Overt Subject Pronoun Use in Switch-Reference Contexts in Child Spanish Developmental Language Disorder: A Discriminant Function Analysis.

PURPOSE: Our study analyzes probabilistic constraints on subject expression previously found in adult Spanish in the speech of typically developing (TD) Spanish-speaking children and children with developmental language disorder (DLD). Previous work shows that children with DLD produce fewer overt subjects than typically developing children, and that the latter acquire constraints on subject expression as they age into adolescence. Our study complements these findings and provides further substance to the grammatical profile of children whose morphosyntactic development diverges from that of typically developing children. METHOD: Data are drawn from unstructured spontaneous production data from a sample of 19 monolingual Mexican, Spanish-speaking children, collected in 2006-2007. This sample includes 19 children diagnosed with DLD and 19 age-matched, typically developing children. We collected all instances of finite verbs that either did or could have occurred with a subject personal pronoun uttered by the child participants and coded them for several factors including tense-mood-aspect, switch reference, and person and number. RESULTS: We find that children with DLD produce fewer overt subject pronouns in switch reference contexts than typically developing controls, with a significant interaction of group and switch reference. Furthermore, a discriminant function analysis shows that overt pronoun use in switch reference contexts can form part of a useful diagnostic discriminant function, with high levels of sensitivity and specificity. CONCLUSIONS: Overall, we find important differences between TD Spanish-speaking children and those diagnosed with DLD regarding rates of overt subjects and sensitivity to the probabilistic constraint of switch reference. This finding contributes to our understanding of the morphosyntactic profiles of children with DLD, as well as the utility of factors such as switch reference in the identification of language disorders.

Cognitive and spectral coherence of EEG alterations in resting state in children with chronic TBI / Alteraciones cognitivas y en la coherencia espectral del EEG en estado de reposo en niños con TCE crónico

Abstract Introduction TBI is associated with alterations in cortico-subcortical connectivity. However, little attention has been paid to its clinical characteristics and functional connectivity in pediatric patients with chronic TBI. Objective To evaluate the cognitive performance and spectral coherence of a group of children with TBI in non-acute phase. Method Cross-sectional study of 15 children with chronic TBI and 17 healthy children. The Neuropsychological Assessment of Children (Evaluación Neuropsicológica Infantil, ENI) was used and the resting activity of the EEG with eyes-closed was recorded. Offline, two-second epochs of the EEG of each participant were chosen and the spectral coherence was estimated in a range of 1.6 to 30 Hz. The cognitive performance between groups was compared with T-test/Mann-Whitney U Test and MANOVA for the coherence values. Results The TBI group showed a lower performance (p ≤ 0.05) in metalinguistic, visuospatial skills, attention, memory, non-verbal flexibility, planning, and organization. Differences (p ≤ 0.000) were found both inter and intrahemispherically in the spectral coherence between the groups, particularly on F1-F3 (95% CI: 0.543 - 0.557) over the whole frequency range and F3-C3 (95% CI: 0.503 - 0.515) in delta, theta, alpha2, and beta frequencies. Discussion and conclusión Our findings suggest alterations of hypo and hyper functional connectivity, particularly on the frontal and parietal lobes of both hemispheres, even after several years of a TBI. It is possible that a subtle difference in the degree of connectivity is crucial in the genesis or successful development of attentional, mnesic, executive, and visuospatial processes.

Resumen Introducción El TCE se asocia con alteraciones en la conectividad cortico-subcortical. Sin embargo, se ha prestado poca atención a las características clínicas y de conectividad funcional en pacientes pediátricos con TCE crónico. Objetivo Evaluar el desempeño cognitivo y la coherencia espectral de un grupo de niños con TCE en fase no aguda. Método Estudio transversal de 15 niños con TCE y 17 niños controles. Se empleó la Evaluación Neuropsicológica Infantil (ENI) y se registró la actividad en reposo del EEG con ojos cerrados. Fuera de línea, se eligieron épocas de 2 s del trazo de cada participante y se estimó la coherencia espectral en un rango de 1.6 a 30 Hz. Se comparó el rendimiento cognitivo entre los grupos con la prueba T/U-Mann de Whitney y MANOVA para los valores de coherencia. Resultados El grupo con TCE mostró un menor rendimiento (p ≤ 0.05) en habilidades metalingüísticas, visuoespaciales, atención, memoria, flexibilidad no verbal, planeación y organización. Se encontraron diferencias (p ≤ 0.000) en la coherencia espectral tanto inter como intrahemisférica entre los grupos. Particularmente, en F1-F3 (95%IC: 0.543 - 0.557) en todo el rango de frecuencias y F3-C3 (95%IC: 0.503 - 0.515) en delta, theta, alfa2 y beta. Discusión y conclusión Los resultados sugieren que distintas redes en estado de reposo muestran alteraciones de hipo e hiperconectividad funcional aun después de varios años de un TCE. Es probable que una sutil diferencia en el grado de conectividad sea determinante en la génesis o desarrollo exitoso de procesos atencionales, mnésicos, ejecutivos y visoespaciales.

