[Neurophysiological approach to Attention Deficit Hyperactivity Disorder].

Attention Deficit Hyperactivity Disorder (ADHD) is the most common neurodevelopmental disorder in childhood. Its diagnosis and treatment are complex due to its clinical heterogeneity and comorbid pathologies, such as epilepsy and sleep disorders, which affect its evolution and management. Studies such as electroencephalogram (EEG), quantified EEG and event related potentials (ERP) provide key neurophysiological information to better understand this disorder. EEG allows the identification of abnormal patterns such as increased frontal theta activity and increased the theta/beta ratio, which are associated with problems with attention and inhibitory control. Comorbidity between epilepsy and ADHD is high. Patients with ADHD are more likely to present subclinical interictal discharges. EEG allows us to differentiate between ADHD and epilepsy symptoms, such as typical absences, which can be confused with inattention, as well as detect the presence of interictal epileptiform discharges, improving diagnosis and treatment. ERP, such as P300, evaluate cognitive functions such as attention, working memory and inhibitory control, providing information for the diagnosis, developmental monitoring and treatment of ADHD. In parallel, sleep studies using polysomnography reveal a high prevalence of sleep disorders such as respiratory disorders and decreased REM sleep, exacerbating ADHD symptoms. Neurophysiological studies allow a more precise approach to ADHD, integrating objective diagnoses and personalized treatments that improve clinical results and long-term prognosis.