] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE To report on indications, surgical technique, results, and morbidity of stereoelectroencephalography (SEEG) in the presurgical evaluation of patients with drug-resistant focal epilepsy. METHODS Two-hundred fifteen stereotactic implantations of multilead intracerebral electrodes were performed in 211 patients (4 patients were explored twice), who showed variable patterns of localizing incoherence among electrical (interictal/ictal scalp electroencephalography), clinical (ictal semeiology), and anatomic (magnetic resonance imaging [MRI]) investigations. MRI scanning showed a lesion in 134 patients (63%; associated with mesial temporal sclerosis in 7) and no lesion in 77 patients (37%; with mesial temporal sclerosis in 14 patients). A total of 2666 electrodes (mean, 12.4 per patient) were implanted (unilaterally in 175 procedures and bilaterally in 40). For electrode targeting, stereotactic stereoscopic cerebral angiograms were used in all patients, coupled with a coregistered three-dimensional MRI scan in 108 patients. RESULTS One hundred eighty-three patients (87%) were scheduled for resective surgery after SEEG recording, and 174 have undergone surgery thus far. Resections sites were temporal in 47 patients (27%), frontal in 55 patients (31.6%), parietal in 14 patients (8%), occipital in one patient (0.6%), rolandic in one patient (0.6%), and multilobar in 56 patients (32.2%). Outcome on seizures (Engel's classification) in 165 patients with a follow-up period of more than 12 months was: Class I, 56.4%; Class II, 15.1%; Class III, 10.9%; and Class IV, 17.6%. Outcome was significantly associated with the results of MRI scanning (P = 0.0001) and with completeness of lesion removal (P = 0.038). Morbidity related to electrode implantation occurred in 12 procedures (5.6%), with severe permanent deficits from intracerebral hemorrhage in 2 (1%) patients. CONCLUSION SEEG is a useful and relatively safe tool in the evaluation of surgical candidates when noninvasive investigations fail to localize the epileptogenic zone. SEEG-based resective surgery may provide excellent results in particularly complex drug-resistant epilepsies.
Collapse
Affiliation(s)
- Massimo Cossu
- Claudio Munari Center for Epilepsy Surgery, Ospedale Niguarda-Ca' Granda, Milan, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Uijl SG, Leijten FSS, Parra J, Arends JBAM, van Huffelen AC, Moons KGM. What is the current evidence on decision-making after referral for temporal lobe epilepsy surgery? Seizure 2005; 14:534-40. [PMID: 16169751 DOI: 10.1016/j.seizure.2005.08.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2004] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVES Many patients thought to have temporal lobe epilepsy, are evaluated for surgical treatment. Decision-making in epilepsy surgery is a multidisciplinary, phased process involving complex diagnostic tests. This study reviews the literature on the value of different tests to decide on whether to operate. METHODS Articles were selected when based on the consensus decision whether to perform temporal lobe surgery, or on the consensus localization or lateralization of the epileptic focus. The articles were scrutinized for sources of bias as formulated in methodological guidelines for diagnostic studies (STARD). RESULTS Most studies did not fulfill the criteria, largely because they addressed prognostic factors in operated patients only. Ten articles met our inclusion criteria. In most articles, a single test was studied; SPECT accounted for five papers. Unbiased comparison of the results was not possible. CONCLUSION Surprisingly little research in epilepsy surgery has focused on the decision-making process as a whole. Future studies of the added value of consecutive tests are needed to avoid redundant testing, enable future cost-efficiency analyses, and provide guidelines for diagnostic strategies after referral for temporal lobe epilepsy surgery.
Collapse
Affiliation(s)
- Sabine G Uijl
- Rudolf Magnus Institute for Neuroscience, Department of Clinical Neurophysiology, hp F02.230, UMC Utrecht, P.O. Box 85500, The Netherlands
| | | | | | | | | | | |
Collapse
|
22
|
Cossu M, Cardinale F, Castana L, Citterio A, Francione S, Tassi L, Benabid AL, Lo Russo G. Stereoelectroencephalography in the Presurgical Evaluation of Focal Epilepsy: A Retrospective Analysis of 215 Procedures. Neurosurgery 2005. [DOI: 10.1093/neurosurgery/57.4.706] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
23
|
Mehta AD, Labar D, Dean A, Harden C, Hosain S, Pak J, Marks D, Schwartz TH. Frameless stereotactic placement of depth electrodes in epilepsy surgery. J Neurosurg 2005; 102:1040-5. [PMID: 16028763 DOI: 10.3171/jns.2005.102.6.1040] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
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.