Psychoacoustics and Neurophysiological Alterations after 30-36 Hours of Sleep Deprivation.

BACKGROUND AND AIM: Sleep deprivation (SD) may result in perceptual and cognitive alterations in healthy subjects. Our objective was to compare whether psychoacoustics and neurophysiological variables in healthy subjects were altered after SD of 30-36 h. METHOD: We examined 22 subjects by means of several psychoacoustics tests, P300 and mismatch negativity (MMN) recordings, and brainstem auditory evoked potentials (BAEP) before and after 30-36 h of SD. RESULTS: In the psychoacoustics tests, we found that after SD, difficulties were experienced by the left ear in the discrimination of words in noise and by the right ear in music discrimination. In the neurophysiological tests, we found delayed latencies of P300 and MMN wave; there was a delay of wave I in both ears, and wave V in the right ear in BAEP. We found significant correlations with positive direction between P300 latency and words in noise and music discrimination in the right ear. CONCLUSIONS: SD results in alterations of central auditory processing perception and delays of brain neurophysiological responses, with some correlations between the psychoacoustics and neurophysiological tests. These alterations may relate to other cognitive alterations that deserve more research in future studies.

Electroencephalographic Indicators in Default Mode, Habituation, and Visual-motor Association in Female College Students.

BACKGROUND: Oscillations, action, and postsynaptic potentials in glial-neuronal ensembles integrate the spectral power (SP) of electroencephalographic (EEG). Our objective is to propose SP indicators of healthy brains (control groups) based on the default mode and their modifications by habituation and visual-motor association (VM-asso), to support diagnostic and rehabilitation processes. However, important differences seem to exist between men and women. Therefore, we aim to analyze EEG characteristics in a female sample. SUBJECTS AND METHODS: In the current study, EEG was recorded at rest with closed eyes before and during repeated photostimulations (RPh) and before (pre) and during association of RPh with switch pressing (VM-asso) in 70 female adults. EEG was analyzed using UAM/INR software, which removes artifacts, identifies corresponding signals, selects 20 samples (2-s) from each condition, applies Welch's periodogram to calculate and average the absolute power (AP; AAPs) of áµ¹, θ, α, and ß, before and during learning, and emits data to a spreadsheet. Differences in each condition were evaluated using non-parametric tests. RESULTS: The AAPs were different; in habituation, áµ¹ and θ increased significantly in fronto-frontal (FF) and frontocentral and decreased in the other leads. During association, they increased in FF and decreased in the other three regions. α AAP decreased in all leads except in FF during habituation, and the decrement was lower in the association. ß AAP increased in all leads during both learning conditions. CONCLUSION: The SP and the topographic distribution are descriptive parameters of habituation and VM-asso; we propose them as EEG indicators.

Correlación del funcionamiento ejecutivo y la potencia absoluta del EEG en niños / Correlation of excutive functioning and the absolute power of the EEG in children

RESUMEN: Introducción: La potencia espectral en reposo a menudo se considera como un marcador robusto de la función cerebral; sin embargo, pocos estudios la han asociado con una función específica. Objetivo: Analizar la relación entre la potencia absoluta (PA) del EEG con el desempeño en las tareas de funcionamiento ejecutivo en niños. Método: Investigación transversal correlacional en 30 niños (8.6 ± 1 años). Se realizó el EEG con ojos cerrados y análisis de derivaciones bipolares. Con la transformada de Fourier se calculó la PA en el espectro de 1.6-30 Hz. Se aplicó la batería NEUROPSI Atención y Memoria y se calculó el Indice de Atención y Funciones Ejecutivas (IAFE). En función de éste, se comparó la PA con Kruskal-Wallis y valor Z, coeficiente de Spearman para la correlación con las subpruebas. Resultados: Los niños con alteraciones severas ( x - = 63 ± 8 IC 95% [57.2, 68.5]) tuvieron mayor PA delta en F1F7, P301 y P402, así como valores Z cercanos a 2 DE en F7T3, F3C3 y F8T4 en frecuencias lentas. Las correlaciones fueron significativas (rho, p ≤ .05) entre el IAFE con la PA delta en P301 (-.57), P402 (-.43) y T5O1 (-.37); con PA alfa principalmente en zonas fronto-temporo-parieto-occipitales izquierdas. La puntuación en Detección Visual y Fluidez Semántica se relacionó con la PA alfa. Discusión y conclusión: El rendimiento en actividades de FE es diferente en relación con la PA delta frontal y parietal. Existe una relación inversa entre la PA delta y alfa en reposo con la atención y fluidez (245/250).

