Optic Nerve and Spinal Cord Are the Major Lesions in Each Relapse of Japanese Multiple Sclerosis
(a) Sex ratio of each localization of MS attacks. Half of the brainstem lesions occurred in males, although there was a remarkable female predominancy for other lesion sites. (b) Age at attack for each localization of MS attacks. Mean age at brainstem attack was 29.6 ± 6.0 years old and is significantly younger than the mean age at optic nerve attack (42.5 ± 14.4 y.o.) and spinal cord attack (42.6 ± 13.6 y.o.) using Welch’s t-test (P < 0.05). Regarding other lesions, mean patient age at attacks involving the cerebrum was 42.3 ± 13.5 y.o., and the mean age at the development of complex lesions was 38.7 ± 10.9 y.o. Boxes represent values from the 25th to the 75th percentiles, inner lines represent the median, and whiskers show the minimal and maximal values.