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Sharma AA, Mackensie Terry D, Popp JL, Szaflarski JP, Martin RC, Nenert R, Kaur M, Brokamp GA, Bolding M, Allendorfer JB. Neuromorphometric associations with mood, cognition, and self-reported exercise levels in epilepsy and healthy individuals. Epilepsy Behav Rep 2023; 25:100643. [PMID: 38264358 PMCID: PMC10803905 DOI: 10.1016/j.ebr.2023.100643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/25/2024] Open
Abstract
Regular physical activity may promote beneficial neuroplasticity, e.g., increased hippocampus volume. However, it is unclear whether self-reported physical exercise in leisure (PEL) levels are associated with the brain structure features demonstrated by exercise interventions. This pilot study investigated the relationship between PEL, mood, cognition, and neuromorphometry in patients with idiopathic generalized epilepsy (IGEs) compared to healthy controls (HCs). Seventeen IGEs and 19 age- and sex-matched HCs underwent magnetic resonance imaging (MRI) at 3T. The Baecke Questionnaire of Habitual Physical Activity, Profile of Mood States, and Montreal Cognitive Assessment (MoCA) assessed PEL, mood, and cognition, respectively. Structural MRI data were analyzed by voxel- and surface-based morphometry. IGEs had significantly lower PEL (p < 0.001), poorer mood (p = 0.029), and lower MoCA scores (p = 0.027) than HCs. These group differences were associated with reduced volume, decreased gyrification, and altered surface topology (IGEs < HCs) in frontal, temporal and cerebellar regions involved in executive function, memory retrieval, and emotional regulation, respectively. These preliminary results support the notion that increased PEL may promote neuroplasticity in IGEs, thus emphasizing the role of physical activity in promoting brain health in people with epilepsy.
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Affiliation(s)
- Ayushe A. Sharma
- University of Alabama at Birmingham (UAB), Department of Neurology, Birmingham, AL, USA
| | - D. Mackensie Terry
- University of Alabama at Birmingham (UAB), Department of Neurology, Birmingham, AL, USA
| | - Johanna L. Popp
- University of Alabama at Birmingham (UAB), Department of Neurology, Birmingham, AL, USA
| | - Jerzy P. Szaflarski
- University of Alabama at Birmingham (UAB), Department of Neurology, Birmingham, AL, USA
- University of Alabama at Birmingham (UAB), Department of Neurobiology, Birmingham, AL, USA
- University of Alabama at Birmingham (UAB), Department of Neurosurgery, Birmingham, AL, USA
- University of Alabama at Birmingham (UAB), UAB Epilepsy Center, Birmingham, AL, USA
| | - Roy C. Martin
- University of Alabama at Birmingham (UAB), Department of Neurology, Birmingham, AL, USA
- University of Alabama at Birmingham (UAB), UAB Epilepsy Center, Birmingham, AL, USA
| | - Rodolphe Nenert
- University of Alabama at Birmingham (UAB), Department of Neurology, Birmingham, AL, USA
| | - Manmeet Kaur
- University of Alabama at Birmingham (UAB), Department of Neurology, Birmingham, AL, USA
- University of Alabama at Birmingham (UAB), UAB Epilepsy Center, Birmingham, AL, USA
| | - Gabrielle A. Brokamp
- University of Alabama at Birmingham (UAB), Department of Neurology, Birmingham, AL, USA
| | - Mark Bolding
- University of Alabama at Birmingham (UAB), Department of Radiology, Birmingham, AL, USA
| | - Jane B. Allendorfer
- University of Alabama at Birmingham (UAB), Department of Neurology, Birmingham, AL, USA
- University of Alabama at Birmingham (UAB), Department of Neurobiology, Birmingham, AL, USA
- University of Alabama at Birmingham (UAB), UAB Epilepsy Center, Birmingham, AL, USA
- University of Alabama at Birmingham (UAB), UAB Center for Exercise Medicine, Birmingham, AL, USA
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Berry BM, Miller LR, Berns M, Kucewicz M. The Possibility of Eidetic Memory in a Patient Report of Epileptogenic Zone in Right Temporo-Parietal-Occipital Cortex. Life (Basel) 2023; 13:956. [PMID: 37109485 PMCID: PMC10145536 DOI: 10.3390/life13040956] [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: 02/20/2023] [Revised: 03/16/2023] [Accepted: 03/18/2023] [Indexed: 04/29/2023] Open
Abstract
Eidetic memory has been reported in children and in patients with synesthesia but is otherwise thought to be a rare phenomenon. Presented herein is a patient with right-sided language dominance, as proven via multiple functional imaging and neuropsychometric methods, who has a seizure onset zone in the right temporo-parietal-occipital cortex. This patient's medically refractory epilepsy and thus hyperactive cortex could possibly contribute to near eidetic ability with paired-associates learning tasks (in both short-term and long-term retention). There are reports of epilepsy negatively affecting memory, but as far as the authors are aware to date, there is limited evidence of any lesion enhancing cognitive functions (whether through direct lesion or via compensatory mechanism) that would be localized to a seizure onset zone in the dominant temporo-parietal-occipital junction.
