What are the earliest signs and symptoms of Alzheimer disease?

The earliest signs of Alzheimer disease often manifest during the stage known as mild cognitive impairment (MCI), which represents a transition from normal aging to dementia.1

The symptoms vary depending on the type of MCI:
* Amnestic MCI: The primary symptom is noticeable forgetfulness or memory dysfunction, while abilities in reasoning, judgment, and perception remain intact.1
* Nonamnestic MCI: Impairments in attention, language, and perception are more prominent than memory deficits.1

Other early clinical manifestations of the disease include temporary confusion, restlessness, poor judgment, lethargy, and a failure to retain new information. In some instances, paranoia and delusions—which may worsen at night—are the initial symptoms. As the condition progresses, these deficits typically worsen, leading to a deterioration of social relationships and more severe memory loss.21

Because the disease process begins before these symptoms become apparent, researchers are actively working on diagnostic imaging and biomarker testing to identify the disease at the preclinical stage.13