Presurgical evaluation for drug refractory epilepsy

Tripathi, Manjari; Ray, Sucharita; Chandra, P. Sarat

doi:10.1016/j.ijsu.2016.10.044

Cited by 19 publications

(4 citation statements)

References 33 publications

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“…Drug‐resistant MTLE‐HS patients ( n = 55) underwent standard pre‐surgical workups, which include video EEG (vEEG), epilepsy protocol MRI, interictal fluoro‐2‐deoxyglucose PET (FDG‐PET), ictal single photon emission computer tomography (SPECT) and magnetoencephalography (MEG) (Tripathi et al, 2016). Patient details were discussed weekly at epilepsy surgery meeting attended by epileptologists, epilepsy surgeon, neuroradiologists and nuclear medicine specialists where patients were selected for surgery based on concordance of the diagnostic procedures listed above.…”

Section: Methodsmentioning

confidence: 99%

Altered hippocampal kynurenine pathway metabolism contributes to hyperexcitability in human mesial temporal lobe epilepsy–hippocampal sclerosis

Dey

Dixit

Tripathi

et al. 2021

British J Pharmacology

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Background and Purpose Glutamate receptor‐mediated enhanced excitatory neurotransmission is typically associated with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE‐HS). Kynurenic acid and quinolinic acid are two important tryptophan–kynurenine pathway metabolites that modulate glutamate receptor activity. This study was designed to test the hypothesis that alteration in metabolism of tryptophan–kynurenine pathway metabolites in the hippocampus of patients with MTLE‐HS contributes to abnormal glutamatergic transmission. Experimental Approach Levels of tryptophan–kynurenine pathway metabolites were determined using HPLC and LC–MS/MS in hippocampal samples from patients with MTLE‐HS, compared with autopsy and non‐seizure control samples. mRNA and protein expressions of tryptophan–kynurenine pathway enzymes were determined by qPCR and Western blot. Spontaneous glutamatergic activities were recorded from pyramidal neurons in the presence of kynurenine and kynurenic acid, using whole‐cell patch clamp. Key Results Levels of kynurenic acid were reduced and quinolinic acid levels were raised in hippocampal samples from MTLE‐HS patients, whereas kynurenine levels remained unaltered, compared with levels in non‐seizure controls. Spontaneous glutamatergic activity in MTLE‐HS hippocampal samples was higher than that in non‐seizure controls. Treatment with kynurenine inhibited glutamatergic activity in non‐seizure control samples but not in MTLE‐HS samples. However, exogenously applied kynurenic acid inhibited glutamatergic activity in both non‐seizure control and MTLE‐HS hippocampal samples. Also, levels of kynurenine aminotransferase II and its cofactor pyridoxal phosphate were reduced in MTLE‐HS samples. Conclusion and Implications Our findings indicate that altered metabolism of tryptophan–kynurenine pathway metabolites in hippocampus could contribute to hyperglutamatergic tone in patients with MTLE‐HS.

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Section: Methodsmentioning

confidence: 99%

Altered hippocampal kynurenine pathway metabolism contributes to hyperexcitability in human mesial temporal lobe epilepsy–hippocampal sclerosis

Dey

Dixit

Tripathi

et al. 2021

British J Pharmacology

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“…Coordination of epilepsy surgery is not simple. For these patients, extensive preoperative evaluation is necessary, involving comprehensive neurological assessment including multiple imaging modalities, video electroencephalography monitoring, and extensive coordination with a multidisciplinary team [22,23]. Young patients may require sedation and anesthesia services for diagnostic studies such as neuroimaging.…”

