Use of single-electrode EEG in the evaluation of attention-deficit/hyperactivity disorder

Attention deficit/hyperactivity disorder (ADHD) maintains a diagnosis based on behavioral data despite its involvement in neuropsychophysiological models. The monopolar electroencephalography (EEG) record focused on differentiating children with ADHD versus controls based on a higher theta/beta ratio has been proposed as an alternative to objectify the diagnosis and guide neurofeedback-based intervention, but its results have been controversial. To analyze the viability of a single electrode to detect differences in the main cerebral rhythms and especially in theta/beta ratio, in children diagnosed with ADHD, analyzing the differences by subtype, age, sex and type of experimental task. 92 children (range: 7-13 years) diagnosed with ADHD were evaluated in a monopolar EEG record on four experimental tasks (rest, reading, active listening and copying a figure). Seven measures on slow and fast EEG rhythms were obtained, plus theta/beta ratio. There were no differences by ADHD subtypes. The task of greatest cognitive demand obtained the highest wave amplitudes. Smaller participants and boys presented higher amplitudes in slow waves and in theta/beta ratio in all the experimental tasks, showing a greater tendency to attentional regulation problems. Monopolar record and theta/beta ratio are a viable alternative in the clinical setting to complement the evaluation of ADHD.