Abstracts

Rationale: Attention is an essential function that is often impaired in people with epilepsy (PWE) regardless of seizure type. Computerized continuous performance tests (CPTs) are frequently used as measures of attention, including the Conners' CPT (CCPT) which provides 15 variables that purportedly measure sustained attention. Factor analysis of adult CCPT performance, however, has shown that four dimensions of attention are measured by the CCPT: Focused Attention, Sustained Attention, Hyperactivity/Impulsivity, and Vigilance (Egeland & Kovalik-Gran, 2010a). Three of these dimensions have been shown to discriminate between clinical groups (Egland et al, 2010b). The factor structure of CCPT performance was therefore analyzed to determine what dimensions of attention are evident in PWE. Methods: A mixed clinical sample of patients (n=322), including 248 PWE, were administered the CCPT-II as part of standard neuropsychological assessment. Age ranged from 6 to 61 years. PWE included 138 adults and 110 children/adolescents (6 to 17 years of age). The majority of PWE were being investigated for medically intractable focal seizures. Results: Principal component factor analyses followed by varimax rotation were done on CCPT performance (age and sex-corrected T-scores) of the total sample, PWE, and separately on PWE grouped according to age: child/adolescent (CWE) and adult. The results are presented in Tables 1 and 2 and showed that for the total sample and PWE four factors accounted for 74% of the variance. These factors were identical to the dimensions of attention described by Egeland et al (2010a). Among PWE, separate analysis of child/adolescent CCPT performance showed three component factors accounting for 71% of the variance, two identical to adults (hyperactive/impulsive, sustain) and one unique to CWE. This last factor was more complex than for adults with epilepsy and children with ADHD and primarily consisted of a combination of focused attention and vigilance. Conclusions: In adults with mixed clinical diagnoses or epilepsy, CCPT performance captures four dimensions of attention: Focus, Sustain, Hyperactive/Impulsive, and Vigilance. In CWE, three dimensions are measurable, two identical to those in adults but one unique and potentially valuable for discriminating between CWE and children with other attention deficits, e.g., ADHD, as well as between CWE with different types of seizures, e.g., focal vs. generalized. Further study of the clinical usefulness of CCPT indices of attention in PWE is merited.