The EEGs in 23 13-year-old Finnish-speaking boys with spelling disabilities and in 21 matched controls were studied in the Departments of Child Neurology, Paediatrics, Clinical Neurophysiology and Psychology, University of Helsinki, Finland. The visual assessment of the records showed an abnormal EEG in 48% of the index group and in 25% of controls. The abnormalities included a general excessive slow activity, temporal slow wave activity and non-paroxysmal slowing. The frequency of paroxysmal activity did not differ significantly in the two groups; 4% in the index group and 9.5% in controls. A neurotic disposition measured by the Tennessee Self-concept scale and clinical subscale was more frequent in the index group than controls and reading was slightly impaired. Arithmetic skills were comparable in the two groups. In covariance analysis the qEEG parameter differences between the index group and controls were partly explained by the neurotic traits and emotional tension characteristic of the children with spelling difficulties. [1]
COMMENT. Poor rhythmicity and low voltage of the background rhythm has been found in the EEG of children with learning disabilities, and visual EEG analysis has shown a large variety of EEG abnormalities associated with dyslexia [2]. The present authors stress that psychopathology may be a confounding factor in the interpretation of EEG abnormalities in association with spelling disabilities and dyslexia.