What could cause hedaches morning nausea seizuures and ringing in ears?

my 17 year old autistic son has had severe headaches,morning nausea and vomiting,seizures,ringing in the ears,complete personality change and aggressive behavior. These symptoms are started about 3 months ago except seizures,which he has been having for the last month. his eeg results showed an abnormality in the right temporal lobe but we have not yet had the mri. I have been on line and the only medical condition I have been able to find with all these symptoms is a brain tumor. I want to know if there is anything else that could cause all these symptoms.