It was missed on the first MRI when he was around 4. I was told it was a normal MRI. Then he fractured his skull, ended up in the hospital where the previous MRI had been done, and the neurosurgeon looked at that old scan. He said that it was "borderline" in terms of the measurements. A couple months after the brain injury we had a "quick MRI" done and it showed the same thing as the other one (now over a year later). The neurosurgeon said that it looked like there was fluid getting through and it was nothing that he would do surgery on. He wanted to do a full MRI with sedation but we refused, because we didn't see what it would show that the previous 2 MRIs didn't show and I didn't want my child with a brain injury to be sedated. DS complains about headaches, but they don't seem to be "chari" headaches. Usually they are on his forehead on one side of the head or the other. He makes random comments that he gets headaches on the right side of his head, but I'm not sure what that's all about. (he had a basillar skull fracture on the right side of his head and it caused paralysis of the sixth cranial nerve, leading to his right eye being "stuck" for months but it gradually regained function). I am not sure if this is something that progresses over time, or if what we are seeing on MRI now is what we will always see. That's one thing you could ask (if you want).