Drug polyconsumption is associated with increased synchronization of brain electrical-activity at rest and in a counting task

Drug abusers typically consume not just one but several types of drugs, starting from alcohol and marijuana consumption, and then dramatically lapsing into addiction to harder drugs, such as cocaine, heroin, or amphetamine. The brain of drug abusers presents various structural and neurophysiological abnormalities, some of which may predate drug consumption onset. However, how these changes translate into modifications in functional brain connectivity is still poorly understood. To characterize functional connectivity patterns, we recorded Electroencephalogram (EEG) activity from 21 detoxified drug abusers and 20 age-matched control subjects performing a simple counting task and at rest activity. To evaluate the cortical brain connectivity network we applied the Synchronization Likelihood algorithm. The results showed that drug abusers had higher synchronization levels at low frequencies, mainly in the θ band (4–8 Hz) between frontal and posterior cortical regions. During the counting task, patients showed increased synchronization in the β (14–35 Hz), and γ (35–45 Hz) frequency bands, in fronto-posterior and interhemispheric temporal regions. Taken together 'slow-down' at rest and task-related 'over-exertion' could indicate that the brain of drug abusers is suffering from a premature form of ageing. Future studies will clarify whether this condition can be reversed following prolonged periods of abstinence

Exploratory analysis of power spectrum and functional connectivity during resting state in young binge drinkers: A MEG study

© Electronic version of an article published as International Journal of Neural Systems, Volume 25, Issue 03, May 2015, 13 Pages (https://doi.org/10.1142/S0129065715500082)Binge Drinking (BD) is a pattern of intermittent intensive alcohol intake which has spread among young adults over the last decades. Adolescence constitutes a critical neuromaturation period in which the brain is particularly sensitive to the effects of alcohol. However, little is known about how BD affects the brain activity. This study aimed to characterize the brain's functional organization in BD and non-BD young population by means of analyzing functional connectivity (FC) and relative power spectra (PS) profiles measured with magnetoencephalography (MEG) during eyes-closed resting state. Our sample composed 73 first-year university students (35 BDs and 38 controls). Results showed that the BD subjects displayed a decreased alpha FC in frontal-parietal regions, and conversely, an enhanced FC in the delta, theta and beta bands in fronto-temporal networks. Besides the FC differences, the BD group showed a decreased PS within alpha range and an increased PS within theta range in the brain's occipital region. These differences in FC and PS measurements provide new evidence of the neurophysiological alterations related to the alcohol neurotoxicity and could represent an initial sign of an anomalous neural activity caused by a BD pattern of alcohol consumption during youthThis study was supported by the project SPI/2010/134 and SPI/2010/051, from the Spanish Ministry of Health and Social Politics (National Plan on Drugs), and two predoctoral fellowships from the Ministry of Education (FPI, BES-2010-036469 and FPU, AP2008-03433)S

Perfiles de actividad magnética cerebral de jóvenes con consumo intensivo de alcohol

