Does Electroencephalography Contribute to Examining Children with Attention Deficit Hyperactivity Disorder?

Dear Editor Attention Deficit Hyperactivity Disorder (ADHD) is the most common behavioral disorder in children (1). Prevailing theories suggest that this disease is caused by the disruption of dopamine transmission in the frontal lobe and frontostriatal pathway (2). The prevalence of such a disorder worldwide is approximately 5.2–12% (1)(2). ADHD is one of the most common disorders followed by epilepsy that affects the quality of the patients' life and is an important risk factor of academic achievement (3). Many recent studies imply that there is a complex and bidirectional relationship between ADHD and epilepsy (3)(4)(5). Previous studies have indicated a strong relationship between epilepsy and neuropsychological disorders such as Electrical Status Epilepticus in Sleep (ESES) and Landau–Kleffner syndrome (LKS) (1) (4). Epilepsy in children is associated with behavioral problems, such as ADHD and cognitive impairments. Cognitive disabilities are more likely to worsen with early onset and uncontrolled epilepsy. Children with some of the epileptic syndromes such as benign childhood epilepsy with centrotemporal spikes (BCECTS), frontal lobe epilepsy, rolandic epilepsy, complex partial seizures (CPS), and absence seizures may be more likely to be associated with these symptoms(6). Epidemiological studies have found that children with epilepsy are more susceptible to ADHD than other children are, so that one-third to two-third of such children will be affected by this disorder (3)(5). Incidences of ADHD in epileptic children will increase due to existing factors such as gender (male), positive family history, mental retardation, frontal lobe damage, intractable seizures, subclinical epileptic waves in interictal phase, focal seizures of frontal and temporal lobe as well as the use of anticonvulsant drugs including Phenobarbital, Benzodiazepine, Topiramate, and Vigabatrin (5). Other studies have shown that ADHD has a higher risk of incidence in generalized seizures than spasms. In some epileptic syndromes, ADHD is observed as a high risk, so that 67% of the patients with frontal lobe epilepsy and 61% with childhood absence epilepsy had ADHD (3). ESES is strongly associated with the behavioral disorders such as ADHD (3). On the other hand, the results of other studies have indicated the presence of epileptic discharges in some children suffering from ADHD without a history of epilepsy. In consideration of this evidence, a causal relationship between subclinical epileptic waves and occurrence of symptoms is raised (2) (4) (5) (7) (8). In other studies, it has been found that if such abnormal waves are treated, symptoms associated with ADHD will …