title: Mediterranean weather conditions and exacerbations of multiple sclerosis.
abstract: BACKGROUND
  Previous studies provide increasing support for the impact of environmental factors on disease incidence and activity in multiple sclerosis (MS).
  
  
  OBJECTIVE
  The purpose of this research was to assess the relationship between the incidence of MS relapses and weather conditions in Israel.
  
  
  METHODS
  Clinical data, including occurrence of relapses in 235 patients, during 3 consecutive years (2001-2003) were assessed against the general daily meteorological variables. Initially, the relationship between the relapses and their mode of distribution was evaluated. Second, the relationship between the number of relapses on a specific date and the meteorological variables was assessed. Third, the tendency to seasonality in the occurrence of relapses was examined.
  
  
  RESULTS
  No significant correlation was found between the number of relapses and a specific season, month or day. Moreover, no clear relationship was found between certain meteorological variables or a combination of variables and the frequency of the relapses.
  
  
  CONCLUSIONS
  The meteorological parameters studied were not found to have a significant impact on the occurrence of relapses in this group of patients. These findings raise questions regarding the clinical significance of the impact of weather conditions, at least in the context of the Mediterranean climate, on the disease course of patients with MS.
authors.affiliation: Department of Geography and the Human Environment, Tel Aviv University, Tel Aviv, Israel. saaroni @ post.tau.ac.il
authors.forename: Hadas
authors.initials: H
authors.lastname: Saaroni
authors.forename: Amit
authors.initials: A
authors.lastname: Sigal
authors.forename: Izabella
authors.initials: I
authors.lastname: Lejbkowicz
authors.forename: Ariel
authors.initials: A
authors.lastname: Miller
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D005260:Female; D006801:Humans; D007557:Israel / Q000453:epidemiology; D008297:Male; D019083:Mediterranean Region / Q000453:epidemiology; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology* / Q000473:pathology; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000453:epidemiology / Q000473:pathology; D012008:Recurrence; D012621:Seasons; D014887:Weather; D055815:Young Adult