? of TIA in my 7 year old

I have a 7 year old son who has had open heart surgery ( VSD and ASD repair) he has been having issues on and off for 6 years of light head, passed out once and close to at other times...He was just diagnosed with neurofibromatosis (a genetic disorder where tumors can grow on the nerves of your body I have this) any way  his fine motor skills are declining per school.. he gets numb from waist down and at schoo has fallen out of his chair due to this...(he has never had any behavior issues at school at all so it isn't as if he is doing this for attention) at the doctors 10 days ago (his neurologist wanted his PCP to evaluate him) so he, my son, said that he was numb in both legs and arms more numb on the right side.. the doctor had to put more pressure on the right side of his body in order for him to feel it and this was with a sharp object she used. she did document it also.. now a week ago he complained his "lungs" felt heavy and he felt as if he was having a hard tie breathing (he looked and sounded fine) plus he had a headache (also gets migranes (migraines) thanks to the NF) so I gave him a neb treatment (in case he was heading for trouble) and tylenol he said he was numb mor so on his right side. after 45 minutes later i went to check on him (he was camping in his brothers room on the floor like a leantoo.. (corry for the spelling error) so I notice he pulled himself out on his left elbow, and pulled himself up using a char (didn't think too much of it) he was bearing weight on his left leg however that leg was shaking so badly and his right leg was up in the air.. I told him to come on lets go out in the living room so I can check you over... he went to step and didn't even move his right leg. I said come on buddy you can walk  "can't" is all he could say.. I told him to try again and he tried, but same thing and "can't"
I carried him out and checked on him and after about 5 mintues (not quite taht long) I brought him to his room and put him down at his dorr and told him to hop into bed nothing,,, same thing as before... so I pluncked hi into bed...they are questioning a TIA? so if that is true why isn't he getting into his neurologist for another week... I am so scared and trying not to show him I am... My husband (dad ( is too) we try not to show him or his brothers how scared we are.. last night he said mom what if I cant walk or talk again... I told him not to worry it mightnot happen again and we will go see a doctor if it happenes again it isn't a big deal he said it scared him so much that he couldn't talk