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Hillebrand A, Holmes N, Sijsma N, O'Neill GC, Tierney TM, Liberton N, Stam AH, van Klink N, Stam CJ, Bowtell R, Brookes MJ, Barnes GR. Non-invasive measurements of ictal and interictal epileptiform activity using optically pumped magnetometers. Sci Rep 2023; 13:4623. [PMID: 36944674 PMCID: PMC10030968 DOI: 10.1038/s41598-023-31111-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 03/06/2023] [Indexed: 03/23/2023] Open
Abstract
Magneto- and electroencephalography (MEG/EEG) are important techniques for the diagnosis and pre-surgical evaluation of epilepsy. Yet, in current cryogen-based MEG systems the sensors are offset from the scalp, which limits the signal-to-noise ratio (SNR) and thereby the sensitivity to activity from deep structures such as the hippocampus. This effect is amplified in children, for whom adult-sized fixed-helmet systems are typically too big. Moreover, ictal recordings with fixed-helmet systems are problematic because of limited movement tolerance and/or logistical considerations. Optically Pumped Magnetometers (OPMs) can be placed directly on the scalp, thereby improving SNR and enabling recordings during seizures. We aimed to demonstrate the performance of OPMs in a clinical population. Seven patients with challenging cases of epilepsy underwent MEG recordings using a 12-channel OPM-system and a 306-channel cryogen-based whole-head system: three adults with known deep or weak (low SNR) sources of interictal epileptiform discharges (IEDs), along with three children with focal epilepsy and one adult with frequent seizures. The consistency of the recorded IEDs across the two systems was assessed. In one patient the OPMs detected IEDs that were not found with the SQUID-system, and in two patients no IEDs were found with either system. For the other patients the OPM data were remarkably consistent with the data from the cryogenic system, noting that these were recorded in different sessions, with comparable SNRs and IED-yields overall. Importantly, the wearability of OPMs enabled the recording of seizure activity in a patient with hyperkinetic movements during the seizure. The observed ictal onset and semiology were in agreement with previous video- and stereo-EEG recordings. The relatively affordable technology, in combination with reduced running and maintenance costs, means that OPM-based MEG could be used more widely than current MEG systems, and may become an affordable alternative to scalp EEG, with the potential benefits of increased spatial accuracy, reduced sensitivity to volume conduction/field spread, and increased sensitivity to deep sources. Wearable MEG thus provides an unprecedented opportunity for epilepsy, and given its patient-friendliness, we envisage that it will not only be used for presurgical evaluation of epilepsy patients, but also for diagnosis after a first seizure.
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Affiliation(s)
- Arjan Hillebrand
- Department of Clinical Neurophysiology and Magnetoencephalography Center, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV, Amsterdam, The Netherlands.
- Brain Imaging, Amsterdam Neuroscience, Amsterdam, The Netherlands.
- Systems and Network Neurosciences, Amsterdam Neuroscience, Amsterdam, The Netherlands.