Collapse
Affiliation(s)
- Ashesh D Mehta
- Department of Neurological Surgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York 10021, USA
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Chapter 51 Intracranial monitoring. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/s1567-424x(09)70387-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
25
|
Cohen-Gadol AA, Spencer DD. Use of an anteromedial subdural strip electrode in the evaluation of medial temporal lobe epilepsy. Technical note. J Neurosurg 2003; 99:921-3. [PMID: 14609175 DOI: 10.3171/jns.2003.99.5.0921] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The temporal lobe is the most common site of partial epilepsy that is amenable to surgical therapy, and therefore ictal localization in this region is important. The authors describe the application of an anteromedial subdural strip electrode for the evaluation of epilepsy originating from the medial temporal lobe. This strip is advanced around the temporal pole and underneath the lesser wing of the sphenoid bone as it follows the medial temporal lobe contour. The advantages of this method of placement are the consistent path and reliable final position of the strip along the medial basal temporal lobe surface. This method allows adequate coverage of the parahippocampal gyrus along its long axis extending posterior to the level of the collicular plate. This technique has been used with no complications during intracranial monitoring of more than 100 patients with presumed temporal lobe epilepsy.
Collapse
Affiliation(s)
- Aaron A Cohen-Gadol
- Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut, USA.
| | | |
Collapse
|
26
|
Schwartz DP, Badier JM, Vignal JP, Toulouse P, Scarabin JM, Chauvel P. Non-supervised spatio-temporal analysis of interictal magnetic spikes: comparison with intracerebral recordings. Clin Neurophysiol 2003; 114:438-49. [PMID: 12705424 DOI: 10.1016/s1388-2457(02)00413-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Our main goal was to evaluate the accuracy of an original non-supervised spatio-temporal magnetoencephalography (MEG) localization method used to characterize interictal spikes generators. METHODS MEG and stereotactic intracerebral recordings (stereo-electro-encephalographic exploration, SEEG) data were analyzed independently in 4 patients. MEG localizations were performed with and without anatomical constraints. RESULTS We analyzed 1326 interictal spikes recorded using MEG. For each patient, 2-3 typical source patterns were described. These source configurations were compared with SEEG. SEEG findings and MEG spatio-temporal localization results were remarkably coherent in our 4 patients. Most of the MEG patterns were similar to interictal SEEG patterns from a spatio-temporal point of view. CONCLUSIONS We were able to evaluate the usefulness of our non-invasive localization method. This approach described correctly the part of the epileptogenic network involved in the generation of interictal events. Our results demonstrate the potential of MEG in the non-invasive spatio-temporal characterization of generators of interictal spikes.
Collapse
Affiliation(s)
- D P Schwartz
- UPRES EA Cortex cérébral et Epilepsie, Université de Rennes 1, Rennes, France.
| | | | | | | | | | | |
Collapse
|
27
|
Abstract
OBJECT Prior reports of seizure control following reoperation for failed epilepsy surgery have shown good results. These studies included patients who presented during the era preceding magnetic resonance (MR) imaging, and the patients were often not monitored intracranially or underwent subtotal hippocampal resections. In this study, the authors hypothesized that reoperation for recurrent seizures following a more comprehensive initial workup and surgery would not yield such good results. METHODS The authors examined a consecutive series of patients who underwent two operations at Yale-New Haven Hospital for medically intractable epilepsy and in whom there was a minimum of 1-year follow up after the second surgery. All patients were evaluated and treated according to a standard protocol, including preoperative MR imaging, a low threshold for invasive monitoring, and a radical amygdalohippocampectomy when indicated. Twenty-seven patients were identified (five with mesial temporal sclerosis, 20 with neocortical disease, and two with multifocal sites of seizure onset) of whom six (22%) underwent intentionally palliative second surgery (corpus callostomy or placement of a vagus nerve stimulator [VNS]). Of the remaining 21 patients, only four (19%) became seizure free after a second resective operation. The most common causes of treatment failure were dual pathology, recurrent tumor, limited resection to preserve function, widespread developmental abnormalities, and electrographic sampling error. Successful outcomes resulted from removal of recurrent tumors, completion of a functional hemispherectomy, or repeated invasive monitoring to correct a sampling error. Five (83%) of the six intentionally palliative second operations resulted in more than a 50% decrease in seizure frequency. CONCLUSIONS If an aggressive preoperative evaluation and surgical resection are performed, reoperation for recurrent seizures has a much lower likelihood of cure than previously reported. Intentionally palliative surgery such as placement of a VNS unit may be considered for patients in whom the initial operation fails to decrease seizure frequency.
