I've had seen one as kid, did EEG. They found slightly underdeveloped cerebellum if I can remember, but ofc might be wrong, since as a child i didn't fully follow their instructions (it's pretty hard to stay still and not really think about anything). The reason why we had done that is because I hit my head heavily when I was 6 yo, and at that time we thought that had some effect on my speach. I think I was 12 when I had EEG.