| | - Niall Holmes
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Ndedi Sijsma
- Department of Clinical Neurophysiology and Magnetoencephalography Center, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV, Amsterdam, The Netherlands
| | - George C O'Neill
- Wellcome Centre for Human Neuroimaging, Department of Imaging Neuroscience, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3AR, UK
| | - Tim M Tierney
- Wellcome Centre for Human Neuroimaging, Department of Imaging Neuroscience, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3AR, UK
| | - Niels Liberton
- Department of Medical Technology, 3D Innovation Lab, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Anine H Stam
- Department of Clinical Neurophysiology and Magnetoencephalography Center, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV, Amsterdam, The Netherlands
| | - Nicole van Klink
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Cornelis J Stam
- Department of Clinical Neurophysiology and Magnetoencephalography Center, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV, Amsterdam, The Netherlands
- Brain Imaging, Amsterdam Neuroscience, Amsterdam, The Netherlands
- Neurodegeneration, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Richard Bowtell
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Matthew J Brookes
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Gareth R Barnes
- Wellcome Centre for Human Neuroimaging, Department of Imaging Neuroscience, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3AR, UK
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Mascia A, Casciato S, De Risi M, Quarato PP, Morace R, D'Aniello A, Grammaldo LG, Pavone L, Picardi A, Esposito V, Di Gennaro G. Bilateral epileptogenesis in temporal lobe epilepsy due to unilateral hippocampal sclerosis: A case series. Clin Neurol Neurosurg 2021; 208:106868. [PMID: 34388593 DOI: 10.1016/j.clineuro.2021.106868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/23/2021] [Accepted: 08/02/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Bitemporal epilepsy (biTLE), a potential cause of failure in TLE surgery, is rarely associated with unilateral HS and could be suggested by not lateralizing ictal scalp EEG/interictal PET-FDG findings. We evaluated the proportion of biTLE in a population of drug-resistant TLE-HS subjects who underwent intracranial investigation for lateralizing purpose. METHODS We retrospectively included all consecutive refractory TLE-HS patients and not lateralizing ictal scalp EEG/interictal PET-FDG findings, investigated by intracranial bilateral longitudinal hippocampal electrodes. Demographic characteristics, electroclinical findings and seizure outcome were evaluated. RESULTS We identified 14 subjects (7 males; mean age 39.5 years; mean age at disease onset 14.4 years), 7 of them had biTLE diagnosed after intracranial investigations. In the remaining 7 with unilateral epileptogenesis (uniTLE) anterior temporal lobectomy was performed (6/7 were in Engel class I). Preoperative neuropsychological assessment differentiated biTLE from uniTLE, as it was normal in six uniTLE patients but only in one with biTLE (p < 0.05). CONCLUSIONS Not lateralizing ictal scalp EEG and functional imaging findings in TLEHS should alert about the possibility of a true biTLE also in presence of unilateral findings at MRI. Intracranial investigations with bilateral longitudinal hippocampal electrodes can localize the EZ with a good risk-benefit profile. Consistently with the warning on memory functions in TLE patients explored by using longitudinal hippocampal electrodes, further studies are needed to better define the optimal investigation strategy.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Angelo Picardi
- Centre of Behavioural Sciences and Mental Health, Italian National Institute of Health, Rome, Italy
| | - Vincenzo Esposito
- IRCCS NEUROMED, Pozzilli, Isernia, Italy; Department of Neurosurgery, "Sapienza" University, Rome, Italy
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Aznarez PB, Cabeza MP, Quintana ASA, Lara-Almunia M, Sanchez JA. Evolution of patients with surgically treated drug-resistant occipital lobe epilepsy. Surg Neurol Int 2020; 11:222. [PMID: 32874725 PMCID: PMC7451154 DOI: 10.25259/sni_251_2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 07/14/2020] [Indexed: 12/15/2022] Open
Abstract
Background This study was to describe the evolution of patients who underwent surgical treatment of drug- resistant occipital lobe epilepsy (OLE) at our institution. Methods We performed a retrospective analysis of data collected from electronic and paper clinical records of 20 patients who were diagnosed of OLE and underwent epilepsy surgery at our institution between 1998 and 2018. We also contacted patients by telephone and asked them to fill out a questionnaire about quality of life in epilepsy (QOLIE-10). Assembled data were analyzed using descriptive statistics. Results The age at surgery ranged between 19 and 55 years. The period encompassing epilepsy onset and the date of surgery was variable. Semiology of seizures included visual symptoms in 75% of patients. In 90% of cases subdural grids, depth electrodes or a combination of both were used to plan the surgery. The most frequent neuroimaging and histopathological finding was cortical dysplasia (55%). The postoperative follow-up period was up to 15 years. The most common score on the Engel scale was I (70%). Visual deficits increased after surgery. Median score on QOLIE-10 questionnaire was 82.5 (interquartile range: 32.5). Conclusion Surgical treatment of drug-resistant OLE offers hopeful results to those patients who have run out of pharmacological options and leads to postoperative deficits that are deemed expectable and occasionally acceptable.
