Attention-deficit hyperactivity disorder and nocturnal epileptiform activity in children with epilepsy admitted to a national epilepsy center

The aim of this study was to determine if there exists a relationship between attention-deficit hyperactivity disorder (ADHD) and the quantity of focal nocturnal epileptiform activity on the EEG (FNEA) measured as the percentage of epileptiform activity during non-REM sleep (spike index). This was accomplished with a prospective study of children aged 6–14 years consecutively admitted to our center. Of 362 patients, 44 (12.2%) had previously been diagnosed with ADHD. Twenty-four-hour ambulatory EEG recording and assessment of ADHD according to DSM-IV were performed in 46 children suspected of having ADHD. ADHD was diagnosed in 30. We could not find any correlation between the spike index in 8 children with FNEA and the severity of their ADHD symptoms. This study is underpowered and should be considered a pilot study. There is a need for further investigation of a possible causal effect of FNEA on ADHD symptoms in larger cohorts of patients with FNEA.