Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients

Sanz-García, Áncor; Vega-Zelaya, Lorena; Pastor, Jesús; Torres, Cristina V.; Sola, Rafael G.; Ortega, Guillermo J.

doi:10.3791/54746

Cited by 3 publications

(6 citation statements)

References 29 publications

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“…(1) Non-invasive tests, consisting of MRI, SPECT, EEG, and neuropsychological and personality studies (Martín et al, 1992(Martín et al, , 1994Maestú et al, 2000) and (2) If temporal lobe epilepsy was confirmed, foramen ovale electrodes were bilaterally implanted under general anesthesia (Figures 1A-F) and subsequent Video-EEG was recorded (Figure 1G; Pastor et al, 2004Pastor et al, , 2006Pastor et al, , 2008aPastor and Sola, 2008;Herrera-Peco et al, 2010Sanz-García et al, 2016).…”

Section: Methodsmentioning

confidence: 99%

Neuroanatomical and psychological considerations in temporal lobe epilepsy

et al. 2022

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Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy and is associated with a variety of structural and psychological alterations. Recently, there has been renewed interest in using brain tissue resected during epilepsy surgery, in particular ‘non-epileptic’ brain samples with normal histology that can be found alongside epileptic tissue in the same epileptic patients — with the aim being to study the normal human brain organization using a variety of methods. An important limitation is that different medical characteristics of the patients may modify the brain tissue. Thus, to better determine how ‘normal’ the resected tissue is, it is fundamental to know certain clinical, anatomical and psychological characteristics of the patients. Unfortunately, this information is frequently not fully available for the patient from which the resected tissue has been obtained — or is not fully appreciated by the neuroscientists analyzing the brain samples, who are not necessarily experts in epilepsy. In order to present the full picture of TLE in a way that would be accessible to multiple communities (e.g., basic researchers in neuroscience, neurologists, neurosurgeons and psychologists), we have reviewed 34 TLE patients, who were selected due to the availability of detailed clinical, anatomical, and psychological information for each of the patients. Our aim was to convey the full complexity of the disorder, its putative anatomical substrates, and the wide range of individual variability, with a view toward: (1) emphasizing the importance of considering critical patient information when using brain samples for basic research and (2) gaining a better understanding of normal and abnormal brain functioning. In agreement with a large number of previous reports, this study (1) reinforces the notion of substantial individual variability among epileptic patients, and (2) highlights the common but overlooked psychopathological alterations that occur even in patients who become “seizure-free” after surgery. The first point is based on pre- and post-surgical comparisons of patients with hippocampal sclerosis and patients with normal-looking hippocampus in neuropsychological evaluations. The second emerges from our extensive battery of personality and projective tests, in a two-way comparison of these two types of patients with regard to pre- and post-surgical performance.

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Section: Methodsmentioning

confidence: 99%

Neuroanatomical and psychological considerations in temporal lobe epilepsy

et al. 2022

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“…In this way, eight electrodes for each lateral side were employed, yielding a total of 16 EEG monopolar recordings for each patient. EEG recordings were continuously acquired for a period of 5.2 ± 2.3 d at a sampling frequency of 500 Hz (NeuroWorks, XLTEK ® , Oakville, ON, Canada), exported to ASCII at 200 Hz, band-pass filtered in the range 0.5-40 Hz [25]. Epochs containing artifacts such as saturated electrical activity, electrode displacements, among others, were discarded.…”

