Functional and Structural Brain Alterations in Encephalitis With LGI1 Antibodies

Area of Science:

• Neuroscience
• Neurology
• Radiology

Background:

• LGI1 antibody encephalitis is an autoimmune condition causing neurological and psychiatric symptoms.
• Understanding the underlying neural mechanisms is crucial for effective treatment.

Purpose of the Study:

• To investigate the neural substrates and mechanisms of memory deficits, seizures, and neuropsychiatric abnormalities in LGI1 antibody encephalitis.
• To utilize a multimodal magnetic resonance imaging (MRI) approach for data-driven analysis.

Main Methods:

• Acquired functional MRI (fMRI) data from 14 anti-LGI1 encephalitis patients and 14 controls.
• Applied Independent Component Analysis with Hierarchical Partner Matching (HPM-ICA) for functional connectivity analysis.
• Used Granger Causality (GC) for effective connectivity and Diffusion Tensor Imaging (DTI) for white matter microstructure.

Main Results:

• Reduced functional connectivity in memory, cognition, and motion circuits; increased connectivity in putamen and caudate.
• Decreased effective connectivity from frontal cortex to supplementary motor area.
• Significant white matter microstructural changes (reduced FA, increased MD) in corpus callosum, internal capsule, corona radiata, and superior longitudinal fasciculus.

Conclusions:

• Neural and behavioral deficits in anti-LGI1 encephalitis are linked to widespread brain connectivity and microstructure alterations.
• Pathological changes affect the basal ganglia, limbic system, temporal, and frontal lobes.