Granule cell dispersion (GCD) into the dentate gyrus (DG) molecular layer was observed in hippocampal specimens in 10 out of 22 cases of human non-lesional temporal lobe epilepsy (TLE) and was associated with hippocampal sclerosis (HS). The presence of GCD was significantly linked to events of epileptic nature arising during the first 4 years of life but not with the durations of epilepsy, nor the number of seizures. Dispersion could be induced by seizure-linked structural plasticity occurring during a specific early permissive period.