Abstracts

Rationale: Among children with epilepsy, some well known comorbidities (e.g., behavioral or cognitive) have been reported to be present at or even prior to the onset of epilepsy and/or the first recognized seizure (Austin et al., 2006). These have been termed “essential comorbidities” (Berg, 2007) and are presumed to represent the adverse effects of yet to be identified neurodevelopmental factors. We have become interested in two prevalent essential comorbidities in children with new onset idiopathic localization-related and generalized epilepsies including ADHD and prior educational problems, either alone or in combination. Whether these essential comorbities at time of diagnosis are associated with altered patterns of cognitive development remain to be determined and represent the subject of this report. Methods: Children with epilepsy (age 8-18, n=75) and their caretakers underwent structured interview to derive Axis I DSM-IV diagnoses and characterize prior academic problems with provision of special educational services. All children with epilepsy and healthy controls (n=62) underwent neuropsychological assessment at baseline and two years later. Evaluated were intelligence, academic achievement, language, memory, executive functions and psychomotor speed. Results: Of 75 children with new onset epilepsy, 53 exhibited either ADHD or educational problems alone or in combination (COMORBID+) at baseline assessment, while 32 children with epilepsy exhibited neither problem (COMORBID+). At baseline, the COMORBID- group differed significantly (p<.05) from healthy controls on only 2 of 20 measures (response inhibition, digit symbol) and over a two year interval showed no significant deviation from healthy controls in the pattern of cognitive change/development. In contrast, the COMORBID+ group exhibited more neuropsychological abnormalities at baseline, as expected, but they also exhibited abnormal (p<.05) cognitive trajectories compared to controls on 10 of 20 cognitive measures over the two year interval. These abnormal trajectories involved measures of intelligence, academic achievement, language, memory, executive function and psychomotor speed. There were some unique developmental abnormalities associated with ADHD (executive and psychomotor speed/dexterity) versus educational comorbidities (intellectual, language, IQ measures). Conclusions: The presence of specific educational and psychiatric comorbidities at seizure onset (essential comorbities) is associated not only with baseline cognitive abnormalities but also with the pattern of prospective 2-year cognitive development. A significant proportion of children with new onset idiopathic epilepsy present without history of prior or current educational or psychiatric comorbidities and demonstrate normal cognition at baseline and normal neurocognitive development. In that these are common and readily detected comorbidities at seizure onset, there is an opportunity for early intervention. (Source of funding: NINDS RO1-44351).