With what you have shared, the first thing I would want to rule out is vision with a Developmental Optometrist (
www.covd.org). It took me awhile to understand that this was not the same as whether he has 20/20 vision and not something a regular optometrist can do.
The second thing I would want is a private eval for Dysgraphia with tests such as TOWL (Test of Written Language). Has your OT done a Beery VMI? Does he have sensory issues? I ask because of the "balance and motion" dysfunction.
The 40pt spread between PSI and PRI is big. Over 2 standard deviations. There have been threads here recently about low processing. We are living that and have learned a lot here regarding how that impacts our DS6.