ABSTRACT: Introduction: The resting EEG power is considered as a robust marker of brain function; however, a few studies have associated it to a specific function. Objective: To analyze the relationship between EEG absolute power (AP) with performance on tasks of executive functioning in children. Method: Correlational cross-sectional study of 30 children (8.6 ± 1 year). EEG was performed with eyes closed and bipolar leads. With the Fourier transform AP was calculated in the spectrum of 1.6, 30 Hz. NEUROPSI Attention and Memory was applied and the Index of Attention and Executive functions (IAFE) was calculated. Based on this, the AP was compared with Kruskal-Wallis and the Z value, Spearman coefficient for correlation with the subtests. Results: Children with severe impairment ( x - = 63 ± 8 CI 95% [57.2, 68.5]) had higher delta AP (α ≤ .05) in F1F7, P301 and P402, and Z values near 2 SD in F7T3, F3C3 and F8T4 at slow frequencies. Correlations were significant between the IAFE and delta AP P301 (-.57), P402 (-.43) and T5O1 (-.37); with AP alpha mainly on left fronto- temporo - parietal- occipital areas. The score in Visual Detection and Semantic Fluency inversely related to AP alpha frequency. Discussion and conclusion: Performance on tasks of executive functioning is different in relation to the frontal and parietal AP delta. There is an inverse relationship between AP delta and alpha at rest with attention and verbal fluency.

Desynchronization/synchronization of parasagittal EEG rhythms during habituation to photostimulation in adults.

INTRODUCTION: Learning by habituation implies a gradual diminution of the organism's responses to non-relevant stimuli. These responses, resulting from electrical oscillations of the brain, can be analyzed through quantitative electroencephalography (qEEG). OBJECTIVE: To characterize the absolute power (AP) in the range of delta (δ), theta (θ), alpha (α), beta (ß) in cortical parasagittal regions during habituation to photostimulation (RPh). MATERIAL AND METHODS: We studied 81 undergraduate students. The EEG was recorded in a Nicolet; awake subjects with closed eyes were photostimulated (5 Hz for 2 s, 20 times, RPh). The UAMI/Yáñez program identifies the RPh signal, chooses and collects 2-sec samples before (Pre) and during RPh, and instruments the Welch periodogram, which integrates the absolute power (AP) of δ, θ, α, and ß. We calculated the average AP (AAP) in Pre and RPh per frequency and lead. AAP differences were assessed with non-parametric tests. Linear regression was used to plot the AAPs of each Pre and each RPh sample, representing the resulting slope with its statistical significance. RESULTS: RPh increased the AAP of δ in frontal and frontocentral leads of both hemispheres, and its slopes were ascendant. AAP of θ increased in fronto-frontal and diminished in the other three leads, its slopes were ascendant in right central parietal and parieto-occipital leads. AAP of α increased in fronto-frontal leads, did not change in fronto-central, and diminished in the other leads; its slopes were descendent in Pre and ascendant in RPh in both hemispheres. AAP of ß increased in the four leads; in Pre, ß slopes were descendent in parieto-occipital leads of both hemispheres. During RPh, δ slopes were ascendant in right parieto-central and in both parieto-occipital leads. CONCLUSION: The progressive diminution of alpha's desynchronization, which ends in synchronization, is probably due to hyperpolarization of neuronal membranes and represents habituation. This is complemented with synchronization of the delta rhythm in anterior cortical areas and of theta and beta in areas of the right hemisphere.

Evaluación de pruebas psicoacústicas y de potenciales relacionados a eventos P300 en adultos mayores con hiperhomocisteinemia / Evaluation of psychoacoustic tests and P300 event-related potentials in elderly patients with hyperhomocysteinemia

Introducción y objetivos: La hiperhomocisteinemia como un factor de riesgo para el daño auditivo, el daño neuronal y el deterioro cognitivo en los pacientes adultos mayores es controvertido y se encuentra limitado por un pequeño número de estudios. El objetivo de este trabajo es determinar si los pacientes adultos mayores con hiperhomocisteinemia presentan mayor riesgo de desarrollar alteraciones en los procesos centrales de la audición frente a un grupo de pacientes con niveles de homocisteína adecuados, y definir el comportamiento de las pruebas psicoacústicas y de potenciales de latencia larga (P300) en estos grupos. Método: Estudio transversal, comparativo y analítico. Se formó un grupo de pacientes con hiperhomocisteinemia y un grupo control con valores normales de homocisteína. A todos los pacientes se les realizó audiometría tonal, impedanciometría y una selección de pruebas psicoacústicas (dígitos dicóticos, palabras filtradas pasa bajo, palabra en ruido y diferencia en niveles de enmascaramiento), así como potenciales evocados auditivos de tallo cerebral y P300. Resultados: Los pacientes con hiperhomocisteinemia presentaron valores en la prueba de diferencia en los niveles de enmascaramiento superiores a los del grupo control (p = 0,049), así como latencias más prologadas en los P300 (p = 0,000). Conclusiones: La hiperhomocisteinemia es un factor que altera las funciones auditivas centrales. Las pruebas psicoacústicas alteradas junto con la alteración en las pruebas electrofisiológicas sugieren que la porción central de la vía auditiva está afectada en los pacientes con hiperhomocisteinemia (AU)

