Introduction: Attention Deficit Hyperactivity Disorder (ADHD) is known to be more common in children with epilepsy than in the general population. Thirty one to forty percents of ADHD are accompanied with epilepsy. Few studies regarding this matter have been reported in Korea. This study was aimed to evaluate the comorbidity of ADHD in children with epilepsy.
Methods: This is a two big center based, retrospective and controlled study at Cheongju in Korea. Thirty four ADHD children with epilepsy and 38 ADHD children without epilepsy from Chungbuk National University hospital and Cheonju St. Mary's hospital were recruited from January 2005 to June 2010.
Results: In ADHD children with epilepsy, twelve (35.2%) had partial seizures, 11 (32.2%) did generalized seizures and 11 (32.2%) were unclassified. EEG abnormalities were found in the frontal lobe (15 cases), in the central lobe (7 cases), in the temporal lobe (6 cases), and in the occipital lobe (3 cases). In ADHD children with epilepsy, the combined type was majority (76.4%) and otherwise in ADHD children without epilepsy, the inattentive type was main (50.5%) (P=0.004). Learning disability was more common in ADHD with epilepsy than in ADHD without epilepsy (P=0.01).
Conclusion: This study showed that ADHD children with epilepsy are more likely to have combined type (76.4%) and learning disability as compared with ADHD without  epilepsy.