Epilepsy and Ecstatic Experiences: The Role of the Insula

Ecstatic epilepsy is a rare form of focal epilepsy in which the aura (beginning of the seizures) consists of a blissful state of mental clarity/feeling of certainty. Such a state has also been described as a “religious” or mystical experience. While this form of epilepsy has long been recognized as a temporal lobe epilepsy, we have accumulated evidence converging toward the location of the symptomatogenic zone in the dorsal anterior insula during the 10 last years. The neurocognitive hypothesis for the genesis of a mental clarity is the suppression of the interoceptive prediction errors and of the unexpected surprise associated with any incoming internal or external signal, usually processed by the dorsal anterior insula. This mimics a perfect prediction of the world and induces a feeling of certainty. The ecstatic epilepsy is thus an amazing model for the role of anterior insula in uncertainty and surprise.

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Astrocyte Role in Temporal Lobe Epilepsy and Development of Mossy Fiber Sprouting

Frontiers in Cellular Neuroscience ◽

10.3389/fncel.2021.725693 ◽

2021 ◽

Vol 15 ◽

Author(s):

Carolyn Twible ◽

Rober Abdo ◽

Qi Zhang

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Mossy Fiber ◽

Focal Epilepsy ◽

Hippocampal Sclerosis ◽

Neuronal Cell ◽

Histopathological Diagnosis ◽

Mossy Fiber Sprouting ◽

Reactive Astrogliosis

Epilepsy affects approximately 50 million people worldwide, with 60% of adult epilepsies presenting an onset of focal origin. The most common focal epilepsy is temporal lobe epilepsy (TLE). The role of astrocytes in the presentation and development of TLE has been increasingly studied and discussed within the literature. The most common histopathological diagnosis of TLE is hippocampal sclerosis. Hippocampal sclerosis is characterized by neuronal cell loss within the Cornu ammonis and reactive astrogliosis. In some cases, mossy fiber sprouting may be observed. Mossy fiber sprouting has been controversial in its contribution to epileptogenesis in TLE patients, and the mechanisms surrounding the phenomenon have yet to be elucidated. Several studies have reported that mossy fiber sprouting has an almost certain co-existence with reactive astrogliosis within the hippocampus under epileptic conditions. Astrocytes are known to play an important role in the survival and axonal outgrowth of central and peripheral nervous system neurons, pointing to a potential role of astrocytes in TLE and associated cellular alterations. Herein, we review the recent developments surrounding the role of astrocytes in the pathogenic process of TLE and mossy fiber sprouting, with a focus on proposed signaling pathways and cellular mechanisms, histological observations, and clinical correlations in human patients.

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Expression Profile of miRs in Mesial Temporal Lobe Epilepsy: Systematic Review

International Journal of Molecular Sciences ◽

10.3390/ijms23020951 ◽

2022 ◽

Vol 23 (2) ◽

pp. 951

Author(s):

Kristina D. Yakovleva ◽

Diana V. Dmitrenko ◽

Iulia S. Panina ◽

Anna A. Usoltseva ◽

Kirill A. Gazenkampf ◽

...

Keyword(s):

Systematic Review ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Structural Damage ◽

Focal Epilepsy ◽

Mesial Temporal Lobe Epilepsy ◽

Diagnostic Methods ◽

Cochrane Reviews ◽

Specificity And Sensitivity

Temporal lobe epilepsy (TLE) is one of the most common forms of focal epilepsy in children and adults. TLE is characterized by variable onset and seizures. Moreover, this form of epilepsy is often resistant to pharmacotherapy. The search for new mechanisms for the development of TLE may provide us with a key to the development of new diagnostic methods and a personalized approach to the treatment. In recent years, the role of non-coding ribonucleic acids (RNA) has been actively studied, among which microRNA (miR) is of the greatest interest. (1) Background: The purpose of the systematic review is to analyze the studies carried out on the role of miRs in the development of mesial TLE (mTLE) and update the existing knowledge about the biomarkers of this disease. (2) Methods: The search for publications was carried out in the databases PubMed, Springer, Web of Science, Clinicalkeys, Scopus, OxfordPress, Cochrane. The search was carried out using keywords and combinations. We analyzed publications for 2016‒2021, including original studies in an animal model of TLE and with the participation of patients with TLE, thematic and systemic reviews, and Cochrane reviews. (3) Results: this thematic review showed that miR‒155, miR‒153, miR‒361‒5p, miR‒4668‒5p, miR‒8071, miR‒197‒5p, miR‒145, miR‒181, miR‒199a, miR‒1183, miR‒129‒2‒3p, miR‒143‒3p (upregulation), miR–134, miR‒0067835, and miR‒153 (downregulation) can be considered as biomarkers of mTLE. However, the roles of miR‒146a, miR‒142, miR‒106b, and miR‒223 are questionable and need further study. (4) Conclusion: In the future, it will be possible to consider previously studied miRs, which have high specificity and sensitivity in mTLE, as prognostic biomarkers (predictors) of the risk of developing this disease in patients with potentially epileptogenic structural damage to the mesial regions of the temporal lobe of the brain (congenital disorders of the neuronal migration and neurogenesis, brain injury, neuro-inflammation, tumor, impaired blood supply, neurodegeneration, etc.).

