EEG Characterization of Subgroups of Children with Learning Disorders

Our objective was to determine
if there were subgroups within a group of scholars with not otherwise specified learning disorders and if they had
specific electroencephalographic patterns. Eighty-five subjects (31 female,
8-11 years) who scored low in at least two subscales -reading, writing and
arithmetic- of the Infant Neuropsychological Evaluation were included. Electroencephalograms
were recorded in 19 leads during rest with eyes closed; absolute power was
obtained every 0.39 Hz. Three subgroups were formed according to children’s performance:
Group 1 (G1, higher scores than Group 2 in reading speed and reading and
writing accuracy), Group 2 (G2, better performance than G1 in composition) and
Group 3 (G3, lower scores than Groups 1 and 2 in the three subscales). G3 had
higher absolute power in frequencies in the delta and theta range at left
frontotemporal sites than G1 and G2. G2 had higher absolute power within alpha frequencies
than G3 and G1 at the left occipital site. G3 had higher absolute power in
frequencies in the beta range than G1 in parietotemporal areas and than G2 in
left frontopolar and temporal sites. G1 had higher absolute power within beta
frequencies than G2 in the left frontopolar site. G3 had lower gamma absolute
power values than the other groups in the left hemisphere, and gamma activity
was higher in G1 than in G2 in frontopolar and temporal areas. This
group of children with learning disorders is very heterogeneous. Three subgroups
were found with different cognitive profiles, as well as a different
electroencephalographic pattern. It is important to consider these differences
when planning interventions for children with learning disorders.