Regularity Analysis of Spontaneous MEG Activity in Attention-Deficit/Hyperactivity Disorder

The aim of this study was to analyze the magnetoencephalography (MEG) background activity in Attention-Deficit/Hyperactivity Disorder (ADHD) using a regularity measure: sample entropy (SampEn). Five minutes of recording were acquired with a 148-channel whole-head magnetometer in 14 ADHD patients and 14 control subjects. Our results showed that ADHD patients' MEGs were more regular than controls' recordings. Additionally, there were statistically significant differences (p < 0.01, Student's t-test with Bonferroni's correction) at the five analyzed brain areas: anterior, central, posterior, left lateral and right lateral. Using receiver operating characteristic (ROC) curves, the highest accuracy (82.14%) was achieved at posterior region, whereas the highest area under the ROC curves (0.8827) were reached at anterior and central brain regions. These results suggest the usefulness of SampEn to reveal an abnormal type of dynamics associated with ADHD.