Those compounds that we use to activate the brain in ADHD work in this area. Temproal lobe epilepsy is a distinct problem. There are forms that arise for the hippocampal formation and some that arise from the temporal lobe itself. This has its manifestations as seizures. As you do not describe seizure events, I would doubt that your son has temporal lobe epilepsy.
Dopamine is a neurotransmitter mostly found in the basal ganglia.
It is the neurotransmitter deficient in Parkinson's Disease. It seems to control fine motor movements and the control of our coordination. Acetylcholine is involved in neuromuscular processess and is not found in the basal ganglia but in neuromuscular junctions. I think it is a good idea to see a child psychiatrist. If your son has a conduct disorder along with ADHD then this might prove to be fruitful.