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Psicología, leída el 24-01-2017El patrón de consumo de alcohol binge drinking se caracteriza por la ingesta intermitente de grandes cantidades del alcohol en un corto espacio de tiempo alternándose con periodos de abstinencia. En España, este tipo de consumo de alcohol se asocia al conocido efecto botellón en el que los jóvenes se reúnen en espacios públicos, principalmente los fines de semana, teniendo el alcohol como protagonista. La adolescencia, edad en la que se inicia este tipo de consumo, es considerada un periodo crítico de desarrollo en el que el cerebro experimenta grandes cambios madurativos, fundamentalmente en los lóbulos frontales. Dada su inmadurez, el cerebro adolescente muestra mayor vulnerabilidad ante el efecto neurotóxico del alcohol que el cerebro adulto. Debido a la alta prevalencia que este tipo de consumo presenta entre los jóvenes, la comunidad científica ha mostrado interés en las últimas décadas por estudiar las posibles consecuencias que puede tener en la estructura y funcionamiento del cerebro de jóvenes que beben de este modo. Sin embargo, hasta el momento no existían estudios que evaluasen el efecto del binge drinking en la actividad magnética cerebral. La Magnetoencefalografía es una técnica no invasiva que mide las corrientes magnéticas generadas por las pequeñas corrientes neurales que producen las neuronas. La presente tesis ha utilizado esta técnica a lo largo de los tres experimentos en los que se estudió: 1) la actividad magnética cerebral en el espacio de los sensores asociada del estado de reposo de jóvenes universitarios de 18-19 años con el patrón binge drinking y un grupo control, 2) la actividad magnética cerebral en espacio de las fuentes del estado de reposo y la conectividad estructural de los mismos jóvenes dos años más tarde, con 20-21 años; y 3) la actividad magnética cerebral en espacio de las fuentes asociada a una tarea Go/NoGo de los mismos jóvenes durante la primera fase del estudio, cuando tenían 18-19 años...The alcohol consumption binge drinking pattern is characterized by intermittent intake of large amounts of alcohol in a short space of time, alternated with periods of abstinence. In Spain, this type of alcohol consumption is associated with the well-known “efecto botellón” where young people gather in public spaces, especially on weekends, having the alcohol as the protagonist. Adolescence, the age in which this type of consumption begins, is considered a critical period of neural development in which the brain undergoes maturational changes, mainly in the frontal lobes. Given its immaturity, adolescent brain is more vulnerable to the neurotoxic effects of alcohol than the adult brain. Because of its high prevalence among young adolescents, since last decades the scientific community has shown increasing interest to study the possible consequences that binge drinking may have on the structure and functioning of the brain. However, so far there are no studies assessing the effect of binge drinking with Magnetoencephalography. Magnetoencephalography is a noninvasive technique that measures the magnetic currents generated by neural currents produced by pyramidal neurons. The present dissertation has used this technique over the three experiments, studying: 1) brain magnetic activity in the sensor space associated to resting state of university students of aged 18-19 years old with alcohol binge drinking pattern and also a control group, 2) brain magnetic activity in the source space also associated to resting state and structural connectivity of the same young students two years later, with 20-21 years old; and finally, 3) the brain magnetic activity in source space associated with a Go/NoGo task in the first phase of the study, when the participants were 18-19...Fac. de PsicologíaTRUEunpu

Using machine-learning approach to distinguish patients with methamphetamine dependence from healthy subjects in a virtual reality environment

Background: The aim of this study was to evaluate whether machine learning (ML) can be used to distinguish patients with methamphetamine dependence from healthy controls by using their surface electroencephalography (EEG) and galvanic skin response (GSR) in a drug-simulated virtual reality (VR) environment. Methods: A total of 333 participants with methamphetamine (METH) dependence and 332 healthy control subjects were recruited between January 2018 and January 2019. EEG (five electrodes) and GSR signals were collected under four VR environments: one neutral scenario and three METH-simulated scenarios. Three ML classification techniques were evaluated: random forest (RF), support vector machine (SVM), and logistic regression (LR). Results: The MANOVA showed no interaction effects among the two subject groups and the 4 VR scenarios. Taking patient groups as the main effect, the METH user group had significantly lower GSR, lower EEG power in delta (p < .001), and alpha bands (p < .001) than healthy subjects. The EEG power of beta band (p < .001) and gamma band (p < .001) was significantly higher in METH group than the control group. Taking the VR scenarios (Neutral versus METH‐VR) as the main effects, the GSR, EEG power in delta, theta, and alpha bands in neutral scenario were significantly higher than in the METH‐VR scenario (p < .001). The LR algorithm showed the highest specificity and sensitivity in distinguishing methamphetamine‐dependent patients from healthy controls. Conclusion: The study shows the potential of using machine learning to distinguish methamphetamine-dependent patients from healthy subjects by using EEG and GSR data. The LR algorithm shows the best performance comparing with SVM and RF algorithm

Redes cerebrales en quejas subjetivas de memoria y deterioro cognitivo leve: caracterización de las etapas de pre-demencia mediante magnetoencefalografía