Introduction and objectives: Hyperhomocysteinemia as a risk factor for hearing impairment, neuronal damage and cognitive impairment in elderly patients is controversial and is limited by the small number of studies. The aim of this work was determine if elderly patients detected with hyperhomocysteinemia have an increased risk of developing abnormalities in the central auditory processes as compared with a group of patients with appropriate homocysteine levels, and to define the behaviour of psychoacoustic tests and long latency potentials (P300) in these patients. Methods: This was a cross-sectional, comparative and analytical study. We formed a group of patients with hyperhomocysteinemia and a control group with normal levels of homocysteine. All patients underwent audiometry, tympanometry and a selection of psychoacoustic tests (dichotic digits, low-pass filtered words, speech in noise and masking level difference), auditory evoked brainstem potentials and P300. Results: Patients with hyperhomocysteinemia had higher values in the test of masking level difference than did the control group (P=0.049) and more protracted latency in P300 (P=0.000). Conclusions: Hyperhomocysteinemia is a factor that alters the central auditory functions. Alterations in psychoacoustic tests and disturbances in electrophysiological tests suggest that the central portion of the auditory pathway is affected in patients with hyperhomocysteinemia (AU)

[Absolute power of cortical oscillations and their topographical distribution in a sample of young adults during resting wakefulness and unspecific attention]. / Potencia absoluta de oscilaciones corticales y su distribución topográfica en una muestra de adultos jóvenes en vigilia inactiva y en atención inespecífica.

INTRODUCTION: The EEG records neuronal membrane potential oscillations that depend on the morpho-functional characteristics of the membrane and of modifications by postsynaptic excitatory (PSEP) and inhibitory (PSIP) potentials. The quantitative EEG (qEEG) measures the absolute power (AP) of oscillations separated in frequencies, resulting from the interaction among subcortical-cortical-subcortical ensembles. The hypothesis is that neuronal networks function at a given frequency and that their APs are codes that, by becoming synchronized in diverse ensembles, generate behavior. OBJECTIVE: To establish the spectral power of cortical oscillations under diverse study paradigms and in different populations. In particular, to identify the AP and topographical distribution of four cerebral frequency bands under resting wakefulness and activation, and to integrate results into a database to establish comparison standards. MATERIAL AND METHODS: Undergraduate students, average age of 20.6 +/- 2.6 years, who participated voluntarily in the study. Recordings were made with a Nicolet EEG. We chose, in the first stage, closed eyes (CE) three samples of 12 s each. In the second stage, we chose pairs of 6 s samples, first with CE and then with OE. For their analysis, we applied the Welch periodogram and we plotted the average AP (AAP) and standard deviation (SD) of delta, theta, alpha, and beta per lead. Differences were compared through non-parametric tests (Wilcoxon and Dunnett T3); setting statistical significance at a = 0.05. RESULTS: Average APs of each frequency band differ significantly in intensity and topographic distribution generating a profile of each rhythm. When opening the eyes, rhythms desynchronized significantly at different intensities in the diverse leads, except for beta in the left fronto-frontal lead. DISCUSSION: Results indicate the existence of cortical ensembles that synchronize at a determined frequency and are modified by visual stimulation, indicating the effects of the subcortico-cortical circuits. The integrated database provides comparison standards to support diagnoses and treatments.

Evaluation of psychoacoustic tests and P300 event-related potentials in elderly patients with hyperhomocysteinemia.

INTRODUCTION AND OBJECTIVES: Hyperhomocysteinemia as a risk factor for hearing impairment, neuronal damage and cognitive impairment in elderly patients is controversial and is limited by the small number of studies. The aim of this work was determine if elderly patients detected with hyperhomocysteinemia have an increased risk of developing abnormalities in the central auditory processes as compared with a group of patients with appropriate homocysteine levels, and to define the behaviour of psychoacoustic tests and long latency potentials (P300) in these patients. METHODS: This was a cross-sectional, comparative and analytical study. We formed a group of patients with hyperhomocysteinemia and a control group with normal levels of homocysteine. All patients underwent audiometry, tympanometry and a selection of psychoacoustic tests (dichotic digits, low-pass filtered words, speech in noise and masking level difference), auditory evoked brainstem potentials and P300. RESULTS: Patients with hyperhomocysteinemia had higher values in the test of masking level difference than did the control group (P=.049) and more protracted latency in P300 (P=.000). CONCLUSIONS: Hyperhomocysteinemia is a factor that alters the central auditory functions. Alterations in psychoacoustic tests and disturbances in electrophysiological tests suggest that the central portion of the auditory pathway is affected in patients with hyperhomocysteinemia.

