Once patients with syphilis and HIV experience neurological symptoms, central nervous system damage caused by neurosyphilis and AIDS should be considered, and MOG/AQP4/GFAP antibodies and oligoclonal bands should be tested to exclude central nervous system demyelinating diseases such as MOGAD, NMOSD, GFAP astrocytopathy, and MS. The gene discussed is GFAP; the disease is AIDS.