A Case Report Of AMPAR Encephalitis Complicated With Deafness And Literature Review

Background and Purpose:Since the first case of anti-N-methyl-aspartate receptor(NMDAR)encephalitis was discovered in 2007,a series of anti-neuron surface or synaptoprotein autoantibodies have been discovered.The new type of autoimmune encephalitis mediated by neuronal surface antibodies leading to relatively reversible neuronal dysfunction is becoming world's medical research hot spot due to its favorable therapeutic effect by early immunotherapy.While AMPA receptor encephalitis is a rare type of new autoimmune encephalitis,there is a lack of large-scale clinical research update.It is easily missed and misdiagnosed since clinicians lack sound comprehension about this disease.This article reported the diagnosis and treatment of a case of AMPAR encephalitis in our hospital,and reviewed the pathophysiological mechanism,clinical manifestations,related auxiliary examination results,treatment and prognosis of AMPAR encephalitis.Methods:We analysed the causes of early misdiagnosis of a patient with AMPAR encephalitis by retrospective analysis of the clinical manifestations,laboratory examinations,imaging and neuroelectrophysiological examinations,and treatment.To discuss the pathophysiology,epidemiology,clinical manifestation,auxiliary examination,treatment and prognosis of the AMPAR encephalitis,We search CNKI,Wanfang,Medline,and Pubmed"with the key words such as AMPAR???????????AMPAR encephalitis,autoimmune encephalitis.Results:Searching for the literatures from the first discovery of AMPA receptor encephalitis in 2009 to update in the domestic and foreign databases,and excluding case data with duplicate,irrelevant or incomplete,finally a total of 18 foreign literatures were obtained.One literature was repeatedly reported and rejected.In addition,there were 3 articles reporting 22 cases,7 cases,and 3 cases respectively,and all of which were included in the study because of their complete data.A total of5 Chinese articles were acquired.Finally,included a total of 22 articles,53 cases,coupled with the case we reported above,a total of 54 cases were analysed.The results were summarized as follows:(1)General information: the average age of onset was 51.39±17.96,the age range was(18-92),and the ratio of male to female was 18:36.(2)Clinical manifestations: there are 5 cases(9.2%)with prodrome,51cases(94.4%)with marginal lobe encephalitis as the first symptom,and 27 cases(50%)including 9 cases(16.7%)of male and 18 cases(33.3%)of female with tumor.Those tumors included 10 cases(37%)of thymic tumor,7 cases(30%)of lung cancer and 5 cases(18.5%)of breast cancer.(3)Imaging examination: MRI examination of 51 patients showed that 35 patients(68.6%)were involved in the limbic system,and 5 patients(9.8%)were involved in the cerebral cortex(including 2patients with extensive cerebral cortex involvement),2 patients with basal ganglia involvement,1 patient with cerebellar hemisphere involvement,and 8 patients(15.7%)with normal craniocerebral MRI examination.(4)Electroencephalogram examination: 43 cases of patients underwent electroencephalogram examination.18cases(41.9%)had slow wave,8 cases(18.6%)had epilepsy wave and 16 cases'(37.2%)EEG were normal.(5)Treatment: 51 of 54 patients received treatment.Among them,34 patients(62.9%)were received first-line treatment(hormone,plasma exchange,immunoglobulin),13 patients were received first-line plus second-line treatment(24.1%),1 patient was received second-line treatment alone.1of the remaining 3 patients hadn't treatment data,1 patient's treatment was unclear,and 1 patient was only received tumor treatment.(6)Prognosis: in the follow-up results of 54 patients,18 patients were in remission(33.3%),19 patients were in partial remission(35.2%),4 patients weren't in remission(7.4%),9 patients died(18.5%),2 patients recurred,2 patients lost follow-up;55.6% of the deaths were associated with paratumor antibodies.Conclusion:1.The incidence of AMPAR encephalitis is mostly in middle-aged and elderly patients,with more women than men.2.The clinical manifestations of AMPAR encephalitis are mainly manifested as symptoms of the limbic system:cognitive decline,mental behavior abnormalities,andseizures.A few can be characterized by obvious disturbances of consciousness and motor dysfunction.A small number of patients may have prodromal symptoms such as fever,headache,diarrhea.About 50% of patients had tumors,mainly thymic tumors,lung cancer,and breast cancer.3.Brain magnetic resonance of AMPAR encephalitis is mainly involved in the limbic system,especially in the medial temporal lobe,but also in the cerebral cortex and cerebellar hemisphere.In some patients,the brain magnetic resonance can be normal.EEG can be slow wave,normal,and epileptic waves.4.Most of the patients with AMPAR encephalitis received immunotherapy and tumor treatment improved(68.5%),a small number of invalid or death;5 cases(55.6%)of patients combined with para-tumor antibodies died;Patients with para-tumor antibodies may indicate poor prognosis.