A Retrospective Analysis And Study Of Clinical Features,Diagnosis And Treatment In Patients With Autoimmune Encephalitis

ObjectivesTo retrospectively analyze and study clinical features,diagnosis and treatment outcome of the patients with autoimmune encephalitis,and to discuss the implication of clinical diagnostic criteria for autoimmune encephalitis published in Lancet Neurol 2016.MethodsTo collect the clinical data of patients with definite or clinically suspected autoimmune encephalitis in department of neurology,Sir Run Run Shaw Hospital affiliated to Zhejiang University,(September 2014-February 2017).Based on existing criteria for autoimmune encephalitis,20 patients were assigned to Group 1(had positive autoantibodies in cerebrospinal fluid(CSF),n=10)or Group 2(had negative CSF autoantibodies or were not tested for antibodies,n=10).The clinical and laboratory results(CSF,head magnetic resonance imaging(MRI),electroencephalogram(EEG),cancer screening and comorbidity test)of patients in each group were analyzed and described.According to the clinical diagnostic criteria for autoimmune encephalitis published in Lancet Neurol 2016,the evidence for autoimmune encephalitis(definite,probable or possible)in 20 patients was achieved and discussed.Furthermore,the treatment course and outcomes of 20 patients were analyzed and assessed.Neurologic symptom severity was evaluated using the modified Rankin Scale(mRS)before and after treatment.mRS score before and after treatment,and the correlation between improved mRS score and disease duration(the duration of the disease until the time point of immunotherapy)or age in patients were analyzed.ResultsAt first,we analyzed clinical features of 20 patients and found that the median admission age was 40 years(range 16-68);11 were man and 9 were women.Ten Group 1 patients(50%)had positive autoantibodies associated with autoimmune encephalitis in CSF,including anti-N-methyl-D-aspartate receptor(NMDAR)encephalitis(6),anti-leucine-rich glioma inactivated gene-1(LGIl)encephalitis(1),anti-gamma amino-butyric acid B receptor(GABABR)encephalitis(1)and anti-amphiphysin encephalitis(2).Group 2 included 10 patients(50%)who had negative antibodies in CSF(5)and were not tested for antibodies(5).Twenty patients usually present with subacute onset and rapid progression of psychiatric symptoms,epilepsy,disorders of consciousness and movement or cognitive impairment.The most common clinical manifestations were psychiatric symptoms in Group 1,while epilepsy in Group 2.Twelve patients(60%)showed different degrees of leukocyte abnormality in CSF.Head images showed brain injury in 16 patients(80%):unilateral or bilateral limbic system was involved in 11 patients(55%),while lesions outside the limbic system were present in 6 patients(30%).EEG changes were present in 15 patients(75%).Tumors were pathologically or radiologically confirmed and tumor markers were found in 5 patients(25%).Next,we further revealed that all 20 patients met the clinical diagnostic new criteria.The evidence for autoimmune encephalitis(Definite 12,Probable 3 and Possible 5)is discussed using new criteria based on clinical neurological assessment and conventional laboratory tests(CSF,Head MRI and EEG)and reasonable exclusion of alternative causes.Patients with negative antibody can still be clinically confirmed.Finally,we showed that 19/20 patients with autoimmune encephalitis were treated with immunotherapy,including hormones,immunoglobulin,plasma exchange and cyclophosphamide.Immunotherapy showed potent therapeutic effects on common symptoms(such as disorders of consciousness,seizures,psychiatric symptoms,movement disorder or cognitive dysfunction)and laboratory results of autoimmune encephalitis.The neurologic symptoms(mRS score)were improved significantly after treatment in all 19 patient and 12 definite patient(p<0.01 or p<0.05).ImprovedmRS score was associated with disease duration(r=-0.565,p<0.01),but not with age.Conclusion1.Our data shows that autoimmune encephalitis is characterised by subacute onset of psychiatric symptoms,seizures,altered mental status,movement disorders or memory deficits.Limbic system is the target for autoimmune encephalitis where brain injuries are detected by imaging methods.CSF with positive antibody and/or pleocytosis and abnormal EEG are also important features of autoimmune encephalitis.2.The clinical diagnostic criteria for autoimmune encephalitis published in Lancet Neurol 2016 did not reliant solely on antibody testing.The diagnosis of definite,probable or possible autoimmune encephalitis can be made early according to the relative specific clinical and laboratory features,which will lead to a quick immunotherapy for autoimmune encephalitis.3.Prompt initiation of immunotherapy in patients of our hospital is the key to improving therapeutic efficacy and prognosis of autoimmune encephalitis.Comprehensive diagnostics based on the new clinical diagnostic criteria have significant clinical implications for timely treatment of autoimmune encephalitis.