[A case of limbic encephalitis associated with Sjögren's syndrome mimicking anti N-methyl D-aspartate receptor encephalitis].

A 25-year-old woman in her 37 weeks and 5 days pregnant presented with abnormal behavior and memory impairment following a high fever. Her manifestations were diagnosed as limbic encephalitis, and she delivered a baby by Cesarean section. In the operation, bilateral ovarian tumors were found and resected, though they were revealed as non-teratoma afterward. After operation, she became agitated, and started to present oral dyskinesia, intractable systemic myoclonus, central hypoventilation, and autonomic manifestations such as labile blood pressure, but her symptoms responded well to immunotherapy. Her clinical course was typical for anti-N-methyl D-aspartate (NMDA) receptor encephalitis, but anti-NMDA receptor antibody was not detected in her serum and CSF. On the other hand, anti SS-A antibody was positive in her serum, and the lip biopsy findings confirmed Sjögren's syndrome (SjS). Only several cases of SjS-associated limbic encephalitis have been reported, but none of them mimicked anti-NMDA receptor encephalitis. This patient indicates that SjS should be considered even in a case of limbic encephalitis with a typical clinical spectrum of anti-NMDAR encephalitis.