Review Article

Diagnostic Value of Structural and Functional Neuroimaging in Autoimmune Epilepsy

Table 1

Types and imaging characteristics of antibodies related to AE.

Antibody typesMRIPETSPECT
Regular MRIfMRI

NMDAR antibodyT2/FLAIR hyperintensity in the cortex and subcortical white matter areas, including temporal lobe, cerebellum, thalamus, basal ganglia, etc.Bilateral functional connectivity of hippocampus decreased. DTI revealed widespread changes in white matter. The decrease of NAA is related to clinical improvementA high to low metabolic gradient from the frontal lobe to the occipital lobeHyperperfusion in basal ganglia and cortex, especially frontal cortex

Limbic encephalitis-related antibodiesT2/FLAIR hyperintensity in MTL. MTL and hippocampal volume from swelling to atrophyExtensive damage to brain network connections. MRS showed that NAA decreased and lactate peak increasedMTL hypermetabolisma is the most common manifestationHypoperfusio-n in the frontal lobe, parietal lobe, thalamus, and cerebellum

GABAAR antibodyMultifocal cortical-subcortical T2/FLAIR abnormalities, predominantly involved temporal and frontal lobes but also basal ganglia and other regionsMRS showed elevated lactate signals and Lac/creatine ratio in the voxel of interest

CASPR2 antibodyT2/FLAIR hyperintensity in MTL and diffuse meningeal enhancement. Bilateral hippocampal and generalized cortical atrophyTemporal hypermetabolism, temporomandibular, frontal and diffuse hypometabolism

GAD antibodyAcute/subacute lesions usually presented as temporal lobe encephalitis with high T2/FLAIR signal and swelling of unilateral or bilateral medial temporal structures. Hippocampal atrophy is associated with drug-resistant temporal lobe epilepsyDTI showed wide range of effects in various regions of brainMultiple hypermetabolism in brain tissue, mainly in the frontal or temporal lobes

Anti-Hu antibodyThe most common abnormality on MRI was T2/FLAIR hyperintensity in the temporal lobe and showed multifocal subcortical/subcortical lesions in patients with SCLCHigh metabolism in one or two temporal lobes, only a small number of brain MRI cases are related to PETSPECT scan revealed asymmetric cortical activity, but distinct seizure focus could not be identified