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Affiliation(s)
- Brent M. Berry
- University of Minnesota Medical School, 420 Delaware St SE, Minneapolis, MN 55455, USA
- Neurology Department, University of Minnesota, 516 Delaware St SE, Minneapolis, MN 55455, USA
- VA Medical Center, 1 Veterans Drive, Minneapolis, MN 55417, USA
- Mayo Clinic, Department of Neurology, Department of Sleep Medicine, Department of Physiology & Biomedical Engineering, 200 First St. SW, Rochester, MN 55905, USA
- BioTechMed Center, Brain & Mind Electrophysiology Lab, Department of Multimedia Systems, Faculty of Electronics, Telecommunication and Informatics, Gdansk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Laura R. Miller
- Mayo Clinic, Department of Neurology, Department of Sleep Medicine, Department of Physiology & Biomedical Engineering, 200 First St. SW, Rochester, MN 55905, USA
| | - Meaghan Berns
- University of Minnesota Medical School, 420 Delaware St SE, Minneapolis, MN 55455, USA
- Neurology Department, University of Minnesota, 516 Delaware St SE, Minneapolis, MN 55455, USA
| | - Michal Kucewicz
- Mayo Clinic, Department of Neurology, Department of Sleep Medicine, Department of Physiology & Biomedical Engineering, 200 First St. SW, Rochester, MN 55905, USA
- BioTechMed Center, Brain & Mind Electrophysiology Lab, Department of Multimedia Systems, Faculty of Electronics, Telecommunication and Informatics, Gdansk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdańsk, Poland
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Zhou Y, You J, Kumar U, Weiss SA, Bragin A, Engel J, Papadelis C, Li L. An approach for reliably identifying high-frequency oscillations and reducing false-positive detections. Epilepsia Open 2022; 7:674-686. [PMID: 36053171 PMCID: PMC9712470 DOI: 10.1002/epi4.12647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 08/31/2022] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE Aiming to improve the feasibility and reliability of using high-frequency oscillations (HFOs) for translational studies of epilepsy, we present a pipeline with features specifically designed to reject false positives for HFOs to improve the automatic HFO detector. METHODS We presented an integrated, multi-layered procedure capable of automatically rejecting HFOs from a variety of common false positives, such as motion, background signals, and sharp transients. This method utilizes a time-frequency contour approach that embeds three different layers including peak constraints, power thresholds, and morphological identification to discard false positives. Four experts were involved in rating detected HFO events that were randomly selected from different posttraumatic epilepsy (PTE) animals for a comprehensive evaluation. RESULTS The algorithm was run on 768-h recordings of intracranial electrodes in 48 PTE animals. A total of 453 917 HFOs were identified by initial HFO detection, of which 450 917 were implemented for HFO refinement and 203 531 events were retained. Random sampling was used to evaluate the performance of the detector. The HFO detection yielded an overall accuracy of 0.95 ± 0.03 , with precision, recall, and F1 scores of 0.92 ± 0.05 , 0.99 ± 0.01 , and 0.94 ± 0.03 , respectively. For the HFO classification, our algorithm obtained an accuracy of 0.97 ± 0.02 . For the inter-rater reliability of algorithm evaluation, the agreement among four experts was 0.94 ± 0.03 for HFO detection and 0.85 ± 0.04 for HFO classification. SIGNIFICANCE Our approach shows that a segregated pipeline design with a focus on false-positive rejection can improve the detection efficiency and provide reliable results. This pipeline does not require customization and uses fixed parameters, making it highly feasible and translatable for basic and clinical applications of epilepsy.