[Desynchronization/synchronization of lateral EEG rhythms during habituation to photostimulation in adults]. / [Desincronización/sincronización de ritmos EEG laterales en la habituación a la fotoestimulación en adultos].

BACKGROUND: Berger related the EEG with cognition; we are attempting to identify which rhythms and circuits participate in habituation, a learning that decreases responses to meaningless stimuli which, changed the absolute power (AP) of EEG oscillations. OBJECTIVE: To characterize habituation, analyzing the AP of four rhythms in lateral regions of both hemispheres (BH), proposing that their diminution, desynchronization (D), means activation whereas their increase, synchronization (S), means inhibition. MATERIAL AND METHODS: qEEG analysis in 83 college students, in waking state with closed eyes, and photostimulated (RPh). The used UAMI/Yáñez software identifies RPh signals and takes 2-s samples before (Pre) and during RPh; the Welch periodogram integrates the AP of the four rhythms. We calculated the average AP (AAP) in Pre and RPh per frequency in bipolar lateral leads per hemisphere. AAP differences were evaluated with the Wilcoxon tests correcting with Bonferroni for repeated samples. Applying the linear regression model, we plotted the AAP distribution slopes during Pre and RPh. RESULTS: We established the differences of the AP of the four rhythms within each hemisphere and between both hemispheres (BH). During PRE, AAP of δ and θ increased whereas α and ß decreased. RPh increased the AAP (p = 0.01) of the four rhythms in fronto-frontal (FF) leads; the increase in δ persisted in fronto-temporal (FT) and temporo-occipital (TO), whereas ß's increase persisted in all leads. The AAP of α decreased with the first RPh (D) increasing with the following ones; its slope starts with desynchronization and ends with synchronization. Theta followed a D/S pattern in temporal leads. Beta followed and ascending (S) slope in all leads. CONCLUSIONS: Habituation results from the D/S of a in all cortical regions, of θ in temporal, of δ in frontal regions and ß in all regions. Synchronization reflects hyperpolarization of neuronal membranes, decreasing their activity.

Cambios del EEG por habituación y condicionamiento en niños de tres a 15 años que acuden al Instituto Nacional de Rehabilitación (INR) / EEG changes induced by habituation and conditioning in 3- to 15-year-old children attending the Instituto Nacional de Rehabilitación

