2024
Modeling seizure networks in neuron-glia cultures using microelectrode arrays
Boddeti U, Langbein J, McAfee D, Altshuler M, Bachani M, Zaveri H, Spencer D, Zaghloul K, Ksendzovsky A. Modeling seizure networks in neuron-glia cultures using microelectrode arrays. Frontiers In Network Physiology 2024, 4: 1441345. PMID: 39290793, PMCID: PMC11405204, DOI: 10.3389/fnetp.2024.1441345.Peer-Reviewed Original ResearchNetwork changesSeizure networkSeizure modelsDays of chronic treatmentDimensionality reductionNetwork developmentDrug-resistant epilepsyNeuron-glia culturesMean firing rateNetworkTreatment failureChronic treatmentMicroelectrode arraysResection surgeryRetrospective studyFiring rateSeizuresExperience seizuresNeurological disordersSystematic 1 Hz direct electrical stimulation for seizure induction: A reliable method for localizing seizure onset zone and predicting seizure freedom
Sivaraju A, Quraishi I, Collins E, McGrath H, Ramos A, Turk-Browne N, Zaveri H, Damisah E, Spencer D, Hirsch L. Systematic 1 Hz direct electrical stimulation for seizure induction: A reliable method for localizing seizure onset zone and predicting seizure freedom. Brain Stimulation 2024, 17: 339-345. PMID: 38490472, DOI: 10.1016/j.brs.2024.03.011.Peer-Reviewed Original ResearchSeizure inductionSeizure onset zoneSurgical outcomesHabitual seizuresOnset zonePredicting seizure freedomExcellent surgical outcomesProspective cohort studyMann-Whitney testConsecutive patientsFisher's exactSeizure freedomRefractory epilepsyCohort studyPost-surgeryInsular regionsMann-WhitneyPatientsIntracranial EEGSeizuresLocalizing seizure onset zonesStimulationElectrical stimulationMedial temporal regionsTemporal regions
2022
Perspectives on Understanding Aberrant Brain Networks in Epilepsy
Sinha N, Joshi R, Sandhu M, Netoff T, Zaveri H, Lehnertz K. Perspectives on Understanding Aberrant Brain Networks in Epilepsy. Frontiers In Network Physiology 2022, 2: 868092. PMID: 36926081, PMCID: PMC10013006, DOI: 10.3389/fnetp.2022.868092.Peer-Reviewed Original ResearchDiscrete cortical areasAberrant brain networksGeneralized seizuresAdjacent cortexSeizure progressionCortical areasEpilepsyNeurological disordersSeizuresAnatomical configurationNetwork diseaseNeural activityBrainAberrant activityBrain networksHuman brainWidespread neural activityPatientsSurgeryCortexDiseaseNovel studyProgression
2021
Increased branched‐chain amino acids at baseline and hours before a spontaneous seizure in the human epileptic brain
Ong C, Damisah EC, Gruenbaum SE, Dhaher R, Deng Y, Sandhu MRS, Zaveri HP, Spencer DD, Eid T. Increased branched‐chain amino acids at baseline and hours before a spontaneous seizure in the human epileptic brain. Epilepsia 2021, 62: e88-e97. PMID: 33949690, PMCID: PMC11259155, DOI: 10.1111/epi.16920.Peer-Reviewed Original ResearchMeSH KeywordsAdolescentAdultAmino Acids, Branched-ChainBrain ChemistryChildChild, PreschoolChromatography, High Pressure LiquidDrug Resistant EpilepsyElectrocorticographyElectroencephalographyEpilepsies, PartialExtracellular SpaceFemaleGlutamic AcidHumansIsoleucineMaleMicrodialysisMiddle AgedSeizuresTandem Mass SpectrometryYoung AdultConceptsSpontaneous seizuresDrug-resistant focal epilepsyExtracellular brain glutamateHuman epileptic brainBranched-chain amino acidsBranched chain amino acids valineRefractory epilepsyBrain microdialysisGlutamatergic neurotransmissionFocal epilepsySeizure onsetBrain glutamateEpileptic brainHuman patientsSeizuresBrain regionsDialysis samplesMammalian targetEpilepsyLiquid chromatography-tandem mass spectrometryBaselineBCAAIntracranial electroencephalographyChromatography-tandem mass spectrometryPatientsAstroglial Glutamine Synthetase and the Pathogenesis of Mesial Temporal Lobe Epilepsy
