Utility of EEG on attention deficit-hyperactivity disorder (ADHD)

The aim of our study was to analyze electrophysiological findings in patient with Attention Deficit Hyperactivity Disorder (ADHD) by electroencephalography (EEG) recording, estimate the prevalence of epilepsy in ADHD population and assess its clinical characteristics.

We conducted a retrospective and analytic study that concerned children with ADHD, followed for at least two-years in the Tunisian National Center for School and University Medicine (NCSUM). All patients recruited underwent at the diagnosis of ADHD, neurological examination and EEG recording in the department of Neurology of Charles Nicolle Hospital. Medical data including family history, ictal semiology and ADHD features were assessed.

Thirty patients were enrolled in our study. Mean age was 12.27 years with a sex ratio of 3.28. Mean age at diagnosis of ADHD was 6.6 years. Attention Deficit Hyperactivity Disordercombined subtype was seen in 18/30 patients, Hyperactive/ Impulsive subtype in 7/30 patients and Inattentive subtype in 5/30 patients. Epilepsy-disease was reported in 20% (Seizures preceded the diagnosis of ADHD in 3/6 cases and appeared after an average of 3.67 years in 3/6 cases). Mean age of seizure onset was 7 years. Seizure-types were generalized (motor 4/6 cases, absence-type (1/6 case)) and focal (1/6 case). Electroencephalography revealed Epileptiform discharges in 30% with frontal and left dominance. Interictal discharges were significantly associated with younger age of onset (p: 0.02), inattentive subtype (p: 0.04) and intellectual disability (p: 0.04). These discharges was not associated with epilepsy.

Our results have shown that epileptiform discharges could be used as risk factor for seizures and cognitive impairment which may influence outcome in ADHD population.