Altered thalamic volume in patients with mild autonomous cortisol secretion: a structural brain MRI study

Area of Science:

• Neuroendocrinology
• Neuroimaging
• Cognitive Neuroscience

Background:

• Mild autonomous cortisol secretion (MACS) is a condition with subclinical hypercortisolism.
• The effects of MACS on brain structure, particularly thalamic volume, are not well understood.
• Overt Cushing's syndrome (CS) is known to affect brain structure and cognitive function.

Purpose of the Study:

• To compare thalamic volumes and cognitive functions in patients with MACS, active CS, CS in remission, and healthy controls.
• To investigate potential structural brain changes associated with varying levels of cortisol excess.

Main Methods:

• A cross-sectional study utilizing 3 Tesla magnetic resonance imaging (MRI) and voxel-based morphometry.
• Assessment of thalamic volumes in 23 MACS patients, 21 active CS patients, 27 CS in remission patients, and 21 controls.
• Cognitive functions were evaluated using validated questionnaires.

Main Results:

• Patients with MACS exhibited smaller left thalamic, left posterior thalamic, left medial thalamic, and right lateral thalamic volumes compared to controls.
• Patients with active CS also showed reduced volumes in these thalamic regions compared to controls.
• Patients with CS in remission had smaller left medial and right lateral thalamic volumes than controls, despite no observed cognitive differences between groups.

Conclusions:

• Mild autonomous cortisol secretion (MACS) is associated with reduced thalamic volume.
• Thalamic volume reduction may occur in MACS independently of overt cognitive deficits.
• These findings suggest that even subclinical hypercortisolism can impact brain structure.