How are senile plaques related to brain atrophy and Alzheimer disease?

In the context of Alzheimer disease, senile plaques—also known as neuritic or amyloid plaques—are closely linked to the progressive atrophy of brain tissue.12

Relationship to Pathology

Alzheimer disease is characterized by the widespread destruction of neurons and neural connections, leading to a significant loss of brain mass. Senile plaques consist of deteriorating neuronal material surrounding deposits of amyloid beta, a protein derived from amyloid precursor protein.21

While it remains debated whether these plaques are a primary cause or a consequence of the disease, their presence is a hallmark of the condition. The accumulation of these plaques is thought to interfere with normal cellular functioning. Furthermore, abnormal insulin signaling in the brain is suspected to trigger inflammation, which in turn promotes the formation of these plaques and contributes to nerve cell dysfunction and death. This ongoing loss of nerve cells is the fundamental driver of the brain atrophy observed in patients.132