Postictal MRI features with a unilateral pattern.

A 14-year-old female presented with focal seizure and secondary generalized convulsive status epilepticus lasting 2 hours. Electroencephalography revealed diffuse slow waves. Magnetic resonance imaging performed 2 days after onset demonstrated cortical swelling, gyri effacement, and restricted diffusion affecting the right temporal and parietal lobes (Figure). The differential diagnosis of these abnormalities included infarction, ischemia, venous thrombosis, vasculitis, infection, neoplasm, and metabolic encephalopathy. Because imaging findings were resolved completely after 38 days without specific treatment aside from supportive seizure therapy, infarction, venous thrombosis, vasculitis, infection, and neoplasm became less likely. Seizure-induced transient cerebral swelling was the most probable diagnosis.