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Affiliation(s)
- Yufeng Zhou
- Department of Biomedical EngineeringUniversity of North TexasTexasUSA
| | - Jing You
- Department of Biomedical EngineeringUniversity of North TexasTexasUSA
| | - Udaya Kumar
- Department of NeurologyUniversity of California Los AngelesLos AngelesCaliforniaUSA
| | - Shennan A Weiss
- Departments of Neurology, Department of Physiology and PharmacologyState University of New York DownstateBrooklynNew YorkUSA,Department of NeurologyNew York City Health + Hospitals/Kings CountyBrooklynNew YorkUSA
| | - Anatol Bragin
- Department of NeurologyUniversity of California Los AngelesLos AngelesCaliforniaUSA,Brain Research InstituteUniversity of CaliforniaLos AngelesCaliforniaUSA
| | - Jerome Engel
- Department of NeurologyUniversity of California Los AngelesLos AngelesCaliforniaUSA,Brain Research InstituteUniversity of CaliforniaLos AngelesCaliforniaUSA,Department of NeurobiologyDavid Geffen School of Medicine at UCLALos AngelesCaliforniaUSA,Department of Psychiatry and Biobehavioral SciencesDavid Geffen School of Medicine at UCLACaliforniaUSA
| | - Christos Papadelis
- Jane and John Justin Neurosciences CenterCook Children's Health Care SystemFort WorthTexasUSA,School of MedicineTexas Christian UniversityFort WorthTexasUSA,Department of BioengineeringUniversity of Texas at ArlingtonArlingtonTexasUSA
| | - Lin Li
- Department of Biomedical EngineeringUniversity of North TexasTexasUSA,Department of NeurologyUniversity of California Los AngelesLos AngelesCaliforniaUSA
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Sugano H, Iimura Y, Suzuki H, Tamrakar S, Mitsuhashi T, Higo T, Ueda T, Nishioka K, Karagiozov K, Nakajima M. Can intraoperative electrocorticography be used to minimize the extent of resection in patients with temporal lobe epilepsy associated with hippocampal sclerosis? J Neurosurg 2022; 137:419-426. [PMID: 34861650 DOI: 10.3171/2021.9.jns211925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 09/21/2021] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Tailored surgery to extensively resect epileptogenic lesions using intraoperative electrocorticography (ioECoG) may improve seizure outcomes. However, resection of large areas is associated with decreased memory function postoperatively. The authors assessed whether ioECoG could provide useful information on how to minimize the focus resection and obtain better seizure outcomes without memory deterioration. They examined the postoperative seizure-free period and memory alteration in a retrospective cohort of patients with mesial temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS) in whom the extent of removal was determined using ioECoG findings. METHODS The authors enrolled 82 patients with TLE associated with HS who were treated surgically. Transsylvian amygdalohippocampectomy was indicated as the first step. When visual inspection identified interictal epileptic discharges from the lateral temporal lobe on ioECoG, anterior temporal lobectomy (ATL) was eventually performed. The patients were divided into the selective amygdalohippocampectomy (SA, n = 40) and ATL (n = 42) groups. Postoperative seizure outcomes were assessed at 1, 2, 3, 5, and 7 years postoperatively using the International League Against Epilepsy classification. The Kaplan-Meier survival analysis was applied to evaluate the period of seizure recurrence between the SA and ATL groups. Factors attributed to seizure recurrence were analyzed using the Cox proportional hazards model, and they were as follows: epileptic focal laterality; age at seizure onset (< 10 or ≥ 10 years old); seizure frequency (more than weekly or less than weekly seizures); history of focal to bilateral tonic-clonic seizure; infectious etiology; and surgical procedure. The Wechsler Memory Scale-Revised was used to evaluate memory function pre- and postoperatively. RESULTS Seizure outcomes were significantly worse in the SA group than in the ATL group at 2 years postoperatively (p = 0.045). The International League Against Epilepsy class 1 outcomes at 7 years postoperatively in the SA and ATL groups were 63% and 81%, respectively. Kaplan-Meier analysis showed that seizure recurred significantly earlier in the SA group than in the ATL group (p = 0.031). The 2-way ANOVA analysis was used to compare the SA and ATL groups in each memory category, and revealed that there was no significant difference regardless of the side of surgery. CONCLUSIONS Visual assessment of ioECoG cannot be used as an indicator to minimize epileptic focus resection in patients with TLE associated with HS. ATL is more effective in obtaining seizure-free outcomes; however, both ATL and SA can preserve memory function.
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5
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Camarillo-Rodriguez L, Leenen I, Waldman Z, Serruya M, Wanda PA, Herweg NA, Kahana MJ, Rubinstein D, Orosz I, Lega B, Podkorytova I, Gross RE, Worrell G, Davis KA, Jobst BC, Sheth SA, Weiss SA, Sperling MR. Temporal lobe interictal spikes disrupt encoding and retrieval of verbal memory: A subregion analysis. Epilepsia 2022; 63:2325-2337. [PMID: 35708911 DOI: 10.1111/epi.17334] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 06/14/2022] [Accepted: 06/14/2022] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The medial temporal lobe (MTL) encodes and recalls memories and can be a predominant site for interictal spikes (IS) in patients with focal epilepsy. It is unclear whether memory deficits are due to IS in the MTL producing a transient decline. Here, we investigated whether IS in the MTL subregions and lateral temporal cortex impact episodic memory encoding and recall. METHODS Seventy-eight participants undergoing presurgical evaluation for medically refractory focal epilepsy with depth electrodes placed in the temporal lobe participated in a verbal free recall task. IS were manually annotated during the pre-encoding, encoding, and recall epochs. We examined the effect of IS on word recall using mixed-effects logistic regression. RESULTS IS in the left hippocampus (odds ratio [OR] = .73, 95% confidence interval [CI] = .63-.84, p < .001) and left middle temporal gyrus (OR = .46, 95% CI = .27-.78, p < .05) during word encoding decreased subsequent recall performance. Within the left hippocampus, this effect was specific for area CA1 (OR = .76, 95% CI = .66-.88, p < .01) and dentate gyrus (OR = .74, 95% CI = .62-.89, p < .05). IS in other MTL subregions or inferior and superior temporal gyrus and IS occurring during the prestimulus window did not affect word encoding (p > .05). IS during retrieval in right hippocampal (OR = .22, 95% CI = .08-.63, p = .01) and parahippocampal regions (OR = .24, 95% CI = .07-.8, p < .05) reduced the probability of recalling a word. SIGNIFICANCE IS in medial and lateral temporal cortex contribute to transient memory decline during verbal episodic memory.
