Learning Disabilities in Different Types of Attention Deficit Hyperactivity Disorders and its Relation to Cortical and Brainstem Function

Abstract

Background: Attention deficit hyperactivity disorder (ADHD) is comprised of the triad of inattention, hyperactivity and impulsivity. It was hypothesized that ADHD children and adults have abnormalities not only in several late-developing fronto-striatal networks but also in temporal-parietal and fronto-cerebellar neural networks which mediate the cognitive control functions that are impaired in this disorder. So the aim of this study is to determine the learning disabilities in different types of ADHD and its relation to brainstem and cortical function. Patients and Methods: Forty children participated in the study. All children were subjected to a full neurological and psychiatric examination: Swanson, Nolan and Pelham Questionnaire 4th edition (SNAP-IV-1992), Myklebust learning disability scale, auditory brainstem response (ABR) and electroencephalography (EEG). Results: Patients with ADHD showed significant lower level of learning disability score, and the inattentive type had the worst score. The mean of ABR had significant delay in wave III, IV, V, I-III and I-V interval, and the delay was significantly high in inattentive type. Fifteen (37.5%) children with ADHD had abnormal non- epileptiform activity and five (15%) had epileptiform activity. Inattentive type showed the highest abnormal activities. Learning disabilities showed non-significant negative correlation to score of inattention type, s ignificant negative correlation to absolute latency of wave III, IV, V, interpeak latency between wave I-III and I-V interval and significant negative correlation to epileptiform activity in EEG. Conclusion: Learning disabilities are strongly co-morbid with ADHD especially inattentive type and both may had brainstem and cortical processing abnormalities. J Neurol Res. 2014;4(1):22-30 doi: http://dx.doi.org/10.14740/jnr268w