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Affiliation(s)
| | - Marta Pastor Cabeza
- Department of Neurosurgery, Germans Trias i Pujol Hospital, Badalona, Catalonia, Spain
| | | | - Monica Lara-Almunia
- Department of Neurosurgery, Jimenez Diaz Foundation University Hospital, Madrid
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Feng AY, Ho AL, Kim LH, Sussman ES, Pendharkar AV, Iv M, Yeom KW, Halpern CH, Grant GA. Utilization of Novel High-Resolution, MRI-Based Vascular Imaging Modality for Preoperative Stereoelectroencephalography Planning in Children: A Technical Note. Stereotact Funct Neurosurg 2020; 98:1-7. [PMID: 32062664 DOI: 10.1159/000503693] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 09/25/2019] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Stereoelectroencephalography (SEEG) is a powerful intracranial diagnostic tool that requires accurate imaging for proper electrode trajectory planning to ensure efficacy and maximize patient safety. Computed tomography (CT) angiography and digital subtraction angiography are commonly used, but recent developments in magnetic resonance angiography allow for high-resolution vascular visualization without added risks of radiation. We report on the accuracy of electrode placement under robotic assistance planning utilizing a novel high-resolution magnetic resonance imaging (MRI)-based imaging modality. METHODS Sixteen pediatric patients between February 2014 and October 2017 underwent SEEG exploration for epileptogenic zone localization. A gadolinium-enhanced 3D T1-weighted spoiled gradient recalled echo sequence with minimum echo time and repetition time was applied for background parenchymal suppression and vascular enhancement. Electrode placement accuracy was determined by analyzing postoperative CT scans laid over preoperative virtual electrode trajectory paths. Entry point, target point, and closest vessel intersection were measured. RESULTS For any intersection along the trajectory path, 57 intersected vessels were measured. The mean diameter of an intersected vessel was 1.0343 ± 0.1721 mm, and 21.05% of intersections involved superficial vessels. There were 157 overall intersection + near-miss events. The mean diameter for an involved vessel was 1.0236 ± 0.0928 mm, and superficial vessels were involved in 20.13%. Looking only at final electrode target, 3 intersection events were observed. The mean diameter of an intersected vessel was 1.0125 ± 0.2227 mm. For intersection + near-miss events, 24 were measured. An involved vessel's mean diameter was 1.1028 ± 0.2634 mm. For non-entry point intersections, 45 intersected vessels were measured. The mean diameter for intersected vessels was 0.9526 ± 0.0689 mm. For non-entry point intersections + near misses, 126 events were observed. The mean diameter for involved vessels was 0.9826 ± 0.1008 mm. CONCLUSION We believe this novel sequence allows better identification of superficial and deeper subcortical vessels compared to conventional T1-weighted gadolinium-enhanced MRI.
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Affiliation(s)
- Austin Y Feng
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA
| | - Allen L Ho
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA
| | - Lily H Kim
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA
| | - Eric S Sussman
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA
| | - Arjun V Pendharkar
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA
| | - Michael Iv
- Department of Radiology, Stanford University Medical Center, Stanford, California, USA
| | - Kristen W Yeom
- Department of Radiology, Pediatric Radiology, Lucile Packard Children's Hospital at Stanford, Stanford, California, USA
| | - Casey H Halpern
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA
| | - Gerald A Grant
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA, .,Division of Pediatric Neurosurgery, Lucile Packard Children's Hospital Stanford, Stanford, California, USA,
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Sudhakar V, Naidoo J, Samaranch L, Bringas JR, Lonser RR, Fiandaca MS, Bankiewicz KS. Infuse-as-you-go convective delivery to enhance coverage of elongated brain targets: technical note. J Neurosurg 2019; 133:530-537. [PMID: 31299656 DOI: 10.3171/2019.4.jns19826] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 04/29/2019] [Indexed: 01/07/2023]
Abstract
OBJECTIVE To develop and assess a convective delivery technique that enhances the effectiveness of drug delivery to nonspherical brain nuclei, the authors developed an occipital "infuse-as-you-go" approach to the putamen and compared it to the currently used transfrontal approach. METHODS Eleven nonhuman primates received a bilateral putamen injection of adeno-associated virus with 2 mM gadolinium-DTPA by real-time MR-guided convective perfusion via either a transfrontal (n = 5) or occipital infuse-as-you-go (n = 6) approach. RESULTS MRI provided contemporaneous assessment and monitoring of putaminal infusions for transfrontal (2 to 3 infusion deposits) and occipital infuse-as-you-go (stepwise infusions) putaminal approaches. The infuse-as-you-go technique was more efficient than the transfrontal approach (mean 35 ± 1.1 vs 88 ± 8.3 minutes [SEM; p < 0.001]). More effective perfusion of the postcommissural and total putamen was achieved with the infuse-as-you-go versus transfronatal approaches (100-µl infusion volumes; mean posterior commissural coverage 76.2% ± 5.0% vs 32.8% ± 2.9% [p < 0.001]; and mean total coverage 53.5% ± 3.0% vs 38.9% ± 2.3% [p < 0.01]). CONCLUSIONS The infuse-as-you-go approach, paralleling the longitudinal axis of the target structure, provides a more effective and efficient method for convective infusate coverage of elongated, irregularly shaped subcortical brain nuclei.
