After police pulled over a woman driving across the Golden Gate Bridge in a way they thought was influenced by alcohol, doctors later discovered that her behavior was driven by a hemorrhage in her brain, initially thought to be caused by an arterial venous malformation (AVM), another form of vascular disruption.

"When we looked closer," Steinberg said, "we discovered that it was not the AVM causing the bleeding but Moyamoya-affected vessels near the AVM." That patient lead to others and one of those early patients created a website on the condition to alert others. "Our patients have been a great source of increasing awareness and support to each other," Steinberg said.