Major decrease in the volume of the entorhinal cortex in patients with Alzheimer's disease carrying the...

Area of Science:

• Neuroscience
• Genetics
• Radiology

Background:

• The apolipoprotein E (ApoE) epsilon4 allele is a known risk factor for Alzheimer's disease (AD).
• AD is characterized by amyloid plaques and neurofibrillary tangles, often beginning in the medial temporal lobe.
• The impact of ApoE epsilon4 on specific brain structure volumes in AD requires further in vivo investigation.

Purpose of the Study:

• To evaluate the effect of the ApoE epsilon4 allele on the in vivo volume of the entorhinal cortex in Alzheimer's disease patients.
• To compare entorhinal cortex volume in AD patients with and without the ApoE epsilon4 allele against healthy controls.

Main Methods:

• Volumetric magnetic resonance imaging (MRI) was used to measure entorhinal cortex volume.
• 16 AD patients with ApoE epsilon4, 11 AD patients without ApoE epsilon4, and 31 healthy controls participated.
• MRI utilized a 1.5 Tesla scanner with a 3D technique for detailed anatomical reconstruction.

Main Results:

• AD patients without ApoE epsilon4 showed 27% reduced entorhinal cortex volume compared to controls.
• AD patients with ApoE epsilon4 exhibited a more pronounced 45% shrinkage in entorhinal cortex volume (p=0.0001).
• The ApoE epsilon4 allele's effect on entorhinal cortex volume was significantly greater in female AD patients (p=0.014) and associated with poorer memory function.

Conclusions:

• In vivo volumetric MRI confirms that the ApoE epsilon4 allele is associated with increased entorhinal cortex atrophy in early Alzheimer's disease.
• This association is particularly pronounced in female patients with Alzheimer's disease.
• ApoE epsilon4 status impacts entorhinal cortex volume and cognitive function in AD.