Imaging biomarkers in antibody-mediated autoimmune encephalitis

Area of Science:

• Neuroimaging
• Autoimmune Diseases
• Neurology

Background:

• Multimodal magnetic resonance imaging (MRI) is vital for diagnosing autoimmune encephalitis (AE).
• Diverse autoantibodies in AE lead to varied and complex imaging presentations across subtypes.
• Comprehensive studies on subtype-specific AE imaging features are lacking.

Purpose of the Study:

• To identify imaging biomarkers for AE subtypes mediated by different antibodies.
• To correlate imaging findings with disease severity, treatment response, and prognosis in AE patients.

Main Methods:

• Analysis of clinical and multimodal brain MRI data from 45 AE patients.
• Generation of lesion probability maps and selection of regions of interest (ROIs).
• Measurement of 3D-T1WI, T2WI, T2 FLAIR, and apparent diffusion coefficient (ADC) values for correlation analysis.

Main Results:

• MRI abnormalities were found in 62.2% of patients, less frequent than EEG (95.6%).
• Common AE imaging features include limbic system involvement with T1 hypointensity and T2 FLAIR hyperintensity.
• Distinct subtype patterns were observed: anti-LGI1 (hippocampus/basal ganglia), anti-NMDAR (diffuse cortical), anti-GABA_BR (temporal lobe/hippocampus), MOG (cortical swelling), and anti-GAD65 (temporal lobe/pontocerebellar).
• ADC values positively correlated with disease severity (r=0.6891) and prognosis (r=0.8102).

Conclusions:

• AE imaging findings, while less frequent than EEG, show subtype-specific characteristics.
• Functional imaging improves diagnostic accuracy in AE.
• ADC values are significant predictors of AE prognosis.