title: Progression of non-age-related callosal brain atrophy in multiple sclerosis: a 9-year longitudinal MRI study representing four decades of disease development.
abstract: BACKGROUND
  In multiple sclerosis (MS), multiple periventricular lesions are commonly the first findings on MRI. However, most of these MS lesions are clinically silent. The brain atrophy rate has shown better correlation to physical disability, but it is not clear how atrophy develops over decades. Corpus callosum forms the roof of the third and lateral ventricles. The corpus callosum area (CCA) in a midsagittal image is age independent in a normal adult population up to the seventh decade; therefore it can be used as a marker for non-age-related, pathological brain atrophy.
  
  
  OBJECTIVE
  To investigate whether and how CCA decreases in size over time in patients with MS.
  
  
  METHODS
  In a clinical observational study, 37 patients with MS with a wide range of disease duration at baseline (1-33 years) were followed. Three different MS courses were represented. The mean of individual MRI follow-up was 9 years. Multiple sclerosis severity score (MSSS) was also applied to evaluate disability at baseline and after 9 years of follow-up.
  
  
  RESULTS
  A significant decrease in CCA over 9 years (p<0.001) and a persisting association between CCA and the disability status were found. The atrophy rate was similar ever four decades of MS for all MS courses. The mean annual CCA decrease was 9.25 mm2 (1.8%). Surprisingly, atrophy rate did not correlate with sex, disease duration, age at MS onset or MS course.
  
  
  CONCLUSIONS
  Serial evaluations of CCA might be a robust method in monitoring a non-age-related decrease in CCA, reflecting progression of irreversible destructive changes in MS.
authors.affiliation: Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden. juha.martola@ki.se
authors.forename: Juha
authors.initials: J
authors.lastname: Martola
authors.forename: Leszek
authors.initials: L
authors.lastname: Stawiarz
authors.forename: Sten
authors.initials: S
authors.lastname: Fredrikson
authors.forename: Jan
authors.initials: J
authors.lastname: Hillert
authors.forename: Jakob
authors.initials: J
authors.lastname: Bergström
authors.forename: Olof
authors.initials: O
authors.lastname: Flodmark
authors.forename: Maria
authors.initials: M
authors.lastname: Kristoffersen Wiberg
mesh_terms: D000328:Adult; D000375:Aging; D001284:Atrophy; D001927:Brain Diseases / Q000209:etiology*; D003337:Corpus Callosum / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications*