Characterization and prognosis of autoimmune encephalitis in the neurological intensive care unit: a retrospective study

Objective: Patients diagnosed with autoimmune encephalitis (AE) require admission to the neurological intensive care unit (ICU) when they exhibit clinical manifestations such as status epilepticus, central hypoventilation, and severe involuntary movements. In order to determine the predictors of ICU admission and prognosis for patients with AE admitted to the neurological ICU, we analyzed the clinical characteristics of this patient population.

Methods: This retrospective study analyzed 123 patients admitted to the First Affiliated Hospital of Chongqing Medical University between 2012 and 2021 who were diagnosed with AE based on serum and/or cerebrospinal fluid (CSF) AE-related antibody positivity. We divided these patients into two groups: those who received ICU treatment and those who did not. We evaluated patient's prognosis using the modified Rankin scales (mRS).

Results: Univariate analysis revealed that epileptic seizures, involuntary movements, central hypoventilation, symptoms of vegetative neurological disorders, increased neutrophil-to-lymphocyte ratio (NLR), abnormal electroencephalogram (EEG) findings, and different treatments were associated with ICU admission for patients with AE. Multivariate logistic regression analysis showed that hypoventilation and NLR were independent risk factors for ICU admission in AE patients. Univariate analysis showed that age and sex were related to prognosis in ICU-treated AE patients, and logistic regression analysis indicated that age was the only independent risk factor for prognosis in ICU-treated AE patients.

Conclusion: Increased NLR, except for hypoventilation, is an indicator of ICU admission in AE patients. Although a large number of patients with AE require ICU admission, the overall prognosis is good, particularly in younger patients.