Working memory impairment and recovery in iron deficient children.
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.


CONCLUSIONS
This is one of very few reports using ERP showing a diminished WM capability in ID school-age children.
Otero
Gloria A
GA
Universidad Autónoma del Estado de México, Facultad de Medicina, Labs de Neurofisología P. Tollocan esq. J. Carranza (s/n), Toluca, Mexico 50180, Mexico.
Pliego-Rivero
F Bernardo
FB
Universidad Autónoma del Estado de México, Facultad de Medicina, Labs. de Neuroquímica, P. Tollacan esq J. Carranza (s/n), Toluca, Mexico 50180, Mexico. Electronic address: bpliego@uaemex.mx.
Porcayo-Mercado
Rosario
R
Universidad Autónoma del Estado de México, Facultad de Ciencias de la Conducta, P. Tollocan esq. J. Carranza (s/n), Toluca, Mexico 50180, Mexico.
Mendieta-Alcántara
Gustavo
G
Hospital para el Niño, IMIEM, Mexico.
D000704:Analysis of Variance; D001288:Attention / Q000187:drug effects / Q000502:physiology; D001773:Blood Cells / Q000502:physiology; D002648:Child; D004569:Electroencephalography / Q000379:methods; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology; D005260:Female; D006400:Hematocrit / Q000379:methods; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000008:administration & dosage / Q000097:blood; D019189:Iron Metabolism Disorders / Q000150:complications* / Q000178:diet therapy / Q000473:pathology; D008297:Male; D008569:Memory Disorders / Q000178:diet therapy* / Q000209:etiology*; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D020127:Recovery of Function / Q000187:drug effects / Q000502:physiology*; D018709:Statistics, Nonparametric; D013997:Time Factors
D006454:Hemoglobins; D007501:Iron