Multiple sclerosis in Korea: Clinical features and prevalence

Abstract

In the only neurologic department of Korea, there were 59 patients seen among some 10,000 admissions between 1958 and 1966 in whom the diagnosis of multiple sclerosis (MS) was entertained. Of these, 22 were classed as such, 22 as possible cases (mostly localized myelopathies), and 15 as unlikely multiple sclerosis cases. The 22 cases of multiple sclerosis (15 male, 7 female) had an average age of onset of 25.8 years and were diagnosed an average of 4.4 years later. Principal complaints at onset were impaired vision, weakness of the limbs, and paresthesiae; sphincter disturbances and incoordination were also relatively frequent. When admitted to hospital, most patients showed evidence of pyramidal tract involvement, and about half had either visual, cerebellar, or sensory disturbances. The frequency of multiple sclerosis among neurologic admissions to hospital is about 0.2% in Korea, Japan, China, India, Iraq, and Indonesia. In contrast, rates from New York and London of 40 years ago were of the order of 3–11%. An estimate of the prevalence of multiple sclerosis in cases per 100,000 general population can be obtained from the ratio of cases of MS/ALS seen in a given place over a given time, since the world-wide prevalence of amyotrophic lateral sclerosis (ALS) is close to 4 100,000 (excepting the isolates of Guam). In this fashion we estimate the prevalence of multiple sclerosis in Korea to be about 2 100,000 population ( 22 37 × 4 100,000 ). Similar estimates for India and Japan were also near 2 100,000 , and the latter was validated with the similar rate found in a direct prevalence study. Also with this method, a rate of about 40 100,000 was estimated for a Pennsylvania hospital, in accord with expectation.