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Affiliation(s)
| | - Iwin Leenen
- Faculty of Psychology, National Autonomous University of Mexico, Mexico City, Mexico
| | - Zachary Waldman
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Mijail Serruya
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Paul A Wanda
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Nora A Herweg
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Daniel Rubinstein
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Iren Orosz
- Department of Neurology, University of California, Los Angeles, Los Angeles, California, USA
| | | | | | - Robert E Gross
- Department of Neurosurgery, Emory University, Atlanta, Georgia, USA
| | | | - Kathryn A Davis
- Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Barbara C Jobst
- Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Sameer A Sheth
- Department of Neurological Surgery, Baylor College of Medicine, Houston, Texas, USA
| | - Shennan A Weiss
- Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, New York, USA.,Department of Physiology and Pharmacology, State University of New York Downstate Medical Center, Brooklyn, New York, USA.,Departments of Neurology, New York City Health + Hospitals/Kings County, Brooklyn, New York, USA
| | - Michael R Sperling
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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6
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Varatharajah Y, Berry B, Joseph B, Balzekas I, Pal Attia T, Kremen V, Brinkmann B, Iyer R, Worrell G. Characterizing the electrophysiological abnormalities in visually reviewed normal EEGs of drug-resistant focal epilepsy patients. Brain Commun 2021; 3:fcab102. [PMID: 34131643 PMCID: PMC8196245 DOI: 10.1093/braincomms/fcab102] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/28/2021] [Accepted: 04/08/2021] [Indexed: 11/13/2022] Open
Abstract
Routine scalp EEG is essential in the clinical diagnosis and management of epilepsy. However, a normal scalp EEG (based on expert visual review) recorded from a patient with epilepsy can cause delays in diagnosis and clinical care delivery. Here, we investigated whether normal EEGs might contain subtle electrophysiological clues of epilepsy. Specifically, we investigated (i) whether there are indicators of abnormal brain electrophysiology in normal EEGs of epilepsy patients, and (ii) whether such abnormalities are modulated by the side of the brain generating seizures in focal epilepsy. We analysed awake scalp EEG recordings of age-matched groups of 144 healthy individuals and 48 individuals with drug-resistant focal epilepsy who had normal scalp EEGs. After preprocessing, using a bipolar montage of eight channels, we extracted the fraction of spectral power in the alpha band (8-13 Hz) relative to a wide band of 0.5-40 Hz within 10-s windows. We analysed the extracted features for (i) the extent to which people with drug-resistant focal epilepsy differed from healthy subjects, and (ii) whether differences within the drug-resistant focal epilepsy patients were related to the hemisphere generating seizures. We then used those differences to classify whether an EEG is likely to have been recorded from a person with drug-resistant focal epilepsy, and if so, the epileptogenic hemisphere. Furthermore, we tested the significance of these differences while controlling for confounders, such as acquisition system, age and medications. We found that the fraction of alpha power is generally reduced (i) in drug-resistant focal epilepsy compared to healthy controls, and (ii) in right-handed drug-resistant focal epilepsy subjects with left hemispheric seizures compared to those with right hemispheric seizures, and that the differences are most prominent in the frontal and temporal regions. The fraction of alpha power yielded area under curve values of 0.83 in distinguishing drug-resistant focal epilepsy from healthy and 0.77 in identifying the epileptic hemisphere in drug-resistant focal epilepsy patients. Furthermore, our results suggest that the differences in alpha power are greater when compared with differences attributable to acquisition system differences, age and medications. Our findings support that EEG-based measures of normal brain function, such as the normalized spectral power of alpha activity, may help identify patients with epilepsy even when an EEG does not contain any epileptiform activity, recorded seizures or other abnormalities. Although alpha abnormalities are unlikely to be disease-specific, we propose that such abnormalities may provide a higher pre-test probability for epilepsy when an individual being screened for epilepsy has a normal EEG on visual assessment.