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Faculty Opinions recommendation of The role of corticothalamic coupling in human temporal lobe epilepsy.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.30563.487064 ◽

2006 ◽

Author(s):

Roderick Duncan

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Human Temporal Lobe

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Synaptic Reshaping and Neuronal Outcomes in the Temporal Lobe Epilepsy

International Journal of Molecular Sciences ◽

10.3390/ijms22083860 ◽

2021 ◽

Vol 22 (8) ◽

pp. 3860

Author(s):

Elisa Ren ◽

Giulia Curia

Keyword(s):

Animal Models ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Current Knowledge ◽

Focal Epilepsy ◽

Ex Vivo ◽

Hippocampal Sclerosis ◽

Control Group ◽

Epileptogenic Zone ◽

Epileptiform Discharges

Temporal lobe epilepsy (TLE) is one of the most common types of focal epilepsy, characterized by recurrent spontaneous seizures originating in the temporal lobe(s), with mesial TLE (mTLE) as the worst form of TLE, often associated with hippocampal sclerosis. Abnormal epileptiform discharges are the result, among others, of altered cell-to-cell communication in both chemical and electrical transmissions. Current knowledge about the neurobiology of TLE in human patients emerges from pathological studies of biopsy specimens isolated from the epileptogenic zone or, in a few more recent investigations, from living subjects using positron emission tomography (PET). To overcome limitations related to the use of human tissue, animal models are of great help as they allow the selection of homogeneous samples still presenting a more various scenario of the epileptic syndrome, the presence of a comparable control group, and the availability of a greater amount of tissue for in vitro/ex vivo investigations. This review provides an overview of the structural and functional alterations of synaptic connections in the brain of TLE/mTLE patients and animal models.

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Accuracy and Efficacy for Robotic Assistance in Implanting Responsive Neurostimulation Device Electrodes in Bilateral Mesial Temporal Lobe Epilepsy

Operative Neurosurgery ◽

10.1093/ons/opx085 ◽

2017 ◽

Vol 14 (3) ◽

pp. 267-272 ◽

Cited By ~ 7

Author(s):

Alvin Y Chan ◽

Lilit Mnatsakanyan ◽

Mona Sazgar ◽

Indranil Sen-Gupta ◽

Jack J Lin ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Focal Epilepsy ◽

Mesial Temporal Lobe Epilepsy ◽

Advanced Technology ◽

Robotic Assistance ◽

Mesial Temporal Lobe ◽

Robotic Devices ◽

New Treatment

Abstract BACKGROUND Responsive neurostimulation (RNS) is a relatively new treatment option that has been shown to be effective for patients with medically refractory focal epilepsy when resection is not possible, especially in bilateral mesial temporal onset. Robotic devices are becoming increasingly popular for use in stereotactic procedures such as stereoelectroencephalography, but have yet to be used when implanting RNS devices. OBJECTIVE To show that these 2 forms of advanced technology were compatible and could be used effectively in patient care. METHODS We implanted RNS devices in 3 patients with bilateral mesial temporal lobe epilepsy. Each patient was placed in the prone position, and electrode trajectories were planned via the robotic navigation system via a transoccipital approach. One lead was placed along each amygdalohippocampal complex. A small craniectomy was then created in the parietal region for RNS generator implantation. Actual and expected target locations and distance were calculated for each depth. There were no complications in this group. RESULTS RNS devices with bilateral leads were successfully implanted in all 3 patients, with bilateral mesial temporal lobe onset. Follow-up ranged from 3 to 6 mo, and there were no complications in this group. The median distance between the estimate and actual targets was 2.18 (range = 1.11-3.27) mm. CONCLUSION We show that implanting RNS devices with robotic assistance is feasible with excellent precision and accuracy. The advantages of using robotic assistance include higher flexibility, accuracy, precision, and consistency.

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Parameters of autonomic regulation in patients with focal frontal and temporal epilepsy

I P Pavlov Russian Medical Biological Herald ◽

10.23888/pavlovj202129145-53 ◽

2021 ◽

Vol 29 (1) ◽

pp. 45-53

Author(s):

Julia I. Medvedeva ◽

Roman A. Zorin ◽

Vladimir A. Zhadnov ◽

Michael M. Lapkin

Keyword(s):

Regression Analysis ◽

Temporal Lobe Epilepsy ◽

Evoked Potentials ◽

Temporal Lobe ◽

Focal Epilepsy ◽

Autonomic Regulation ◽

Control Group ◽

Temporal Epilepsy ◽

Logit Regression ◽

Autonomic Support

Aim. This study aimed to investigate the mechanisms of autonomic regulation and autonomic support in focal frontal and temporal lobe epilepsy. Materials and Methods. Thirty-six individuals were examined (19 men and 17 women; mean age 33.71.4 years) in the control group (without history of epileptic seizures) and 68 patients (32 men and 36 women, 34.11.5 years) with focal epilepsy (36 patients with frontal lobe epilepsy, of which 32 had temporal lobe epilepsy). Physiological parameters of heart rate variability and of skin sympathetic evoked potentials were evaluated. Results. Predomination of sympathetic influences in both groups of patients was found. According to the analysis of skin sympathetic evoked potentials, a high activity of the suprasegmental autonomic centers was determined in patients with epilepsy. Based on the results of the correlation analysis, the initial state in patients with temporal lobe epilepsy was characterized by greater intrasystemic tension that reflects the high level of physiological costs. The logit regression analysis model makes it possible to distribute patients with focal epilepsy into groups with different disease courses on the basis of the parameters of the autonomic support of the activity. Conclusion. In patients with focal epilepsy, predomination of sympathetic influences was observed, as well as greater activity of the suprasegmental centers of the autonomic regulation. Intrasystemic ratios of autonomic regulation parameters demonstrate an increase in the intrasystemic tension and a limitation of functional reserves in patients with temporal lobe epilepsy. A complex of parameters of autonomic support allows, based on the logit regression analysis, to distribute patients into groups with different courses of focal epilepsy.

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