scholarly journals The comparative study of invasive electroencephalography modalities in temporal lobe epilepsy

2021 ◽  
Vol 23 (3) ◽  
pp. 14-22
Author(s):  
V. M. Dzhafarov ◽  
A. B. Dmitriev ◽  
N. P. Denisova ◽  
D. A. Rzaev

Introduction. Invasive video-EEG monitoring (invasive EEG) is indicated in patients with refractory focal epilepsy while localization of the epileptogenic zone is unclear. Methods of invasive EEG in different groups of patients demonstrate variable results.Objective: to analyse the results of invasive EEG via subdural and depth electrodes in patients with refractory temporal lobe epilepsy with mesial temporal lobe seizures.Materials and methods. The series of 37 patients who underwent invasive EEG from 2013 to 2020 was retrospectively analysed. The study includes primary adult patients with structural refractory focal epilepsy with mesial temporal lobe seizures without tumor and vascular pathology. Patients were divided onto 3 groups: 1) with foramen ovale electrodes 2) subdural strip electrodes and 3) combination of subdural strips and depths electrodes. The results of anteromedial temporal lobectomy after 6 months were classified according to Engel scale.Results. A group with foramen ovale electrodes included 7 patients, subdural strips – 23, combination – 7. The seizure onset zone was detected in 36 (97 %) cases. Serious complications were observed in 2 (29 %) cases in the group with foramen ovale electrodes. The mean follow-up in 23 (76 %) patients after resective surgery was 28.3 months. Favourable results (Engel I, II) were observed in 4 (80 %) patients with foramen ovale electrodes, in 8 (67 %) patients with subdural electrodes, in 6 (100 %) with combination. Unfavourable results (Engel III, IV) were noted in 1 (20 %) patient with foramen ovale electrode, in 4 (33 %) patients with subdural strips.Conclusion. All the presented modalities of invasive EEG are effective for localizing of seizure onset zone in this category of patients. Foramen ovale electrode using may be limited due to increased risk of complications.

Epilepsia ◽  
2006 ◽  
Vol 47 (8) ◽  
pp. 1300-1307 ◽  
Author(s):  
Tonicarlo R. Velasco ◽  
Americo C. Sakamoto ◽  
Veriano Alexandre ◽  
Roger Walz ◽  
Charles L. Dalmagro ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Robert D. G. Blair

Epilepsy represents a multifaceted group of disorders divided into two broad categories, partial and generalized, based on the seizure onset zone. The identification of the neuroanatomic site of seizure onset depends on delineation of seizure semiology by a careful history together with video-EEG, and a variety of neuroimaging technologies such as MRI, fMRI, FDG-PET, MEG, or invasive intracranial EEG recording. Temporal lobe epilepsy (TLE) is the commonest form of focal epilepsy and represents almost 2/3 of cases of intractable epilepsy managed surgically. A history of febrile seizures (especially complex febrile seizures) is common in TLE and is frequently associated with mesial temporal sclerosis (the commonest form of TLE). Seizure auras occur in many TLE patients and often exhibit features that are relatively specific for TLE but few are of lateralizing value. Automatisms, however, often have lateralizing significance. Careful study of seizure semiology remains invaluable in addressing the search for the seizure onset zone.


2021 ◽  
Vol 22 (8) ◽  
pp. 3860
Author(s):  
Elisa Ren ◽  
Giulia Curia

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.


Author(s):  
Mohammed M. Jan ◽  
Mark Sadler ◽  
Susan R. Rahey

Electroencephalography (EEG) is an important tool for diagnosing, lateralizing and localizing temporal lobe seizures. In this paper, we review the EEG characteristics of temporal lobe epilepsy (TLE). Several “non-standard” electrodes may be needed to further evaluate the EEG localization, Ictal EEG recording is a major component of preoperative protocols for surgical consideration. Various ictal rhythms have been described including background attenuation, start-stop-start phenomenon, irregular 2-5 Hz lateralized activity, and 5-10 Hz sinusoidal waves or repetitive epileptiform discharges. The postictal EEG can also provide valuable lateralizing information. Postictal delta can be lateralized in 60% of patients with TLE and is concordant with the side of seizure onset in most patients. When patients are being considered for resective surgery, invasive EEG recordings may be needed. Accurate localization of the seizure onset in these patients is required for successful surgical management.


2017 ◽  
Vol 14 (3) ◽  
pp. 267-272 ◽  
Author(s):  
Alvin Y Chan ◽  
Lilit Mnatsakanyan ◽  
Mona Sazgar ◽  
Indranil Sen-Gupta ◽  
Jack J Lin ◽  
...  

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.


2002 ◽  
Vol 51 (1-2) ◽  
pp. 211
Author(s):  
Achim Olbrich ◽  
Lydia Urak ◽  
Gudrun Gröppel ◽  
Wolfgang Serles ◽  
Klaus Novak ◽  
...  

2015 ◽  
Vol 86 (11) ◽  
pp. 1273-1276 ◽  
Author(s):  
Lukas Heydrich ◽  
Guillaume Marillier ◽  
Nathan Evans ◽  
Olaf Blanke ◽  
Margitta Seeck

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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