title: Use of the Modified Rankin Scale to assess outcome after arteriovenous malformation radiosurgery.
abstract: OBJECTIVE
  To present the results of arteriovenous malformation (AVM) radiosurgery using the Modified Rankin Scale (MRS) as the primary outcome measure and to analyze whether previous AVM rupture or other factors have an effect on outcomes after AVM radiosurgery.
  
  
  METHODS
  We reviewed outcomes after AVM radiosurgery for 243 patients from 1990 and 2001. The mean follow-up after radiosurgery was 65 months.
  
  
  RESULTS
  Forty-one patients (17%) sustained a decline in MRS (median -2) after AVM radiosurgery. We noted a decline in MRS in 4% of patients 1 year after radiosurgery, 8% of patients at 3 years after radiosurgery, and 15% of patients at 7 years after radiosurgery. The radiosurgery-based AVM score correlated with a decline in MRS after AVM radiosurgery in multivariate testing (odds ratio 2.1; 95% CI 1.2 to 3.6; p < 0.01).
  
  
  CONCLUSIONS
  Previous AVM rupture did not influence neurologic deterioration after AVM radiosurgery. The radiosurgery-based AVM score predicted the chance of a worse MRS after radiosurgery.
authors.affiliation: Department of Neurological Surgery, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA. pollock.bruce@mayo.edu
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Pollock
authors.forename: Robert D
authors.initials: RD
authors.lastname: Brown
mesh_terms: D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000098:blood supply / Q000473:pathology / Q000601:surgery*; D002536:Cerebral Arteries / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D002550:Cerebral Veins / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D002648:Child; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D020300:Intracranial Hemorrhages / Q000209:etiology / Q000517:prevention & control / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination / Q000592:standards; D010043:Outcome and Process Assessment, Health Care / Q000379:methods*; D016634:Radiosurgery / Q000009:adverse effects* / Q000592:standards / Q000706:statistics & numerical data; D016896:Treatment Outcome