During waking, stimuli activate the sensory pathways giving rise to sensation and the response to such stimulation. The electrobiochemical changes and modifications in EEG rhythms event-related synchronization or event-related desynchronization, ERD or ERS) propagated in the specific and unspecific cortex are added to the changes elicited by the responses and to the new signals originated by those same responses, bringing about perception. Diverse factors can alter these glialneuronal circuits, producing alterations in attention processes (ADD) and in the integration with their meaning. The inability to identify signals and integrate correct coordinated responses leads to deficiencies in responding to the environment and to associated morbidities that are added to ADD. ADD and its associated morbidities cause high social and economic impacts and, even more so, because of their persistence into adolescence and adulthood. Therefore, highly accurate diagnostic procedures are needed for these diseases. According to the CIE-10, in the clinical setting symptoms are analyzed without studying the neuro-developmental and neuro-degenerative signs that identify alterations in neuronal circuits. As is known, behavior (including motivation, memory, thoughts) results from the Central Nervous System (CNS) activity, and the EEG records the electrical activity of neurons and synapses of the cerebral cortex, where cognitive processes are most likely to take place. To establish more accurate diagnostic procedures for ADD, we are integrating an electronic database, considering the intensity and cerebral distribution of theta (θ), alpha (α), and beta (β) rhythms. We propose that the ERD of α and β reflects a cortical activation that gives rise to sensory-motor coordination processes. The first stimulations induce ERD, and their repetitions produce its decrement (ERS): ERD habituation. In addition, this ERD to ERS change might be reversed when giving meaning to the stimulation. We present herein the changes in θ, α, and β rhythms induced by repeated photostimulation (RPS), with the same characteristics, that, when presented, requires the subject to press a knob. Hundred-twenty-four children were studied at the Instituto Nacional de Rehabilitación (INR, for its initials in Spanish) in Mexico City. Children were of either gender and aged from 3 to 15 years, separated in four groups of 3-year intervals. During clinical exploration, we searched for possible delays in physical-emotional-intellectual development, epilepsy, and medical or psychological treatments during the last six months, which were considered exclusion factors. Parents were briefed on the study, explaining them that the procedure had a low-risk nature and allowed for the analyzis of the electrical activity of the brain. Once having understood and accepted the procedure, they signed the informed consent form prepared by the institution. Children were explained <> work and that the procedure caused no pain at all. They were asked to close their eyelids during the recordings, and to remain as motionless as possible. The exclusion factors left a sample of 94 children for the habituation analysis and of 47 for the simple conditioning procedures. The EEG was recorded in dorsal decubitus position, with a digital 24-channel electroencephalograph, according to the 10/20 international system. In addition, we recorded eye movements and the EKG. After 5-min recordings with closed eyelids, photo-stimulation was started at 5 flashes per second during 2s, repeated 20 times (RPS), at 21 to 25 sec. intervals. After finishing the series, 5 min rest were provided, and then a round device with a knob was placed in the children's hands, telling them to press the knob at the start of the RPS and to release it at the end. Analyses were performed with 1.6 to 40 Hz bandwidth filters. From the bipolar leads, samples recorded 2 sec. before, during, and after the 1st, 5th, 10th, 20th associations (PS-knob pressing) were manually chosen. For conditioning analyses, we also measured the response latency. The Fourier's FT was applied to the samples and the absolute potency (AP) was calculated for θ (4.0 to 7.5 Hz), α (8.0 to 12.5 Hz), and β (13 to 20 Hz). The average of these frequencies was obtained for each hemisphere (Right, RH; Left, LH) and for both (BH). Wilcoxon's test for related samples was used with (α > 0.05 as significant. Analyses of the AP of the three frequencies in all children revealed a background activity below 10 µV². The first RPS produced a decrease in the AP of θ and α, with an increase in β in BH. At the 5th RPS, θ and α continued to decrease along with an increase in β. At the 10th RPS, θ and α decreased less but the increase in β persisted. At the 15th RPS, θ continued to decrease but α increased in the LH and decreased somewhat in the RH, whereas β continued its increase in BH. At the 20th RPS, the AP of θ and a decreased in BH, but the difference was smaller than that recorded during the previous RPS. The AP of β continued to increase in BH. The most relevant aspects are: a) in G-1 (children aged 3 to 6 years), the AP of the three frequencies is higher, predominating θ, which is twice the magnitude of that of the whole group; b) the 1st PS produced an increase in the AP of all three frequencies, which was not recorded in the other groups (children aged 6.5 to 15 years); c) in G-4 (children 12.5 to 15 years of age), the 1st and 5th PS produced a clear diminution in the AP of θ and a (ERD), which was smaller at the 10th RPS and reversed at the 15th and 20th RPS (ERS). After indicating to the children that with each RPS they would have to press a knob, the background activity increased to 12 µV². During the 1st association (assoc), the AP of θ and α decreased with a slight decrease in β; the response latency was 930 ms. At the 5th assoc, θ decreased together with a small increase in a and β, and the response latency decreased to 750 ms. On the 10th and 15th assoc, the three frequencies increased and the latency decreased to 650 and 640 ms, respectively. On the 20th assoc, the AP increase of each rhythm was smaller, and the latency increased to 750 ms. The EEG analysis per group revealed a higher AP for 0 in the smaller children that decreased along increasing age together with a relative increase in a, which reached its maximal value in G-4. In the four groups, the RPS induced an undulating tendency towards a decrease in the EEG desynchronization that represents habituation, being more noticeable in G-4. Although the reached synchronization level did not reflect a better inhibition, as described in adults, it suggested that, in these children, the inhibitory activity on sensory control has not yet developed completely. Another important finding is that in G-1, the 1st RPS induced and increase in θ and α that was not observed in the other groups.

