Multi-mode MRI Studies In Cushing’s Disease

Cushing’s disease(CD)provides a unique and naturalist model for studying the influence of hypercortisolism on the human brain and the reversibility of these effects after resolution of the condition.Chronic exposed to hypercortisolism would cause irreversible effects on the central nerve system.The authors of the previous structural longitude studies tended to explore the potential reversibility long-term(more than 12 months)after the resolution of the hypercortisolism.However,in animal studies,a partial reversal started after several weeks of resolution of the hypercortisolism.The structural recovery process from hypercortisolism in short-term remains unknown.Thus,a whole-brain analysis among short-term remission CD patients,active CD patients and healthy controls may provide more insight into the process of the recovery after the resolution of hypercortisolism,which is lacked in the previous studies.Additionally,to our knowledge,there was no study for the functional pontenial reviersibility even published.In the sturacutal previous studies,the gray matter alterations and white matter alterations were analysis sepeartely.This cross-sectional study used resting state f MRI(rs-f MRI),Diffusional Kurtosis Imaging(DKI)and voxel-based morphometry(VBM)to investigate the potential reversibility in altered spontaneous brain activity,microstructure alterations and gray matter volume among patients with active CD,patients with short-term remission CD and healthy control subjects,and to determine the relationship of these changes with clinical characteristics.The mean duration of remission in our previous study was only 60 days.Furthermore,we also aimed to find the correlations between these alterations and the clinical charateritics.Our study resulted in three major findings: 1)active CD patients showed significantly altered spontaneous brain activity in the posterior cingulate cortex(PCC)/precuneus(PCu),occipital lobe(OC)/cerebellum,thalamus,right postcentral gyrus(Po CG)and left prefrontal cortex(PFC).2)CD patients mainly exhibited significantly altered diffuse parameters in the left parahippocampal gyrus and left temporal lobe.The mean values of increased radial diffusivity(RD)of CD patients in left parahippocampal gyrus correlated positively with the clinical severity.3)Smaller gray matter volumes of active CD patients and normal gray matter volumes of short-term remitted CD patients were found in medial frontal gyrus(MFG)and cerebellum.And significant correlations were found between remission time and gray matter values in these regions of short-term remitted CD patients.This study provides seeral new approachs to investigating brain functional and structural abnormalities in patients with CD and enhances our understanding of the effect of hypercortisolism on the human brain.Furthermore,our explorative potential reversibility study of patients with CD may facilitate the development of future longitudinal studies.