1H MRSI and social communication deficits in pediatric complex partial seizures

Purpose: To investigate relationships between regional brain metabolites, social communication deficits, and seizure frequency in children and adolescents with cryptogenic epilepsy with complex partial seizures (CPS). Methods: In 12 children and adolescents with CPS and 23 age-and gender-matched healthy controls, we acquired proton magnetic resonance spectroscopic imaging (MRSI) at 1.5 T and 30 ms echo-time from bilateral inferior frontal and superior temporal gyri, regions associated with social communication deficits. Videotaped speech samples of all the subjects were coded for social communication deficits and parents provided information on seizure frequency. Key Findings: Four MRSI findings emerged in right inferior frontal gyrus. N-acetyl-aspartate (NAA) plus N-acetylaspartyl-glutamate (NAAG)-together called "tNAA"-was 11.4% lower in patients with CPS than in controls. Choline-compounds (Cho) were 15.4% lower in CPS than in controls. Within CPS, higher tNAA was associated with more frequent seizures and abnormal social communication. Significance: Localization of findings to right inferior frontal cortex supports the involvement of this area in social communication deficits and may be related to atypical lateralization of expressive language in pediatric epilepsy. Lower levels of tNAA and Cho may indicate local neuronal or glial damage or underpopulation due to excitotoxicity or other causes. The sensitivity of tNAA to seizure frequency suggests effects of ongoing CPS on neuronal and glial function in this brain region.