Recent development of a non-invasive MR examination has increased the opportunity to identify asymptomatic patients with moyamoya disease who have experienced no stroke episodes. However, their clinical features, prognosis, and treatment strategy are still unclear. Therefore, we have designed Asymptomatic Moyamoya Registry (AMORE) Study in Japan.

     The objectives of this nation-wide, multi-center prospective study are to clarify long-term prognosis of asymptomatic patients with moyamoya disease and to determine the risk factors to cause ischemic and hemorrhagic stroke in them.

     In this study, all consecutive patients diagnosed as asymptomatic moyamoya disease between January 2012 and December 2014 are registered.

     AMORE Study is conducted in Japan, using a multicenter prospective observational design. The AMORE Study Group is composed of 16 Japanese neurosurgery/neurology centers. In addition to MRI/MRA, cerebral blood flow and its reactivity to acetazolamide must be quantitatively measured. They are followed up at outpatient clinic for at least 5 years after enrollment. MR imaging and angiography are repeated every year during follow-up period.

     The following items constitute the primary end point: TIA, ischemic or hemorrhagic stroke, or extracranial-intracranial (EC-IC) bypass surgery as decided by the participating neurologists or neurosurgeons. The following items constitute the secondary end point: radiological occurrence of silent cerebral infarction, silent intracranial bleeding, or silent disease progression; all death or adverse events.

     This was a prospective registry of non-randomized subjects.

     In this conference, we emphasize the importance to determine the prognosis of asymptomatic moyamoya disease. 

     We also present the precise protocol of AMORE Study.