Effect of Experimental Thyrotoxicosis on Brain Gray Matter: A Voxel-Based Morphometry Study.

Area of Science:

• Neuroendocrinology
• Neuroimaging
• Brain Structure and Function

Background:

• Thyroid hormones significantly influence brain function and behavior.
• Thyroid hormones play a crucial role in brain development and structural organization.

Purpose of the Study:

• To investigate the effects of experimentally induced hyperthyroidism on brain gray matter in healthy adults.
• To identify specific brain regions affected by short-term hyperthyroid conditions.

Main Methods:

• Acquisition of high-resolution 3D T1-weighted MRI scans in 29 healthy young adults.
• Induction of hyperthyroidism by daily T4 administration (250 µg) for 8 weeks.
• Voxel-based morphometry analysis using Statistical Parametric Mapping 8 (SPM8).

Main Results:

• Laboratory tests confirmed successful induction of hyperthyroidism.
• Increased gray matter volume in the right posterior cerebellum (lobule VI).
• Decreased gray matter volume in the bilateral visual cortex and anterior cerebellum (lobules I-IV).

Conclusions:

• Short-term hyperthyroidism induces distinct structural alterations in the brain.
• Affected cerebellar regions are linked to sensorimotor functions and working memory.
• Findings highlight the sensitivity of brain structures to thyroid hormone levels.