OMG and myeloid sarcoma: The patient may have had other diseases, such as MS, multiphasic disseminated encephalomyelitis, anti-myelin oligodendrocyte glycoprotein antibody-associated disease, or Susac syndrome, at the time of initial onset and first relapse at the age of 42 years and then separately developed PCNSV at the age of 55 years after the improvement of the other diseases.