Section: Eegmentioning

confidence: 99%

Potential EEG biomarkers of sedation doses in intensive care patients unveiled by using a machine learning approach

et al. 2019

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Objective. Sedation of neurocritically ill patients is one of the most challenging situation in ICUs. Quantitative knowledge on the sedation effect on brain activity in that complex scenario could help to uncover new markers for sedation assessment. Hence, we aim to evaluate the existence of changes of diverse EEG-derived measures in deeply-sedated (RASS-Richmond agitation-sedation scale −4 and −5) neurocritically ill patients, and also whether sedation doses are related with those eventual changes. Approach. We performed an observational prospective cohort study in the intensive care unit of the Hospital de la Princesa. Twentysix adult patients suffered from traumatic brain injury and subarachnoid hemorrhage were included in the present study. Long-term continuous electroencephalographic (EEG) recordings (2141 h) and hourly annotated information were used to determine the relationship between intravenous sedation infusion doses and network and spectral EEG measures. To do that, two different strategies were followed: assessment of the statistical dependence between both variables using the Spearman correlation rank and by performing an automatic classification method based on a machine learning algorithm. Main results. More than 60% of patients presented a correlation greater than 0.5 in at least one of the calculated EEG measures with the sedation dose. The automatic classification method presented an accuracy of 84.3% in discriminating between different sedation doses. In both cases the nodes' degree was the most relevant measurement. Significance. The results presented here provide evidences of brain activity changes during deep sedation linked to sedation doses. Particularly, the capability of network EEG-derived measures in discriminating between different sedation doses could be the framework for the development of accurate methods for sedation levels assessment.

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“…In each patient, six-contact platinum FOEs with 1-cm center-to-center spacing (AD-Tech, Racine, WI, USA) were inserted bilaterally under general anesthesia [20][21][22]. Correct implantation was assured using fluoroscopic imaging in the operating room.…”

Section: Neurophysiological Datamentioning

confidence: 99%

“…Correct implantation was assured using fluoroscopic imaging in the operating room. The overall procedure of FOE surgical implantation as well as typical scalp + FOE recordings may be visualized in reference [22]. Table 1 includes clinical information, presurgical studies evaluations, and overall diagnosis.…”

Section: Neurophysiological Datamentioning

confidence: 99%

“…One way is to eliminate the presence of scalp-EEG artifacts by using a selected artifacts removal algorithm [25]. Another way, the one implemented here, is to select by visual inspection those recordings free of artifacts, suitable for numerical analysis, as we have done in previous works [22,26]. This election portrays the benefits of using the data, particularly FOE recordings barely affected by muscle artifacts, as they are recorded without introducing extra manipulations.…”

Section: Neurophysiological Datamentioning

confidence: 99%

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Towards Operational Definition of Postictal Stage: Spectral Entropy as a Marker of Seizure Ending

Sanz-García

Vega-Zelaya

Pastor

et al. 2017

Entropy

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Abstract:The postictal period is characterized by several neurological alterations, but its exact limits are clinically or even electroencephalographically hard to determine in most cases. We aim to provide quantitative functions or conditions with a clearly distinguishable behavior during the ictal-postictal transition. Spectral methods were used to analyze foramen ovale electrodes (FOE) recordings during the ictal/postictal transition in 31 seizures of 15 patients with strictly unilateral drug resistant temporal lobe epilepsy. In particular, density of links, spectral entropy, and relative spectral power were analyzed. Partial simple seizures are accompanied by an ipsilateral increase in the relative Delta power and a decrease in synchronization in a 66% and 91% of the cases, respectively, after seizures offset. Complex partial seizures showed a decrease in the spectral entropy in 94% of cases, both ipsilateral and contralateral sides (100% and 73%, respectively) mainly due to an increase of relative Delta activity. Seizure offset is defined as the moment at which the "seizure termination mechanisms" actually end, which is quantified in the spectral entropy value. We propose as a definition for the postictal start the time when the ipsilateral SE reaches the first global minimum.

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Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients

Cited by 3 publications

References 29 publications

Neuroanatomical and psychological considerations in temporal lobe epilepsy

Neuroanatomical and psychological considerations in temporal lobe epilepsy

Potential EEG biomarkers of sedation doses in intensive care patients unveiled by using a machine learning approach

Towards Operational Definition of Postictal Stage: Spectral Entropy as a Marker of Seizure Ending

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