Brain atrophy in 18 patients with Down syndrome: a CT study

Area of Science:

• Neurology
• Neuroimaging
• Genetics

Background:

• Individuals with Down syndrome (DS) have a high risk of developing Alzheimer disease (AD) neuropathology after age 40.
• This increased risk is linked to genetic factors on chromosome 21.
• Understanding brain changes in DS is crucial for early detection and intervention.

Purpose of the Study:

• To compare brain atrophy patterns in individuals with Down syndrome and healthy controls using CT scans.
• To investigate the relationship between brain structure, age, and cognitive status in Down syndrome.
• To determine if specific brain measurements can predict dementia in the Down syndrome population.

Main Methods:

• Computed tomography (CT) scans of 18 individuals with Down syndrome (ages 26-70) and 175 healthy controls were analyzed.
• Cortical and subcortical atrophy were assessed, focusing on the suprasellar cistern ratio as a marker for mesial temporal lobe atrophy.
• Brain measurements were correlated with age and cognitive status, including dementia assessment.

Main Results:

• A distinct pattern of increased brain abnormality with age was observed in individuals with Down syndrome compared to controls.
• The suprasellar cistern ratio correlated significantly with cognitive impairment severity, even after accounting for age.
• The suprasellar cistern ratio predicted dementia status in Down syndrome subjects with over 75% accuracy.

Conclusions:

• Brain imaging reveals age-related structural changes in Down syndrome that differ from normal aging.
• Suprasellar cistern ratio is a reliable indicator of mesial temporal lobe atrophy and predicts dementia in Down syndrome.
• These findings highlight the utility of neuroimaging markers for assessing Alzheimer disease risk and progression in Down syndrome.