Aroma helps to preserve information processing resources of the brain in healthy subjects but not in temporal lobe epilepsy

The default mode network (DMN) is involved in conscious, resting state cognition and is thought to be affected in TLE where seizures cause impairment of consciousness. The study aimed to evaluate the brain activation of the DMN regions in both temporal lobe epilepsy (TLE) patients and healthy subjects by using resting-state functional Magnetic Resonance Imaging (rsfMRI) technique. A same number of fourteen participants with age and gender matched for the healthy subjects and TLE patients were selected with the average age is 36.9 and 37.0 years old, respectively. The rsfMRI imaging protocol was executed using a 3-T Phillips Achieva MRI scanner at the Radiology Department, Hospital Universiti Sains Malaysia (HUSM). For healthy subjects, the brain activation cluster in bilateral superior parietal lobes (SPL),precuneus (PRE), supramarginal gyrus (SMG) and inferior parietal lobes (IPL) were found higher than TLE patients. While for TLE patients displays higher activation clusters in bilateral MFG, STG, and ANG. The result from random effects (RFX) on two-sample t-tests thresholded at p = 0.001 revealed that the TLE patients display significantly higher activations on the bilateral superior frontal gyrus (SFG), left SMG, left middle frontal gyrus (MFG) and right IPL. However for the core-region of DMN such as bilateral precuneus, left MFG, bilateral STG and bilateral IPL were significantly activated but the number of voxels survives are substantially smaller than other regions such as bilateral SFG. The findings suggested that TLE patients may suffer from an impairment in some DMN region, which may cause certain neuropsychological and cognitive degradation. Keywords: resting-state fMRI, temporal lobe epilepsy, brain activation, two-sample t-tests

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The Relationship between Glucose Metabolism, Resting-State fMRI BOLD Signal, and GABAA-Binding Potential: A Preliminary Study in Healthy Subjects and Those with Temporal Lobe Epilepsy

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2014.228 ◽

2015 ◽

Vol 35 (4) ◽

pp. 583-591 ◽

Cited By ~ 59

Author(s):

Allison C Nugent ◽

Ashley Martinez ◽

Alana D'Alfonso ◽

Carlos A Zarate ◽

William H Theodore

Keyword(s):

Glucose Metabolism ◽

Temporal Lobe Epilepsy ◽

Human Brain ◽

Temporal Lobe ◽

Resting State ◽

Healthy Subjects ◽

Binding Potential ◽

Bold Signal ◽

Healthy Human ◽

The Brain

Glucose metabolism has been associated with magnitude of blood oxygen level-dependent (BOLD) signal and connectivity across subjects within the default mode and dorsal attention networks. Similar correlations within subjects across the entire brain remain unexplored. [18F]-fluorodeoxyglucose positron emission tomography ([18F]-FDG PET), [11C]-flumazenil PET, and resting-state functional magnetic resonance imaging (fMRI) scans were acquired in eight healthy individuals and nine with temporal lobe epilepsy (TLE). Regional metabolic rate of glucose (rMRGlu) was correlated with amplitude of low frequency fluctuations (ALFFs) in the fMRI signal, global fMRI connectivity (GC), regional homogeneity (ReHo), and gamma-aminobutyric acid A—binding potential (GABAA BPND) across the brain. Partial correlations for ALFFs, GC, and ReHo with GABAA BPND were calculated, controlling for rMRGlu. In healthy subjects, significant positive correlations were observed across the brain between rMRGlu and ALFF, ReHo and GABAA BPND, and between ALFFs and GABAA BPND, controlling for rMRGlu. Brain-wide correlations between rMRGlu and ALFFs were significantly lower in TLE patients, and correlations between rMRGlu and GC were significantly greater in TLE than healthy subjects. These results indicate that the glutamatergic and GABAergic systems are coupled across the healthy human brain, and that ALFF is related to glutamate use throughout the healthy human brain. TLE may be a disorder of altered long-range connectivity in association with glutamate function.

