Comparison of clinical features of autoimmune encephalitis with viral encephalitis in patients with limbic encephalitis syndrome / 中华神经科杂志

ABSTRACT

Objective To investigate the frequency of autoimmune encephalitis (AE) in limbic encephalitis (LE) syndrome and compare its clinical features with viral encephalitis.Methods Patients diagnosed with LE syndrome who admitted to Huashan Hospital between December 2015 and June 2016 were enrolled and screened for autoantibodies associated with AE (anti-N-methyl-D-aspartate receptor, anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor, anti-gamma-amino-butyric acid B-receptor, anti-leucine-rich glioma inactivated 1 and anti-contactin-associated protein-like 2 antibodies) in cerebrospinal fluid (CSF) and serum. Their clinical features and auxiliary examinations were also collected and analyzed retrospectively. Results Fifty-four patients were diagnosed with LE syndrome, including 35 males and 19 females. The age of these patients was (38.98±17.29) (15-75) years. Twenty patients (37.0%) were identified as AE, 17 patients (31.5%) as viral encephalitis. Other cases included three (5.5%) with neurosyphilis, one (1.9%) with glioma and 13 (24.1%) of unknown cause. Young patients(15-29 years old)and patients older than 45 years accounted for 46.0% (17/37) and 37.8% (14/37) of all AE and viral encephalitis cases respectively. Patients with AE had longer disease progression time than patients with viral encephalitis ((22.45±11.62) d vs (6.24±2.95) d, t=6.015, P<0.01).Emergency hospitalization of patients with AE was less frequent than that of patients with viral encephalitis (3/20 vs 12/17, P=0.001). Patients with AE were less common to present with fever at disease onset than patients with viral encephalitis (8/20 vs 15/17, P=0.006). Seizures as the first neurological symptom were less common in AE than in viral encephalitis (2/20 vs 8/17, P=0.023). White blood cell counts in CSF were less frequently elevated in AE than in viral encephalitis (7/17 vs 12/15, P=0.036). The differences of age, gender, disease severity as well as abnormal rates of brain MRI, electroencephalogram and CSF protein were not statistically significant between the two groups. Tumors were discovered in 6 (6/19) patients with AE. Conclusions The frequency of AE in LE syndrome is not low. It is worthwhile to screen for autoantibodies associated with AE in patients diagnosed with LE syndrome. AE and viral encephalitis have their own characteristics, which could offer help in differential diagnosis between them and application of effective treatment.