Objective The aim of this study was to analyze the clinical and laboratory features of each subtype of multiple sclerosis (MS) (relapsing-remitting, primary progressive, and secondary progressive) in the Tokyo metropolitan area.
Methods and Patients We retrospectively analyzed the medical records of 104 consecutive patients with a diagnosis of MS, who had been admitted to our university hospital from 1988 to 2002. They all met criteria for definite MS, by clinical or laboratory standards.
Results Eighty-four (80.8%) patients were classified as having relapsing-remitting MS, while 8 patients (7.7%) and 12 patients (11.5%) were classified as having primary progressive MS and secondary progressive MS, respectively. A significant female predominance existed in the relapse-remitting MS (female : male=2.4 : 1) cohort, but this ratio was 1 : 1 in both primary progressive and secondary progressive MS. The age at onset was older in the primary progressive MS (36.6±17.1 years of old) population than in either the relapsing-remitting MS (27.9±11.1) or the secondary progressive MS (27.8±11.5) subjects. Although the duration of illness was similar among the three types of MS, the number of exacerbations in the secondary progressive (5.9±4.6) cohort was significantly higher than that in the relapsing-remitting MS subjects (3.2±2.6). Patients with primary progressive MS showed a significantly higher rate of gait disturbance (87.5%) as the initial symptom than those with relapsing-remitting MS (23.8%), and this was thought to be due to the higher incidence of brainstem and spinal cord lesions. Visual disturbance as the initial symptom was frequently noted in those with secondary progressive MS (50.0%), while it was noted only in 29.8% and 12.5% in the relapsing-remitting and primary progressive patients, respectively. Primary progressive MS subjects had a higher propensity to be wheelchair-bound (75.0%) than those suffering from relapsing-remitting MS (1.2%). Increased total protein in the cerebrospinal fluid (CSF) of the secondary progressive cohort was statistically significant compared to the relapsing-remitting cohort. The frequency of oligoclonal IgG bands was rather low in each type of MS (17.1-33.3%). Gadolinium enhancement of plaques on MRI was more frequently present in secondary progressive MS (66.7%) than in either relapsing-remitting MS (32.1%) or primary progressive MS (50.0%). Of note, the opticospinal form was found in only 16.3% of the total MS patients, a proportion less than that in previous reports from southern Japan.
Conclusion The present study confirms that while the clinical and laboratory features of the MS patients in the Tokyo metropolitan area are similar to those in Western countries in most regards, features such as proportionally fewer primary and secondary progressive MS patients as well as less oligoclonal IgG bands on CSF analysis are different from those in Western countries.
2005 by The Japanese Society of Internal Medicine