Abstract
Background Various functional asymmetries detected by different neurophysiological and neuroimaging methods have been reported in the literature on the Attention Deficit Hyperactivity Disorder (ADHD), some of them pointing to the right hemisphere activity. In our attempt to discriminate the ADHD patients from normal subjects by hierarchical clustering of behavioural, psychological and event related potential (ERP) variables, the late P3 component of potentials from the right central region (C4) proved to be one of the most informative parameters (in preparation for publication). Here, we have studied the differences in ERPs between the left (C3) and right (C4) central leads and relation of this asymmetry to ADHD diagnosed using DSM.
Methods 20 typically developing (TD) boys and 19 boys diagnosed with ADHD according to DSM-IV-TR, aged 10-13 years, were examined by the Attentional Network Test (ANT), with simultaneous recording of the respective ERPs. The intergroup differences in the ERP amplitude parameters in the left (C3) and right (C4) central channels and in the difference in these parameters between the two channels (C3 minus C4) were accessed. These characteristics were compared to the subjects DSM scores and ANT performance.
Results The target-related potentials late characteristics from the C4 and C3 did not shown significant difference between the groups. The difference between ERPs of the C3 and C4 channels inside the interval of 40-290 ms after target onset was larger in the ADHD group than in control, mainly for incongruent target condition. This asymmetry and right late component were correlated with DSM scores, mainly to hyperactive and impulsive criteria.
Conclusion In ADHD patients, the results suggest ERP pattern of right-side functional predominance in the motor control, which correlates to DSM scores, mainly to hyperactive and impulsive criteria.
