Functional asymmetry in the central brain regions in boys with Attention Deficit Hyperactivity Disorder detected by Event Related Potentials during performance of the Attentional Network Test

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: 16 typically developing (TD) boys and 16 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 showed significant difference between the groups, while no difference was observed for the C3. Only in the ADHD patients, both the left and right late target ERP characteristics correlated with the reaction time, while the DSM scores did not show any correlations in both groups. The difference between ERPs of the C3 and C4 channels inside the interval of 40-290 ms after target onset was positive in the ADHD group and negative in the control group. This asymmetry 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.

Estimating the Biological Validity of the DSM for Attention Deficit/Hyperactivity Disorder Using Multivariate Analysis for Small Samples

“…In this pool, the most informative neurophysiological variables proved to be topographically asymmetrical and represent the binded information from parietal and frontal regions linked to right frontal sites and the early (45 to 290ms after target) 'C3 minus C4' asymmetry. This asymmetry has already been shown to correlate with DSM scores, mainly with hyperactivity/impulsivity (32). Our results are evidence that some people could be biologically classified as "inattentive and hyperactive".…”

Estimating biological accuracy of DSM for attention deficit/hyperactivity disorder based on multivariate analysis for small samples

“…The P3 wave, a late potential related to cognitive tasks (Hruby & Marsalek, 2003) is particularly sensitive to ADHD conditions (Barry, Johnstone & Clarke, 2003; Kratz et al, 2011), which justifies the importance of cue- and target-related late potentials in classification, mainly in the mid-parietal region where this wave is most pronounced. In a recent study, we found an ERP asymmetry (from 45 to 290 ms after target onset) in the ‘C3 minus C4’ channel, which was shown to correlate with ADHD phenomenology (Abramov et al, 2016). Several studies have shown brain asymmetries related to ADHD phenomenology, especially in the frontal-striatal network (Barkley, 1997; Barkley, 2006; Langleben et al, 2001; Dang et al, 2016).…”