 Despite this being an extremely rare disease, there are 4 registries collecting data on the illness; two are the United States, one in Germany, and one in Portugal.Susac's syndrome is named for Dr. John Susac (1940–2012), of Winter Haven, Florida, who first described it in 1979.Susac's syndrome is a very rare disease, of unknown cause, and many persons who experience it do not display the bizarre symptoms named here.