Which brain regions are first affected in Alzheimer's disease?

• A. Medial temporal lobe and hippocampus.
• B. Frontal lobes.
• C. Cerebellum.
• D. Parietal lobe.

Answer: (A)

Early Alzheimer’s disease targets the brain areas key to forming and storing new memories. The medial temporal lobe, especially the hippocampus, is affected first. This region is essential for encoding new information and creating lasting memories, so degeneration here leads to the hallmark early symptom of memory problems, particularly difficulty forming new memories. As the disease advances, other areas such as the frontal lobes, cerebellum, and parietal lobes become involved, producing later deficits in planning, coordination, and visuospatial skills. Because memory-related structures in the medial temporal lobe and hippocampus are the earliest affected, this choice best reflects the initial pattern of brain involvement.