Faculty Opinions recommendation of Disrupted ipsilateral network connectivity in temporal lobe epilepsy.

OBJECTIVEFunctional connectivity magnetic resonance imaging (fcMRI) is a form of fMRI that allows for analysis of blood oxygen level–dependent signal changes within a task-free, resting paradigm. This technique has been shown to have efficacy in evaluating network connectivity changes with epilepsy. Presurgical data from patients with unilateral temporal lobe epilepsy were evaluated using the fcMRI technique to define connectivity changes within and between the diseased and healthy temporal lobes using a within-subjects design.METHODSUsing presurgical fcMRI data from pediatric patients with unilateral temporal lobe epilepsy, the authors performed seed-based analyses within the diseased and healthy temporal lobes. Connectivity within and between temporal lobe seeds was measured and compared.RESULTSIn the cohort studied, local ipsilateral temporal lobe connectivity was significantly increased on the diseased side compared to the healthy temporal lobe. Connectivity of the diseased side to the healthy side, on the other hand, was significantly reduced when compared to connectivity of the healthy side to the diseased temporal lobe. A statistically significant regression was observed when comparing the changes in local ipsilateral temporal lobe connectivity to the changes in inter–temporal lobe connectivity. A statistically significant difference was also noted in ipsilateral connectivity changes between patients with and those without mesial temporal sclerosis.CONCLUSIONSUsing fcMRI, significant changes in ipsilateral temporal lobe and inter–temporal lobe connectivity can be appreciated in unilateral temporal lobe epilepsy. Furthermore, fcMRI may have a role in the presurgical evaluation of patients with intractable temporal lobe epilepsy.

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Default Mode Network Ventral Hub Connectivity Associated with Memory Impairment in Temporal Lobe Epilepsy Surgery

10.1101/2020.11.11.377929 ◽

2020 ◽

Author(s):

Elliot G. Neal ◽

Long Di ◽

You Jeong Park ◽

Austin Finch ◽

Ferdinand Korneli ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Epilepsy Surgery ◽

Default Mode Network ◽

Memory Task ◽

Network Connectivity ◽

Default Mode ◽

Non Invasive ◽

Before And After ◽

The Relationship

AbstractIn patients undergoing surgery for intractable temporal lobe epilepsy, the relationship between the default mode network and patients’ neurocognitive outcome remains unclear. The objective of this study is to employ non-invasive network mapping to identify the relationship between subdivisions of the default mode network and neurocognitive function before and after epilepsy surgery in patients with temporal lobe epilepsy.Twenty-seven medically patients with medically refractory temporal lobe epilepsy were prospectively enrolled and received resting state functional MRI and neuropsychological testing both pre- and post-operatively. Connectivity within the default mode network was modeled and average connectivity within the networks was calculated.Higher pre-operative connectivity in the ventral default mode network hub correlated with impaired baseline performance in a visual memory task. Post-operatively, a decrease in ventral but not dorsal default mode network connectivity was correlated with a deterioration of verbal and logical memory after surgery.Overall, higher connectivity in the ventral default mode network hub was associated with poor memory function in patients with temporal lobe epilepsy both before and after temporal lobe surgery. Pre-operatively, higher ventral connectivity was associated with worse visual function. Post-operatively, decreased connectivity of the ventral and dorsal default mode network was correlated with a greater decrease in logical and verbal memory when compared with the pre-operation baseline. An imbalance in default mode network connectivity towards the ventral stream and more widespread epilepsy networks may be used to predict memory impairments following surgical intervention and may lead to more tailored surgical decision making based on this non-invasive network modeling.

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Left temporal lobe language network connectivity in temporal lobe epilepsy

Brain ◽

10.1093/brain/awy164 ◽

2018 ◽

Vol 141 (8) ◽

pp. 2406-2418 ◽

Cited By ~ 23

Author(s):

Karin Trimmel ◽

Andre L van Graan ◽

Lorenzo Caciagli ◽

Anja Haag ◽

Matthias J Koepp ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Network Connectivity ◽

Left Temporal Lobe ◽

Language Network

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Hippocampal Pathophysiology: Commonality Shared by Temporal Lobe Epilepsy and Psychiatric Disorders

Neuroscience Journal ◽

10.1155/2018/4852359 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 12

Author(s):

Soichiro Nakahara ◽

Megumi Adachi ◽

Hiroyuki Ito ◽

Mitsuyuki Matsumoto ◽

Katsunori Tajinda ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Dentate Gyrus ◽

Psychiatric Disorders ◽

Temporal Lobe ◽

Seizure Activity ◽

Mossy Fiber ◽

Focal Point ◽

Network Connectivity ◽

Present Review ◽

The Brain

Accumulating evidence points to the association of epilepsy, particularly, temporal lobe epilepsy (TLE), with psychiatric disorders, such as schizophrenia. Among these illnesses, the hippocampus is considered the regional focal point of the brain, playing an important role in cognition, psychosis, and seizure activity and potentially suggesting common etiologies and pathophysiology of TLE and schizophrenia. In the present review, we overview abnormal network connectivity between the dentate gyrus (DG) and the Cornus Ammonis area 3 (CA3) subregions of the hippocampus relative to the induction of epilepsy and schizophrenia. In light of our recent finding on the misguidance of hippocampal mossy fiber projection in the rodent model of schizophrenia, we discuss whether ectopic mossy fiber projection is a commonality in order to evoke TLE as well as symptoms related to schizophrenia.

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