Rasmussen encephalitis is a chronic idiopathic CNS inflammatory disease predominantly diagnosed in children, usually affecting a single cerebral hemisphere and causing severe/refractory epilepsy. On most recent follow-up of this young man with a recorded history of RE diagnosed as a child at pediatric institution, imaging demonstrated progressive left hemispheric abnormality in the inferior parietal lobule likely representing a site of new chronic encephalitis. Over the 10+ years of scanning, it is easier to appreciate progressive disease course with mild dilatation of the left trigone and stable mild left hippocampal atrophy.