The patient has a longstanding history of generalized tonic-clonic convulsions since his childhood, not controlled by antiepileptics. Normal brain parenchyma was seen in a CT study done 5 years previously whereas the current study shows gross hemispheric atrophy, both cerebral and cerebellar. A presumptive diagnosis of Rasmussen encephalitis has been made. The patient is currently on high-dose steroids and immunoglobulins.

The radiographic differential diagnosis here is Dyke-Davidoff-Masson syndrome, Sturge-Weber syndrome, unilateral megalencephaly and hemiconvulsion-hemiplegia epilepsy syndrome.