[PS14-2B-2] Electrophysiological and hemodynamic evaluation of executive function in children with ADHD
Children with attention deficit hyperactivity disorder (ADHD) often exhibit deficit in executive function, for example inhibition function, working memory, cognitive shifting, etc. In general, ADHD is behaviourally diagnosed because objective biomarker for ADHD is unclear. For ADHD children, objective biomarker must be simple, definite, and non-invasive evaluations. In recent years, neurophysiological findings with non-invasive brain functional evaluations have been reported for ADHD. We review non-invasive brain functional evaluations for developmental disorders, especially with event-related potentials (ERPs), near-infrared spectroscopy (NIRS), and focus executive functions in ADHD. It is well known that ERPs in Go/NoGo task could reflect frontal inhibitory function. Especially, NoGo-P300, which is elicited from orbitofrontal regions, peak latencies were prolonged, and amplitude was decreased in ADHD children. The rate of NoGo-P300/Go-P300 latency correlated with variability of reaction time in continuous performance task (CPT) and/or Stroop test. In working memory task, N200 amplitude was also reported to be reduced in patients with ADHD. In addition, previous article reported medication and training were improved those ERPs and symptoms. On the other hand, Oxy-Hb with NIRS was decreased in frontal region of ADHD during inhibitory and/or working memory task, that is, Go/NoGo, reverse-Stroop, and n-back task, etc. NIRS is easy to measure and spatially demonstrable, but is not quantitative. ERPs are reproducible measurement, but is limited spatially resolution. It is better to take a flexible approach for assessment. Hemodynamic and electrophysiological findings during cognitive function task might be useful as a biomarker of executive function in ADHD children.