Understanding Primary Motor Stereotypies

Did you know that...

I'm a mother of a 20-month old who hand-flaps and grits his teeth when he's too excited.  It became most noticeable when he turned 18 months. For peace of mind, I had him assessed at 19 months (last month), but mostly for speech delay. We thought it was just that.  But the moment of truth came when my son failed all parts of the assessment. (PEDS, MCHAT, etc)

This had me looking into ASD, which I haven't entertained before. Dev't Pedia said he got a lot of Red Flags. It was a roller-coaster of emotion. I started my research on ASD since then (a month ago). But first & foremost, the changes that we had to do to see if his speech will improve.

Doctor's top of list:
1. NO TV! It sure helped a lot. Saw quick improvement in days.
2. Let him mingle with other children.  Since he's our first born, we were so overprotective and we didn't even notice that my son has no playmate for 1 1/2 years. Just us,all adults.

After a month of following the NO TV route and letting him play with other children, his speech greatly improved. As well as his social skills. He plays and reacts with other kids already unlike the past months which he was more responsive with adults. He's role-playing and following instructions already.
Note: he's a happy, warm and cuddly baby boy. He's got the most infectious smile and eyes that could penetrate your soul. Thus, I'd really like to rule out ASD.

However, with all the improvement, hand-flapping and teeth-gritting are still there when he gets overly excited. In my research for answers, this site: http://www.hopkinsmedicine.org/neurology_neurosurgery/specialty_areas/pediatric-neurology/conditions/motor-stereotypies/symptoms.html crossed my path.  Reading it helped me a lot to understand the repetitive movements that he's doing. I am also thankful to this site: http://www.sensory-processing-disorder.com/hand-flapping.html, because someone mentioned primary motor stereotypies.

He shows signs of improvement day by day.  Of course, we gave him attention twice as much. We're more sensitive now on how we react to him.  I don't have concrete answers for now. I just hope that he outgrows these involuntary movements in time or at least when he could express himself thru words already. My heart will always be hopeful and faithful...