Abhinbhen Wasontiwong Saraya
◽
Kanthita Worachotsueptrakun
◽
Kritchai Vutipongsatorn
◽
Chanikarn Sonpee
◽
Thiravat Hemachudha
Abstract
Background
Since the discovery of N-methyl-D-aspartate receptor (NMDAr) antibody in 2007, the incidence of autoantibody-mediated encephalitis has risen globally. Here we analyzed and compared groups of autoantibody-associated encephalitis patients based on clinical findings and laboratory results in order to find differences between two major groups of autoantibody-mediated encephalitis: intracellular and neuronal surface antibodies.
Methods
77 records of autoimmune encephalitis/encephalomyelitis patients admitted to King Chulalongkorn Memorial Hospital (KCMH) between October 2010 and February 2017 were reviewed. Patients with infections or those with classic central nervous system demyelinating features were excluded. Categorical data was analyzed using chi-square and Fisher’s exact test. Unpaired, two-tailed t-test was performed to analyze numerical data.
Results
Of 77 patients, 40% presented with neuronal surface antibodies and 33% had intracellular antibodies. The most common autoantibody detected in each group was anti-NMDA receptor antibody (25/31, 81%) and anti-Ri antibody (7/25, 28%) respectively. In the neuronal surface antibody group, behavioral change was the most common complaint (45%), followed by seizures (39%), abnormal movements (29%) and psychosis/mood disorder (23%). In the latter group, seizure was the most common presenting symptom (32%), followed by motor weakness (20%), behavioral change (16%) and abnormal movements (16%). Patients with neuronal surface antibodies were significantly younger (35 vs 48 years old, p=0.04) and were more likely to present with behavioral change (45% vs 16%, p=0.02). Mortality rate was higher in the intracellular group although this was statistically insignificant (16% vs 3.2%, p=0.09). No significant differences were detected in magnetic resonance imaging and cerebrospinal fluid (CSF) profile.
Conclusions
The prevalence of neuronal surface antibody group was much higher than the intracellular group. In the earlier stages of the disease, both groups have comparable clinical outcomes. Furthermore, it is difficult to distinguish autoantibody-associated encephalitis patients based on clinical data, neuroimaging and CSF profile. Therefore, we recommend that patients with features of autoimmune encephalitis should be screened for both the neuronal surface and intracellular antibodies regardless of clinical presentation.