Preliminary Studies on the Clinical Features of Multiple Sclerosis in Korea

BACKGROUND AND PURPOSE: Multiple sclerosis (MS) in Asians is characterized by frequent involvement of the spinal cord and optic nerve and low prevalence rates, but even the most fundamental epidemiologic findings and unique clinical features of MS patients in Korea have not been studied extensively. We performed this study to establish the clinical spectrum of MS patients in Korea. METHODS: Sixty-two MS patients (25 men and 37 women) who satisfied the diagnostic criteria for definite MS were reviewed retrospectively using medical records from two university hospitals and one general hospital. The MS patients were classified into the three clinical subtypes according to the involved site (opticospinal, spinal, and conventional MS). RESULTS: The age at MS onset was 35.2±13.3 (mean±SD) years, and the predominant initial clinical manifestations were myelopathy (54.8%) and optic neuropathy (33.9%). The single most common involved lesion site was the spinal cord (35.5%). Spinal (35.5%) and opticospinal (25.8%) MS were the most common type, and they had a frequent relapsing-remitting course and long lesions extending over two vertebral segments (as assessed using spinal cord MRI). The interval between the first symptom and relapse was 35.6±71.1 months, and the number of relapses was 3.8±2.6. The spinal form of MS was associated with a higher age at onset and a higher male-to-female ratio than the other types. Positive rates of CSF oligoclonal bands and IgG index and the number of patients with characteristic brain MRI lesions were low. However, the abnormal rate of visual evoked potentials was relatively high (64.4%). CONCLUSION: The clinical features of MS patients in Korea are different from those in Western patients, but similar to those in Far East Asian patients. The value of the various diagnostic tools used for MS should therefore be reevaluated, at least for Korean patients.