Entropy analysis of MEG background 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 fuzzy entropy (FuzzyEn), an entropy measure that quantifies signal irregularity. Five minutes of recording were acquired with a 148-channel whole-head magnetometer in 14 ADHD patients and 14 control children. Our results showed that MEG activity was more regular in ADHD patients than in controls. Additionally, there were statistically significant differences (p < 0.01, Student's t-test with Bonferroni's correction) in the five analyzed brain regions: anterior, central, posterior, left lateral, and right lateral. Using receiver operating characteristic (ROC) curves, the highest values of accuracy (82.14%) and area under the ROC curve (0.9005) were achieved in anterior area. Our results support the hypothesis that ADHD is characterized by a delay of cortical maturation in the prefrontal cortex.