Hi My Father Had A Seizure A Couple Of Weeks

Hi my father had a seizure a couple of weeks ago. He was rushed to hospital and the MRI scan showed a shadow on his brain. He was told it is not a tumour as that would show as white spot. He is still not well and is confused with what day it is and sometimes is unresponsive. Could it be a tumour or is it the start of Alzheimer's