title: Metabolic changes in the visual cortex are linked to retinal nerve fiber layer thinning in multiple sclerosis.
abstract: OBJECTIVE
  To investigate the damage to the retinal nerve fiber layer as part of the anterior visual pathway as well as an impairment of the neuronal and axonal integrity in the visual cortex as part of the posterior visual pathway with complementary neuroimaging techniques, and to correlate our results to patients' clinical symptoms concerning the visual pathway.
  
  
  METHODS
  Survey of 86 patients with relapsing-remitting multiple sclerosis that were subjected to retinal nerve fiber layer thickness (RNFLT) measurement by optical coherence tomography, to a routine MRI scan including the calculation of the brain parenchymal fraction (BPF), and to magnetic resonance spectroscopy at 3 tesla, quantifying N-acetyl aspartate (NAA) concentrations in the visual cortex and normal-appearing white matter.
  
  
  RESULTS
  RNFLT correlated significantly with BPF and visual cortex NAA, but not with normal-appearing white matter NAA. This was connected with the patients' history of a previous optic neuritis. In a combined model, both BPF and visual cortex NAA were independently associated with RNFLT.
  
  
  CONCLUSIONS
  Our data suggest the existence of functional pathway-specific damage patterns exceeding global neurodegeneration. They suggest a strong interrelationship between damage to the anterior and the posterior visual pathway.
authors.affiliation: NeuroCure Clinical Research Center, Charité Universitaetsmedizin Berlin, Berlin, Germany. caspar.pfueller@charite.de
authors.forename: Caspar F
authors.initials: CF
authors.lastname: Pfueller
authors.forename: Alexander U
authors.initials: AU
authors.lastname: Brandt
authors.forename: Florian
authors.initials: F
authors.lastname: Schubert
authors.forename: Markus
authors.initials: M
authors.lastname: Bock
authors.forename: Bernadeta
authors.initials: B
authors.lastname: Walaszek
authors.forename: Helmar
authors.initials: H
authors.lastname: Waiczies
authors.forename: Thomas
authors.initials: T
authors.lastname: Schwenteck
authors.forename: Jan
authors.initials: J
authors.lastname: Dörr
authors.forename: Judith
authors.initials: J
authors.lastname: Bellmann-Strobl
authors.forename: Christian
authors.initials: C
authors.lastname: Mohr
authors.forename: Nicholetta
authors.initials: N
authors.lastname: Weinges-Evers
authors.forename: Bernd
authors.initials: B
authors.lastname: Ittermann
authors.forename: Jens T
authors.initials: JT
authors.lastname: Wuerfel
authors.forename: Friedemann
authors.initials: F
authors.lastname: Paul
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000473:pathology; D003710:Demography; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D015233:Models, Statistical; D009103:Multiple Sclerosis / Q000378:metabolism* / Q000473:pathology*; D009412:Nerve Fibers / Q000378:metabolism* / Q000473:pathology*; D012160:Retina / Q000378:metabolism* / Q000473:pathology*; D014793:Visual Cortex / Q000378:metabolism* / Q000473:pathology; D055815:Young Adult
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate