Neuropathology of Alzheimer's Disease Gross Brain Changes The following are the gross changes in the brains of the people with Alzheimer’s disease: Reduced weight of the brain Reduced cortical volume Dilated ventricles Deepening of sulci Magnetic Resonance Imaging On magnetic resonance imaging, the diagnostically most important finding is atrophy , especially of the medial temporal lobe. It affects the entorhinal cortex the earliest but then it spreads to other regions of the temporal lobe and limbic lobe for example hippocampus, amygdala, and parahippocampus. Later, the pathology extends to parietal lobe and eventually global atrophy. It spares frontal lobes until the late stage. The progression of atrophy occurs in a similar pattern as the progression of the neuropathology. Dilated ventricles can show global atrophy, but the most reliable method is a direct measurement of volume. Expansion of the fissures is the indirect, and less reliable way to measure the atrophy. For Alzheime