[Clinical correlation of hypnagogic hypersynchrony during sleep in normal children and those with learning disability]. / Correlación clínica de la hipersincronía hipnagógica durante el sueño, en niños normales y con problemas de aprendizaje.

INTRODUCTION: One of the electroencephalographic (EEG) patterns that can be mistaken for paroxysmal clinical activity, when not taken into account and especially in children, is hypnagogic hypersynchrony (HH). This consists in generalised, paroxysmal, synchronic, symmetrical, slow, high voltage waves lasting 2 8 seconds, which appear in drowsiness and in stage I. It was observed that this pattern often appeared in children with learning disability (LD). AIMS. To correlate clinical data with the presence of HH during sleep in normal children and those with LD. PATIENTS AND METHODS: We assessed 180 children between the ages of 6 12 years with normal neurological development, 130 of which suffered LD and 50 who did not have LD. EEG was performed with sleep deprivation, following the International Federation of Clinical Neurophysiology guidelines. RESULTS: The presence or absence of HH, together with its characteristics, was assessed. Of the children with LD, 35.38% displayed HH and of the children without LD, only 4% displayed HH. Since the characteristics of HH in the children with LD were different to previous descriptions, we put forward criteria with which to evaluate those differences. CONCLUSIONS: HH appeared more often in children with LD than in normal children. Qualitative, quantitative (p< 0.05) and morphological changes were found in the paroxysmal activity of HH during the stages of sleep in children with LD.

Correlación clínica de la hipersincronía hipnagógica durante el sueño, en niños normales y con problemas de aprendizaje / Clinical correlation of hypnagocic hypersynchrony during sleep in normal children and those with learning disability

Introducción. Uno de los patrones electroencefalográficos (EEG) que puede confundirse con actividad clínica paroxística cuando no se toma en cuenta, especialmente en los niños, es la hipersincronía hipnagógica (HH), que consiste en ondas lentas generalizadas, paroxísticas, sincrónicas y simétricas, de altos voltajes, cuya duración es de 2-8 segundos, que se presentan en la somnolencia y el estadio I. Observamos que este patrón se presentó frecuentemente en los niños con problemas de aprendizaje (PA). Objetivo. Correlacionar los datos clínicos con la presencia de HH durante el sueño en niños normales y con PA. Pacientes y métodos. Se evaluaron 180 niños, de 6-12 años, con desarrollo neurológico normal, 130 de los cuales presentaron PA y 50 no los presentaron. Se realizaron EEG con deprivación de sueño, bajo las recomendaciones de la Federación Internacional de Neurofisiología. Resultados. Se evalúo la presencia o ausencia de HH, así como sus características. El 35,38 por ciento de los niños con PA presentaron HH. De los niños sin PA, sólo el 4 por ciento presentaron HH. Como las características de la HH en los niños con PA eran diferentes de lo descrito previamente, proponemos criterios para evaluar dichas diferencias. Conclusiones. La frecuencia de presentación de la HH fue mayor en los niños con PA que en los niños normales. Se encontraron cambios cualitativos, cuantitativos (p< 0,05) y morfológicos en la actividad paroxística de la HH durante los estadios del sueño en niños con PA (AU)

Introduction. One of the electroencephalographic (EEG) patterns that can be mistaken for paroxysmal clinical activity, when not taken into account and especially in children, is hypnagogic hypersynchrony (HH). This consists in generalised, paroxysmal, synchronic, symmetrical, slow, high voltage waves lasting 2-8 seconds, which appear in drowsiness and in stage I. It was observed that this pattern often appeared in children with learning disability (LD). Aims. To correlate clinical data with the presence of HH during sleep in normal children and those with LD. Patients and methods. We assessed 180 children between the ages of 6-12 years with normal neurological development, 130 of which suffered LD and 50 who did not have LD. EEG was performed with sleep deprivation, following the International Federation of Clinical Neurophysiology guidelines. Results. The presence or absence of HH, together with its characteristics, was assessed. Of the children with LD, 35.38% displayed HH and of the children without LD, only 4% displayed HH. Since the characteristics of HH in the children with LD were different to previous descriptions, we put forward criteria with which to evaluate those differences. Conclusions. HH appeared more often in children with LD than in normal children. Qualitative, quantitative (p< 0.05) and morphological changes were found in the paroxysmal activity of HH during the stages of sleep in children with LD (AU)