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Affiliation(s)
- Vivek Sudhakar
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - Jerusha Naidoo
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - Lluis Samaranch
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - John R Bringas
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - Russell R Lonser
- 2Department of Neurological Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Massimo S Fiandaca
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - Krystof S Bankiewicz
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
- 2Department of Neurological Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio
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Willems LM, Reif PS, Spyrantis A, Cattani A, Freiman TM, Seifert V, Wagner M, You SJ, Schubert-Bast S, Bauer S, Klein KM, Rosenow F, Strzelczyk A. Invasive EEG-electrodes in presurgical evaluation of epilepsies: Systematic analysis of implantation-, video-EEG-monitoring- and explantation-related complications, and review of literature. Epilepsy Behav 2019; 91:30-37. [PMID: 29907526 DOI: 10.1016/j.yebeh.2018.05.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/04/2018] [Accepted: 05/05/2018] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Stereoelectroencephalography (sEEG) is a diagnostic procedure for patients with refractory focal epilepsies that is performed to localize and define the epileptogenic zone. In contrast to grid electrodes, sEEG electrodes are implanted using minimal invasive operation techniques without large craniotomies. Previous studies provided good evidence that sEEG implantation is a safe and effective procedure; however, complications in asymptomatic patients after explantation may be underreported. The aim of this analysis was to systematically analyze clinical and imaging data following implantation and explantation. RESULTS We analyzed 18 consecutive patients (mean age: 30.5 years, range: 12-46; 61% female) undergoing invasive presurgical video-EEG monitoring via sEEG electrodes (n = 167 implanted electrodes) over a period of 2.5 years with robot-assisted implantation. There were no neurological deficits reported after implantation or explantation in any of the enrolled patients. Postimplantation imaging showed a minimal subclinical subarachnoid hemorrhage in one patient and further workup revealed a previously unknown factor VII deficiency. No injuries or status epilepticus occurred during video-EEG monitoring. In one patient, a seizure-related asymptomatic cross break of two fixation screws was found and led to revision surgery. Unspecific symptoms like headaches or low-grade fever were present in 10 of 18 (56%) patients during the first days of video-EEG monitoring and were transient. Postexplantation imaging showed asymptomatic and small bleedings close to four electrodes (2.8%). CONCLUSION Overall, sEEG is a safe and well-tolerated procedure. Systematic imaging after implantation and explantation helps to identify clinically silent complications of sEEG. In the literature, complication rates of up to 4.4% in sEEG and in 49.9% of subdural EEG are reported; however, systematic imaging after explantation was not performed throughout the studies, which may have led to underreporting of associated complications.