Sandhu MRS, Gruenbaum BF, Gruenbaum SE, Dhaher R, Deshpande K, Funaro MC, Lee TW, Zaveri HP, Eid T. Astroglial Glutamine Synthetase and the Pathogenesis of Mesial Temporal Lobe Epilepsy. Frontiers In Neurology 2021, 12: 665334. PMID: 33927688, PMCID: PMC8078591, DOI: 10.3389/fneur.2021.665334.Peer-Reviewed Original ResearchMesial temporal lobe epilepsyAstroglial glutamine synthetaseTemporal lobe epilepsyLobe epilepsyIntractable mesial temporal lobe epilepsyAstrocytic glutamine synthetaseDepressive-like featuresPathogenesis of epilepsyType of epilepsyDiscrete brain regionsNeocortical epilepsyHippocampal neuronsEpilepsyBrain regionsGlutamate-ammonia ligaseLaboratory animalsPathogenesisPossible roleExperimental inhibitionGlutamine synthetaseEnzyme glutamine synthetaseDysfunctionSeizuresAstrocytesSyndrome
2020
Circadian-Like Rhythmicity of Extracellular Brain Glutamate in Epilepsy
Sandhu MRS, Dhaher R, Gruenbaum SE, Raaisa R, Spencer DD, Pavlova MK, Zaveri HP, Eid T. Circadian-Like Rhythmicity of Extracellular Brain Glutamate in Epilepsy. Frontiers In Neurology 2020, 11: 398. PMID: 32499751, PMCID: PMC7242976, DOI: 10.3389/fneur.2020.00398.Peer-Reviewed Original ResearchMesial temporal lobe epilepsyExtracellular brain glutamateSeizure onset regionTemporal lobe epilepsyType of epilepsyExcitatory neurotransmitter glutamateSeizure onset areaTranslational rodent modelEpileptogenic hippocampusLobe epilepsyIntracerebral microdialysisExtracellular glutamateBrain glutamateIndividual patientsRodent modelsControl animalsNeurotransmitter glutamateExtracellular levelsEpilepsySeizuresOnset areaCircadian-like rhythmGlutamateEssential modulatorPatientsOral glutamine supplementation increases seizure severity in a rodent model of mesial temporal lobe epilepsy
Dhaher R, Chen EC, Perez E, Rapuano A, Sandhu MRS, Gruenbaum SE, Deshpande K, Dai F, Zaveri HP, Eid T. Oral glutamine supplementation increases seizure severity in a rodent model of mesial temporal lobe epilepsy. Nutritional Neuroscience 2020, 25: 64-69. PMID: 31900092, PMCID: PMC8970572, DOI: 10.1080/1028415x.2019.1708568.Peer-Reviewed Original ResearchConceptsMesial temporal lobe epilepsyOral glutamine supplementationSeverity of seizuresTemporal lobe epilepsyGlutamine supplementationSeizure severityLobe epilepsyRefractory mesial temporal lobe epilepsyMale Sprague-DawleySeizure frequencyConvulsive seizuresSeizure propagationEpilepsy modelSprague-DawleyEffective treatmentRodent modelsSeizuresSupplementationSeverityPotential roleEpilepsyFunction mutationsHippocampusGlutamine synthetaseDays
2019
The connectivity index: an effective metric for grading epileptogenicity.
Yan Q, Gaspard N, Zaveri HP, Blumenfeld H, Hirsch LJ, Spencer DD, Alkawadri R. The connectivity index: an effective metric for grading epileptogenicity. Journal Of Neurosurgery 2019, 133: 971-978. PMID: 31561212, DOI: 10.3171/2019.4.jns195.Peer-Reviewed Original ResearchSingle-pulse electrical stimulationSeizure onset zoneSite of stimulationSOZ contactsIrritative zoneComprehensive Epilepsy CenterControl contactsStimulation current intensityHabitual aurasHabitual seizuresEpilepsy centersSeizure generationBrain sitesFrequency stimulationEpileptic activityElectrical stimulationOnset zonePatientsRecording contactsStimulation sessionsBrain regionsFunctional connectivityStimulationOutcome casesSeizures
2018
Seizure susceptibility and infraslow modulatory activity in the intracranial electroencephalogram
Joshi RB, Duckrow RB, Goncharova II, Gerrard JL, Spencer DD, Hirsch LJ, Godwin DW, Zaveri HP. Seizure susceptibility and infraslow modulatory activity in the intracranial electroencephalogram. Epilepsia 2018, 59: 2075-2085. PMID: 30187919, DOI: 10.1111/epi.14559.Peer-Reviewed Original ResearchConceptsAED taperYale-New Haven HospitalAdult epilepsy patientsSeizure forecasting algorithmsElectrode contact pairsSeizure onset areaSeizure susceptibilityClinical recordsDrug taperElectrophysiological changesEpilepsy patientsIntracranial electroencephalographic dataMagnitude-squared coherenceModulatory activitySeizuresPatientsOnset areaPreseizurePostseizureProgressive desynchronizationIntracranial electroencephalogramDaysIctogenesisEffect of timeHospitalExpanding Brain–Computer Interfaces for Controlling Epilepsy Networks: Novel Thalamic Responsive Neurostimulation in Refractory Epilepsy
