Anti-N-methyl-d-aspartate receptor encephalitis in Korea: clinical features, treatment, and outcome.
OBJECTIVE
Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is the most common type of autoimmune synaptic encephalitis and it often responds to treatment. We analyzed the clinical characteristics of anti-NMDAR encephalitis in Korea.


METHODS
Serum and/or cerebrospinal fluid (CSF) of adult patients (aged ≥18 years) with encephalitis of undetermined cause were screened for anti-NMDAR antibodies using a cell-based indirect immunofluorescence assay. The patients came from 41 university hospitals.


RESULTS
Of the 721 patients screened, 40 were identified with anti-NMDAR antibodies and clinical details of 32 patients were obtained (median age, 41.5 years; 15 females). Twenty-two patients (68.8%) presented with psychiatric symptoms, 16 (50%) with seizures, 13 (40.6%) with movement disorders, 15 (46.9%) with dysautonomia, 11 (34.4%) with memory disturbance, and 11 (34.4%) with speech disturbance. Magnetic resonance imaging, electroencephalography, and CSF examinations yielded nonspecific findings. Tumor information was only available for 22 patients: 5 patients had tumors, and 2 of these patients had ovarian teratomas. Twenty-two patients received immunotherapy and/or surgery, and therapeutic responses were analyzed in 21 patients, of which 14 (66.7%) achieved favorable functional outcomes (score on the modified Rankin Scale of 0-2).


CONCLUSIONS
This study investigated the clinical characteristics of adult anti-NMDAR encephalitis in Korea. Currently, elderly patients who do not have tumors are commonly diagnosed with this condition. Understanding the detailed clinical characteristics of this disease will improve the early detection of anti-NMDAR encephalitis in patients both young and old.
Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital; Program in Neuroscience, Seoul National University College of Medicine, Seoul, Korea.
Jung-Ah
JA
Lim
Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital; Program in Neuroscience, Seoul National University College of Medicine, Seoul, Korea.
Soon-Tae
ST
Lee
Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital; Program in Neuroscience, Seoul National University College of Medicine, Seoul, Korea.
Keun-Hwa
KH
Jung
Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital; Program in Neuroscience, Seoul National University College of Medicine, Seoul, Korea.
Soyun
S
Kim
Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital; Program in Neuroscience, Seoul National University College of Medicine, Seoul, Korea.
Jung-Won
JW
Shin
Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital; Program in Neuroscience, Seoul National University College of Medicine, Seoul, Korea.
Jangsup
J
Moon
Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital; Program in Neuroscience, Seoul National University College of Medicine, Seoul, Korea.
Jung-Ick
JI
Byun
Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital; Program in Neuroscience, Seoul National University College of Medicine, Seoul, Korea.
Tae-Joon
TJ
Kim
Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital; Program in Neuroscience, Seoul National University College of Medicine, Seoul, Korea.
Yong-Won
YW
Shin
Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital; Program in Neuroscience, Seoul National University College of Medicine, Seoul, Korea.
Keon-Joo
KJ
Lee
Department of Neurology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea.
Young-Su
YS
Kim
Department of Neurology, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea.
Kyung-Il
KI
Park
Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital; Program in Neuroscience, Seoul National University College of Medicine, Seoul, Korea.
Sang Kun
SK
Lee
Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital; Program in Neuroscience, Seoul National University College of Medicine, Seoul, Korea.
Kon
K
Chu
N-methyl-D-aspartate receptor antibody; autoimmune encephalitis; encephalitis