What finding on CT scan would suggest Alzheimer's disease?

The presence of global cerebral atrophy on a CT scan is a significant finding that suggests Alzheimer's disease. In Alzheimer's disease, the brain undergoes widespread degeneration, leading to a reduction in overall brain volume. This atrophy is not isolated to specific regions but affects multiple structures throughout the brain, resulting in a generalized shrinkage that can be appreciated on imaging studies.

The progressive atrophy in Alzheimer's is associated with the accumulation of amyloid plaques and neurofibrillary tangles, which disrupt normal neural function. Consequently, global cerebral atrophy is a hallmark feature that clinicians look for when evaluating patients for Alzheimer's disease, as it reflects the extensive neurodegeneration characteristic of this condition.

In contrast, frontal lobe atrophy, while it can be seen in Alzheimer's, is more specifically associated with frontotemporal dementia and may not indicate Alzheimer's disease by itself. Cerebellar atrophy is often linked to other neurodegenerative conditions, such as spinocerebellar ataxias. A normal cerebral size would indicate no significant neurodegeneration, making it an unlikely finding in a patient with Alzheimer's disease. Thus, global cerebral atrophy stands as the most indicative feature of Alzheimer's on a CT scan.