Treatment-responsive subacute limbic encephalitis and NMDA receptor antibodies in a man

Disturbances of memory, behavior, cognition, and seizures can result from immune-mediated encephalitides. These disorders can be paraneoplastic or not and may associate with several antibodies.1 Recently, a treatment-responsive paraneoplastic encephalitis that associates with antibodies to NR1/NR2 heteromers of the NMDA receptor (NMDAR) was reported.2 Patients were young women with teratomas, usually of the ovary, who presented with prominent psychiatric symptoms, and less frequently with features of limbic encephalitis. We report a man with treatment-responsive limbic encephalitis and antibodies to NR1/NR2 heteromers. ### Case report. For 3 months this 53-year-old man had progressive short-term memory deficits and disorientation that forced him to leave his job. During the month before hospital admission he had multiple episodes compatible with partial complex seizures. He had no past medical history of interest. The neurologic examination only revealed short-term memory deficits and impairment of temporal orientation. Blood cell count, general chemistry, B12, folic acid, thyroid function test, thyroglobulin antibodies, RPR, Lyme serology, antibodies to double stranded DNA, and SSA/Ro and SSB/La were unrevealing. CSF analysis showed 5 WBC/μL (100% lymphocytes) and normal glucose and protein concentration. Serum and CSF disclosed the same oligoclonal IgG bands. Paraneoplastic antineuronal and VGKC antibodies were negative. EEG demonstrated bilateral temporal lobe epileptic activity. MRI of the brain revealed noncontrast enhancing T2 and FLAIR hyperintensities involving the medial aspect of the temporal lobes and nonspecific hyperintensities in the frontal lobes (figure, A). Ultrasound of the testis, CT of the chest, abdomen and …