Eric,
Hope this finds your son doing well. I know it is quite frightening to learn of such a thing happening to your young son.
Mine was a little over 3 1/2 when he had a left-hemisphere stroke that got our attention. Tests showed evidence of prior damage - we will never know when/how much. But he is now 19 1/2 yrs, an Eagle Scout and a sophmore at Tx A&M in Galveston. His SAT scores were above National avg. Yes, he did have many years of therapy, though only the first 6 months were frequent, after that, 2 x week for speech thru 2nd gr, 1 x for occupational thru 6th gr. He did get special services for reading & writing, but in hindsight, I wish we had just hired private tutors and kept him in regular classes all day - sadly, children can be cruel even in K.
The effects of stroke & MM can be very different for each pt., but I think you will find he will do fine. I highly recommend having him tested before pre-K age to see if he is on target with skills. Your school district may have an early education program you could enroll him in (free) to help in recovery with language and physical skills b4 he starts K if its needed. Talk with his neurologist/pediatrician for advice on this - the sooner therapy begins, the better the recovery.
wishing you all the best - and God's blessings!
oh, almost forgot - he only takes 1/2 baby aspirin. he was on meds for migraines for several yrs, but off this yr - so far OK; BP was a problem during puberty due to kidneys being smaller than normal b/c of reduced blood flow with MM, but off meds for that, too. he was dx'd with attention issues (not complete ADD dx) and is supposed to take meds for that (not methamphetamines) but he is not too good about remembering to take those while in colleg.
Note that attention difficulties are NOT uncommon with any brain injury so maybe keep a watch, learn what you can do to help with behavior mod's that might keep him off meds.
The best advice I can give you (other than trying to learn as much as you can - and you've already started that!
) is just encourage him to try whatever he is interested in - he may not be the best baseball (or whatever) player, but, hey, how many really are? the important thing is to try and just keep trying and enjoy all life has to offer! recovery is done one brain cell at a time and there are lots of them - but he is young and has lots of time.