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Affiliation(s)
- Yogatheesan Varatharajah
- Department of Bioengineering, University of Illinois, Urbana, IL 61801, USA.,Mayo Systems Electrophysiology Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA.,Electrical and Computer Engineering, University of Illinois, Urbana, IL 61801, USA
| | - Brent Berry
- Mayo Systems Electrophysiology Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Boney Joseph
- Mayo Systems Electrophysiology Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Irena Balzekas
- Mayo Systems Electrophysiology Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Tal Pal Attia
- Mayo Systems Electrophysiology Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Vaclav Kremen
- Mayo Systems Electrophysiology Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA.,Czech Institute of Informatics, Robotics and Cybernetics, Czech Technical University in Prague, 160 00 Prague 6, Czech Republic
| | - Benjamin Brinkmann
- Mayo Systems Electrophysiology Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Ravishankar Iyer
- Electrical and Computer Engineering, University of Illinois, Urbana, IL 61801, USA
| | - Gregory Worrell
- Mayo Systems Electrophysiology Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
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7
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Lisgaras CP, Mikroulis A, Psarropoulou C. Region-specific Effects of Early-life Status Epilepticus on the Adult Hippocampal CA3 - Medial Entorhinal Cortex Circuitry In vitro: Focus on Interictal Spikes and Concurrent High-frequency Oscillations. Neuroscience 2021; 466:235-247. [PMID: 33961962 DOI: 10.1016/j.neuroscience.2021.04.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 04/25/2021] [Accepted: 04/26/2021] [Indexed: 11/29/2022]
Abstract
Convulsive status epilepticus (SE) in immature life is often associated with lasting neurobiological changes. We provoked SE by pentylenetetrazole in postnatal day 20 rat pups and examined communication modalities between the temporal hippocampus and medial entorhinal cortex (mEC) in vitro. After a minimum of 40 days post-SE, we prepared combined temporal hippocampal - medial entorhinal cortex (mEC) slices from conditioned (SE) and naïve (N) adult rats and recorded 4-aminopyridine-induced spontaneous epileptiform interictal-like discharges (IED) simultaneously from CA3 and mEC layer V-VI. We analyzed IED frequency and high frequency oscillations (HFOs) in intact slices and after surgical separation of hippocampus from mEC, by two successive incisions (Schaffer collateral cut, Parasubiculum cut). In all slices, IED frequency was higher in CA3 vs mEC (5N, 4SE) and Raster plots indicated no temporal coincidence between them either in intact or in CA1-cut slices (4N, 4SE). IED frequency was significantly higher in SE mEC, but similar in SE and N CA3, independently of connectivity state. Ripples (R) and Fast Ripples (FR) coincided with IEDs and their power differed between SE and N intact slices (22N, 12SE), both in CA3 and mEC. CA3 FR/R ratios were higher in the absence of mEC (14N, 8SE). Moreover, SE (vs N) slices showed significantly higher FR/R ratios independently of the presence of mEC. Taken together, these findings suggest lasting effects of immature SE in network dynamics governing hippocampal-entorhinal communication which may impact adult cognitive, behavioral, and/or seizure threshold sequalae.
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Affiliation(s)
- Christos Panagiotis Lisgaras
- Laboratory of Animal and Human Physiology, Department of Biological Applications and Technology, Faculty of Health Sciences, University of Ioannina, 45110 Ioannina, Greece.
| | - Apostolos Mikroulis
- Laboratory of Animal and Human Physiology, Department of Biological Applications and Technology, Faculty of Health Sciences, University of Ioannina, 45110 Ioannina, Greece.
| | - Caterina Psarropoulou
- Laboratory of Animal and Human Physiology, Department of Biological Applications and Technology, Faculty of Health Sciences, University of Ioannina, 45110 Ioannina, Greece.
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Henin S, Shankar A, Borges H, Flinker A, Doyle W, Friedman D, Devinsky O, Buzsáki G, Liu A. Spatiotemporal dynamics between interictal epileptiform discharges and ripples during associative memory processing. Brain 2021; 144:1590-1602. [PMID: 33889945 DOI: 10.1093/brain/awab044] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 11/16/2020] [Accepted: 12/06/2020] [Indexed: 12/13/2022] Open
Abstract
We describe the spatiotemporal course of cortical high-gamma activity, hippocampal ripple activity and interictal epileptiform discharges during an associative memory task in 15 epilepsy patients undergoing invasive EEG. Successful encoding trials manifested significantly greater high-gamma activity in hippocampus and frontal regions. Successful cued recall trials manifested sustained high-gamma activity in hippocampus compared to failed responses. Hippocampal ripple rates were greater during successful encoding and retrieval trials. Interictal epileptiform discharges during encoding were associated with 15% decreased odds of remembering in hippocampus (95% confidence interval 6-23%). Hippocampal interictal epileptiform discharges during retrieval predicted 25% decreased odds of remembering (15-33%). Odds of remembering were reduced by 25-52% if interictal epileptiform discharges occurred during the 500-2000 ms window of encoding or by 41% during retrieval. During encoding and retrieval, hippocampal interictal epileptiform discharges were followed by a transient decrease in ripple rate. We hypothesize that interictal epileptiform discharges impair associative memory in a regionally and temporally specific manner by decreasing physiological hippocampal ripples necessary for effective encoding and recall. Because dynamic memory impairment arises from pathological interictal epileptiform discharge events competing with physiological ripples, interictal epileptiform discharges represent a promising therapeutic target for memory remediation in patients with epilepsy.
