PLEASE HELP! What does "prominence of anterior extra axial space" mean?!?!?!

I am wanting to know if there is anyone out there who has dealt with this before... I am in need of some kind of information and all I can find is abstracts from medical journals and what looks to be "student" material for radiologists?!?!?! My son was referred to have a head CT when our pediatrician thought his head (which along with the rest of him has been off the charts since he was born despite the fact that he was almost five weeks early) circumference had increased more quickly than it should have between his 4 and 6 month well baby visits. Initially they wanted to rule out extra fluid by checking the ventricles to ensure everything was in working order however when we got the results back I was told that the pediatrician couldn't give me any information other than the fact that he wasn't sure what this entailed and had to call the radiologist himself to have them interpret the report and that he was directed by them to refer us to a neurosurgeon. The report stated: prominence of anterior extra axial space. As I stated before I cannot find any information that will even help put my mind to rest for the next few days while I wait for the neurosurgeons consultation and find out the "further tests" they want to have done. I just need to know SOMETHING... possible causes, possible treatments, just how bad is this?!?!?!?! I would feel so much more at ease if I only had something to go on even if it is not good news. We wanted for so long for this "miracle baby" that I cannot imagine this is actually happening...