What is a characteristic sign of Alzheimer's disease?

Plaques and tangles are a hallmark characteristic of Alzheimer's disease. These pathological features are found in the brains of individuals who have this condition. Plaques are primarily composed of beta-amyloid proteins that accumulate between nerve cells, disrupting communication and contributing to cell death. Tangles, on the other hand, are formed from twisted strands of a protein called tau, which normally helps stabilize microtubules in neurons. In Alzheimer's, tau becomes hyperphosphorylated and forms these tangles, which are toxic to brain cells.

The presence of plaques and tangles is critical for diagnosing Alzheimer's disease and differentiating it from other types of dementia. While impaired blood flow, personality changes, and hearing loss may occur in various forms of dementia or other health conditions, they are not specifically indicative of Alzheimer's disease. Only the presence of plaques and tangles confirm the pathological changes associated with this specific disease.