Tesis de la Universidad Complutense de Madrid, Facultad de Psicología, leída el 22/03/2018. Tesis formato europeo (compendio de artículos)La demencia es un cuadro que puede ser originado por múltiples causas, produciendo un deterioro cognitivo muy marcado y limitando la independencia del paciente. La causa más común de demencia es la Enfermedad de Alzheimer (EA) que representa aproximadamente el 60% de los casos totales. Aunque existen numerosos factores que parecen modular el riesgo de desarrollar EA tales como factores genéticos (APOE, PS1, etc.) o variables relacionadas con el estilo de vida (estudios, ocupación, dieta, etc.), la edad es sin duda la variable más influyente y el mayor factor de riesgo ante la aparición de la EA. Por este motivo, el número de personas mayores afectadas por esta enfermedad no ha parado de aumentar durante las últimas décadas, y se espera que aumente su incidencia aún más. Debido al fracaso generalizado de los ensayos farmacológicos, numerosos esfuerzos en investigación se centran ahora en la detección temprana de la EA. El curso de la EA es lento e insidioso, y la acumulación de neuropatología puede comenzar hasta 15 años antes de su diagnóstico. A lo largo de esta etapa preclínica los pacientes atraviesan un estadio conocido como deterioro cognitivo leve (DCL). Esta etapa se caracteriza por alteraciones en uno o varios dominios cognitivos que no genera aún graves alteraciones del funcionamiento diario. Este estadio está altamente asociado al desarrollo posterior de EA y por tanto se considera bajo determinadas condiciones una etapa prodrómica de la enfermedad. Las personas mayores con DCL suelen presentar alteraciones a nivel cerebral o metabólico característicos de la EA, tales como atrofia cortical, alteraciones sinápticas o acumulación de proteínas relacionadas con la fisiopatología de la EA. La literatura científica reciente ha descrito una etapa anterior incluso al DCL que podría asociarse al desarrollo de demencia futuro. Las quejas subjetivas de memoria (QSM) se caracterizarían por la presencia de un sentimiento subjetivo de deterioro cognitivo en ausencia de afectación objetiva, es decir, la evaluación neuropsicológica de estas personas mayores se encuentra en el rango normal. Sin embargo, el estado de la actividad cerebral en esta etapa, o su integridad estructural aún no ha sido apenas descrito. Existen resultados contradictorios con respecto a si la presencia de QSM en personas mayores se asocia a un riesgo más elevado de desarrollar demencia. Además, mientras algunos estudios reportan alteraciones a nivel cerebral compatibles con EA en esta etapa, otros no encuentran tales signos. El objetivo fundamental de esta tesis es la caracterización de las alteraciones en las redes cerebrales en personas mayores sanas, personas mayores con QSM y personas mayores con DCL. El estado actual de la literatura nos permite anticipar la presencia de alteraciones cerebrales relacionadas con EA en el grupo con DCL, sin embargo este trabajo pretende estudiar si dichas alteraciones, o formas más sutiles, se encuentran presentes en el grupo con QSM. Esto nos permitirá en primer lugar clarificar si las QSM tienen alguna relevancia clínica y si se encuentran asociadas a cambios objetivos en la actividad cerebral. Además, se podrá describir el curso exacto de las alteraciones que tienen lugar a lo largo de las etapas preclínicas en la EA gracias a la inclusión del grupo con DCL, caracterizando así en cada estudio las dos etapas que anteceden a la EA descritas a día de hoy...Dementia is a clinical entity producing major cognitive impairment that interferes with daily living activities that can be caused by a variety of conditions. Among them, Alzheimer´s Disease (AD) represents around a 60% of the total dementia cases. AD risk is modulated by multiple variables such as genotype (APOE, PS1, etc.) or lifestyle variables (studies, occupation, dietary patterns, etc.), although age is the most crucial risk factor for AD development. As a consequence, the number of AD patients has rapidly grown over the last few decades and is expected to increase even more dramatically in the near future. Given the poor results obtained in pharmacological trials to cure or slow AD progression, early AD detection is receiving increasing research efforts over the last few years. Considering the slow and insidious progression of AD, brain pathology starts accumulating in the brain as soon as 15 years before clinical symptoms are severe enough to establish an AD diagnostic. Before reaching AD dementia, patients develop mild cognitive impairment (MCI). This stage is characterized by the presence of a significant cognitive impairment affecting one or more domains. However, this cognitive decline does not significantly limit patients’ daily functioning. MCI patients are known to show increased conversion rates to AD with respect to healthy elders and thus this stage is commonly accepted as a prodromal stage of AD according to recent MCI criteria. MCI patients are known to exhibit AD-like brain and metabolic alterations such as cortical atrophy or AD-related protein accumulation. Recent scientific literature has described a stage preceding MCI which could be associated with future dementia development. Subjective cognitive decline is defined by the presence of a subjective feeling of cognitive worsening in the absence of objective impairment in classical neuropsychological assessment. However, the integrity of brain activity or structure has been scarcely described yet. Furthermore, there exist some contradictory results regarding whether the presence of cognitive concerns is truly related to increased dementia risk. In the same vein, some studies have found brain alterations in SCD patients resembling of those associated with AD while others failed to find such signs. The main objective of this thesis is characterizing brain network alterations in healthy elders, elders with SCD and elders with MCI. The current state-of-the-art lets us anticipate the presence of brain disruption in the MCI group, nonetheless, this work aims to provide evidence of whether similar alterations are already present in the SCD stage. The results presented in this thesis will clarify the clinical relevance of SCD by discerning whether cognitive concerns are truly mediated by network disruption or not. Moreover, the exact course and development of electrophysiological brain alterations during the preclinical stages of the disease will be described by including also MCI patients. By including these three groups we will be able to characterize brain function in the different AD preclinical stages considered in current literature...Fac. de PsicologíaTRUEunpu