Gummadavelli A, Zaveri HP, Spencer DD, Gerrard JL. Expanding Brain–Computer Interfaces for Controlling Epilepsy Networks: Novel Thalamic Responsive Neurostimulation in Refractory Epilepsy. Frontiers In Neuroscience 2018, 12: 474. PMID: 30108472, PMCID: PMC6079216, DOI: 10.3389/fnins.2018.00474.Peer-Reviewed Original ResearchResponsive neurostimulationRefractory epilepsyThalamic nucleiComplex network disorderIntralaminar thalamic nucleiSubcortical brain structuresCortical onsetSeizure controlGeneralized epilepsySeizure networkSeizure onsetEpilepsy networkNeuromodulatory techniquesEpilepsyExcitatory eventsClinical treatmentBrain regionsBrain structuresSeizuresPotential targetIntracranial electroencephalographyNetwork disorderPatientsFeasible targetNeurostimulation
2016
The relationship between seizures, interictal spikes and antiepileptic drugs
Goncharova II, Alkawadri R, Gaspard N, Duckrow RB, Spencer DD, Hirsch LJ, Spencer SS, Zaveri HP. The relationship between seizures, interictal spikes and antiepileptic drugs. Clinical Neurophysiology 2016, 127: 3180-3186. PMID: 27292227, DOI: 10.1016/j.clinph.2016.05.014.Peer-Reviewed Original ResearchConceptsFirst seizureSeizure occurrenceAED taperSpike rateEEG monitoringMarker of inhibitionIntracranial EEG monitoringOccurrence of seizuresScalp EEG monitoringConsecutive patientsAntiepileptic drugsDrug taperHigh spike ratesInterictal spikesSeizuresDay 4Intracranial electrodesPatientsAEDsSignificant relationshipProgressive change in sleep over multiple nights of intracranial EEG monitoring
Joshi RB, Gaspard N, Goncharova II, Pavlova M, Duckrow RB, Gerrard JL, Spencer DD, Hirsch LJ, Zaveri HP. Progressive change in sleep over multiple nights of intracranial EEG monitoring. Clinical Neurophysiology 2016, 127: 2302-2307. PMID: 27072103, DOI: 10.1016/j.clinph.2016.02.018.Peer-Reviewed Original Research
2013
Intracranially recorded interictal spikes: Relation to seizure onset area and effect of medication and time of day
Goncharova II, Spencer SS, Duckrow RB, Hirsch LJ, Spencer DD, Zaveri HP. Intracranially recorded interictal spikes: Relation to seizure onset area and effect of medication and time of day. Clinical Neurophysiology 2013, 124: 2119-2128. PMID: 23856192, DOI: 10.1016/j.clinph.2013.05.027.Peer-Reviewed Original Research
2012
Evidence for astrocytes as a potential source of the glutamate excess in temporal lobe epilepsy
Perez EL, Lauritzen F, Wang Y, Lee TS, Kang D, Zaveri HP, Chaudhry FA, Ottersen OP, Bergersen LH, Eid T. Evidence for astrocytes as a potential source of the glutamate excess in temporal lobe epilepsy. Neurobiology Of Disease 2012, 47: 331-337. PMID: 22659305, PMCID: PMC3392431, DOI: 10.1016/j.nbd.2012.05.010.Peer-Reviewed Original ResearchConceptsTemporal lobe epilepsyRecurrent seizuresConcentration of glutamateHippocampal formationLobe epilepsyExtracellular glutamateRefractory temporal lobe epilepsyEpileptogenic hippocampal formationExtracellular brain glutamateSubset of patientsSaline-treated ratsStart of infusionRatio of glutamateExcessive glutamateGlutamate excessBrain glutamateExtracellular brainAstrocytesExcessive releaseGS deficiencyRatsSeizuresGlutamateSeparate groupsEpilepsy
2009
The development of recurrent seizures after continuous intrahippocampal infusion of methionine sulfoximine in rats A video-intracranial electroencephalographic study