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Induction of the Nrf2 Pathway by Sulforaphane Is Neuroprotective in a Rat Temporal Lobe Epilepsy Model

Antioxidants ◽

10.3390/antiox10111702 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1702

Author(s):

Sereen Sandouka ◽

Tawfeeq Shekh-Ahmad

Keyword(s):

Oxidative Stress ◽

Cell Death ◽

Status Epilepticus ◽

Temporal Lobe Epilepsy ◽

Antioxidant Capacity ◽

Temporal Lobe ◽

Epileptiform Activity ◽

Neuronal Cell Death ◽

Neuronal Cell ◽

The Brain

Epilepsy is a chronic disease of the brain that affects over 65 million people worldwide. Acquired epilepsy is initiated by neurological insults, such as status epilepticus, which can result in the generation of ROS and induction of oxidative stress. Suppressing oxidative stress by upregulation of the transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2) has been shown to be an effective strategy to increase endogenous antioxidant defences, including in brain diseases, and can ameliorate neuronal damage and seizure occurrence in epilepsy. Here, we aim to test the neuroprotective potential of a naturally occurring Nrf2 activator sulforaphane, in in vitro epileptiform activity model and a temporal lobe epilepsy rat model. Sulforaphane significantly decreased ROS generation during epileptiform activity, restored glutathione levels, and prevented seizure-like activity-induced neuronal cell death. When given to rats after 2 h of kainic acid-induced status epilepticus, sulforaphane significantly increased the expression of Nrf2 and related antioxidant genes, improved oxidative stress markers, and increased the total antioxidant capacity in both the plasma and hippocampus. In addition, sulforaphane significantly decreased status epilepticus-induced neuronal cell death. Our results demonstrate that Nrf2 activation following an insult to the brain exerts a neuroprotective effect by reducing neuronal death, increasing the antioxidant capacity, and thus may also modify epilepsy development.

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Magnetic resonance spectroscopy of the brain in the diagnosis of temporal lobe epilepsy

Neurology neuropsychiatry Psychosomatics ◽

10.14412/2074-2711-2018-1s-51-55 ◽

2018 ◽

Vol 10 (1S) ◽

pp. 51-55

Author(s):

E. S. Solomatova ◽

N. A. Shnaider ◽

A. A. Molgachev ◽

D. V. Dmitrenko ◽

I. G. Strotskaya

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Spectroscopy ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

English Language ◽

Russian Language ◽

Resonance Spectroscopy ◽

Epileptogenic Focus ◽

Patients With Epilepsy ◽

The Brain

The temporal lobe is the most epileptogenic region of the brain. 90% of patients with temporal ictal epileptomorphic EEG activity have a variable long history of seizures. Magnetic resonance spectroscopy (MRS) may be useful in identifying an epileptogenic focus in patients with epilepsy without apparent structural pathology at neuroimaging.Objective: to systematize the results of early studies on this issue.Materials and methods. An electronic search was carried out in two English-language (Medline, PubMed) and one Russian-language (eLIBRARY.RU) databases. The search queries found 18,019 citations, by which 12 full-text articles were selected.Results and discussion. The main criteria for the diagnosis of temporal lobe epilepsy by MRS is to lower the level of N-acetylaspartate (NAA), the ratio of NAA to creatinine + choline (NAA/(Cr + Cho) in the brain region where there is neuronal death or damage, as well as a change in the level of myo-inositol, the elevated level of which indicates the presence of an epileptogenic focus, while the decreased one shows the spread of pathological activity to the adjacent tissues.Conclusion. This review will contribute to a better diagnosis of temporal lobe epilepsy, as well as to the intravital noninvasive detection of metabolic changes in the brain long before the development of structural pathology.

