Endocrine Abstracts

Aim: To investigate the volumetric changes in cortical and subcortical deep gray matter (GM) structures and cognitive alterations in patients with mild autonomous cortisol secretion (MACS). We also sought to assess whether the anticipated changes in brain volume and cognitive functions of the patients with MACS differ from the changes in patients with overt Cushing’s Syndrome (CS).

Methods: In this cross-sectional study, volumes of the cortex, hippocampus, amygdala, thalamus, caudate, and putamen were examined using 3T magnetic resonance imaging and a voxel-based morphometry approach in 23 patients with MACS, 21 patients with active CS, 27 patients with CS in remission, and 21 controls. Cognitive functions were assessed using validated questionnaires.

Results: Patients with MACS had smaller volume of left thalamus (F = 3.8, P=0.023), left posterior thalamus (F = 4.9, P=0.01), left medial thalamus (F = 4.7, P=0.028), and right lateral thalamus (F = 4.1, P=0.025) than controls. Patients with active CS also had smaller volume of the left thalamus (F = 3.8, P=0.044), left posterior thalamus (F = 4.9, P=0.007), left medial thalamus (F = 4.7, P=0.006), and right lateral thalamus (F = 4.1, P=0.042) in relation to controls. Furthermore, patients with active CS and MACS had smaller volumes belonging to the pulvinar and mediodorsal nuclei of the left hemisphere in comparison to controls. Patients with CS in remission showed smaller volumes only in left medial (F = 4.7, P=0.030) and right lateral thalamus (F = 4.1, P=0.028) when compared with controls. Neuropsychological tests showed no difference between the groups.

Conclusion: MACS may be related to reduced volumes of the whole thalamus and thalamic nuclei similar to patients with overt hypercortisolism.