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Affiliation(s)
- Simon Henin
- NYU Langone Health, Department of Neurology, New York, NY 10017, USA.,NYU Langone Health, Comprehensive Epilepsy Center, New York, NY 10016, USA
| | - Anita Shankar
- NYU Langone Health, Department of Neurology, New York, NY 10017, USA.,NYU Langone Health, Comprehensive Epilepsy Center, New York, NY 10016, USA
| | - Helen Borges
- NYU Langone Health, Department of Neurology, New York, NY 10017, USA.,NYU Langone Health, Comprehensive Epilepsy Center, New York, NY 10016, USA
| | - Adeen Flinker
- NYU Langone Health, Department of Neurology, New York, NY 10017, USA.,NYU Langone Health, Comprehensive Epilepsy Center, New York, NY 10016, USA
| | - Werner Doyle
- NYU Langone Health, Comprehensive Epilepsy Center, New York, NY 10016, USA.,NYU Langone Health, Department of Neurosurgery, New York, NY 10016, USA
| | - Daniel Friedman
- NYU Langone Health, Department of Neurology, New York, NY 10017, USA.,NYU Langone Health, Comprehensive Epilepsy Center, New York, NY 10016, USA
| | - Orrin Devinsky
- NYU Langone Health, Department of Neurology, New York, NY 10017, USA.,NYU Langone Health, Comprehensive Epilepsy Center, New York, NY 10016, USA
| | - György Buzsáki
- NYU Langone Health, Department of Neurology, New York, NY 10017, USA.,New York University, Neuroscience Institute, New York, NY 10016, USA
| | - Anli Liu
- NYU Langone Health, Department of Neurology, New York, NY 10017, USA.,NYU Langone Health, Comprehensive Epilepsy Center, New York, NY 10016, USA.,New York University, Neuroscience Institute, New York, NY 10016, USA
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9
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Agudelo Valencia P, van Klink NEC, van 't Klooster MA, Zweiphenning WJEM, Swampillai B, van Eijsden P, Gebbink T, van Zandvoort MJE, Zijlmans M. Are HFOs in the Intra-operative ECoG Related to Hippocampal Sclerosis, Volume and IQ? Front Neurol 2021; 12:645925. [PMID: 33841312 PMCID: PMC8024640 DOI: 10.3389/fneur.2021.645925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 03/02/2021] [Indexed: 11/13/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is the most common form of refractory focal epilepsy and is often associated with hippocampal sclerosis (HS) and cognitive disturbances. Over the last decade, high frequency oscillations (HFOs) in the intraoperative electrocorticography (ioECoG) have been proposed to be biomarkers for the delineation of epileptic tissue but hippocampal ripples have also been associated with memory consolidation. Healthy hippocampi can show prolonged ripple activity in stereo- EEG. We aimed to identify how the HFO rates [ripples (80–250 Hz, fast ripples (250–500 Hz); prolonged ripples (80–250 Hz, 200–500 ms)] in the pre-resection ioECoG over subtemporal area (hippocampus) and lateral temporal neocortex relate to presence of hippocampal sclerosis, the hippocampal volume quantified on MRI and the severity of cognitive impairment in TLE patients. Volumetric measurement of hippocampal subregions was performed in 47 patients with TLE, who underwent ioECoG. Ripples, prolonged ripples, and fast ripples were visually marked and rates of HFOs were calculated. The intellectual quotient (IQ) before resection was determined. There was a trend toward higher rates of ripples and fast ripples in subtemporal electrodes vs. the lateral neocortex (ripples: 2.1 vs. 1.3/min; fast ripples: 0.9 vs. 0.2/min). Patients with HS showed higher rates of subtemporal fast ripples than other patients (Z = −2.51, p = 0.012). Prolonged ripples were only found in the lateral temporal neocortex. The normalized ratio (smallest/largest) of hippocampal volume was correlated to pre-resection IQ (r = 0.45, p = 0.015). There was no correlation between HFO rates and hippocampal volumes or HFO rates and IQ. To conclude, intra-operative fast ripples were a marker for HS, but ripples and fast ripples were not linearly correlated with either the amount of hippocampal atrophy, nor for pre-surgical IQ.