Collapse
Affiliation(s)
- T H Schwartz
- Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut, USA.
| | | |
Collapse
|
28
|
Eisenschenk S, Gilmore RL, Cibula JE, Roper SN. Lateralization of temporal lobe foci: depth versus subdural electrodes. Clin Neurophysiol 2001; 112:836-44. [PMID: 11336899 DOI: 10.1016/s1388-2457(01)00517-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Definitive localization of an epileptic focus correlates with a favorable outcome following epilepsy surgery. This study was undertaken to determine the incremental value of data yielded for surgical decision making when using subdural electrodes alone and in addition to depth electrodes for temporal lobe epilepsy. METHODS Standardized placement for intracranial electrodes included: (1) longitudinal placement of bilateral temporal lobe depth electrodes; (2) bilateral subtemporal subdural strips; and (3) bilateral orbitofrontal subdural strips. Sixty-three events were randomly reviewed for: (1) subdural electrodes alone; and (2) depth electrodes in conjunction with subdural electrodes. RESULTS Of the 63 seizures, 54 (85.7%) demonstrated congruent lateralization to ipsilateral subtemporal subdural strip electrodes (based on depth electrode localization) when subdural strip electrodes were utilized alone. In 3 of 22 patients, 7 seizures demonstrated 'false localization' on subdural electrode analysis alone when compared with depth recording and post-surgical outcome. For these 3 patients, retrospective review of neuroimaging demonstrated suboptimal ipsilateral placement of subtemporal subdural electrodes with the most mesial electrode lateral to the collateral sulcus. Four additional patients had suboptimal placement of subtemporal subdural electrodes. Two of these 4 patients had congruent localization with subdural electrodes to ipsilateral depth electrodes despite suboptimal placement. Subtemporal subdural electrodes accurately localized for all seizures from the mesial temporal lobe when the mesial electrodes of the subtemporal subdural strip recorded mesial to the collateral sulcus from the parahippocampal region. CONCLUSION We conclude that although there are high concordance rates between subdural and depth electrodes, localization of seizure onset based on subdural strip electrodes alone may result in inaccurate focus identification with potential for possible suboptimal treatment of temporal lobe epilepsy. When subtemporal subdural electrodes provide recording from the parahippocampal region, there is accurate localization of the seizure focus. If suboptimal placement occurs lateral to the collateral sulcus, the electroencephalographer cannot make a definitive identification of the seizure focus.
Collapse
Affiliation(s)
- S Eisenschenk
- Department of Neurology, University of Florida, University of Florida Brain Institute, 100 South Newell Drive, Room L3-100, Gainesville, FL 32601-0236, USA.
| | | | | | | |
Collapse
|
29
|
Blume WT, Holloway GM, Wiebe S. Temporal epileptogenesis: localizing value of scalp and subdural interictal and ictal EEG data. Epilepsia 2001; 42:508-14. [PMID: 11440346 DOI: 10.1046/j.1528-1157.2001.02700.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
PURPOSE To determine the value of scalp epileptiform EEG data and subdural interictal spikes in localizing temporal epileptogenesis among patients requiring invasive recordings. For this delineation, we related such factors to site of subdural seizure origin in 27 consecutive patients. METHODS Patients with temporal lobe epilepsy whose non-invasive lateralizing data were inconclusive and therefore required subdural electroencephalography were studied. All patients had (a) 24-h scalp telemetered EEGs, (b) adequate bitemporal subdural placements with an inferomesial line extending from a posterior burr hole anteriorly to <2.5 cm from anterior uncus and a lateral line reaching within 2.5 cm of the temporal tip, and (c) > or =2 subdurally recorded seizures. RESULTS Three hundred one (96%) of 314 subdurally recorded clinical seizures involving all 27 patients arose from a discrete focus; 266 (85%) arose from mesial temporal regions, which was the origin of the majority of seizures in 24 (89%) patients. The majority of subdural seizures arose ipsilateral to the majority of scalp EEG spikes in 22 (81%) of 27, and most subdural seizures of 15 (75%) of 20 arose ipsilateral to scalp seizures. Lateralization of interictal subdural spikes correlated with that of subdural seizures in 74-92% of patients, depending on the method of spike compilation: for example, most subdural seizures arose from the same lobe of most consistent principal temporal spikes in 92% of patients. These indices of epileptogenesis also appeared more commonly on the side of effective (> or =90% improvement) temporal lobectomy than contralaterally in the following proportions: most consistent principal subdural spikes, 86% of patients ipsilateral vs. 9% contralateral; scalp-recorded clinical seizures, 55% vs. 18%; scalp EEG spikes, 45% vs. 9%. CONCLUSIONS Even among patients whose scalp data are sufficiently complex to require invasive recording for clarification, lateralization of temporal scalp interictal and ictal epileptiform activity and subdural interictal spikes should be included when assessing the side of temporal epileptogenesis.
