Noninvasive identification of seizure lateralization in children

Abstract

Objective With this prospective, observational study, we aimed to determine whether noninvasive language tasks, developed specifically for children, could reliably identify the hemisphere of seizure onset in pediatric epilepsy. Methods Seventy-eight children with unilateral epilepsy (44 left), aged 6–15 years (mean age = 11.8, SD = 2.6), completed the Children s Auditory Naming and Visual Naming Tests, the Boston Naming Test, and other verbal and nonverbal tasks. Multivariate analysis of variance was used to compare test performance between left and right hemisphere epilepsy groups, and χ2 analyses and odds ratios were used to examine classification of left vs right hemisphere epilepsy for individual patients based on test performance. Results Group comparisons revealed poorer auditory naming in children with left hemisphere epilepsy (p = 0.02), yet no significant differences on measures of visual naming, general intelligence, or other cognitive functions. Moreover, χ2 analyses using auditory naming cutoff scores to define intact vs impaired performance correctly classified seizure laterality in a significant proportion of children (p = 0.004). The odds of left hemisphere epilepsy were 4.2 times higher (95% confidence interval 1.4–11.7) than the odds of right hemisphere epilepsy with poor auditory naming performance. In the subset of patients with temporal lobe epilepsy (TLE), the odds of left TLE were 11.3 times higher (95% confidence interval 2.00–63.17) than the odds of right TLE with poor auditory naming performance. Conclusion Contrary to previous findings, naming performance can lateralize hemisphere of seizure onset in children with epilepsy, thereby assisting in the preoperative workup for pediatric epilepsy surgery.