[Central nervous system involvement in rheumatic diseases].

Among various rheumatic diseases, systemic lupus erythematosus and Behcet's disease are frequently complicated with serious neurological involvement, called CNS lupus and neuro-Behcet's syndrome (NB), respectively. CNS lupus includes lupus psychosis, such as organic brain syndrome and non-organic psychosis, as well as non-psychotic CNS lupus, such as epilepsy and focal lesions. Anti-ribosomal P antibody is closely associated with lupus psychosis, whereas anti-phospholipid antibodies appear to be involved in some manifestations of non-psychotic CNS lupus. NB includes acute type and chronic progressive type. Acute NB is characterized by acute meningoencephalitis with focal lesions, which respond to steroid therapy. By contrast, chronic progressive NB is characterized by intractable slowly progressive dementia and/or psychosis with persistent elevation of cerebrospinal fluid IL-6 activity, which is resistant to conventional steroid therapy. However, recent studies suggest the efficacy of low dose methotrexate in chronic progressive NB.