Algunos cambios del ambiente activan las vías sensoriales generando la sensación y la respuesta a dicha estimulación. Los cambios electrobioquímicos modifican el EEG que al propagarse en la corteza cerebral se suman a los potenciales que generan las respuestas y éstas producen nuevas señales que dan lugar a la percepción. Diversos factores pueden alterar la organización de esos circuitos glioneuronales produciendo trastornos de la atención (TDA), de su integración con su significado, lo que regula el tipo e intensidad de respuestas adecuadas al contexto social. La discapacidad de estas funciones genera comorbilidades que se suman al TDA. Estas enfermedades son de alto impacto socio-económico y cultural y lo son más cuando persisten en la adolescencia y la adultez. Por esto es necesario desarrollar metodologías diagnósticas de alta precisión. Actualmente se acepta que la conducta integral resulta de la actividad del Sistema Nervioso (SN). El EEG registra la actividad eléctrica de las neuronas de la corteza cerebral donde se realizan procesos cognitivos. Para caracterizar el EEG estamos integrando, en una base de datos electrónica, la intensidad y distribución cerebral de los ritmos delta (Δ), theta (θ), alfa (α) y beta (β). Proponemos que la desincronización (DRE) refleja la activación cortical, base de los procesos de coordinación sensoriomotora. Las primeras estimulaciones producen DRE que, al repetirse, disminuyen la habituación de la DRE. Además, es posible que se invierta este cambio DRE a sincronización (SRE) al darle significado a la misma estimulación. En este trabajo se presentan los cambios de θ, α y β ante la fotoestimulación repetida y cuando el sujeto tiene que presionar un botón al inicio de dicha estimulación. Sujetos y método Se atendieron 124 niños, de tres a 15 años, separados en cuatro grupos con intervalos de tres años. En el interrogatorio clínico se indagó el posible retraso del desarrollo físico-emocional-intelectual, de epilepsia o tratamientos médicos o psicológicos convirtiéndose en factores de exclusión. A los niños, delante de los padres, se les explicó cómo funciona su cerebro, que el estudio no produce dolor, que estarán acostados con los párpados cerrados (OC), permaneciendo lo más inmóviles posible, los padres al comprenderlo y aceptar firmaron la autorización. Los factores de exclusión dejaron 94 niños para análisis de habituación y 47 para condicionamiento. El EEG se registró utilizando los montajes bipolares A-P parasagitales del sistema internacional 10/20, además se registraron los movimientos oculares y el EKG. El sujeto con OC se fotoestimulaba 20 veces (FR a 5/s X 2s). Después de 5 min de terminada la serie se les ponía en la mano dominante un aditamento con un botón, indicándoles que lo apretaran al inicio de cada FR y lo liberaran al terminarse (asociaciones). El análisis se efectuó con filtro de 1.6 y 40 Hz. Seleccionando manualmente, de la 1era, 5ª, 10ª 15ª y 20ª FR muestras de registros bipolares de 2s antes, durante y después. Para el condicionamiento se agregó la medición de la latencia de la respuesta. Se aplicó la TRF y se calculó la Potencia Absoluta (PA) de θ (4.0-7.5 Hz), α (8.0-1 2.5 Hz) y β (1 3-20 Hz), se obtuvo el promedio en cada hemisferio (HI, HD) y de ambos (AH). Se utilizó la prueba de Wilcoxon con α >0.05. Resultados El promedio de la PA de la actividad de fondo, de todos los niños, está por debajo de 10 µV². La 1era FR disminuye la PA de θ y de α con incremento de β en AH. En la 5ª FR disminuye θ y α con incremento de β. En la 10° disminuye menos θ y α, persistiendo el incremento de β. En la 15ª continúa la disminución de θ, pero aumenta α en el HI y disminuye en el HD. En AH se incrementa β. En la 20° se vuelve a disminuir θ y α en AH; sin embargo, el rango de la diferencia es menor que el registrado en anteriores FR. La PA de β sigue aumentando en AH. El análisis por grupo muestra que en el G-1, la PA de los tres ritmos es mayor, con predominio de θ, siendo del doble del grupo total. En la 1era FR incrementa la PA de los 3 ritmos, lo cual no se registró en los otros grupos. En el G-4, la 1era y 5ª FR disminuyen la PA de θ y de α (DRE), siendo menor la disminución en la 10ª y se invierte en la 1 5ª y 20ª (SER). Consecutivamente a la explicación de que con la FR deben presionar el botón, se incrementa el promedio de la PA a 12 µV² en promedio de la muestra. En la 1era Aso disminuye la PA de 6 y de θ incluyendo una discreta disminución de β, la latencia es de 930 ms. En la 5ª Aso disminuye θ con pequeño incremento de θ y α y la latencia es de 750 ms. En la 10ª y 15ª continúa el incremento de los tres ritmos y la latencia disminuye a 650 y 640 ms, respectivamente. Mientras que en la 20ª el incremento de la PA de cada ritmo es menor y la latencia se incrementa a 750 ms.

