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Introduction: Approximately 30% of patients with mesial temporal lobe epilepsy (MTLE) will develop drug resistance, which requires early surgical treatment. The success of the surgical procedure largely depends on the correct lateralisation of the epileptogenic zone, which can only be determined in 70% of patients with such conventional diagnostic tools as video electroencephalography and volumetric structural magnetic resonance imaging. We evaluated the performance of a memory functional magnetic resonance imaging (fMRI) paradigm in lateralising the epileptogenic zone in patients with drug-resistant MTLE., Methods: We included 18 patients with MTLE attended at the Instituto Neurológico Colombiano in Medellin (Colombia) between 2018 and 2019. The volume of functional activation in both temporal lobes was determined with a memory fMRI paradigm. A concordance analysis was performed to compare the performance of fMRI against that of conventional tests., Results: In patients with left MTLE, lower total activation was found in the hemisphere ipsilateral to the epileptogenic zone as compared to the contralateral hemisphere (121.15 ± 16.48 voxels vs 170.23 ± 17.8 voxels [P < .001]), showing substantial concordance with conventional tests. Patients with right MTLE displayed lower hippocampal activation ipsilateral to the epileptogenic zone (18.5 ± 3.38 voxels vs 27.8 ± 3.77 voxels in the contralateral hippocampus [P = .048]), showing moderate concordance with conventional tests., Conclusions: These findings suggest that lower functional activation as determined by a memory fMRI paradigm has a high level of concordance with conventional tests for lateralising the epileptogenic zone in patients with drug-resistant MTLE., (Copyright © 2022 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.)

Aim: To determine post-surgical cognitive risk and associated factors according to lesion location in a sample of patients evaluated for epilepsy surgery with Wada test at the Fundacion Instituto Neurologico de Colombia., Materials and Methods: An observational, retrospective, analytical study was completed in patients with drug-resistant temporal lobe epilepsy candidates for epilepsy surgery treated from 2001 to 2021, who completed the Wada test as part of the pre-surgical evaluation. A descriptive analysis of sociodemographic, clinical, imaging and neuropsychological variables was completed; a multivariate logistic regression was performed analyzing factors associated with resection risk in patients with left lesions. RESULTS A total of 369 patients were included, 54.74% of the cases were women, with a median age of seizure onset of 11 years. 92.66% of the cases had lesional epilepsy and 68.56% were secondary to hippocampal sclerosis. Left hemisphere was the most frequently affected (65.68%) being dominant for memory and language in most of the patients with a proportion of 42.82% and 81.3%, respectively. The median functional adequacy was 43.75 (IQR 0-75) and the functional reserve was 75 (IQR 25 -93.75). In 104 patients, the Wada test determined a resection risk. In patients with a left lesion, it was found that functional reserve (PRadjusted 0.99, CI 95% 0.9997-0.9998) and having a right hemispheric dominance for memory (PRadjusted 0.92, CI 95% 0.547-0.999) were protective factors for post-surgical resection risk., Conclusion: Wada test is a useful tool for surgical decision-making in patients with drug-resistant temporal lobe epilepsy. When considering cognitive risk, components such as memory dominance and functional reserve should be considered as protective factors for postsurgical cognitive function preservation in patients with left lesions.

Detecting determinism and nonlinear properties from empirical time series is highly nontrivial. Traditionally, nonlinear time series analysis is based on an error-prone phase space reconstruction that is only applicable for stationary, largely noise-free data from a low-dimensional system and requires the nontrivial adjustment of various parameters. We present a data-driven index based on Fourier phases that detects determinism at a well-defined significance level, without using Fourier transform surrogate data. It extracts nonlinear features, is robust to noise, provides time-frequency resolution by a double running window approach, and potentially distinguishes regular and chaotic dynamics. We test this method on data derived from dynamical models as well as on real-world data, namely, intracranial recordings of an epileptic patient and a series of density related variations of sediments of a paleolake in Tlaxcala, Mexico., (© 2024 Author(s). Published under an exclusive license by AIP Publishing.)

Introduction: The aim of this research is to determine the changes in brain structures, both cortical and subcortical, in patients with drug-resistant juvenile myoclonic epilepsy (JME), in order to contribute to the understanding of the characteristics of the drug-resistant syndrome and to offer possible answers and hypotheses for further studies and more adequate treatments., Subjects and Methods: Observational case-control study. A convenience sample size of four cases and 16 healthy controls was defined to ensure the feasibility of the project (ratio of 4:1). The data collected for patients with drug-resistant JME came from 1.5T MRI equipment. FreeSurfer software was used to determine cortical and subcortical areas in both drug-resistant JME patients and healthy controls., Results: A total of 20 participants were included in the study, of whom four (20%) were drug-resistant JME patients and 16% (80%) were healthy controls. The clusters with statistically significant differences in cortical thickness are located in the precentral gyrus, superior temporal gyrus, transverse temporal gyrus, medial temporal gyrus and supramarginal gyrus, predominantly in the left hemisphere., Conclusions: Structural brain changes are observed in patients with drug-resistant JME that may go undetected by the conventional processing techniques used in magnetic resonance imaging.

The cytoskeleton is the main intracellular structure that determines the morphology of neurons and maintains their integrity. Therefore, disruption of its structure and function may underlie several neurodegenerative diseases. This review summarizes the current literature on the tau protein, microtubule-associated protein 2 (MAP2) and neurofilaments as common denominators in pathological conditions such as Alzheimer's disease (AD), cerebral ischemia, and multiple sclerosis (MS). Insights obtained from experimental models using biochemical and immunocytochemical techniques highlight that changes in these proteins may be potentially used as protein targets in clinical settings, which provides novel opportunities for the detection, monitoring and treatment of patients with these neurodegenerative diseases., Competing Interests: The authors declare that they have no competing interests., (Copyright: © Gutiérrez-Vargas et al.)

