Comparative Study On Clinical Characteristics Of Anti-NMDA Receptor Encephalitis With Or Without Serum NMDA Receptor Antibody

Objective:To investigate the effect of serum NMDA receptor antibodies on the clinical features of anti-NMDA receptor encephalitis,so as to determine the relationship between antibody titer and disease condition and prognosis.Method:The clinical data of 62 patients diagnosed with anti-NMDA receptor encephalitis in the First Affiliated Hospital of Kunming Medical University from January 2016 to November 2020 were collected retrospectively and followed up.According to the results of antibody test,the patients were divided into serum and cerebrospinal fluid antibody double positive group(DP group)and only cerebrospinal fluid antibody single positive group(SP group),using statistical methods to compare the demographic,symptoms,auxiliary examination and prognosis differences between the two groups,and do the correlation analysis of antibody titer and symptoms and prognosis.Results:1.A total of 35 patients(56.5%)had simultaneous presence of cerebrospinal fluid(CSF)and serum NMDA receptor antibodies;2.Patients in the DP(n=35)group had younger onset age[23 years(IQR16-39)vs 34 years(IQR22-48),P=0.038]compared with those in the SP(n=27)group,with concomitant psychosis and behavioral abnormalities(91.4%vs 37.0%,P<0.001),status epilepticus(45.7%vs 14.8%,P=0.021),autonomic dysfunction(42.9%vs 14.8%,P=0.036),and central hypoventilation(48.6%vs 11.1%,P=0.004).A higher proportion of subjects received ICU admission during treatment(60.0%vs 22.2%,P=0.003)and improved their condition for more than four weeks(54.3%vs 25.9%,P=0.025).3.In cerebrospinal fluid examination,the increases of total protein(5.7%vs 29.6%,P=0.016)and immunoglobulin IgG(40.0%%vs 70.4,P=0.017)in SP group were more significant.4.Correlation analysis showed that with the increase of cerebrospinal fluid antibody titer,our patient experienced psychobehavioral abnormalities(R=0.368,P=0.004),status epilepticus(R=0.287,P=0.025),language dysfunction(R=0.409,P=0.001),decreased consciousness level(R=0.280,P=0.029),central hypoventilation(R=0.474,P<0.001),autonomic dysfunction(R=0.395,P=0.002),and ICU admission(R=0.476,P<0.001)increased gradually.With the increase in serum antibody titer,the status epilepticus(R=0.511,P=0.003),decreased consciousness level(R=0.413,P=0.016),central hypoventilation(R=0.460,P=0.007)and autonomic nervous dysfunction(R=0.502,P=0.003)gradually increased in our patient.Conclusion:1.In anti-NMDA receptor encephalitis,antibodies are found in cerebrospinal fluid and serum of more than half of patients;2.Anti-NMDA receptor encephalitis patients with serum antibodies are younger,in a more severe clinical feature and easier to present with psychiatric symptoms;3.Anti-NMDA receptor encephalitis patients without serum NMDA receptor are more likely to have increased cerebrospinal fluid albumin and immunoglobulin IgG;4.The prognosis of anti-NMDA receptor encephalitis patients are no difference whether serum NMDA receptor antibody are positive or not;5.CSF and serum antibody titers are correlated with the severity of the disease but do not affect the prognosis;...