title: Clinicoepidemiological features of asymptomatic moyamoya disease in adult patients.
abstract: OBJECTIVE
  The aim of this study was to document the natural course of asymptomatic adult moyamoya disease (MMD) and the factors related to disease progression to aid in treatment decisions.
  
  
  METHODS
  Among 459 adult MMD patients (aged ≥ 20 years), 42 patients were included in this retrospective cohort study. Clinical records of adult asymptomatic MMD patients (n = 42) and follow-up data from September 2013 were reviewed to determine the factors related to disease progression.
  
  
  RESULTS
  The mean age of patients at the time of diagnosis was 41.2 years (range, 23-64 years), and the mean follow-up period was 37.3 months (range, 7.4-108.7 months). Of the 42 patients and 75 hemispheres, there were 12 patients (28.6%) and 13 hemispheres (17.3%) with disease progression. There were four hemispheres (5.3%) with symptomatic progression (three hemorrhage, one transient ischemic attack) and nine hemispheres (12.0%) with asymptomatic radiographic progression. There were no relationships with sex, diabetes, hypertension, thyroid disease, family history of MMD, or family history of stroke. However, reduced initial cerebrovascular reserve capacity was observed in seven hemispheres (9.3%) in patients with disease progression. A relationship was found between disease progression and initial cerebrovascular reserve capacity (p = 0.05). None of the patients underwent bypass surgery during the follow-up period.
  
  
  CONCLUSIONS
  It appears that asymptomatic adult MMD is not a permanent stable disease. In particular, reduced cerebrovascular reserve capacity is an indication of MMD progression, so close regular observation is needed.
authors.affiliation: Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Jeyul
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Neurosurgery, Suseong Metro Hospital, Taegu, Korea.
authors.forename: Joo Chul
authors.initials: JC
authors.lastname: Hong
authors.affiliation: Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Chang Wan
authors.initials: CW
authors.lastname: Oh
authors.affiliation: Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: O-Ki
authors.initials: OK
authors.lastname: Kwon
authors.affiliation: Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Gyojun
authors.initials: G
authors.lastname: Hwang
authors.affiliation: Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jeong Eun
authors.initials: JE
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea.
authors.forename: Hyun-Seung
authors.initials: HS
authors.lastname: Kang
authors.affiliation: Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea.
authors.forename: Won-Sang
authors.initials: WS
authors.lastname: Cho
authors.affiliation: Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Tackeun
authors.initials: T
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Jong Un
authors.initials: JU
authors.lastname: Moon
authors.affiliation: Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Seong Yeol
authors.initials: SY
authors.lastname: Ahn
authors.affiliation: Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Jun Hak
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Jae Seung
authors.identifier: 0000-0001-9543-8758
authors.initials: JS
authors.lastname: Bang
keywords: Asymptomatic disease; Cerebrovascular insufficiency; Moyamoya disease