Background: Seizure relapses are the leading cause of admission to emergency rooms (ER) in people with epilepsy., Objective: To analyze administrative and clinical factors associated with the duration between seizure relapses in people with epilepsy admitted to the Neurological Institute of Colombia (Medellin) between July 2018 and July 2019., Materials and Methods: A retrospective follow-up study of 156 patients over 18 years old, diagnosed with epilepsy, and treated for over a year. The outcome variable was the time between seizure relapses, identified through the record of ER attendances. In addition, difficulties in the prescription filling process (delay, omission, or brand change) and clinical characteristics were analyzed as potential associated influence factors. The statistical analysis was performed using the Prentice, Williams & Peterson-Gap Time survival model for recurrent events. Finally, Adjusted Hazard Ratios (aHR) with 95% confidence intervals (95%CI) are also presented., Results: One hundred fifty-six patients were analyzed. Their average age of diagnosis was 15.5 years (SD = 22.5), the median number of monthly seizures was 3 (SD = 9.3), and 50.6% were women. Moreover, difficulties in the prescription filling process were associated with a time reduction between seizure relapses (aHR = 2.61; 95%CI 1.49-4.57), showing a similar impact as having a history of three or four types of events (aHR = 2.96; 95%CI 1.23-7.12) and neuropsychiatric comorbidity (aHR = 1.89; 95%CI 1.04-3.54)., Conclusion: Neuropsychiatric comorbidity, history of several types of events, and experiencing difficulties with prescription filling are associated with lower benefit from treatment to control seizure relapses., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Aim: To identify the clinical and psychosocial factors of a Colombian cohort of patients with juvenile myoclonic epilepsy and its relation to crisis control., Patients and Methods: Retrospective cohort study of patients over 14 years of age with a diagnosis of juvenile myoclonic epilepsy, with 12 months of follow-up in an epilepsy program, where the sociodemographic and clinical characteristics and the survey for the assessment of relapse conditioners. A bivariate and multivariate analysis was performed using binary logistic regression., Results: Clinical records between November 2014 and December 2016 where 145 patients with a diagnosis of juvenile myoclonic epilepsy who met the selection criteria were evaluated. The factors associated with crisis control were: health plan, accessibility, personal attitudes, history of consumption, drug resistance, and crisis number per month; of these, health plans, personal attitudes, and crisis number per month persist with statistical significance after the logistic regression analysis., Conclusion: Psychosocial factors not only impact on crisis control, added to clinical factors explain 40% of crisis control in patients with juvenile myoclonic epilepsy and therefore affect their long-term prognosis.

The characterization of the functional network of the brain dynamics has become a prominent tool to illuminate novel aspects of brain functioning. Due to its excellent time resolution, such research is oftentimes based on electroencephalographic recordings (EEG). However, a particular EEG-reference might cause crucial distortions of the spatiotemporal interrelation pattern and may induce spurious correlations as well as diminish genuine interrelations originally present in the dataset. Here we investigate in which manner correlation patterns are affected by a chosen EEG reference. To this end we evaluate the influence of 7 popular reference schemes on artificial recordings derived from well controlled numerical test frameworks. In this respect we are not only interested in the deformation of spatial interrelations, but we test additionally in which way the time evolution of the functional network, estimated via some bi-variate interrelation measures, gets distorted. It turns out that the median reference as well as the global average show the best performance in most situations considered in the present study. However, if a collective brain dynamics is present, where most of the signals get correlated, these schemes may also cause crucial deformations of the functional network, such that the parallel use of different reference schemes seems advisable., (Copyright © 2019 Ríos-Herrera, Olguín-Rodríguez, Arzate-Mena, Corsi-Cabrera, Escalona, Marín-García, Ramos-Loyo, Rivera, Rivera-López, Zapata-Berruecos and Müller.)

Introduction: Temporal lobe epilepsy (TLE) is the most common adult epileptic syndrome. About 30-70% of those cases have neuropsychiatric complications. More than 10% of patients have TLE because of focal cortical dysplasia (FCD) type IIIa., Objectives: The objective of this study was to review the evidence of reelin (RELN) deficiency and tau phosphorylation role in the histopathological, neuropsychiatric, and hyperexcitability features in TLE because of dysplasia type IIIa., Methods: The current literature was reviewed using Cochrane, EMBASE, PROSPERO, MEDLINE, and PubMed from 1995 to July 2018. Articles of interest were reviewed by one investigator (RAM)., Results: Reelin deficit is related to an abnormal migration of neurons in dentate gyrus, and its deficit causes dentate gyrus abnormalities, which in turn has been associated with memory deficits in patients with TLE. A decreased in the expression of RELN ribonucleic acid (RNA) was found in patients with TLE and dysplasia type IIIa compared with patients with TLE and isolated hippocampal sclerosis (HS). Reelin might affect the distribution and dynamic instability of microtubules within neurons in the cerebral cortex and their phosphorylation. Amyloid pathology, tauopathy, or phosphorylated tau (p-tau) overexpression has been reported in epileptic human brain and in animal models of epilepsy., Conclusion: Reelin deficit may determine an abnormal cortical lamination and dentate gyrus dispersion and might be associated with an abnormal tau phosphorylation. These processes can be associated with an abnormal hyperexcitability, neuropsychiatric complications, and a myriad of typical histopathological features seen in patients with TLE because of dysplasia type IIIa., (Copyright © 2019 Elsevier Inc. All rights reserved.)