What is the best advice to give my brother who has been diagnosed with temporal lobe epilepsy?

To take his medicine: Since you are 62, your brother cannot be a lot younger, which suggests that his epilepsy is probably due to a concussion (even if it occurred a long time ago), a small stroke, or another brain lesion. Mri scan may be able to establish the underlying cause and possibly lead to removal of this cause. However, whatever the cause, it is not likely that the epilepsy will stop on its own any time soon.