Universitätskinderklinik, Schwanenweg 20, D-24105 Kiel, Germany
Background: Long-term outcome of rolandic epilepsy (RE) is associated with a diversity of neuropsychological deficits in childhood, although RE is historically considered as a benign epileptic disorder. Dyslexia and other developmental disorders are associated with rolandic EEG traits.
Aim: To investigate if there is an association between the manifestation of a specific EEG trait of RE and dyslexia. If the EEG traits are causing dyslexia, the cognitive deficits are supposed to be normalised after the EEG trait have resolved.
Method: Thirty adolescents and young adults, who had previously received a diagnosis of dyslexia by standard criteria, were included. Fifteen probands (mean age = 15.9) with dyslexia and rolandic EEG traits were compared with 15 age- and sex-matched controls (mean age = 16.0) with normal EEG.
Results: There were no statistical differences between the groups according to intelligence (Verbal IQ, Performance IQ and Arithmetical IQ) or spelling ability. However, there was a significant difference between the groups in reading ability of non-related words with the group without RE performing better than the group with RE (p < 0.01). Attentional shifts in dichotic listening with forced or directed attention are generally found in 50-60% in normative samples. However, the present date suggest an impaired attentional shift in dichotic listening test for both groups. Only one third was able to modulate their ear-preference. There were no group differences.
Conclusion: In general, both dyslectic groups did not show significant neuropsychological deficits as compared to standard controls. However, there were more reading errors and a tendency to attention impairments in the group with rolandic EEG trait as compared to the dyslectic group with normal EEG. Possible pathogenic factors are discussed.