Cortical dysfunction

My son had an accident in March of 2007. He had is orbital born fractured in 4 places. He had two plates incerted into his orbital whic was due from getting hit with a baseball bat. His personality has changed..more anger issues, doesn't think about what his doing, then can be nice as anything, mood changes often. Now he is compalining of severve headaches. We had an EEG done. It came back that he has cortical dysfunction in the right temporal region. They are suggesting anti-epelptic meds. Was this caused by the baseball accident or something he could have had prior tho the accident. Is this somethings that worsens as an adult? Is this really serious?