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Recent developments in cognitive fMRI for temporal lobe epilepsy

Zeitschrift für Epileptologie ◽

10.1007/s10309-019-00303-w ◽

2019 ◽

Vol 33 (1) ◽

pp. 30-36 ◽

Cited By ~ 1

Author(s):

Victor Schmidbauer ◽

Silvia Bonelli

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Visual Memory ◽

Imaging Modality ◽

Memory Function ◽

Brain Regions ◽

Epileptogenic Zone ◽

Brain Areas ◽

Recent Developments ◽

The Brain

AbstractEpilepsy is frequently accompanied by severe cognitive side effects. Temporal lobe epilepsy (TLE), and even successful surgical treatment, may affect cognitive function, in particular language as well as verbal and visual memory function. Epilepsy arising from the temporal lobe can be controlled surgically in up to 70% of patients. The goals of epilepsy surgery are to remove the brain areas generating the seizures without causing or aggravating neuropsychological deficits. This requires accurate localization of the brain areas generating the seizures (“epileptogenic zone”) and the areas responsible for motor and cognitive functions, such as language and memory (“essential brain regions”) during presurgical evaluation. In the past decades, functional magnetic resonance imaging (fMRI) has been increasingly used to noninvasively lateralize and localize not only primary motor and somatosensory areas, but also brain areas that are involved in everyday language and memory processes. The imaging modality also shows potential for predicting the effects of temporal lobe resection on language and memory function. Together with other MRI modalities, cognitive fMRI is a promising tool to improve surgical strategies tailored to individual patients with regard to functional outcome, by virtue of definition of epileptic cerebral areas that need to be resected and eloquent areas that need to be spared.The aim of this review is to provide an overview of recent developments and practical recommendations for the clinical use of cognitive fMRI in TLE.

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Comparison of Blood Perfusion Parameters in the Ipsilateral and Contralateral Sides of the Brain in Known Cases of Mesial Temporal Lobe Epilepsy

Iranian Journal of Radiology ◽

10.5812/iranjradiol.107887 ◽

2021 ◽

Vol 18 (2) ◽

Author(s):

Amin Farzadniya ◽

Jafar Mehvari ◽

Reza Basiratnia ◽

Farzad Mehrabi

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Blood Perfusion ◽

Mesial Temporal Lobe Epilepsy ◽

Enhanced Mri ◽

Affected Side ◽

Contrast Enhanced ◽

Mesial Temporal Lobe ◽

The Brain ◽

Contrast Enhanced Mri

Background: Temporal lobe epilepsy (TLE) is the most common form of focal seizures. To localize the epileptic site for surgery, different neuroimaging tools are used. Perfusion magnetic resonance imaging (MRI) is one of the modalities used to evaluate the cerebral hemodynamics and localize intracranial neoplasia and cerebrovascular events. Two contrast-based perfusion imaging sequences are described, including dynamic susceptibility contrast-enhanced MRI (DSC-MRI) and dynamic contrast-enhanced MRI (DCE-MRI). The most commonly measured parameters include the relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), and mean transit time (MTT). Objectives: This study aimed to evaluate the blood perfusion parameters, such as rCBV and rCBF, in patients diagnosed with mesial temporal lobe epilepsy (MTLE), using DSC-perfusion MRI to determine whether there is a change in these parameters and if this modality can be used to diagnose and localize the epileptic side. Methods: Twenty-two patients, who were diagnosed with TLE clinically and electrophysiologically by a neurologist, were investigated in this study. The patients were examined for the presence of any other lesions, such as tumors or cerebrovascular disease as the exclusion criteria. Perfusion images were processed by the Siemens perfusion software, and the rCBV and rCBF maps were generated based on the gamma variate fit. For qualitative analysis, coronal reconstruction of rCBV and rCBF maps was performed. For quantitative analysis, a single neuroradiologist placed the region of interest (ROI) on the hippocampus and the parahippocampal gyrus on T1W images at the same level of DSC images. After determining the CBV and CBF values relative to the ROI of each side, the asymmetry index (AI) was calculated. Results: In patients with unilateral epilepsy, the blood perfusion parameters in the ipsilateral side of the brain were significantly lower than the contralateral side (P < 0.0001); the mean values of both parameters were significantly lower in the affected side as compared to the opposite side. Conclusions: In patients with TLE, significantly lower blood perfusion parameters in the affected side of the brain can help radiologists and neurologists to lateralize the MTLE side.