Collapse
Affiliation(s)
- W T Blume
- London Health Sciences Centre, University Campus, The University of Western Ontario, Canada
| | | | | |
Collapse
|
30
|
Lazeyras F, Blanke O, Perrig S, Zimine I, Golay X, Delavelle J, Michel CM, de Tribolet N, Villemure JG, Seeck M. EEG-triggered functional MRI in patients with pharmacoresistant epilepsy. J Magn Reson Imaging 2000; 12:177-85. [PMID: 10931578 DOI: 10.1002/1522-2586(200007)12:1<177::aid-jmri20>3.0.co;2-3] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) triggered by scalp electroencephalography (EEG) recordings has become a promising new tool for noninvasive epileptic focus localization. Studies to date have shown that it can be used safely and that highly localized information can be obtained. So far, no reports using comprehensive clinical information and/or long-term follow-up after epilepsy surgery in a larger patient group have been given that would allow a valuable judgment of the utility of this technique. Here, the results of 11 patients with EEG-triggered fMRI exams who also underwent presurgical evaluation of their epilepsy are given. In most patients we were able to record good quality EEG inside the magnet, allowing us to trigger fMRI acquisition by interictal discharges. The fMRI consisted of echoplanar multislice acquisition permitting a large anatomical coverage of the patient's brain. In 8 of the 11 patients the exam confirmed clinical diagnosis, either by the presence (n = 7) or absence (n = 1) of focal signal enhancement. In six patients, intracranial recordings were carried out, and in five of them, the epileptogenic zone as determined by fMRI was confirmed. Limitations were encountered a) when the focus was too close to air cavities; b) if an active epileptogenic focus was absent; and c) if only reduced cooperation with respect to body movements was provided by the patient. We conclude that EEG-triggered fMRI is a safe and powerful noninvasive tool that improves the diagnostic value of MRI by localizing the epileptic focus precisely.
Collapse
Affiliation(s)
- F Lazeyras
- Department of Radiology, University Hospitals of Geneva, Switzerland.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Dubeau F, McLachlan RS. Invasive electrographic recording techniques in temporal lobe epilepsy. Can J Neurol Sci 2000; 27 Suppl 1:S29-34; discussion S50-2. [PMID: 10830324 DOI: 10.1017/s0317167100000615] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The management of uncontrolled partial epilepsy is a process dependent on a multidisciplinary and analytic approach. It is necessary to understand which lesions are epileptogenic, and if they are indeed responsible for the generation of seizures. In addition to localizing seizure onset, the functional and eloquent areas of the brain need to be identified. As in many other centres, we perform resective surgeries on the basis of combined information derived from seizure semiology, EEG abnormalities, neuroimaging and other tests of cerebral function. If surface EEG recording yields inconclusive or ambiguous results, then invasive intracranial techniques using intracerebral depth or subdural electrodes can be used to improve diagnostic or prognostic accuracy. The indications, principles, results and complications of these recording techniques based on extensive experience at two epilepsy surgery centres are reviewed.
Collapse
Affiliation(s)
- F Dubeau
- Department of Neurology & Neurosurgery, McGill University, Montreal, Canada
| | | |
Collapse
|
32
|
Abstract
Intracranial EEG monitoring before epilepsy surgery, while becoming less commonly performed in patients with unilateral mesial temporal lobe epilepsy, is still widely used when bilateral independent temporal lobe seizures are suspected or when extratemporal foci cannot be ruled out by noninvasive means. Additionally, many epilepsy centers are reporting excellent surgical outcome in patients with neocortical temporal lobe epilepsy, when resections are guided by intracranial EEG studies. This article reviews the indications, technical aspects, risks, and interpretation of intracranial EEG in patients with temporal lobe seizures. It also considers intracranial EEG features predictive of surgical outcome.
Collapse
Affiliation(s)
- S V Pacia
- Department of Neurology and the Comprehensive Epilepsy Center, New York University School of Medicine, New York 10016, USA
| | | |
Collapse
|
33
|
Lehman RA. Re: Brekelmans et al: Comparison of combined versus subdural or intracerebral electrodes alone in presurgical focus localization. Epilepsia 1998; 39:1290-301. Epilepsia 1999; 40:1169-71. [PMID: 10448835 DOI: 10.1111/j.1528-1157.1999.tb00838.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|