Attention Deficit Hyperactivity Disorder in Paediatric Patients with Malignant Haematologic Diseases or Epilepsy: Experience at a Tertiary Care Hospital in Korea

Background: Paediatric patients with epilepsy and malignant haematologic diseases (MHD) are at increased risk of mental health problems compared to the general population. The purpose of this study was to determine the prevalence of attention-deficit hyperactivity disorder (ADHD) among paediatric patients treated for MHD or epilepsy compared to that in healthy children in South Korea. Methods: We retrospectively reviewed 184 patients diagnosed with epilepsy and 172 patients diagnosed with malignant haematologic diseases in the paediatric department of Seoul St. Mary's Hospital from May 2009 to May 2013. Normal controls were selected from the out-patient clinic among those who visited the clinic for vaccination. Results: Paediatric patients with epilepsy or MHD exhibited significantly higher rate of ADHD compared to the controls (37.5% or 29.6% vs. 11.9%, P=0.039). Among children with both MHD and ADHD, 69.5% had the inattentive subtype and 30.5% had the combined subtype of ADHD. Among children with both epilepsy and ADHD, 70.6% had the inattentive subtype, 23.5% had the combined subtype, and 5.9% had the hyperactive type of ADHD. There were statistically significant differences between MHD patients with ADHD and MHD patients without ADHD of sex, age at onset of haematologic diseases (=5 years), intrathecal chemotherapy, treatment duration and cranial radiation. Patients with epilepsy and concomitant ADHD showed significantly poorer response to epilepsy treatment than patients without ADHD. Conclusions: Paediatric patients with MHD and epilepsy are at significant risk for ADHD. Baseline testing of all patients with MHD or epilepsy is needed to assess their neuropsychological and academic skills over time to facilitate early intervention and prevent academic failure.