Neuropsychiatric lupus includes extremely diverse clinical manifestations, ranging from mild cognitive dysfunction to a severe, life-threatening presentation. We report a 28-year-old patient with systemic lupus erythematosus who had persistent fever for 3 months, and developed within a few hours motor and sensory aphasia, rotator nystagmus with deviation of the eyes, and severe nuchal rigidity. An extensive series of imaging and laboratory tests were interpreted as normal, except for an elevated opening pressure at lumbar puncture, cerebrospinal fluid inflammatory findings, and asymmetrical cortical perfusion on single-photon emission computed tomography. The patient received one course of high-dose intravenous immunoglobulin (IVIg) and within 5 days her condition returned to that of 3 months before admission. The mechanisms of injury, along with the management of cerebral lupus and the mechanisms of action of IVIg, are discussed.