Prenatal drug exposure, abnormal EEG's and seizures?

Hi, I'm seeking out suggestions and advice. We have a 3 year old son that we have had since he was 3 weeks old. He was drug exposed for multiple drugs and alcohol. He has had several milestone delays, but the biggest one being behavioral issues. At 9 mo. old he would seek out tile or hard objects to bang his head on when upset and would sometimes take hours to console up until about 6 moths ago. We have multiple therapies a week for speech, OT, etc. Autism has been ruled out. He got sick in Dec. and we were told in the hospital it was a febrile seizure, but our pediatrician wasn't comfortable with it so ordered an EEG. The results came back with abnormal spikes so the neurologist has suggested Keppra. Because of his history of behaviors and his mother's own mental health issues of depression and schizophrenia, we are hesitant to begin medications after 1 seizure even though the EEG was abnormal. I have been told by a few people and have tried to do some research on if drug exposure can cause an abnormal EEG in the absence of a seizure disorder. I may just be in denial because I fear the side effects that have been told may happen such as increased activity, anger, and sleep issues that we already deal with non medicated. Do we just keep the PRN on hand or begin the Keppra? Any suggestions or information is helpful.