Subcortical low-intensity and restricted diffusion after first seizure in a child.

Our purpose was to increase the knowledge about subcortical low-intensity images on long repetition time by describing brain magnetic resonance images of a young boy after his first spontaneous seizure. Evident in the epileptogenic area were transient images of reversible subcortical low intensity on long-repetition time, T2*-weighted, and b = 0 s/mm2 diffusion, isointense signal on b = 1000 s/mm2 diffusion, and restricted diffusion. Most likely, mechanism was axonal flow disruption with iron accumulation and free radicals production induced during seizure.