I am no help on the PANDAS... It was mentioned to me when I first noticed a tic and DS was also at the same time exhibiting uncharacteristic OCD-like behavior and expressed concern (just by a friend I was complaining to, who actually is an adult with OCD) but my DS has never had strep so I never looked into it. He's only had antibiotics once at 3 years old for the only ear infection he has ever had.