title: Proposal for a new grading of Moyamoya disease in adult patients.
abstract: BACKGROUND
  Moyamoya disease (MMD) is graded based on digital subtraction angiography (DSA) with limited clinical applications. The aim was to identify clinically relevant parameters that may be used to develop a novel MMD grading system.
  
  
  METHODS
  In 40 MMD patients bilateral revascularization surgery was performed. Clinical data including DSA, MRI and regional cerebral blood flow studies were assessed. χ(2) test corrected for dependency of measurements at the same subject and analysis of receiver operating characteristics were used to identify key parameters. Grading system included: DSA (stenosis/occlusion = 1 point; stenosis/occlusion + intracranial compensation = 2 points; stenosis/occlusion + intracranial compensation + extra-intracranial compensation = 3 points), MRI (no sign of ischemia = 0 points; signs of ischemia = 1 point) and cerebrovascular reserve capacity (CVRC > -5% = 0 points; CVRC < -5% = 2 points). MMD grade I referred to 1-2 points, grade II to 3-4 and grade III to 5-6 points.
  
  
  RESULTS
  DSA, MRI and CVRC were dependent factors associated with the occurrence of clinical symptoms. Receiver operating characteristics analysis indentified the grading system as superior to each single parameter in predicting clinical symptoms. Fourteen hemispheres were graded as mild (grade I), 35 as moderate (grade II) and 31 as severe (grade III); 21% of grade I, 63% of grade II and 93% of grade III hemispheres were clinically symptomatic.
  
  
  CONCLUSIONS
  The proposed grading system allows to stratify for clinical symptomatology in MMD patients. Future studies will have to investigate its value for assessing clinical symptoms and treatment risks.
authors.affiliation: Department of Neurosurgery, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Czabanka
authors.forename: P
authors.initials: P
authors.lastname: Peña-Tapia
authors.forename: G A
authors.initials: GA
authors.lastname: Schubert
authors.forename: F L
authors.initials: FL
authors.lastname: Heppner
authors.forename: P
authors.initials: P
authors.lastname: Martus
authors.forename: P
authors.initials: P
authors.lastname: Horn
authors.forename: P
authors.initials: P
authors.lastname: Schmiedek
authors.forename: P
authors.initials: P
authors.lastname: Vajkoczy
mesh_terms: D000328:Adult; D015901:Angiography, Digital Subtraction / Q000379:methods*; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D003097:Collateral Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009072:Moyamoya Disease / Q000145:classification* / Q000175:diagnosis*; D012372:ROC Curve; D014057:Tomography, X-Ray Computed