Wang Y, Zaveri HP, Lee TS, Eid T. The development of recurrent seizures after continuous intrahippocampal infusion of methionine sulfoximine in rats A video-intracranial electroencephalographic study. Experimental Neurology 2009, 220: 293-302. PMID: 19747915, PMCID: PMC2989153, DOI: 10.1016/j.expneurol.2009.08.034.Peer-Reviewed Original ResearchConceptsMesial temporal lobe epilepsyHuman mesial temporal lobe epilepsyRecurrent seizuresNeuronal lossPartial seizuresPathophysiology of mTLEDiffuse neuronal lossSaline-treated animalsTemporal lobe epilepsyMinimal neuronal lossGlutamine synthetase inhibitor methionine sulfoximineEpileptogenic hippocampusHippocampal sclerosisLobe epilepsyElectroencephalogram monitoringStage IElectrophysiological mechanismsSeizuresElectroencephalographic studiesDays durationIntrahippocampal infusionHippocampusInfusionMethionine sulfoximineIntracranial EEGSpatial distribution of intracranially recorded spikes in medial and lateral temporal epilepsies
Goncharova II, Zaveri HP, Duckrow RB, Novotny EJ, Spencer SS. Spatial distribution of intracranially recorded spikes in medial and lateral temporal epilepsies. Epilepsia 2009, 50: 2575-2585. PMID: 19674048, DOI: 10.1111/j.1528-1167.2009.02258.x.Peer-Reviewed Original ResearchConceptsMedial temporal structuresInterictal spikesLT patientsCortical areasNeocortical seizure onsetsSleep-related increaseSpike rateLateral temporal epilepsyExtratemporal areasTemporal epilepsySeizure onsetIntracranial monitoringLT groupMT groupPatientsFrontal spikesSeizuresGreater numberSleepGroupTemporal structureEpilepsySpikesA decrease in EEG energy accompanies anti-epileptic drug taper during intracranial monitoring
Zaveri HP, Pincus SM, Goncharova II, Novotny EJ, Duckrow RB, Spencer DD, Spencer SS. A decrease in EEG energy accompanies anti-epileptic drug taper during intracranial monitoring. Epilepsy Research 2009, 86: 153-162. PMID: 19632096, DOI: 10.1016/j.eplepsyres.2009.06.002.Peer-Reviewed Original ResearchLocalization-related epilepsy exhibits significant connectivity away from the seizure-onset area
Zaveri HP, Pincus SM, Goncharova II, Duckrow RB, Spencer DD, Spencer SS. Localization-related epilepsy exhibits significant connectivity away from the seizure-onset area. Neuroreport 2009, 20: 891-895. PMID: 19424095, DOI: 10.1097/wnr.0b013e32832c78e0.Peer-Reviewed Original ResearchConceptsSeizure onset areaLocalization-related epilepsyControl of seizuresDiscrete cortical areasStandard clinical proceduresBeta frequency bandsUnselected patientsComplete resectionEpilepsy surgeryCortical areasFunctional connectivitySeizuresClinical proceduresEpilepsyIntracranial electroencephalogramSignificant connectivityResectionPatientsSurgery
2008
Interictal spikes on intracranial recording: Behavior, physiology, and implications
Spencer SS, Goncharova II, Duckrow RB, Novotny EJ, Zaveri HP. Interictal spikes on intracranial recording: Behavior, physiology, and implications. Epilepsia 2008, 49: 1881-1892. PMID: 18479398, DOI: 10.1111/j.1528-1167.2008.01641.x.Peer-Reviewed Original ResearchConceptsInterictal spikesAED withdrawalSeizure onsetSpike rateMedial temporal lobe seizuresAntiepileptic drug changesRefractory epileptic patientsTemporal lobe seizuresOnset seizuresDrug changesEpileptic patientsNeocortical locationsClinical meaningMedial temporalSeizuresIntracranial electrodesDays of recordingAED mechanismsIntracranial recordingsSignificant increaseAEDsPrevious reportsOnsetSpecific effectsWithdrawalTemporal distributions of seizure occurrence from various epileptogenic regions
Durazzo TS, Spencer SS, Duckrow RB, Novotny EJ, Spencer DD, Zaveri HP. Temporal distributions of seizure occurrence from various epileptogenic regions. Neurology 2008, 70: 1265-1271. PMID: 18391158, DOI: 10.1212/01.wnl.0000308938.84918.3f.Peer-Reviewed Original ResearchConceptsMesial temporal lobeSeizure occurrencePartial epilepsyTemporal lobeBrain regionsParietal seizuresSeizure distributionNeocortical temporal lobeParietal lobe seizuresTemporal lobe seizuresFrontal lobe seizuresConsecutive adult subjectsCortical brain regionsCircadian rhythmNeocortical temporalSurgical resectionTemporal seizuresIntracranial EEG recordingsEpileptogenic regionSeizuresAdult subjectsEpilepsyEndogenous circadian rhythmLobeEEG recordings