Complex Partial Epilepsy (CPE), Focal Epilepsy: Temporal lobe epilepsy (TLE): TLE accounts for approximately 70% of all chronic CPE

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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Epilepsy and Ecstatic Experiences: The Role of the Insula

Brain Sciences ◽

10.3390/brainsci11111384 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1384

Author(s):

Fabienne Picard ◽

Peter Bossaerts ◽

Fabrice Bartolomei

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Mystical Experience ◽

Focal Epilepsy ◽

Anterior Insula ◽

External Signal ◽

Prediction Errors ◽

Rare Form ◽

The World

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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Levetiracetam Reduced the Basal Excitability of the Dentate Gyrus without Restoring Impaired Synaptic Plasticity in Rats with Temporal Lobe Epilepsy

Brain Sciences ◽

10.3390/brainsci10090634 ◽

2020 ◽

Vol 10 (9) ◽

pp. 634

Author(s):

Guillermo González-H ◽

Itzel Jatziri Contreras-García ◽

Karla Sánchez-Huerta ◽

Claudio M. T. Queiroz ◽

Luis Ricardo Gallardo Gudiño ◽

...

Keyword(s):

Synaptic Plasticity ◽

Temporal Lobe Epilepsy ◽

Dentate Gyrus ◽

Temporal Lobe ◽

Focal Epilepsy ◽

Chronic Phase ◽

Long Term Potentiation ◽

Excitatory Postsynaptic Potential ◽

Output Curve

Temporal lobe epilepsy (TLE), the most common type of focal epilepsy, affects learning and memory; these effects are thought to emerge from changes in synaptic plasticity. Levetiracetam (LEV) is a widely used antiepileptic drug that is also associated with the reversal of cognitive dysfunction. The long-lasting effect of LEV treatment and its participation in synaptic plasticity have not been explored in early chronic epilepsy. Therefore, through the measurement of evoked field potentials, this study aimed to comprehensively identify the alterations in the excitability and the short-term (depression/facilitation) and long-term synaptic plasticity (long-term potentiation, LTP) of the dentate gyrus of the hippocampus in a lithium–pilocarpine rat model of TLE, as well as their possible restoration by LEV (1 week; 300 mg/kg/day). TLE increased the population spike (PS) amplitude (input/output curve); interestingly, LEV treatment partially reduced this hyperexcitability. Furthermore, TLE augmented synaptic depression, suppressed paired-pulse facilitation, and reduced PS-LTP; however, LEV did not alleviate such alterations. Conversely, the excitatory postsynaptic potential (EPSP)-LTP of TLE rats was comparable to that of control rats and was decreased by LEV. LEV caused a long-lasting attenuation of basal hyperexcitability but did not restore impaired synaptic plasticity in the early chronic phase of TLE.

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Lateralising value of experiential hallucinations in temporal lobe epilepsy

Journal of Neurology Neurosurgery & Psychiatry ◽

10.1136/jnnp-2014-309452 ◽

2015 ◽

Vol 86 (11) ◽

pp. 1273-1276 ◽

Cited By ~ 5

Author(s):

Lukas Heydrich ◽

Guillaume Marillier ◽

Nathan Evans ◽

Olaf Blanke ◽

Margitta Seeck

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Single Photon ◽

Focal Epilepsy ◽

Photon Emission ◽

Mesial Temporal Lobe Epilepsy ◽

Positron Emission ◽

Mesial Temporal Lobe ◽

Deja Vu ◽

Déjà Vu

ObjectivesEver since John Hughlings Jackson first described the so-called ‘dreamy state’ during temporal lobe epilepsy, that is, the sense of an abnormal familiarity (déjà vu) or vivid memory-like hallucinations from the past (experiential hallucinations), these phenomena have been studied and repeatedly linked to mesial temporal lobe structures. However, little is known about the lateralising value of either déjà vu or experiential hallucinations.MethodsWe analysed a sample of 28 patients with intractable focal epilepsy suffering from either déjà vu or experiential hallucinations. All the patients underwent thorough presurgical examination, including MRI, positron emission tomography, single-photon emission CT, EEG and neuropsychological examination.ResultsWhile déjà vu was due to right or left mesial temporal lobe epilepsy, experiential hallucinations were strongly lateralised to the left mesial temporal lobe. Moreover, there was a significant effect for interictal language deficits being more frequent in patients suffering from experiential hallucinations.ConclusionsThese results suggest a lateralising value for experiential hallucinations to the left temporal lobe.

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Temporal Lobe Epilepsy

10.1093/med/9780199937837.003.0038 ◽

2017 ◽

Author(s):

Edward H. Bertram

Keyword(s):

Animal Models ◽

Temporal Lobe Epilepsy ◽

Entorhinal Cortex ◽

Temporal Lobe ◽

Medial Temporal Lobe ◽

Focal Epilepsy ◽

Neural Circuitry ◽

Human Condition ◽

Physiological Changes ◽

Limbic Structures

Temporal lobe epilepsy, as discussed in this chapter, is a focal epilepsy that involves primarily the limbic structures of the medial temporal lobe (amygdala, hippocampus, and entorhinal cortex). In recent years animal models have been developed that mirror the pathology and pathophysiology of this disease. This chapter reviews the human condition, the structural and physiological changes that support the development of seizures. The neural circuitry of seizure initiation will be reviewed with a goal of creating a framework for developing more effective treatments for this disease.

