Fourier phase index for extracting signatures of determinism and nonlinear features in time series.

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.

Neurodegeneration and convergent factors contributing to the deterioration of the cytoskeleton in Alzheimer's disease, cerebral ischemia and multiple sclerosis (Review).

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.

Factors involved in time reduction between seizure relapses in patients with epilepsy attending emergency rooms in Medellín, Colombia.

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.

Memoria episódica posterior a cirugía de epilepsia del lóbulo temporal / Episodic memory after temporal lobe epilepsy surgery

RESUMEN INTRODUCCIÓN: La cirugía resectiva del lóbulo temporal anterior con amigdalo-hipocampectomía es un tratamiento efectivo para la epilepsia farmacorresistente del lóbulo temporal con esclerosis hipocampal. Sin embargo, este procedimiento conlleva riesgo de deterioro de la memoria episódica verbal y no verbal postoperatoria, dependiendo de la dominancia hemisférica para la memoria y el lenguaje. OBJETIVO: Explorar el desenlace de la memoria episódica posterior a la cirugía resectiva mediante lobectomía temporal anterior con amigdalo-hipocampectomía. MÉTODOS: Se analizó retrospectivamente la memoria episódica verbal y no verbal mediante pruebas neurop-sicológicas de 51 pacientes consecutivos sometidos a lobectomía temporal anterior con amigdalo-hipocampectomía del lado izquierdo y derecho. Todos los pacientes fueron sometidos a resonancia magnética cerebral preoperatoria, video-electroencefalografía y evaluaciones neuropsicológicas. A 12 pacientes (24 %) no se les realizó el test de Wada. RESULTADOS: Hubo disminución en la memoria episódica verbal postoperatoria con diferencias respecto a la preoperatoria, en la subprueba de textos II recuerdo de la escala de memoria de Wechsler III (p = 0,035). El resultado en la memoria episódica visual se mantuvo igual, no hubo diferencias en el grupo de lobectomía temporal estándar. CONCLUSIÓN: La lobectomía temporal anterior más amigdalo-hipocampectomía izquierda afecta levemente el desempeño de la memoria episódica postoperatoria, que clínicamente no es significativo en pacientes con epilepsia del lóbulo temporal mesial farmacorresistente.

SUMMARY INTRODUCTION: Resective surgery of the anterior temporal lobe with amygdalohippocampectomy is an effective treatment for drug-resistant epilepsy of the temporal lobe with hippocampal sclerosis. However, this procedure carries a risk of post-operative episodic verbal and nonverbal memory impairment depending on the hemispheric dominance for memory and language. OBJECTIVE: To explore the outcome of episodic memory after resective surgery by means of anterior temporal lobectomy with amygdalohippocampectomy. METHODS: Verbal and non-verbal episodic memory was retrospectively analyzed by neuropsychological tests of 51 consecutive patients undergoing anterior temporal lobectomy with amygadalohyppocampectomy on the left and right sides. All patients underwent preoperative brain MRI, video electroencephalography, and neuropsychological evaluations. 12 patients (24%) did not undergo the Wada test. RESULTS: There was a decrease in postoperative verbal episodic memory with differences compared to preoperative, in the text II subtest recall of the Wechsler III memory scale (p = 0.035). The result in visual episodic memory remained the same, there were no differences in the standard temporal lobectomy group. CONCLUSION: Anterior temporal lobectomy plus left amygadalohyppocampectomy slightly affects the performance of postoperative episodic memory, which is clinically not significant in patients with drug-resistant mesial temporal lobe epilepsy.

Reelin, tau phosphorylation and psychiatric complications in patients with hippocampal sclerosis and structural abnormalities in temporal lobe epilepsy.

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.