title: [Cortical variations of the dimension of correlation in children with attention deficit hyperactivity syndrome].
abstract: OBJECTIVE
  The syndrome of deficient attention and hyperactivity affects approximately 5% of children of school age. Clinically it is characterized by deficient attention, impulsiveness and excessive motor activity. Developments in nonlinear dynamic theory have made it possible to think of modelling cerebral activity as a dynamic system of chaotic type. One the most widely standardized measurements is the dimension of correlation (D2). In this paper we study the electroencephalographic traces of a control group of 9 healthy children and another group of 19 children with the syndrome of deficient attention, at rest and whilst carrying out a visuomotor task (Test of perception of differences).
  
  
  METHODS
  The dimension of correlation was estimated for both groups. Statistical comparison was made between the cortical distributions of the D2 between both types of recordings and between both groups.
  
  
  RESULTS
  The children with lack of attention showed a larger number of activated cortical areas than those of the control group when carrying out the same task. However, during the resting state there were no differences in the D2 between the control children and the children with deficient attention. The indicates that both groups have the same basal level of activation.
  
  
  CONCLUSIONS
  The dimension of correlation is a method which permits the demonstration of an increase in neuronal activity in the stimulated areas, in this case in the occipital region.
authors.affiliation: Servicio de Neurofisiología Clínica, Hospital Miguel Servet de Zaragoza, España.
authors.forename: J R
authors.initials: JR
authors.lastname: Valdizán
authors.forename: M A
authors.initials: MA
authors.lastname: Navascués
authors.forename: M V
authors.initials: MV
authors.lastname: Sebastián
authors.forename: M A
authors.initials: MA
authors.lastname: Olivito
authors.forename: M A
authors.initials: MA
authors.lastname: Idiazábal
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis*; D001931:Brain Mapping; D002648:Child; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales
vernacular_title: Variaciones corticales de la dimensión de correlación en niños con síndrome de hipercinesia con atención deficiente.