Attention-deficit/hyperactivity disorder as a model of transitory cognitive impairment in epilepsy

Epilepsy and Attention-Deficit/Hyperactivity Disorder (ADHD) are associated with neuropsychological, psychosocial and academic dysfunction. In addition to a high rate of comorbidity, research has suggested that epilepsy and ADHD share underlying electrophysiological abnormalities. Thus, ADHD could be theoretically considered a model of transitory cognitive impairment (TCI). 88 children with seizures (SZ−), 38 children with seizures and symptoms of ADHD (SZ+), 15 children with ADHD and no history of seizures (ADHD) and matched sibling controls were administered a battery of neuropsychological tests. Neurophysiological data for the two clinical seizure samples were collected from the most recent EEG in each child\u27s medical file; EEGs were recorded independently from the neuropsychological testing. Analyses revealed that the three clinical groups performed significantly more poorly than normative samples on neuropsychological measures. The performances of the sibling groups also fell significantly below national norms on some measures. However, none of the group performances differed significantly from each other. A profile analysis for the clinical groups was not significant. Analyses did not reveal any effect for the presence of spike-wave activity, localization of spike-wave activity, or the presence of slow-wave background activity in the clinical seizure samples. Results revealed that each of the three clinical groups demonstrated neuropsychological impairment soon after diagnosis. Moreover, the presumably healthy sibling control samples also demonstrated neuropsychological deficiencies. The pattern of deficits in all samples was generally commensurate with those previously reported in the literature for epilepsy and ADHD. The profiles of neuropsychological performance in the clinical samples appear to suggest a model of comorbidity, although the qualitative differences among the groups did not reach a level of statistical significance. The absence of a relationship between neurophysiological abnormalities and neuropsychological deficits in the seizure samples appears to support previous research findings, which indicated the neurophysiological-neuropsychological relationship is most evident in samples with chronic epilepsy. In general, the results indicate that cognitive interventions and academic modifications may be necessary and beneficial for children recently diagnosed, as well as their asymptomatic siblings, in order to ameliorate the longterm negative academic and psychosocial outcomes typically associated with epilepsy and ADHD