No one really knows that right now, as CADASIL is often
misdiagnosed or NOT diagnosed. It is genetic, so a genetic blood
test will tell you if you have this serious degenerative
condition.
I attended the first-ever CADASIL conference in the USA in July
in DeKalb, Illinois, put on by the ULF (United Leukodystrophy
Foundation) and TWHH (CADASIL Together We Have Hope). Of the
approx. 50 CADASIL patients who attended, about half raised their
hands when asked if they had been misdiagnosed as having MS
(Multiple Sclerosis) first.
When I was diagnosed in the fall of 2009, less than 500 people
in the USA and 1000 in the world had also been diagnosed with
CADASIL. That number is growing daily, as more people are made
aware of this genetic disease and are tested.