I was diagnosed with MMD (bilateral) and had direct (EC-IC) bypass surgery on the left-side in August of this year. I am worried about the other side.

I have never had any "symptoms" on the other side. The surgeons here generally suggest monitoring the other side for symptoms and then decide whether to undergo surgery.

I know that MMD is a progressive disease. I read that people with MMS often develop MM vessels after they receive surgery on one side.

I'm currently residing in Korea and don't know what the process is like in other countries. Can someone inform me? Also, does anyone know of bilateral MMD patients who only need surgery on one side? Or will the other side progress further (resulting in TIAs and strokes) as I get older?   

Thanks in advance.

i'm unsure about adult onset moyamoya, but with bilateral in children, there appears to be much support for surgery on both sides

can you contact one of the respected clinics in Japan or the U.S. and seek second, third opinions?

good luck!

this is good advice from Heath.  Better to find out now if you can, than w/ a stroke later.
Best wishes...keep us posted on your progress!

I am in the same situation.  The neurosurgeon explained that even though the stenosis has started on the other side they can not do a bypass until there is actual blockage.  In my case I have the 6th month follow up after surgery, and then will be checked once a year to watch the progression of my left side.  You will get warning signs, hopefully, before a major stroke.  If you get tingling and numbness I should think that will be a sign; unfortunately that also means t.i.a's will be occuring in all likelihood.  But I had those for 3 years before I had a stroke so I suspect that means you'll have plenty of time, just don't ignore the signs.  I hope that helps. 

Yeah, don't ignore the signs.  make sure your family, close friends, co-workers, etc also know the signs.  My son was too young to know & tell us anything (we didn't know either), but I remember him complaining about the sun hurting his eyes. other than the couple of migraines a few months before, we had no other cues that he was about to have a stroke.

My daughter had her first surgery with Dr Steinberg in April of 2008.  At that time we were told she was only 50% blocked on the left side and we did CT Angio's each year.  It was in November of 2010, 2 1/2 years later before she had the second surgery.  So each one is different and it sometimes does require you to wait until the time is right.  Good luck and keep us informed as to how things are going.
Margaret