Due to the incidental nature of RIS, exact figures on prevalence is unknown, though it has been suggested that RIS is the most common type of asymptomatic MS. The prevalence may be higher in relatives of patients with MS. One study, at a university hospital that is located in a high region of MS disease incidence, put the disease prevalence at approximately 1 in 2000. An earlier study in 1961 of 15,644 autopsies found 12 cases (0.08%) of unexpected MS findings without a previous history of MS symptoms. The mean age of first indication of RIS from 451 patients is 37.2 years.
Radiologically isolated syndrome
Overlap syndrome
Polymyalgia rheumatica
Decompression sickness
Complex regional pain syndrome
Edwards syndrome
Unstable angina
Uremic pericarditis