In Alzheimer's disease, which memory pattern is most characteristic?

• A. In Alzheimer's disease, short-term memory is often impaired while long-term memory remains relatively intact.
• B. Long-term memory is impaired while short-term memory is preserved.
• C. Both short-term and long-term memory are equally affected from onset.
• D. No memory impairment is seen in the early stages.

Answer: (A)

The key idea is that Alzheimer’s disease typically starts with trouble forming new memories while older, well-established memories stay intact early on. The hippocampus and nearby medial temporal structures, critical for encoding and retaining new information, are affected early. This leads to difficulties with short-term or recent memory—forgetting recent events, misplacing items, repeating questions, and trouble learning new information. Meanwhile distant memories from years ago, which are more deeply consolidated in cortical networks, remain relatively preserved at the outset.

As the disease progresses, the ability to recall later memories and some long-term information can decline, but the hallmark early pattern is clear: impaired short-term memory with relatively preserved long-term memory initially. This contrasts with situations where long-term memories are affected from the start or where memory loss is not evident in the early stages. Understanding this pattern helps distinguish the early memory profile of Alzheimer's from other conditions.