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Seizure Freedom After Epilepsy Surgery and Higher Baseline Cognition May Be Associated With a Negatively Correlated Epilepsy Network in Temporal Lobe Epilepsy

Frontiers in Neuroscience ◽

10.3389/fnins.2020.629667 ◽

2021 ◽

Vol 14 ◽

Author(s):

Elliot G. Neal ◽

Mike R. Schoenberg ◽

Stephanie Maciver ◽

Yarema B. Bezchlibnyk ◽

Fernando L. Vale

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Epilepsy Surgery ◽

Memory Function ◽

Brain Regions ◽

Seizure Freedom ◽

Epileptogenic Zone ◽

Temporal Lobes ◽

Scalp Eeg ◽

The Brain

Background: Brain regions positively correlated with the epileptogenic zone in patients with temporal lobe epilepsy vary in spread across the brain and in the degree of correlation to the temporal lobes, thalamus, and limbic structures, and these parameters have been associated with pre-operative cognitive impairment and seizure freedom after epilepsy surgery, but negatively correlated regions have not been as well studied. We hypothesize that connectivity within a negatively correlated epilepsy network may predict which patients with temporal lobe epilepsy will respond best to surgery.Methods: Scalp EEG and resting state functional MRI (rsfMRI) were collected from 19 patients with temporal lobe epilepsy and used to estimate the irritative zone. Using patients’ rsfMRI, the negatively correlated epilepsy network was mapped by determining all the brain voxels that were negatively correlated with the voxels in the epileptogenic zone and the spread and average connectivity within the network was determined.Results: Pre-operatively, connectivity within the negatively correlated network was inversely related to the spread (diffuseness) of that network and positively associated with higher baseline verbal and logical memory. Pre-operative connectivity within the negatively correlated network was also significantly higher in patients who would go on to be seizure free.Conclusion: Patients with higher connectivity within brain regions negatively correlated with the epilepsy network had higher baseline memory function, narrower network spread, and were more likely to be seizure free after surgery.

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Evaluation of intense physical effort in subjects with temporal lobe epilepsy

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2009000600009 ◽

2009 ◽

Vol 67 (4) ◽

pp. 1007-1012 ◽

Cited By ~ 25

Author(s):

Fabio Camilo ◽

Fúlvio Alexandre Scorza ◽

Marly de Albuquerque ◽

Rodrigo Luiz Vancini ◽

Esper Abrão Cavalheiro ◽

...

Keyword(s):

Physical Activity ◽

Blood Pressure ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Healthy Subjects ◽

Recovery Period ◽

Physical Effort ◽

Objective Evidence ◽

Blood Pressure Responses ◽

Intensity Of Exercise

People with epilepsy have been discouraged from participating in physical activity due to the fear that it will exacerbate seizures. Although the beneficial effect of aerobic exercise in people with epilepsy, little objective evidence regarding the intensity of exercise has been reported. We investigated the effect of incremental physical exercise to exhaustion in people with epilepsy. Seventeen persons with temporal lobe epilepsy and twenty one control healthy subjects participated in this study. Both groups were submitted to echocolordoppler and electrocardiogram at rest and during physical effort. None of patients reported seizures during physical effort or in the recovery period of ergometric test. Both groups presented physiological heart rate and blood pressure responses during the different stages of the ergometric test. Only few patients presented electrocardiography or echocardiography alterations at rest or during effort. In conclusion, this work suggests that physical effort to exhaustion is not a seizure-induced component.

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