He hasn't had any other testing done except a reading and writing achievment test (4 years above his age in reading, and pretty much age level in writing). He also had a test for auditory processing, which didn't show a disorder in this area (although I have noted that he has trouble locating sounds and often doesn't seem to hear me when I talk).
He has some sensory processing issues, that seem to have gotten better with age. He still seems to have some trouble regulating his level of arousal. He is low key and somewhat lethargic much of the time.
The psychologist who did the testing suggested NVLD, but I'm not so sure. He has no trouble organizing his thoughts on paper, has excellent reading comprehension and a great sense of humour.