RESUMO
OBJECTIVE: Iron is an important oligoelement participating in multiple metabolic processes, including the synthesis of catecholamines, and its deficiency (ID) throughout development is particularly insidious on brain maturation and the emergence of cognitive functions during school age. A working memory (WM) study in 8-10-year-old ID children is presented. It is hypothesized that an impairment in WM exists in ID school-age children and a substantial restoration of this mental ability should occur after iron supplementation. METHODS: Event-related potentials (ERPs) were recorded during the completion of a Sternberg-type task in control, ID and ID-iron supplemented children. RESULTS: ID children showed less correct answers and diminished ERP amplitude in frontal, central, parietal and temporal regions compared to control children. After iron supplementation and normalizing bodily iron stores, behavioral and ERP differences disappeared between ID and control children. CONCLUSIONS: Considering that WM is fundamentally related to attention ability, the results presented here confirm and reinforce previous observations: ID severely diminishes attention [Otero GA, Pliego-Rivero FB, Contreras G, Ricardo J, Fernandez T. Iron supplementation brings up a lacking P300 in iron deficient children. Clin Neurophysiol 2004;115:2259-66] and WM while iron supplementation substantially restores the cognitive capabilities tested. SIGNIFICANCE: This is one of very few reports using ERP showing a diminished WM capability in ID school-age children.
Assuntos
Distúrbios do Metabolismo do Ferro/complicações , Transtornos da Memória/dietoterapia , Transtornos da Memória/etiologia , Memória de Curto Prazo/fisiologia , Recuperação de Função Fisiológica/fisiologia , Análise de Variância , Atenção/efeitos dos fármacos , Atenção/fisiologia , Células Sanguíneas/fisiologia , Criança , Eletroencefalografia/métodos , Potenciais Evocados/efeitos dos fármacos , Potenciais Evocados/fisiologia , Feminino , Hematócrito/métodos , Hemoglobinas/metabolismo , Humanos , Ferro/administração & dosagem , Ferro/sangue , Distúrbios do Metabolismo do Ferro/dietoterapia , Distúrbios do Metabolismo do Ferro/patologia , Masculino , Testes Neuropsicológicos , Recuperação de Função Fisiológica/efeitos dos fármacos , Estatísticas não Paramétricas , Fatores de TempoRESUMO
Direct evidence of CNS developmental alterations in iron-deficient anaemic (IDA) infants was obtained. Twenty 3-15-month-old IDA and 20 non-IDA infants (age and gender matched), healthy in every other respect, were studied. Complete blood and iron kinetics tests determined an IDA status. Psychomotor development was assessed through the test of Rogers and co-workers [Rogers SJ, Donovan CM, D'Eugenio D, Brown SL, Whiteside E, Moersch MS, Schafer DS. (eds) Developmental Programming for Infants and Young Children, Vol 2. University of Michigan Press, 1981] and under the 10-20 International System qEEG was performed (sleep/stage II). A Pearson's correlation test was applied between haematological, psychomotor and broad band EEG variables, and through ANOVA psychomotor and AP means were compared. IDA infants showed lower scores in cognition, fine motor and social/emotional areas, higher delta/theta and lower alpha power. Most correlations between haematological/psychological variables were positive. Delta/theta correlations were negative with self-care/gross and motor items while alpha/beta AP showed positive correlations with psychomotor and haematological variables. A clear association was found between EEG alterations and a low haematological/iron profile leading to a delayed psychomotor development.
