Patients with SLE show in a variety of neuropsychiatric symptoms, although we could not use standardized methods for evaluating and making diagnosis of the syndromes. ACR felt to develop objective and valuable tools for the diagnosis and classification of neuropsychiatric lupus, therefore, they proposed a new tentative set of nomenclatures describing neuropsychiatric lupus syndromes in accordance with 4th edition of Diagnostic and Statistical Manual of Mental Disorders provided by American Psychiatric Association. For this purpose, The Ad Hoc Committee collected and evaluated 108 case presentations of neuropsychiatric lupus from USA, Canada, and UK. Re-evaluation of the tentative nomenclatures selected 19 neuropsychiatric syndrome to facilitate and enhance clinical research. They grouped into peripheral and central nervous system lupus, and central nervous system lupus was divided into neurologic syndromes and diffuse psychiatric/ neuropsychological syndromes. Instead of organic brain syndrome, a term of acute confusional state was introduced.