Fast Five Quiz: Alzheimer's Disease Signs and Symptoms

Jasvinder P. Chawla, MD, MBA


February 22, 2022

Figure 1. Color-enhanced coronal MRI of the brain showing the regions that are most severely affected in AD. The temporal lobes colored in dark blue are involved with memory. The rest of the affected areas appear in purple. The parietal regions at the top on both sides are also severely involved in the disease. The pattern of abnormality described here is suggestive of AD but not definitive.

The pathologic changes characteristic of AD begin in the medial temporal lobes, particularly the hippocampus and the entorhinal cortex. These are the initial sites of tangle deposition and atrophy that can be seen on brain MRI early in AD. Notably, such brain changes occur decades before any signs or symptoms occur. As AD progresses, parietal, temporal, and frontal association cortices are affected; the primary motor and sensory cortices are less frequently involved.

Learn more about the anatomy of AD.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.