scholarly journals Language Processing and Reorganization in the Brain in Patients with Temporal Lobe Epilepsy

2019 ◽  
Vol 6 (4) ◽  
pp. 4-15
Author(s):  
Anna Yurchenko ◽  

This paper explores language comprehension and production in patients with temporal lobe epilepsy, a neurological disorder characterized by an epileptogenic focus near language areas or their homologues in the brain. Behavioral studies have shown that language processing in patients with temporal lobe epilepsy could be impaired across language domains — from single words to discourse. Neuroimaging data suggest that temporal lobe epilepsy may lead to changes in the lateralization and localization of language functions, reorganization of functional connections, and alterations in cortical structure and white matter tracts. The severity of language impairments and the degree of functional and structural reorganization in the brain correlate with clinical factors, including lateralization of the epileptogenic focus, age at seizure onset, disease duration, and frequency of epileptiform activity

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1702
Author(s):  
Sereen Sandouka ◽  
Tawfeeq Shekh-Ahmad

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.


2018 ◽  
Vol 10 (1S) ◽  
pp. 51-55
Author(s):  
E. S. Solomatova ◽  
N. A. Shnaider ◽  
A. A. Molgachev ◽  
D. V. Dmitrenko ◽  
I. G. Strotskaya

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.


NeuroImage ◽  
2001 ◽  
Vol 13 (6) ◽  
pp. 153
Author(s):  
Sven Hoegg ◽  
Hans-Jürgen Huppertz ◽  
Christian Sick ◽  
Josef Zentner ◽  
Andreas Schulze-Bonhage ◽  
...  

2014 ◽  
Vol 125 ◽  
pp. S170-S171
Author(s):  
J.A. Bragatti ◽  
I.C. Bandeira ◽  
A.M. Carvalho ◽  
P.A. Cherubini ◽  
C.M. Torres ◽  
...  

2019 ◽  
Vol 33 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Victor Schmidbauer ◽  
Silvia Bonelli

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.


2010 ◽  
Vol 112 (6) ◽  
pp. 1301-1307 ◽  
Author(s):  
Chandan G. Reddy ◽  
Nader S. Dahdaleh ◽  
Gregory Albert ◽  
Fangxiang Chen ◽  
Daniel Hansen ◽  
...  

A wide range of devices is used to obtain intracranial electrocorticography recordings in patients with medically refractory epilepsy, including subdural strip and grid electrodes and depth electrodes. Penetrating depth electrodes are required to access some brain regions, and 1 target site that presents a particular technical challenge is the first transverse temporal gyrus, or Heschl gyrus (HG). The HG is located within the supratemporal plane and has an oblique orientation relative to the sagittal and coronal planes. Large and small branches of the middle cerebral artery abut the pial surface of the HG and must be avoided when planning the electrode trajectory. Auditory cortex is located within the HG, and there are functional connections between this dorsal temporal lobe region and medial sites commonly implicated in the pathophysiology of temporal lobe epilepsy. At some surgical centers, depth electrodes are routinely placed within the supratemporal plane, and the HG, in patients who require intracranial electrocorticography monitoring for presumed temporal lobe epilepsy. Information from these recordings is reported to facilitate the identification of seizure patterns in patients with or without auditory auras. To date, only one implantation method has been reported to be safe and effective for placing HG electrodes in a large series of patients undergoing epilepsy surgery. This well-established approach involves inserting the electrodes from a lateral trajectory while using stereoscopic stereotactic angiography to avoid vascular injury. In this report, the authors describe an alternative method for implantation. They use frameless stereotaxy and an oblique insertion trajectory that does not require angiography and allows for the simultaneous placement of subdural grid arrays. Results in 19 patients demonstrate the safety and efficacy of the method.


1989 ◽  
Vol 43 (3) ◽  
pp. 393-400 ◽  
Author(s):  
Kazumi Matsuda ◽  
Kazuichi Yagi ◽  
Tadahiro Mihara ◽  
Takayasu Tottori ◽  
Yutaka Watanabe ◽  
...  

2016 ◽  
Vol 23 (12) ◽  
pp. 1713-1721 ◽  
Author(s):  
A. R. Giovagnoli ◽  
A. Parente ◽  
G. Didato ◽  
V. Manfredi ◽  
F. Deleo ◽  
...  

2020 ◽  
Vol 4 (1) ◽  
pp. 23-30
Author(s):  
Shuhada J.M ◽  
Husbani M.A.R ◽  
A I A Hamid ◽  
Muhammad

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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