Abstract:

Objective To investigate the mechanism of hippocampus in cognitive dysfunction in patients with anti⁃N⁃methyl⁃D⁃aspartate receptor（NMDAR）encephalitis by voxel⁃based morphology（VBM）and functional connectivity（FC）. Methods A total of 21 patients with anti⁃NMDAR encephalitis and 21 healthy controls（HC group）who matched gender，age and education were recruited. All participants received neuropsychological test. T1 image and rs⁃fMRI were acquired by 3T MRI scanner. The hippocampus gray matter volume between two group were compared by SPM8. Four zones of bilateral hippocampus were defined as ROIs. ROIs⁃based functional connec⁃ tivity analysis in the global brain level were calculated. Correlation analyses were performed to investigate the associations between brain dysfunction，hippocampus gray matter volume and neuropsychological performance. Results Compared with HC group，gray matter volume of right anterior hippocampus in patients was decreased， the FC value between left posterior hippocampus，thalamus_L and supplementary motor area_R was decreased，the FC value of the right posterior hippocampus and postcentral_L was increased. The volume of gray matter of right anterior hippocampus was positively correlated with MoCA⁃B score. The FC value of the supplementary motor area was positively correlated with the course of the disease. Conclusions There were abnormalities in the volume of hippocampus gray matter and the functional connectivity between hippocampus and other brain regions in patients with anti⁃NMDAR encephalitis，and these were related to cognitive impairment and course of disease.

Key words:

anti?NMDAR encephalitis, hippocampus, voxel?based morphology, functional connec? tivity, cognitive function