Hello & welcome! So glad you found us.
I feel so bad for you and your son. Poor little guy having to go through so much in such a small time here.

But don't despair!
I really only have two comments/suggestions.
First suggestion is to contact via e-mail or phone Dr. Scott in Boston. You can find his info on this site under "surgeons". He is known to be an awesome pediatric neurosurgen with a high expertise in MoyaMoya. Many people on this board have had wonderful experiences with him.
Or, contact Dr. Steinberg in California- equally wonderful.
Or one of the other doctors on this board that people have had good experience with. All of them have a reputation of responding to e-mails very quickly and giving second opinions if you send films/test results to them. I didn't get a chance to see where you live and which is closer to you. Regardless, the thing your son needs most right now is a surgeon
experienced with MM! You'll find that everyone here can't stress that enough. Experience, experience, experience.
Secondly, you will find on this board that once diagnosed with MoyaMoya, and especially after having a stroke, waiting for surgery isn't a good thing. This is a progressive disease, there is no medication or any other remedy but surgery. Strokes will continue to occur. Although, I must say that your son's SPECT scan results sound promising. What are they basing the possible MM diagnosis on? Did they do an MRI/MRA? Angiogram?
Hang in there and know you are not alone!
Lisa
P.S. I'm sure more people, especially those whose children have MM, will post a lot more but the board is slow right now because of the holiday.