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Affiliation(s)
- Paula Agudelo Valencia
- Department of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Utrecht, Utrecht, Netherlands
| | - Nicole E C van Klink
- Department of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Utrecht, Utrecht, Netherlands
| | - Maryse A van 't Klooster
- Department of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Utrecht, Utrecht, Netherlands
| | - Willemiek J E M Zweiphenning
- Department of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Utrecht, Utrecht, Netherlands
| | - Banu Swampillai
- Department of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Utrecht, Utrecht, Netherlands
| | - Pieter van Eijsden
- Department of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Utrecht, Utrecht, Netherlands
| | - Tineke Gebbink
- Department of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Utrecht, Utrecht, Netherlands
| | - Martine J E van Zandvoort
- Department of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Utrecht, Utrecht, Netherlands
| | - Maeike Zijlmans
- Department of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Utrecht, Utrecht, Netherlands.,Stiching Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
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10
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Thomschewski A, Gerner N, Langthaler PB, Trinka E, Bathke AC, Fell J, Höller Y. Automatic vs. Manual Detection of High Frequency Oscillations in Intracranial Recordings From the Human Temporal Lobe. Front Neurol 2020; 11:563577. [PMID: 33192999 PMCID: PMC7604344 DOI: 10.3389/fneur.2020.563577] [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: 05/22/2020] [Accepted: 08/26/2020] [Indexed: 12/14/2022] Open
Abstract
Background: High frequency oscillations (HFOs) have attracted great interest among neuroscientists and epileptologists in recent years. Not only has their occurrence been linked to epileptogenesis, but also to physiologic processes, such as memory consolidation. There are at least two big challenges for HFO research. First, detection, when performed manually, is time consuming and prone to rater biases, but when performed automatically, it is biased by artifacts mimicking HFOs. Second, distinguishing physiologic from pathologic HFOs in patients with epilepsy is problematic. Here we automatically and manually detected HFOs in intracranial EEGs (iEEG) of patients with epilepsy, recorded during a visual memory task in order to assess the feasibility of the different detection approaches to identify task-related ripples, supporting the physiologic nature of HFOs in the temporal lobe. Methods: Ten patients with unclear seizure origin and bilaterally implanted macroelectrodes took part in a visual memory consolidation task. In addition to iEEG, scalp EEG, electrooculography (EOG), and facial electromyography (EMG) were recorded. iEEG channels contralateral to the suspected epileptogenic zone were inspected visually for HFOs. Furthermore, HFOs were marked automatically using an RMS detector and a Stockwell classifier. We compared the two detection approaches and assessed a possible link between task performance and HFO occurrence during encoding and retrieval trials. Results: HFO occurrence rates were significantly lower when events were marked manually. The automatic detection algorithm was greatly biased by filter-artifacts. Surprisingly, EOG artifacts as seen on scalp electrodes appeared to be linked to many HFOs in the iEEG. Occurrence rates could not be associated to memory performance, and we were not able to detect strictly defined "clear" ripples. Conclusion: Filtered graphoelements in the EEG are known to mimic HFOs and thus constitute a problem. So far, in invasive EEG recordings mostly technical artifacts and filtered epileptiform discharges have been considered as sources for these "false" HFOs. The data at hand suggests that even ocular artifacts might bias automatic detection in invasive recordings. Strict guidelines and standards for HFO detection are necessary in order to identify artifact-derived HFOs, especially in conditions when cognitive tasks might produce a high amount of artifacts.
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Affiliation(s)
- Aljoscha Thomschewski
- Department of Neurology, Christian-Doppler Medical Center, Paracelsus Medical University, Salzburg, Austria,Department of Mathematics, Paris-Lodron University of Salzburg, Salzburg, Austria,Department of Psychology, Paris-Lodron University of Salzburg, Salzburg, Austria,*Correspondence: Aljoscha Thomschewski
| | - Nathalie Gerner
- Department of Neurology, Christian-Doppler Medical Center, Paracelsus Medical University, Salzburg, Austria
| | - Patrick B. Langthaler
- Department of Neurology, Christian-Doppler Medical Center, Paracelsus Medical University, Salzburg, Austria,Department of Mathematics, Paris-Lodron University of Salzburg, Salzburg, Austria
| | - Eugen Trinka
- Department of Neurology, Christian-Doppler Medical Center, Paracelsus Medical University, Salzburg, Austria
| | - Arne C. Bathke
- Department of Mathematics, Paris-Lodron University of Salzburg, Salzburg, Austria,Intelligent Data Analytics Lab Salzburg, Paris-Lodron University of Salzburg, Salzburg, Austria
| | - Jürgen Fell
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Yvonne Höller
- Faculty of Psychology, University of Akureyri, Akureyri, Iceland
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11
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Varatharajah Y, Berry B, Joseph B, Balzekas I, Kremen V, Brinkmann B, Worrell G, Iyer R. Electrophysiological Correlates of Brain Health Help Diagnose Epilepsy and Lateralize Seizure Focus. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:3460-3464. [PMID: 33018748 DOI: 10.1109/embc44109.2020.9176668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The absence of epileptiform activity in a scalp electroencephalogram (EEG) recorded from a potential epilepsy patient can cause delays in clinical care delivery. Here we present a machine-learning-based approach to find evidence for epilepsy in scalp EEGs that do not contain any epileptiform activity, according to expert visual review (i.e., "normal" EEGs). We found that deviations in the EEG features representing brain health, such as the alpha rhythm, can indicate the potential for epilepsy and help lateralize seizure focus, even when commonly recognized epileptiform features are absent. Hence, we developed a machine-learning-based approach that utilizes alpha-rhythm-related features to classify 1) whether an EEG was recorded from an epilepsy patient, and 2) if so, the seizure-generating side of the patient's brain. We evaluated our approach using "normal" scalp EEGs of 48 patients with drug-resistant focal epilepsy and 144 healthy individuals, and a naive Bayes classifier achieved area under ROC curve (AUC) values of 0.81 and 0.72 for the two classification tasks, respectively. These findings suggest that our methodology is useful in the absence of interictal epileptiform activity and can enhance the probability of diagnosing epilepsy at the earliest possible time.
