Abstracts

To investigate the developmental process associated with language network location and laterality using a fMRI auditory description decision task., 22 right-handed, healthy children (mean 8.45; range 5.0 -12.92; 32 male) and 22 right-handed, patients with left hemisphere focus epilepsy (mean 8.9; range 5.33 [ndash] 12.92; 11 males) underwent BOLD fMRI (3.0 Tesla) and neuropsychological testing. Subjects completed an auditory comprehension task targeting receptive and expressive language: auditory description decision task (ADDT). For the task children decided whether descriptions of named objects were correct (A large grey animal is an elephant). Task was monitored for performance and reaction time. Task was controlled for primary auditory processing, attention, and motor responses, and was adjusted for subject[apos]s developmental level. Group activation maps were analyzed with SPM2 and analyzed with regressors for age, accuracy, and cognitive measures of attention and language skills. Patient activation patterns were also compared against a larger normative dataset that includes 63 (32 Males; age 4.17-12.92 years) healthy volunteers., ADDT was left lateralized with activation maximum in middle frontal gyrus, middle temporal gyrus, and IFG in healthy controls. Patient maps had a similar profile. Comparison between matched controls showed patients had greater activation in right IFG, and right midfrontal gyrus when compared to patients. Results of regression analyses revealed younger controls had more activation in BA 30 whereas younger patients exhibited more activation in right IFG. No correlates were found with regressors for accuracy and no significant differences between groups on reaction time and accuracy were detected with a t-test., Group maps did not reveal any differences between groups in left lateralized primary language areas. Matched patient group maps suggest greater recruitment of homologous right language areas than healthy controls. Greater recruitment of right language areas suggest 1) transfer of language to right homologous regions secondary to epilepsy or 2) recruitment of alternate language networks due to greater task effort to achieve similar accuracy for patients. Changes related to age likely represent maturation of attentional, planning, and self monitoring systems., (Supported by NINDS RO1 NS44280; Mental Retardation and Developmental Disabilities Center Grant NICHD P30HD40677, General Clinical Research Center Grant MO1RR020359)