Serum neuron-specific enolase can predict the severity and outcome of anti-N-methyl-D-aspartate receptor encephalitis

Little is known about the association between serum neuron-specific enolase (NSE) concentration and anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. This study aims to investigate if serum NSE concentration is related to the clinical features of anti-NMDAR encephalitis.

Serum NSE levels were detected in 58 anti-NMDAR encephalitis cases, 58 matched healthy controls and 58 matched disease controls. Demographic features, clinical symptoms, cerebrospinal fluid parameters and brain MRI indexes of the cases were evaluated.

Serum NSE concentrations were significant higher in case group than those in healthy controls and disease controls (both p < 0.001). Serum NSE concentrations in patients with mRS≥3 one year after onset were obviously higher than in those with mRS<3 (p < 0.001). Patients with status epilepticus or central hypoventilation had higher serum NSE levels than those without (p = 0.003 and p = 0.006). Serum NSE concentrations in cases with brain lesions or brain atrophy were significant higher than in those without (p = 0.001 and p < 0.001, respectively). Serum NSE concentrations were found to be significant higher in cases with limited response to treatment compared to those with favourable therapy outcomes (p < 0.001). Spearman's correlation analysis showed a significant positive association between serum NSE concentration and mRS score at the most critical time (max mRS) (r = 0.575, p < 0.001) and one year after onset (r = 0.705, p < 0.001). Cox regression results reflected that high serum NSE level was an independent predictor of poor prognosis in anti-NMDAR encephalitis group (p = 0.001), and the ROC curve threshold value was 15.72 ng/ml.

Serum NSE concentrations in anti-NMDAR encephalitis cases are higher than those in controls. It can be used to predict the brain damage degree and prognosis of anti-NMDAR encephalitis cases.