title: Structural sex differences at disease onset in multiple sclerosis patients.
abstract: BACKGROUND
  Male sex is associated with worsening disability and a more rapid progression of multiple sclerosis (MS). This study analysed structural sex differences in magnetic resonance images of the brain, comparing women whose disease started before and after the menopause with a control group of men.
  
  
  METHODS
  This was a case control study in which female patients whose MS started before (Group 1) and after (Group 2) the menopause were included. The control group was matched by age, disease duration, Expanded Disability Status Scale and disease-modifying treatment. Patients were analysed according to demographic and clinical variables, as well as in terms of radiological measurements at disease onset and during the first 12 months of follow-up. These measurements included normalised total brain volume (NTBV), normalised cortical volume (NCV), normalised white matter volume, left and right hippocampus, the thalamus, brain stem volume, lesion load and percentage brain volume change. A linear regression model was used to analyse the data.
  
  
  RESULTS
  A total of 97 patients were included: 53 in Group 1 (27 females) and 44 in Group 2 (22 females). In Group 1, we observed a reduction in brain volume in males compared with females at disease onset in NTBV (p = 0.01), NCV (p = 0.001) and brain stem volume (p = 0.01). We did not observe differences in Group 2 at disease onset in the brain volumes analysed.
  
  
  CONCLUSIONS
  We observed structural sex differences in brain volume at disease onset in the pre-menopausal group. However, no structural differences were observed at disease onset between the sexes after the menopause had started.
authors: MS Center of Buenos Aires, Italian Hospital of Buenos Aires, Argentina juan.rojas@hospitalitaliano.org.ar.
authors: Juan Ignacio
authors: JI
authors: Rojas
authors: MS Center of Buenos Aires, Italian Hospital of Buenos Aires, Argentina.
authors: Francisco
authors: F
authors: Sánchez
authors: MS Center of Buenos Aires, Italian Hospital of Buenos Aires, Argentina.
authors: Liliana
authors: L
authors: Patrucco
authors: MS Center of Buenos Aires, Italian Hospital of Buenos Aires, Argentina.
authors: Jimena
authors: J
authors: Miguez
authors: Neuroradiology Department, Italian Hospital of Buenos Aires, Argentina.
authors: Jorge
authors: J
authors: Funes
authors: MS Center of Buenos Aires, Italian Hospital of Buenos Aires, Argentina.
authors: Edgardo
authors: E
authors: Cristiano
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology*; D012189:Retrospective Studies; D012727:Sex Characteristics; D018709:Statistics, Nonparametric
keywords: Multiple sclerosis; sex differences; structural