Section: The Impact Of Surgical Epilepsy Referrals In Drementioning

confidence: 99%

Disparities in pediatric drug-resistant epilepsy care

2023

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Introduction Epilepsy affects millions of children worldwide, with 20–40% experiencing drug-resistant epilepsy (DRE) who are recommended for epilepsy surgery evaluation and may benefit from surgical management. However, many patients live with DRE for multiple years prior to surgical epilepsy referral or treatment or are never referred at all. Objective We aimed to describe factors associated with referral for epilepsy surgery in the USA, in order to identify disparities in DRE, characterize why they may exist, and recognize areas for improvement. Methods Pediatric patients diagnosed with DRE between January 1, 2004 and December 31, 2020 were identified from the Pediatric Health Information System (PHIS) Database. Patients treated with antiseizure medications (ASMs) only, ASMs plus vagus nerve stimulation (VNS), and ASMs plus cranial epilepsy surgery were studied regarding access to epilepsy surgery and disparities in care. This study used chi-square tests to determine associations between treatment time and preoperative factors. Preoperative factors studied included epilepsy treatment type, age, sex, race/ethnicity, insurance type, geographic region, patient type, epilepsy type, and presence of pediatric complex chronic conditions (PCCCs). Results A total of 18,292 patients were identified; 10,240 treated with ASMs, 5019 treated with ASMs + VNS, and 3033 treated with ASMs + cranial epilepsy surgery. Sex was not found to significantly vary among groups. There was significant variation in age, census region, race/ethnicity, patient type, presence of PCCCs, diagnosis, and insurance (p < 0.001). Those treated surgically, either with VNS or cranial epilepsy surgery, were 2 years older than those medically treated. Additionally, those medically treated were less likely to be living in the Midwest (25.46%), identified as non-Hispanic white (51.78%), have a focal/partial epilepsy diagnosis (8.74%), and be privately insured (35.82%). Conclusions We studied a large administrative US database examining variables associated with surgical epilepsy evaluation and management. We found significant variation in treatment associated with age, US census region, race/ethnicity, patient type, presence of PCCCs, diagnosis, and health insurance type. We believe that these disparities in care are related to access and social determinants of health, and we encourage focused outreach strategies to mitigate these disparities to broaden access and improve outcomes in children in the USA with DRE.

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“…Prior to epilepsy surgery, patients undergo a series of imaging and electrographic studies to localize the epileptic foci [6]. Standard non-invasive methods include electroencephalography (EEG), magnetoencephalography (MEG), magnetic resonance imaging (MRI), fluorodeoxyglucose-positron emission tomography (FDG-PET), and single-photon emission computed tomography (SPECT) [6][7][8]. Multiple testing modalities are often necessary to accurately localize the epileptic foci [6][7][8] and eloquent areas [9,10].…”

Section: Introductionmentioning

confidence: 99%

“…Standard non-invasive methods include electroencephalography (EEG), magnetoencephalography (MEG), magnetic resonance imaging (MRI), fluorodeoxyglucose-positron emission tomography (FDG-PET), and single-photon emission computed tomography (SPECT) [6][7][8]. Multiple testing modalities are often necessary to accurately localize the epileptic foci [6][7][8] and eloquent areas [9,10]. In addition to the non-invasive modalities, invasive intracranial studies such as stereo-electroencephalography (SEEG) and other intracranial electroencephalography (iEEG), such as subdural electrodes (SDE), may be indicated if non-invasive investigations are unable to definitively confirm the seizure onset zone.…”

Section: Introductionmentioning

confidence: 99%

The Impact of Magnetoencephalography-Directed Stereo-Electroencephalography Depth Electrode Implantation on Seizure Control Outcome in Children

Mozaffari¹,

Hofmann²,

Boyd³

et al. 2022

Cureus

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The use of magnetoencephalography (MEG) in localizing epileptic foci and directing surgical treatment of medically refractory epilepsy is well established in clinical practice; however, it has not yet been incorporated into the routine planning of stereo-electroencephalography (EEG) (SEEG) depth electrode trajectories during invasive intracranial evaluation for epileptic foci localization. In this study, we assess the impact of MEG-directed SEEG on seizure outcomes in a pediatric cohort. MethodsA retrospective analysis was performed on a single-institution cohort of pediatric patients with medically refractory epilepsy who underwent epilepsy surgery. The primary endpoint was the reduction in seizure burden as determined by dichotomized Engel scores (favorable outcome: Engel scores I and II; poor outcome: Engel scores III and IV). ResultsThirty-seven patients met the inclusion criteria (24 males and 13 females). The median age at seizure onset was three years, the median age at surgery was 14.1 years, and the median follow-up length was 30.8 months. Concordance was noted in 7/10 (70%) patients who received MEG-directed SEEG. Good clinical outcomes were achieved in 70% of MEG-directed SEEG patients, compared to 59.4% in their counterparts; however, this difference was not statistically significant (p=0.72). We noted no statistically significant association between sex, disease laterality, or age at surgery and good clinical outcomes. ConclusionsPatients who underwent MEG-directed SEEG had favorable clinical outcomes, which demonstrated the practicability of this technique for determining SEEG electrode placement. Although no significant difference in clinical outcomes was obtained between the two groups, this may have been due to low statistical power. Future prospective, multi-institutional investigations to assess the benefit of MEGdirected SEEG are warranted.

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Presurgical evaluation for drug refractory epilepsy

Cited by 19 publications

References 33 publications

Altered hippocampal kynurenine pathway metabolism contributes to hyperexcitability in human mesial temporal lobe epilepsy–hippocampal sclerosis

Altered hippocampal kynurenine pathway metabolism contributes to hyperexcitability in human mesial temporal lobe epilepsy–hippocampal sclerosis

Disparities in pediatric drug-resistant epilepsy care

The Impact of Magnetoencephalography-Directed Stereo-Electroencephalography Depth Electrode Implantation on Seizure Control Outcome in Children

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