The Neurodevelopmental Impact of Childhood-onset Temporal Lobe Epilepsy on Brain Structure and Function

Summary:  Purpose: To characterize the neurodevelopmental correlates of childhood-onset temporal lobe epilepsy on brain structure and cognition compared with late-onset chronic temporal lobe epilepsy and healthy controls. Methods: Healthy controls (n = 62) and patients with early (n = 37) versus late (n = 16) age at onset of temporal lobe epilepsy were compared with high-resolution quantitative magnetic resonance imaging (MRI) volumetrics and comprehensive neuropsychological assessment. Results: Patients with childhood-onset temporal lobe epilepsy (mean onset age, 7.8 years) exhibited widespread compromise in neuropsychological performance and substantial reduction in brain tissue volumes extending to extratemporal regions compared with healthy controls and late-onset temporal lobe epilepsy patients (mean onset age, 23.3 years). Most evident was reduced total white-matter volume among the childhood-onset patients. Reduction in brain tissue volume, especially total white-matter volume, was associated with significantly poorer cognitive status, attesting to the clinical significance of the volumetric abnormalities. Conclusions: Childhood-onset temporal lobe epilepsy appears to be associated with an adverse neurodevelopmental impact on brain structure and cognition that appears generalized in nature and especially evident in white-matter tissue volume.