Neurodevelopmental disruption in early-onset temporal lobe epilepsy: Evidence from a voxel-based morphometry study

Childhood onset of epilepsy has long been associated with an adverse impact on brain development and cognition. In this study it is proposed that earlier (vs later) onset of temporal lobe epilepsy (TLE) has a negative developmental impact on distant brain structures. One hundred ten patients with TLE were assigned to early (≤ 14 years, N = 58) and late (> 15 years, N = 52) age at onset of epilepsy groups. Voxel-based morphometry revealed onset-dependent abnormalities (in terms of a gray matter excess in the early-onset group), which were found mainly in frontal regions. An excess of gray matter is not a usual finding in TLE. However, within a neurodevelopmental framework, retained gray matter is discussed as reflecting neurodevelopmental disruption. The findings indicate the importance of quantitative MRI for the detection of subtle secondary abnormalities in focal TLE and once more underline the importance of early seizure management in children with intractable TLE.

Research Highlights
► Whether early-onset epilepsy has an adverse impact on brain development was studied.
► Brain morphology and cognition of patients with temporal lobe epilepsy were compared.
► Voxel-based morphometry revealed a gray matter excess in the early-onset group.
► Gray matter excess is discussed as reflecting disruption of normal brain development.
► The results support the idea of early seizure management in temporal lobe epilepsy.