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Affiliation(s)
- Laurent M Willems
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Goethe-University, Frankfurt am Main, Germany; LOEWE Center for Personalized Translational Epilepsy Research (CePTER), Goethe-University, Frankfurt am Main, Germany.
| | - Philipp S Reif
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Goethe-University, Frankfurt am Main, Germany; LOEWE Center for Personalized Translational Epilepsy Research (CePTER), Goethe-University, Frankfurt am Main, Germany
| | - Andrea Spyrantis
- Department of Neurosurgery, Goethe-University, Frankfurt am Main, Germany
| | - Adriano Cattani
- Department of Neurosurgery, Goethe-University, Frankfurt am Main, Germany
| | - Thomas M Freiman
- Department of Neurosurgery, Goethe-University, Frankfurt am Main, Germany; LOEWE Center for Personalized Translational Epilepsy Research (CePTER), Goethe-University, Frankfurt am Main, Germany
| | - Volker Seifert
- Department of Neurosurgery, Goethe-University, Frankfurt am Main, Germany
| | - Marlies Wagner
- Department of Neuroradiology, Goethe-University, Frankfurt am Main, Germany; LOEWE Center for Personalized Translational Epilepsy Research (CePTER), Goethe-University, Frankfurt am Main, Germany
| | - Se-Jong You
- Department of Neuroradiology, Goethe-University, Frankfurt am Main, Germany
| | - Susanne Schubert-Bast
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Goethe-University, Frankfurt am Main, Germany; Department of Neuropediatrics, Goethe-University, Frankfurt am Main, Germany; LOEWE Center for Personalized Translational Epilepsy Research (CePTER), Goethe-University, Frankfurt am Main, Germany
| | - Sebastian Bauer
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Goethe-University, Frankfurt am Main, Germany; LOEWE Center for Personalized Translational Epilepsy Research (CePTER), Goethe-University, Frankfurt am Main, Germany
| | - Karl Martin Klein
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Goethe-University, Frankfurt am Main, Germany; LOEWE Center for Personalized Translational Epilepsy Research (CePTER), Goethe-University, Frankfurt am Main, Germany
| | - Felix Rosenow
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Goethe-University, Frankfurt am Main, Germany; LOEWE Center for Personalized Translational Epilepsy Research (CePTER), Goethe-University, Frankfurt am Main, Germany
| | - Adam Strzelczyk
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Goethe-University, Frankfurt am Main, Germany; LOEWE Center for Personalized Translational Epilepsy Research (CePTER), Goethe-University, Frankfurt am Main, Germany
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Robotic-Guided Bihippocampal and Biparahippocampal Depth Placement for Responsive Neurostimulation in Bitemporal Lobe Epilepsy. World Neurosurg 2018; 111:181-189. [DOI: 10.1016/j.wneu.2017.10.164] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 10/27/2017] [Accepted: 10/28/2017] [Indexed: 11/16/2022]
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Richardson AG, Liu X, Weigand PK, Hudgins ED, Stein JM, Das SR, Proekt A, Kelz MB, Zhang M, Van der Spiegel J, Lucas TH. Hippocampal gamma-slow oscillation coupling in macaques during sedation and sleep. Hippocampus 2017; 27:1125-1139. [PMID: 28667703 DOI: 10.1002/hipo.22757] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 05/22/2017] [Accepted: 06/16/2017] [Indexed: 11/07/2022]
Abstract
Behavioral and neurophysiological evidence suggests that the slow (≤1 Hz) oscillation (SO) during sleep plays a role in consolidating hippocampal (HIPP)-dependent memories. The effects of the SO on HIPP activity have been studied in rodents and cats both during natural sleep and during anesthetic administration titrated to mimic sleep-like slow rhythms. In this study, we sought to document these effects in primates. First, HIPP field potentials were recorded during ketamine-dexmedetomidine sedation and during natural sleep in three rhesus macaques. Sedation produced regionally-specific slow and gamma (∼40 Hz) oscillations with strong coupling between the SO phase and gamma amplitude. These same features were seen in slow-wave sleep (SWS), but the coupling was weaker and the coupled gamma oscillation had a higher frequency (∼70 Hz) during SWS. Second, electrical stimuli were delivered to HIPP afferents in the parahippocampal gyrus (PHG) during sedation to assess the effects of sleep-like SO on excitability. Gamma bursts after the peak of SO cycles corresponded to periods of increased gain of monosynaptic connections between the PHG and HIPP. However, the two PHG-HIPP connectivity gains during sedation were both substantially lower than when the animal was awake. We conclude that the SO is correlated with rhythmic excitation and inhibition of the PHG-HIPP network, modulating connectivity and gamma generators intrinsic to this network. Ketamine-dexmedetomidine sedation produces a similar effect, but with a decreased contribution of the PHG to HIPP activity and gamma generation.
