Thank You for a great site. Without examining him or going over his records it is impossible for me to give you a diagnosis over the internet. It is not normal for a child to have tremor. There various types of tremors, there are those that are found at rest, those that are manifested while trying to perform tasks, there are those that affect the trunk part of the body and those that affect the extremities. There are some types that are inherited, some are due to medications, some are due to trauma, some are just found without any reason.
Epilepsy can look like tremor, also.
I think what you need to do, is see a good pediatric neurologist. There are some tests that your son needs. I would try and find the best pediatric neurologist in your area. Best of luck and let us know what happens. All rights reserved.