Seasonal distribution and evolving forms of multiple sclerosis patients diagnosed from April 2004 to November 2007.

Background: Multiple sclerosis (MS) was first reported in Cuba in 1965. The most frequent appearance is observed in the first six months of the year.

Objective: To determine the seasonal distribution and evolving forms of MS patients diagnosed with the disease between April 2004 and November 2007.

Method: Twenty-one patients with suspected MS and 42 outbreaks were studied. Patients were classified according to Lublin and Revingold's criteria for clinical forms and according to McDonald.

Results: Most patients were classified in outbreak and remission and only two patients classified as primary-progressive multiple sclerosis. The higher number of outbreaks occurred in the first two quarters of the year.

Conclusion: It is recommended to study further weather variables that may be related to the emergence of these outbreaks in our environment.