An interesting early observation from the study has been the seemingly high frequency of Moyamoya disease in the population of potential candidates for this trial. The term Moyamoya is derived from the Japanese word for “puff of smoke” which is how the small weak vessels that develop to compensate for the constriction caused by this disease appear on angiography.
In Japan, which has the highest incidence, the disease is believed to be hereditary, but in North America it is being increasingly noted in women in their 30’s and 40’s and often is associated with recurrent stroke. It is postulated that this higher incidence in the U.S. might be due to a different underlying pathophysiology.
To better explore the incidence of Moyamoya and other vascular abnormalities, a recent modest change was made to the section of the EDC system where it asks for the reason a patient is considered a screen failure. Previously, vascular abnormalities were lumped in with infratentorial bleeds. Now, these two are split into separate categories and a “specify” box has been added to collect the specific type of vascular abnormality.