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12
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Aeed F, Shnitzer T, Talmon R, Schiller Y. Layer- and Cell-Specific Recruitment Dynamics during Epileptic Seizures In Vivo. Ann Neurol 2019; 87:97-115. [PMID: 31657482 DOI: 10.1002/ana.25628] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 10/22/2019] [Accepted: 10/22/2019] [Indexed: 12/29/2022]
Abstract
OBJECTIVE To investigate the network dynamics mechanisms underlying differential initiation of epileptic interictal spikes and seizures. METHODS We performed combined in vivo 2-photon calcium imaging from different targeted neuronal subpopulations and extracellular electrophysiological recordings during 4-aminopyridine-induced neocortical spikes and seizures. RESULTS Both spikes and seizures were associated with intense synchronized activation of excitatory layer 2/3 pyramidal neurons (PNs) and to a lesser degree layer 4 neurons, as well as inhibitory parvalbumin-expressing interneurons (INs). In sharp contrast, layer 5 PNs and somatostatin-expressing INs were gradually and asynchronously recruited into the ictal activity during the course of seizures. Within layer 2/3, the main difference between onset of spikes and seizures lay in the relative recruitment dynamics of excitatory PNs compared to parvalbumin- and somatostatin-expressing inhibitory INs. Whereas spikes exhibited balanced recruitment of PNs and parvalbumin-expressing INs, during seizures IN responses were reduced and less synchronized than in layer 2/3 PNs. Similar imbalance was not observed in layers 4 or 5 of the neocortex. Machine learning-based algorithms we developed were able to distinguish spikes from seizures based solely on activation dynamics of layer 2/3 PNs at discharge onset. INTERPRETATION During onset of seizures, the recruitment dynamics markedly differed between neuronal subpopulations, with rapid synchronous recruitment of layer 2/3 PNs, layer 4 neurons, and parvalbumin-expressing INs and gradual asynchronous recruitment of layer 5 PNs and somatostatin-expressing INs. Seizures initiated in layer 2/3 due to a dynamic mismatch between local PNs and inhibitory INs, and only later spread to layer 5 by gradually and asynchronously recruiting PNs in this layer. ANN NEUROL 2020;87:97-115.
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Affiliation(s)
- Fadi Aeed
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Tal Shnitzer
- Viterbi Faculty of Electrical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ronen Talmon
- Viterbi Faculty of Electrical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Yitzhak Schiller
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.,Department of Neurology, Rambam Medical Center, Haifa, Israel
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13
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Weiss SA, Waldman Z, Raimondo F, Slezak D, Donmez M, Worrell G, Bragin A, Engel J, Staba R, Sperling M. Localizing epileptogenic regions using high-frequency oscillations and machine learning. Biomark Med 2019; 13:409-418. [PMID: 31044598 DOI: 10.2217/bmm-2018-0335] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Pathological high frequency oscillations (HFOs) are putative neurophysiological biomarkers of epileptogenic brain tissue. Utilizing HFOs for epilepsy surgery planning offers the promise of improved seizure outcomes for patients with medically refractory epilepsy. This review discusses possible machine learning strategies that can be applied to HFO biomarkers to better identify epileptogenic regions. We discuss the role of HFO rate, and utilizing features such as explicit HFO properties (spectral content, duration, and power) and phase-amplitude coupling for distinguishing pathological HFO (pHFO) events from physiological HFO events. In addition, the review highlights the importance of neuroanatomical localization in machine learning strategies.
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Affiliation(s)
- Shennan A Weiss
- Departments of Neurology & Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Zachary Waldman
- Departments of Neurology & Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Federico Raimondo
- Department of Computer Science, Faculty of Exact & Natural Sciences, University of Buenos Aires, Buenos Aires, Argentina.,Institute of Research in Computer Science, National Scientific & Technical Research Council, University of Buenos Aires, Buenos Aires, Argentina
| | - Diego Slezak
- Department of Computer Science, Faculty of Exact & Natural Sciences, University of Buenos Aires, Buenos Aires, Argentina.,Institute of Research in Computer Science, National Scientific & Technical Research Council, University of Buenos Aires, Buenos Aires, Argentina
| | - Mustafa Donmez
- Departments of Neurology & Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Gregory Worrell
- Department of Neurology, Mayo Systems Electrophysiology Laboratory (MSEL), Mayo Clinic, Rochester, MN 55905, USA
| | - Anatol Bragin
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Jerome Engel
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Richard Staba
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Michael Sperling
- Departments of Neurology & Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
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