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Affiliation(s)
- Andrew G Richardson
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Xilin Liu
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Pauline K Weigand
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Eric D Hudgins
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Joel M Stein
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Sandhitsu R Das
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Alexander Proekt
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Max B Kelz
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Milin Zhang
- Department of Electronic Engineering, Tsinghua University, Beijing, China
| | - Jan Van der Spiegel
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Timothy H Lucas
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania
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Chan AY, Lin JJ, Mnatsakanyan L, Sazgar M, Sen-Gupta I, Hsu FP, Vadera S. Robot-assisted placement of depth electrodes along the long Axis of the amygdalohippocampal complex. INTERDISCIPLINARY NEUROSURGERY-ADVANCED TECHNIQUES AND CASE MANAGEMENT 2016. [DOI: 10.1016/j.inat.2016.04.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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10
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Mathon B, Clemenceau S, Hasboun D, Habert MO, Belaid H, Nguyen-Michel VH, Lambrecq V, Navarro V, Dupont S, Baulac M, Cornu P, Adam C. Safety profile of intracranial electrode implantation for video-EEG recordings in drug-resistant focal epilepsy. J Neurol 2015; 262:2699-712. [DOI: 10.1007/s00415-015-7901-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 09/08/2015] [Accepted: 09/09/2015] [Indexed: 11/25/2022]
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Wu C, LaRiviere MJ, Laxpati N, Evans JJ, Gross RE, Sharan AD. Extraventricular long-axis cannulation of the hippocampus: technical considerations. Neurosurgery 2015; 10 Suppl 2:325-32; discussion 332-3. [PMID: 24553091 DOI: 10.1227/neu.0000000000000320] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Patients with hippocampal epileptogenic foci may benefit from targeted intracranial monitoring of seizures and treatments such as hippocampal electrical stimulation, closed-loop stimulation, and stereotactic laser ablation. Each may benefit from a greater volume of hippocampal coverage with long-axis cannulation. Furthermore, an extraventricular trajectory avoids brain shift and reduces the risk of hemorrhage from ependymal breach. Unfortunately, detailed descriptions of the technical aspects of longitudinal cannulation of the hippocampus remain sparse. OBJECTIVE To develop a standard protocol for extraventricular longitudinal hippocampal cannulation. METHODS Images from 25 patients stereotactically implanted with 27 longitudinal hippocampal devices were retrospectively reviewed to determine the location of the burr hole or twist drill craniostomy. Simulated planning for bilateral occipital trajectories was then performed on a second cohort of 25 patients (50 trajectories) with mesial temporal sclerosis. An entry point derived from these 77 trajectories was subsequently validated on a third cohort of 25 patients (50 trajectories). RESULTS Extraventricular long-axis hippocampal implantation necessitates a lateral-to-medial and cephalad-to-caudal trajectory that skirts the inferomedial border of the temporal horn. Measurements from 64 trajectories suggested a consensus entry point that successfully facilitated 50 test trajectories as well as frame placement on 4 patients requiring long-axis hippocampal cannulation. CONCLUSION Although trajectories must be individually tailored for each patient, we recommend a starting entry point approximately 5.5 cm superior to the external occipital protuberance and 5.5 cm lateral to midline for extraventricular long-axis hippocampal cannulation in adult patients. Identification of this point is particularly important when positioning the stereotactic frame.
