2 1/2 yr old not talking

My grandson progressed normally in talking until 1 1/2 yrs. was saying 1/2 doz. words.  mom,dad,water,hat,ball... and then reverted to saying the same 2, two sylable words. "AH-EE and EYEEE.  HE understands comands and sees them through. He understands our conversations, and at times, reacts to them with a laugh or babble as he is joining the conversation. If you repeat what was just said , he will babble again and laugh. And will repeat 3 or 4 times.  
When playing,tossing ball, throwing frizbee etc., he will throw it but not put his hands out to catch. When we play a game of pool for example, when a shot is made or a ball hit he will clap his hands and  say ADEEEE and will repeat for a whole rack of balls. Even when grandpa says after each shot "no, thats good shot grandpa", he will repeat adeeee and clap his hands. Seems as he is aware of things around him, not in his own world. Recognizes faces, places, looks you in the eye as he speaks.
In times of frustration he will bang his head on the floor or wall or hit himself in the head with his hand.
He has started one day a week of daycare. We had an incident of him hitting a boy in the head with a stick. Wants to take them down and wrestle. likes to WAY rough and tumble play.  Has great coordination ie.  stood on an excersize ball to reach a toy.  Very trusting ie will jump from furniture to your arms, even when you might not be ready for it.
Have started speech therapy for past 2mo. No difference seen in speech.  Considering neurologist evaluation.
Could this regressive characteristics be related to the flu vaccination he recieved at 1 1/2 years old?
What should he be tested for?
Has been tested for lead with neg results.  history  ADD,father side,  depression,mother side.  on the throwing of balls and stuff he does to appear to be accurate in his tosses.  very much so..   isnt at all doing the 'one on one' interaction one would expect.  as in starting conversations other that the babble with the hahahaha.

[Kevin Kennedy, Ph.D.]

It would be useful to find out if the vaccination he received contained the preservative Thimerosal. This is an agent that contains mercury and some suspect that it plays a role in the development of conditons along the Pervasive Developmental Disorder spectrum. So the correlation between your grandson's symptoms and the immunization can't be dismissed out of hand. There are some children who talk rather late in their development, but the worriosme aspect of your grandson's situation is the interruption in his speech/language development and the plateau he seems to have reached. An evalutation by a developmental pediatrician would be a good idea. By the way, a one-day-a-week exposure to daycare is not such a good thing. It doesn't permit enough time for this to become part of his structure. My advice would be either to stop the one-day plan or, preferable, increase it to at least three days.

[sarahot]

When you say one-on-one interaction, do you mean interacting with others including those his age? Sounds like his motor planning is great. Neurology consult and O.T. evaluation might be a good idea.

[TennesseeJed]

'1 on 1' interaction is when he is  interacting with just 1 person and repeating eeyaaaiii  ..... 0ver and over

[TennesseeJed]

also he has ABSOLUTELY no interaction with kids.  that is why gramma and grampa suggested a day a week of day care.  the other 2-3 days, daycare is done by gramma and as we  live out of town.....    we appreciate the response  and will inform the kids as to the suggestions we received.  (c:

[babeangel]

My two yr old doesn't meet average talking on the scale either. He was tested for autism, hearing problems/loss, speech imptetement, etc. He does need speech therapy, however. Tell your children to see an ENT doctor to check for hearing and/or ear problems first, then speak to pediatrician concerning speech and language progression. He can give you an estimate  of how many words he speaks, etc. This will help your children and you feel more comfortable in knowing what the real problem is. Good luck!

[sunflowerhappyme]

My daughter who is turning 2 in Jan is not talking at all, never has.  She understands what I say to a certain extent. Like when I sing her barney, she immediately comes and hugs me. When I sing the wheels on the bus, she goes through the motions without me having to prompt her. When I sing are youhappy and you know it, clap your hands, she does.  I asked my family doctor about it a couple of weeks ago and she said I have to make her talk. If she wants juice, make her say juice , or don't give it to her. I cant stand the idea of that. My daughter has never even mumbled juice, so how do i know she can speak it.  i am very worried. I think I am going to ask my family doctor to refer me to an ENT doctor because I feel like she should be talking by now. You can barely make out her saying dada and sometimes she will mutter mama, but that is it.