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Ictal Occurrence of High-Frequency Oscillations Correlates With Seizure Severity in a Rat Model of Temporal Lobe Epilepsy

Frontiers in Human Neuroscience ◽

10.3389/fnhum.2021.624620 ◽

2021 ◽

Vol 15 ◽

Author(s):

Nadja Birk ◽

Jan Schönberger ◽

Karin Helene Somerlik-Fuchs ◽

Andreas Schulze-Bonhage ◽

Julia Jacobs

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Rat Model ◽

High Frequency ◽

Focal Epilepsy ◽

Epileptic Activity ◽

Seizure Severity ◽

Chronic Epilepsy ◽

High Frequency Oscillations

High-frequency oscillations (HFOs, ripples 80–250 Hz, fast ripples 250–500 Hz) are biomarkers of epileptic tissue. They are most commonly observed over areas generating seizures and increase in occurrence during the ictal compared to the interictal period. It has been hypothesized that their rate correlates with the severity of epilepsy and seizure in affected individuals. In the present study, it was aimed to investigate whether the HFO count mirrors the observed behavioral seizure severity using a kainate rat model for temporal lobe epilepsy. Seizures were selected during the chronic epilepsy phase of this model and classified by behavioral severity according to the Racine scale. Seizures with Racine scale 5&6 were considered generalized and severe. HFOs were marked in 24 seizures during a preictal, ictal, and postictal EEG segment. The duration covered by the HFO during these different segments was analyzed and compared between mild and severe seizures. HFOs were significantly increased during ictal periods (p < 0.001) and significantly decreased during postictal periods (p < 0.03) compared to the ictal segment. Ictal ripples (p = 0.04) as well as fast ripples (p = 0.02) were significantly higher in severe seizures compared to mild seizures. The present study demonstrates that ictal HFO occurrence mirrors seizure severity in a chronic focal epilepsy model in rats. This is similar to recent observations in patients with refractory mesio-temporal lobe epilepsy. Moreover, postictal HFO decrease might reflect postictal inhibition of epileptic activity. Overall results provide additional evidence that HFOs can be used as biomarkers for measuring seizure severity in epilepsy.

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Mental and behavioral disorders in temporal lobe epilepsy

Psihiatru ro ◽

10.26416/psih.58.3.2019.2526 ◽

2019 ◽

Vol 58 (3) (1) ◽

pp. 23-27

Author(s):

Diana Vulea ◽

Simona Butnăraşu ◽

Ciprian Băcilă

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Medical Condition ◽

Focal Epilepsy ◽

Epileptic Seizures ◽

General Medical Condition ◽

Legal Implications ◽

The Right ◽

Psychiatric Manifestations ◽

Mental And Behavioral Disorders

The evolution of temporal lobe epilepsy often implies complex psychiatric manifestations, as the elements can be part of an aura, as well as of a psychiatric pathology of its own. This paper presents the case of a patient diagnosed with focal epilepsy of the right mesial temporal lobe, who subsequently developed psychotic disorder due to a general medical condition with medico-legal implications, treatment noncompliance and difficulties in controlling epileptic seizures.

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Menstrual cycle worsening of epileptic seizures in women with symptomatic focal epilepsy

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2005000500006 ◽

2005 ◽

Vol 63 (3b) ◽

pp. 751-756 ◽

Cited By ~ 27

Author(s):

Ana Carolina Belini Bazán ◽

Maria Augusta Montenegro ◽

Fernando Cendes ◽

Li Li Min ◽

Carlos A.M. Guerreiro

Keyword(s):

Menstrual Cycle ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Seizure Frequency ◽

Focal Epilepsy ◽

Epileptic Seizures ◽

Mesial Temporal Lobe Epilepsy ◽

Menstrual Cycles ◽

Medical Appointment ◽

Mesial Temporal Lobe

INTRODUCTION: Hormonal fluctuation is responsible for worsening of epileptic seizures during the menstrual cycle. OBJETIVE: To identify irregularities in the menstrual cycles of women with mesial temporal lobe epilepsy (MTLE) and extratemporal focal epilepsy (ETFE) and correlate the frequency of seizures during the menstrual cycles. METHOD: We evaluated prospectively women in the menacme with MTLE and ETFE. Calendars were provided for these patients, and they were asked to mark their seizure frequency according to the menses. Calendars were reviewed in each routine medical appointment. RESULTS: Thirty-nine patients with MTLE and 14 with ETFE were evaluated. We registered 211 cycles in the patients with MTLE and 49 in those with ETFE. Irregular menstrual cycles were found in 28 (28/39, 71.7%) patients with MTLE and 6 (6/14, 42.8%) with ETFE (p=0.052). Premenstrual seizure worsening was observed in 46 (21.8%) patients with MTLE and 9 (18.3%) with ETFE (p=0.596). Menstrual worsening was observed in 47 (22.2%) patients with MTLE and 15 (30.6%) with ETFE (p=0. 217). Ovulatory worsening was observed in 36 (17%) patients with MTLE and 13 (26.5%) with ETFE (p=0,126). Catamenial worsening was observed in 58 (27.4%) of the patients with MTLE and in 17 (34.7%) of the patients with ETFE (p=0.315). CONCLUSION: There was no difference between the group of patients with MTLE and ETFE regarding the frequency of irregular cycles and seizure worsening during the premenstrual, menstrual, catamenial or ovulatory periods.

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