Introduction Paraneoplastic immune mediated encephalopathy i
Paraneoplastic immune-mediated encephalopathy is a newly described disease. In 2005, Vitaliani et al first reported that four young women with ovarian teratoma (OT) had developed acute psychiatric and neurologic symptoms, e.g., seizures, memory deficits, decreased level of consciousness, and central hypoventilation. Later, in 2007, the neuro-oncologist Dr. Dalmau and his team from the University of Pennsylvania in the United States linked the presence of anti-N-methyl-d-aspartate receptor (anti-NMDAR) purchase EAI045 to this disease in a woman with ovarian teratoma. Between Jan 1, 2007, and Jan 1, 2012, many cases of treatable autoimmune encephalitis were reported from all over the world: 577 cases were reported during this 5-year period in studies led by Dalmau et al at the University of Pennsylvania (PA, USA) and in Barcelona (Spain). Thirty-two anti-NMDAR encephalitis cases were found among 79 encephalitis cases being reported by the California Encephalitis Project, established to study the epidemiology of encephalitis (CA, USA).
After using the keywords “anti-NMDAR encephalitis” and “Taiwan” in PubMed to search for studies of autoimmune encephalopathy in Taiwan, we found only six articles out of 571 articles reporting anti-NMDAR encephalitis. As we reviewed the six reports from Taiwan, we found that five of them reported anti-NMDAR encephalitis, and one suggested the need for earlier recognition of psychiatric symptoms in cases of anti-NMDAR encephalitis. From 2009 to 2013, 12 cases of autoimmune encephalitis were reported by an author from Chang Gung Memorial Hospital. In these cases, half of the patients were less than 18 years old; 91.6% of the patients presented with mood, behavioral, or personality changes; 91.6% developed seizures; 100% showed stereotyped movements; 83.3% had autonomic instability; and 66.7% exhibited symptoms of hypoventilation. Three out of the 12 patients had been diagnosed with an ovarian teratoma. Four additional articles reported 4 cases of anti-NMDAR encephalitis, but only one of these reported the association with ovarian teratoma. Thus, there is a need for Taiwanese experts in oncology, neurology, psychiatry, and immunology to learn more about this new autoimmune disease and its relationship to ovarian teratomas. This treatable autoimmune encephalitis should be recognized with increased frequency and treated as early as possible since untreated anti-NMDAR encephalitis might lead to many severe and prolonged neuropsychiatric syndromes. To this end, the purpose of this article is to review the paraneoplastic, immune-mediated encephalopathy known as anti-NMDAR encephalitis. Furthermore, this article emphasizes the importance of early recognition and early treatment with Immunotherapy for patients with paraneoplastic, immune-mediated encephalopathy, especially for those young children and adolescents who could be misdiagnosed with autism or schizophrenia.
Conclusions Anti-NMDAR encephalitis is a new and not well documented immune-mediated disease in Taiwan, particularly among children and young women who present with a characteristic set of neuropsychiatric signs and symptoms (Table 1). Early consideration of this diagnosis would allow the clinician to provide effective treatment, but despite a growing body of literature, this new paraneoplasm continues to be under-recognized. It is important for related clinical specialties to work as a team to identify these antibody-positive patients, and to provide prompt intervention with immunotherapy in order to bring about recovery. It is especially important that individuals with a first presentation of psychosis, with or without tumor, exhibiting features of autonomic disturbances, and with seizure or abnormal neurologic movements, be tested for autoimmune encephalitis. A cell-based indirect immunofluorescent antibody test for the detection of IgG antibodies to NMDAR should become more available for diagnostic use in Taiwan. Most importantly, early immune modulatory therapies, including steroid, IVIG, and plasma exchange, should also become more financially feasible for use in treatment in Taiwan.