Early predictors of new-onset immune-related seizures: a preliminary study

Abstract

Background: Approximately 60% of patients with autoimmune encephalitis (AE) exhibit secondary acute symptomatic seizures and showed highly sensitive to immunotherapy. However, it is difficult for many patients to receive early immunotherapy since the early identification of the cause in AE is more complex. This study aimed to investigate the early predictors of initial immune-related seizures and to guide the evaluation of treatment and prognosis. Methods:One hundred and fifty-four patients with new-onset "unknown etiology" seizures with a course of disease less than 6 months were included. Serum and/or cerebrospinal fluid neuron-specific autoantibodies (NSAbs), including N-methyl-D-aspartate receptor (NMDAR), α-amino-3-hydroxy-5- Methyl-4-isoxazole propionic acid receptor 1 (AMPAR1), AMPAR2, anti-leucine rich glioma inactivated 1 antibody (LGI1), anti-gamma-aminobutyric acid type B receptor (GABABR), anti-contact protein-related protein-2 (CASPR2) were used to screen for immune etiology of the seizures. In addition, patients with epilepsy and encephalopathy were also examined via brain MRI, long-term video EEG, antibody prevalence in epilepsy and encephalopathy (APE2) score, and modified Rankin Scale (mRS). A logistic regression model was used to analyze the early predictors of immune etiology. Results: Among all patients, 34 cases (22.1%) were positive for NSAbs. Of these 34, 23 cases of autoimmune encephalitis (AE) (21 cases of NSAbs positive), 2 cases of viral encephalitis, 1 case of ganglionic glioma (NSAbs positive), 128 cases of epilepsy or seizures (12 cases of NSAbs positive) were recorded. Also, there were 19 patients (12.3%) with APE2 ≥ 4 points and 17 patients (89.5%) in the AE group. The sensitivity and specificity of APE2 ≥ 4 points for predicting AE were 73.9% and 98.5%. The results of multivariate analysis showed that the NSAbs and APE2 scores independently influenced the early prediction of initial immune-related seizures (P < 0.05). Conclusions: NSAbs and APE2 scores could act as early predictors of initial immune-related seizures.