[Factorial division of the visual N1 wave and functional significance]. / Division factorial de la onda N1 visual y su significado funcional.

INTRODUCTION: It has been argued if the frontal, N1a, is the early part of the occipito-temporal, N1b, or there are two different waves. It is also not clear whether the N1 of distractor is equivalent to the target N1, neither to distinguish these four waves has some functional value. PATIENTS AND METHODS: We performed a principal component analysis of latencies and amplitudes of N1 derived from an oddball visual paradigm in a sample of 82 persons with intellectual disability, and factor scores were correlated with measures of intellectual performance on the Wechsler Intelligence Scale for Children-Fourth Edition. RESULTS AND CONCLUSIONS: There is not significant dependency between N1a and N1b waves. The N1 from the target stimulus is functionally different to the N1 from the distractor. The N1a 'target' is related to the perceptual reasoning while the N1a 'distractor' is related to the working memory. The correlation between latencies and amplitudes of the target stimuli in posterior locations suggests that, similar to as observed in auditory areas, there is a visual synchronization with the prefrontal cortex; its dysfunction may explain some of the perceptual problems of people with intellectual disabilities.

Visual perception and frontal lobe in intellectual disabilities: a study with evoked potentials and neuropsychology.

BACKGROUND: Perception disorders are frequently observed in persons with intellectual disability (ID) and their influence on cognition has been discussed. The objective of this study is to clarify the mechanisms behind these alterations by analysing the visual event related potentials early component, the N1 wave, which is related to perception alterations in several pathologies. Additionally, the relationship between N1 and neuropsychological visual tests was studied with the aim to understand its functional significance in ID persons. METHOD: A group of 69 subjects, with etiologically heterogeneous mild ID, performed an odd-ball task of active discrimination of geometric figures. N1a (frontal) and N1b (post-occipital) waves were obtained from the evoked potentials. They also performed several neuropsychological tests. RESULTS: Only component N1a, produced by the target stimulus, showed significant correlations with the visual integration, visual semantic association, visual analogical reasoning tests, Perceptual Reasoning Index (Wechsler Intelligence Scale for Children Fourth Edition) and intelligence quotient. CONCLUSIONS: The systematic correlations, produced by the target stimulus in perceptual abilities tasks, with the N1a (frontal) and not with N1b (posterior), suggest that the visual perception process involves frontal participation. These correlations support the idea that the N1a and N1b are not equivalent. The relationship between frontal functions and early stages of visual perception is revised and discussed, as well as the frontal contribution with the neuropsychological tests used. A possible relationship between the frontal activity dysfunction in ID and perceptive problems is suggested. Perceptive alteration observed in persons with ID could indeed be because of altered sensory areas, but also to a failure in the frontal participation of perceptive processes conceived as elaborations inside reverberant circuits of perception-action.

Papel del linezolid en el tratamiento de endocarditis / No disponible

No disponible

Paciente con osteomielitis crónica que desarrolla caquexia / Patient with chronic osteomyelitis who developed cachexia

No disponible

[Electroencephalographic alterations in children with attention deficit hyperactivity disorder]. / Alteraciones electroencefalograficas en ni os con trastorno por deficit de atencion con hiperactividad.

INTRODUCTION: Attention deficit hyperactivity disorder (ADHD) is a syndrome that affects between 3 5% of the population of school aged children, and may be accompanied by learning, language, behavioural or motor disorders. Although various electroencephalographic alterations have been described in these patients, their pathological significance has not been determined. There have also been reports of children with neuropsychological and language disorders having epileptiform anomalies in the EEG recording. PATIENTS AND METHODS: We conducted a study of 15 children, with no history of seizures, who had been referred to Child Neurology for treatment and who satisfied the criteria for ADHD according to the DSM IV and the ADHRS (attention deficit/hyperactivity rating scale). RESULTS: The EEG recording in the waking state showed significant anomalies in two of our patients (acute spike and wave paroxysmal activity in the left temporoparietal region and spike wave discharges during hyperventilation). The polysomnographic study revealed specific alterations in four children. There was a continuous spike wave trace during slow sleep (CSWS) in one case, paroxysmal activity (slow acute waves, spikes) in the temporoparietal region with secondary generalization or transmission (two cases), and frequent generalized paroxysmal discharges of slow acute waves in all phases of sleep (one case). CONCLUSIONS: The neurophysiological disorders observed in some of our patients could make it necessary to consider performing a night time polysomnographic study in certain cases of ADHD.

Alteraciones electroencefalográficas en niños con trastorno por déficit de atención con hiperactividad / Electroencephalographic alterations in children with attention deficit hyperactivity disorder

Introducción. El trastorno por déficit de atención con hiperactividad (TDAH) es una entidad nosológica que afecta al 3-5 por ciento de la población infantil en edad escolar, y puede ir acompañada de trastornos de aprendizaje, de lenguaje, conductuales o motores. Aunque se han descrito diversas alteraciones electroencefalográficas en estos pacientes, no se ha determinado su significación patológica. Por otro lado, se ha referido que los niños con trastornos neuropsicológicos y del lenguaje pueden tener anomalías epileptiformes en el EEG. Pacientes y métodos. Se han estudiado 15 pacientes remitidos a la consulta de Neurología infantil, sin antecedentes de crisis convulsivas, que cumplían los criterios del TDAH según el DSM-IV y la EDAH (escala de déficit de atención con hiperactividad). Resultados. El EEG en vigilia mostró anomalías significativas en dos de nuestros pacientes (actividad paroxística de puntas y ondas agudas en la región temporoparietal izquierda y descargas de punta-onda durante la hiperventilación). En el registro polisomnográfico observamos alteraciones específicas en cuatro niños: un trazado de punta-onda continua durante el sueño lento (POCS) en un caso; actividad paroxística (puntasondas agudas y lentas) en la zona parietotemporal con transmisión o generalización secundaria (dos casos), y frecuentes descargas paroxísticas generalizadas de ondas lentas y agudas en todas las fases del sueño (un caso). Conclusión. Las alteraciones neurofisiológicas observadas en algunos de nuestros pacientes podrían plantear la necesidad de realizar una polisomnografía nocturna en determinados casos de TDAH (AU)

Introduction. Attention deficit hyperactivity disorder (ADHD) is a syndrome that affects between 3-5% of the population of school-aged children, and may be accompanied by learning, language, behavioural or motor disorders. Although various electroencephalographic alterations have been described in these patients, their pathological significance has not been determined. There have also been reports of children with neuropsychological and language disorders having epileptiform anomalies in the EEG recording. Patients and methods. We conducted a study of 15 children, with no history of seizures, who had been referred to Child Neurology for treatment and who satisfied the criteria for ADHD according to the DSM-IV and the ADHRS (attention deficit/ hyperactivity rating scale). Results. The EEG recording in the waking state showed significant anomalies in two of our patients (acute spike and wave paroxysmal activity in the left temporoparietal region and spike-wave discharges during hyperventilation). The polysomnographic study revealed specific alterations in four children. There was a continuous spike-wave trace during slow sleep (CSWS) in one case, paroxysmal activity (slow acute waves, spikes) in the temporoparietal region with secondary generalization or transmission (two cases), and frequent generalized paroxysmal discharges of slow acute waves in all phases of sleep (one case). Conclusions. The neurophysiological disorders observed in some of our patients could make it necessary to consider performing a night-time polysomnographic study in certain cases of ADHD (AU)