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Affiliation(s)
- Chengyuan Wu
- *Thomas Jefferson University, Department of Neurosurgery, Philadelphia, Pennsylvania; ‡Emory University School of Medicine, Atlanta, Georgia; §Emory University Department of Neurosurgery, Atlanta, Georgia
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Hedegärd E, Bjellvi J, Edelvik A, Rydenhag B, Flink R, Malmgren K. Complications to invasive epilepsy surgery workup with subdural and depth electrodes: a prospective population-based observational study. J Neurol Neurosurg Psychiatry 2014; 85:716-20. [PMID: 24293000 PMCID: PMC4078707 DOI: 10.1136/jnnp-2013-306465] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE In some patients who undergo presurgical workup for drug-resistant epilepsy invasive seizure monitoring is needed to define the seizure onset zone and delineate eloquent cortex. Such procedures carry risks for complications causing permanent morbidity and even mortality. In this study, prospective data on complications in a national population-based sample were analysed. DESIGN Complication data from the prospective Swedish National Epilepsy Surgery Register were analysed for 271 patients in whom therapeutic surgery was preceded by invasive monitoring 1996-2010. RESULTS Complications occurred in 13/271 patients (4.8%). Subdural grids carried the highest risk of complications (7.4%). There was no surgical mortality or permanent morbidity. Subdural haematomas were most common (n=7) followed by epidural haematomas (n=3). Valproate treatment and having a haematoma was associated with an OR of 1.53 (CI 0.38 to 6.12) compared to having a haematoma without valproate treatment. Having a complication during invasive monitoring was associated with a significant OR of 6.27 (CI 1.32 to 29.9) of also having a complication at therapeutic surgery compared to the risk of having a complication only at surgery. CONCLUSIONS In this prospective population-based epilepsy surgery series, the most common complications were haematomas, and subdural grids carried the highest risk. Close supervision and rapid interventions led to avoidance of permanent morbidity. The clinical implications of the slightly increased risk of haematomas with valproate treatment needs further investigation as does the finding of an increased risk for complications at epilepsy surgery for patients who had a complication during invasive monitoring.
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Affiliation(s)
- Emelie Hedegärd
- Epilepsy Research Group, Institute of Neuroscience and Physiology, Sahlgrenska Academy at Gothenburg University, Göteborg, Sweden
| | - Johan Bjellvi
- Epilepsy Research Group, Institute of Neuroscience and Physiology, Sahlgrenska Academy at Gothenburg University, Göteborg, Sweden
| | - Anna Edelvik
- Epilepsy Research Group, Institute of Neuroscience and Physiology, Sahlgrenska Academy at Gothenburg University, Göteborg, Sweden
| | - Bertil Rydenhag
- Epilepsy Research Group, Institute of Neuroscience and Physiology, Sahlgrenska Academy at Gothenburg University, Göteborg, Sweden
| | - Roland Flink
- Department of Clinical Neurophysiology, Uppsala University Hospital, Uppsala, Sweden
| | - Kristina Malmgren
- Epilepsy Research Group, Institute of Neuroscience and Physiology, Sahlgrenska Academy at Gothenburg University, Göteborg, Sweden
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Sweet JA, Hdeib AM, Sloan A, Miller JP. Depths and grids in brain tumors: implantation strategies, techniques, and complications. Epilepsia 2014; 54 Suppl 9:66-71. [PMID: 24328876 DOI: 10.1111/epi.12447] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Patients with intracranial mass lesions are at increased risk of intractable epilepsy even after tumor resection due to the potential epileptogenicity of lesional and perilesional tissue. Risk factors for tumoral epilepsy include tumor location, histology, and extent of tumor resection. In epilepsy that occurs after tumor resection, the epileptogenic zone often does not correspond precisely with the area of abnormality on imaging, and seizures often arise from a relatively restricted area despite widespread changes on imaging. Invasive monitoring via subdural grids and/or depth electrodes can therefore be helpful to delineate areas of eloquence and localize the epileptogenic zone for subsequent resection. Subdural grids offer excellent contiguous coverage of superficial cortex and allow resection using the same craniotomy, facilitating understanding of anatomic relationships. Depth electrodes offer superior coverage of deep structures, are easier to use in cases where a previous craniotomy is present, are not associated with anatomic distortion due to brain shift, and may be associated with a lower complication rate. We review the biology of focal postoperative epilepsy and invasive diagnostic strategies for the surgical evaluation of medically refractory epilepsy in patients who have undergone resection of intracranial mass lesions.
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Affiliation(s)
- Jennifer A Sweet
- Department of Neurological Surgery, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio, U.S.A
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