Unilateral cortical atrophy, hyper intense areas in the affected hemisphere without gyral enhancement is key feature in this case. And history of meningo-encephalitis , age of the patient supports Rasmussen encephalitis. And these features are compatible with Rasmussen encephalitis(chronic focal encephalitis)
How ever left periventricular T2 and FLAIR hyper intensities are rare finding in Rasmussen encephalitis. And these changes are there in the previous MRI done at 2 years of age. This is probably complications of meningo encephalitis . Because secondary CNS vasculitis is a known complication of meningoencephalitis.
EEG shows sleep background showed asymmetrical and slightly disorganized theca and delta rhythm. Intermittent focal sharp waves were seen in right centro-temporal region. Impression was abnormal background and epileptogenic zone in R/ Centro temporal region.
Main differential diagnosis of this case Dyke-Davidoff-Masson syndrome. However in this patient there is no significant calvarial thickening, dilatation of mastoid air cells or elevation of petrous ridge to support Dyke-Davidoff-Masson syndrome.