Las afasias: conceptos clínicos / The afasias: clinical concepts

"Dentro de las alteraciones que más afectan e invalidan o incapacitan al hombre se encuentran aquellas que lo aislan de su entorno impidiendo su vida de relación: verdadera tragedia, sobre todo cuando se trata de la pérdida de la función cognoscitiva más elevada y diferenciada que es el lenguaje, alterándose tanto la expresión como la comprensión, síndrome conocido en medicina como AFASIA, con todas las variables que se presentan dependiendo entre otros factores del sitio de lesión cerebral". (AU). Contenido: Presentación. 1) Antecedentes históricos. 2) Clasificación de las afasias. 3) Etiología de las afasias. 4) Traumatismos craneoencefálicos. 5) Análisis de casos clínicos. Conclusiones. Bibliografía

Detección con emisiones otoacústicas de trastornos de audición en recién nacidos en alto riesgo / Auditory screening with otoacoustic emissions in high risk neonates

Cincuenta y siete niños, de edades entre 16 días y 11 meses, con prematurez y bajo peso (20 niños) y con hiperbilirubinemia (37 niños) fueron estudiados con emisiones otoacústicas (EMOAT)y potenciales provocados auditivos de tallo cerebral (PPATC). Se encontraron pruebas anormales en 13.2 por ciento de EMOAT y 15 por ciento de PPATC. En 2 niños (4 oídos)hubo EMOAT normales con PPATC anormales y en un niño, un oído con EMOAT ausentes con PPATC normales. Se concluye que las EMOAT constituyen un método eficaz y confiable para detectar trastornos auditivos en neonatos.

Hallazgos electrofisiológicos mediante mapeo cerebral en niños con trastorno de déficit de atención con hiperactividad / Electrofisiological findings in the broun maping of children with attention deficit and hiperactivity

El trabajo se realizó con el objetivo de detectar posibles alteraciones electrofisiológicas en el estudio de mapeo cerebral en niños con trastorno de déficit de atención con hiperactividad (TDAH). El diagnóstico TDAH fue hecho mediante historia clínica, aplicación de escalas de Swanson-Nolan-Pelham y criterios diagnósticos del "Manual diagnóstico y estadístico de los trastornos mentales" (DSM IV), incluyéndose en el grupo de estudio a los que resultaron positivos a esta valoración. En el grupo control a niños con criterios negativos. Se practicó mapeo cerebral en ambos grupos con colocación de electrodos bajo la norma internacional 10-20 en un solo momento y una condición: vigilia con ojos cerrados. Los resultados del mapeo cerebral en el grupo de estudio para el intervalo de frecuencia 6-12 Hz fue de; C3 9.68 por ciento, C4 12.90 por ciento, P3 24.19 por ciento, P4 32.26 por ciento, o1 51.61 por ciento, O2 50 por ciento,T3 6.45 por ciento,T4 12.90 por ciento,T5 24.19 por ciento,T6 38.71 por ciento,Cz 12.90 por ciento para el intervalo de frecuencia 6-12 Hz fue de; C3 9.68 por ciento,C4 12.90 por ciento, P3 24.19 por ciento,P4 32.26 por ciento, O1 51.61 por ciento, O2 50 por ciento, T3 6.45 por ciento, T4 12.90 por ciento,T5 24.19 por ciento,T6 38.71 por ciento,Cz 12.90 por ciento para el grupo control fue de; C3 9.68 por ciento, C4 12.90 por ciento, P3 24.19 por ciento, P4 32.26 por ciento, o1 51.61 por ciento, O2 50 por ciento,T3 6.45 por ciento,T4 12.90 por ciento,T5 24.19 por ciento, T6 38.71 por ciento, Cz 12.90 por ciento. Los hallazgos más significativos se encontraron en relación con la disminución del pico de frecuencia de theta-alpha del grupo de estudio en relación al control, lo cual apoyaría la teoría de organicidad del TDAH, pero debemos considerar como un dato inespecífico y no se puede generalizar en un solo mecanismo, lo que abre nuevas pautas para continuar la investigación con relación a este factor.

Anomalías en mapeo cerebral de pacientes disfémicos / Abnormal barin mapping in stuttering patients

La disfemia es una enfermedad que se cree debida a diversos factores etiológicos siendo la organicidad uno de ellos. El objeto de este estudio es investigar esta teoría, mediante el uso de estudio electroencefalográficos, registrados en un mapa cerebral. Se estudiaron un grupo apareado por edad y un grupo de pacientes disfémicos sin patología neurológica o problema de comunicación humana agregado, con un rango de edad de 5 a 18 años clasificados en tres subgrupos, de 5 a 9, de 10 a 14 y de 15 a 18 años. El mapeo cerebral fue practicado en ambos grupos bajo tres condiciones (ojos abiertos, ojos cerrados y post-hiperventilación) y los resultados se registraron en una base de datos el equipo. Como único hallazgo, se encontró en los histogramas disminución en el pico de frecuencia de alfa con promedio de 0.8 a 0.9 Hz en el subgrupo de 10 a 14 años y de 0.9 a 1.0 Hz en el subgrupo de 15 a 18 años de pacientes disfémicos, comparados con el grupo control. Aunque esto apoyaría la teoría de organicidad, se debe considerar que es solo un dato inespecífico que no puede ser indicativo de daño a mecanismos conocidos