Conectividad funcional y procesos inhibitorios en las recaídas en el consumo de alcohol

El consumo crónico de alcohol supone ciertas disfunciones cognitivas, aunque los déficits ejecutivos son centrales y están relacionados con el curso de la enfermedad. Específicamente, el control inhibitorio, cognitivo y conductual o la capacidad de toma de decisiones resultan clave en el éxito terapéutico y mantenimiento de la abstinencia. Estas alteraciones se han asociado a deficiencias en el funcionamiento neural tanto en estados interoceptivos de reposo, como durante procesos cognitivos asociados a la inhibición, el control atencional o la toma de decisiones. Por lo tanto, se plantean los siguientes objetivos en este trabajo: 1. Evaluar en contextos relacionados con la sustancia la toma de decisión léxica y la inhibición motora. 2. Evaluar la actividad psicofisiológica subyacente a procesos léxicos e inhibitorios y en presencia de estímulos asociados a la sustancia. 3. Evaluar la actividad cerebral en reposo en términos de oscilaciones y conectividad funcional..

Drug polyconsumption is associated with increased synchronization of brain electrical-activity at rest and in a counting task

Drug abusers typically consume not just one but several types of drugs, starting from alcohol and marijuana consumption, and then dramatically lapsing into addiction to harder drugs, such as cocaine, heroin, or amphetamine. The brain of drug abusers presents various structural and neurophysiological abnormalities, some of which may predate drug consumption onset. However, how these changes translate into modifications in functional brain connectivity is still poorly understood. To characterize functional connectivity patterns, we recorded Electroencephalogram (EEG) activity from 21 detoxified drug abusers and 20 age-matched control subjects performing a simple counting task and at rest activity. To evaluate the cortical brain connectivity network we applied the Synchronization Likelihood algorithm. The results showed that drug abusers had higher synchronization levels at low frequencies, mainly in the. band (48Hz) between frontal and posterior cortical regions. During the counting task, patients showed increased synchronization in the beta (14-35 Hz), and. (35-45 Hz) frequency bands, in fronto-posterior and interhemispheric temporal regions. Taken together ` slow-down' at rest and task-related 'over-exertion' could indicate that the brain of drug abusers is suffering from a premature form of ageing. Future studies will clarify whether this condition can be reversed following prolonged periods of abstinence

Drug polyconsumption is associated with increased synchronization of brain electrical-activity at rest and in a counting task

Drug abusers typically consume not just one but several types of drugs, starting from alcohol and marijuana consumption, and then dramatically lapsing into addiction to harder drugs, such as cocaine, heroin, or amphetamine. The brain of drug abusers presents various structural and neurophysiological abnormalities, some of which may predate drug consumption onset. However, how these changes translate into modifications in functional brain connectivity is still poorly understood. To characterize functional connectivity patterns, we recorded Electroencephalogram (EEG) activity from 21 detoxified drug abusers and 20 age-matched control subjects performing a simple counting task and at rest activity. To evaluate the cortical brain connectivity network we applied the Synchronization Likelihood algorithm. The results showed that drug abusers had higher synchronization levels at low frequencies, mainly in the θ band (4-8 Hz) between frontal and posterior cortical regions. During the counting task, patients showed increased synchronization in the β (14-35 Hz), and γ (35-45 Hz) frequency bands, in fronto-posterior and interhemispheric temporal regions. Taken together 'slow-down' at rest and task-related 'over-exertion' could indicate that the brain of drug abusers is suffering from a premature form of ageing. Future studies will clarify whether this condition can be reversed following prolonged periods of abstinence. © 2014 World Scientific Publishing Company