ABSTRACT
History and investigation are the leader in helping physicians to reach a proper diagnosis; this aim is applied in both simple and complicated cases such as Herpes Simplex Encephalitis [HSE]. USE can be consider as life threatening condition due to its high mortality rate in delayed treated condition and neurological sequelae even if treatment initiated early. This was applied on a four years old girl presented to us with one day history of head trauma which was supported by hemorrhage seen in CT-Head, 72 hours later her condition deteriorate by recurrent convulsions, aphasia, change level of consciousness and spikes of fever, diagnosis of USE was delayed till day 10 of presentation when she start to have frequent attacks of convulsions, which was proved by positive CSF PCR for HSV