myelinolysis . to demyelination : a case of central pontine Decreased magnetisation transfer ratio due

roglobulin, antimicrosome, or antiskeletal muscle autoantibodies whereas the generalised type showed a high titre and incidence of autoantibodies including AChR antibody.5 Seronegative patients or those with low AChR antibody may form a low responder subgroup of myasthenia gravis distinct from the high responders, who show a high titre of AChR antibody. Twelve patients (37 5%) were of the ocular type, which is higher than the incidence in the report of Confalonieri et al.' All subjects in Cohen-Kaminsky's report had generalised myasthenia gravis of type hIa or IIb.2 Chiu et a16 reported a difference in myasthenia gravis expression between Chinese and Caucasians. The characteristic population pattern in our study may be common to east Asians and may partly cause a different correlation between sIL-2R and disease activity. 2 The study of this characteristic population may lead to the elucidation of the pathogenesis of low responder myasthenia gravis.