title: Disease course and prognostic factors of progressive muscular atrophy.
abstract: OBJECTIVE
  To investigate the natural history and prognostic factors in patients with nonhereditary, adult-onset progressive muscular atrophy.
  
  
  METHODS
  Inception cohort conducted for 18 months. Settings Three university hospitals in the Netherlands (referral centers for neuromuscular diseases). Patients Thirty-seven consecutive patients newly diagnosed (onset of weakness <4 years) with progressive muscular atrophy enrolled between 1998 and 2001.
  
  
  METHODS
  Disease progression was measured at 0, 3, 6, 9, 12, 15, and 18 months by the Medical Research Council sum score, number of affected limb regions, and the Amyotrophic Lateral Sclerosis Functional Rating Scale score. Multivariate linear regression analysis was used to identify predictors of poor outcome. Clinical features and classification of phenotype during follow-up were evaluated. Survival analysis was planned after data collection, performed 5 years after the end of the study.
  
  
  RESULTS
  Significant decline of muscle strength (mean, 6.01 Medical Research Council sum score points [95% confidence interval [CI], 3.84-8.18]; P value <.001) and significant increase in the number of affected regions (mean, 0.53 affected region [95% CI, 0.42-0.65]; P value <.001) and functional impairment (mean, 1.85 Amyotrophic Lateral Sclerosis Functional Rating Scale score points [95% CI, 1.38-2.33]; P value <.001) were found. Vital capacity (VC) at baseline and decrease of VC during the first 6 months were significantly associated with outcome. Median survival duration after initial weakness was 56 months.
  
  
  CONCLUSIONS
  This study shows that patients with progressive muscular atrophy have a relentlessly progressive disease course. Patients with a low VC at baseline and a sharp decline of VC during the first 6 months have an especially poor prognosis.
authors.affiliation: Department of Neurology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands. j.visser@amc.uva.nl
authors.forename: Jeldican
authors.initials: J
authors.lastname: Visser
authors.forename: Renske M
authors.initials: RM
authors.lastname: van den Berg-Vos
authors.forename: Hessel
authors.initials: H
authors.lastname: Franssen
authors.forename: Leonard H
authors.initials: LH
authors.lastname: van den Berg
authors.forename: John H
authors.initials: JH
authors.lastname: Wokke
authors.forename: J M Vianney
authors.initials: JM
authors.lastname: de Jong
authors.forename: Rebecca
authors.initials: R
authors.lastname: Holman
authors.forename: Rob J
authors.initials: RJ
authors.lastname: de Haan
authors.forename: Marianne
authors.initials: M
authors.lastname: de Visser
mesh_terms: D000328:Adult; D000368:Aged; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006785:Hospitals, University; D006801:Humans; D053208:Kaplan-Meier Estimate; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D053580:Muscle Strength / Q000502:physiology; D018908:Muscle Weakness / Q000503:physiopathology; D009133:Muscular Atrophy / Q000473:pathology* / Q000503:physiopathology*; D009426:Netherlands; D011379:Prognosis; D013997:Time Factors