[An autopsy case of primary progressive multiple sclerosis with minimal acute inflammation and remyelination over an 11-year course].

A 32-year-old man presented with the symptoms of a floating sensation, weakness on the right side of the body, and tremor of the right hand. Head MRI was performed, and T-weighted images showed high-signal lesions around the lateral ventricles, subcortical white matter, and dorsal medulla oblongata. Moreover, MRI of the cervical spine showed multiple high-signal lesions without contrast enhancement. Based on these findings, the patient was diagnosed with primary progressive multiple sclerosis (PPMS) and was treated with steroid pulse therapy, plasma exchange, and oral fingolimod. However, the patient's condition deteriorated slowly, and he died at the age of 43 years. An autopsy revealed multiple demyelinating lesions in the central nervous system. No inflammatory cell infiltration or macrophage accumulation was observed, and there was no evidence of an active lesion. Herein, we present this rare autopsy case of PPMS in Japan with a review of the literature.